entropy/lib/entropy/db/sql.py

# -*- coding: utf-8 -*-
"""

    @author: Fabio Erculiani <lxnay@sabayon.org>
    @contact: lxnay@sabayon.org
    @copyright: Fabio Erculiani
    @license: GPL-2

    I{EntropyRepository} is an abstract class that implements
    most of the EntropyRepository methods using standard SQL.

"""
import os
import hashlib
import itertools
import time
import threading

from entropy.const import etpConst, const_debug_write, \
    const_debug_enabled, const_isunicode, const_convert_to_unicode, \
    const_get_buffer, const_convert_to_rawstring, const_is_python3
from entropy.exceptions import SystemDatabaseError, SPMError
from entropy.spm.plugins.factory import get_default_instance as get_spm
from entropy.output import bold, red
from entropy.misc import ParallelTask

from entropy.i18n import _

import entropy.dep
import entropy.tools

from entropy.db.skel import EntropyRepositoryBase
from entropy.db.cache import EntropyRepositoryCacher
from entropy.db.exceptions import Warning, Error, InterfaceError, \
    DatabaseError, DataError, OperationalError, IntegrityError, \
    InternalError, ProgrammingError, NotSupportedError

def _get_main_thread():
    for _thread in threading.enumerate():
        if _thread.name == "MainThread":
            return _thread
    raise AssertionError("Where the fuck is the MainThread?")


class SQLConnectionWrapper(object):

    """
    This class wraps an implementation dependent
    Connection object, exposing a common API which
    resembles the Python DBAPI 2.0.
    All the underlying library calls are wrapped
    around using a proxy method in order to catch
    and then raise entropy.db.exceptions exceptions.
    """

    def __init__(self, connection, exceptions):
        self._con = connection
        self._excs = exceptions

    def __hash__(self):
        return id(self)

    @staticmethod
    def _proxy_call(exceptions, method, *args, **kwargs):
        """
        This method is tricky because it wraps every
        underlying engine call catching all its exceptions
        and respawning them as entropy.db.exceptions.
        This provides optimum abstraction.
        """
        try:
            # do not change the exception handling
            # order, we need to reverse the current
            # hierarchy to avoid catching super
            # classes before their subs.
            return method(*args, **kwargs)
        except exceptions.InterfaceError as err:
            raise InterfaceError(err)

        except exceptions.DataError as err:
            raise DataError(err)
        except exceptions.OperationalError as err:
            raise OperationalError(err)
        except exceptions.IntegrityError as err:
            raise IntegrityError(err)
        except exceptions.InternalError as err:
            raise InternalError(err)
        except exceptions.ProgrammingError as err:
            raise ProgrammingError(err)
        except exceptions.NotSupportedError as err:
            raise NotSupportedError(err)
        except exceptions.DatabaseError as err:
            # this is the parent of all the above
            raise DatabaseError(err)

        except exceptions.Error as err:
            raise Error(err)
        except exceptions.Warning as err:
            raise Warning(err)

    @staticmethod
    def connect(module_proxy, module, subclass, *args, **kwargs):
        conn_impl = SQLConnectionWrapper._proxy_call(
            module_proxy.exceptions(), module.connect,
            *args, **kwargs)
        return subclass(conn_impl, module_proxy.exceptions())

    def commit(self):
        return self._proxy_call(self._excs, self._con.commit)

    def rollback(self):
        return self._proxy_call(self._excs, self._con.rollback)

    def close(self):
        return self._proxy_call(self._excs, self._con.close)

    def cursor(self):
        return self._proxy_call(self._excs, self._con.cursor)

    def ping(self):
        """
        Ping the underlying connection to keep it alive.
        """
        raise NotImplementedError()

    def unicode(self):
        """
        Enforce Unicode strings.
        """
        raise NotImplementedError()

    def rawstring(self):
        """
        Enforce byte strings.
        """
        raise NotImplementedError()

    def interrupt(self):
        """
        Interrupt any pending activity.
        """
        raise NotImplementedError()


class SQLCursorWrapper(object):
    """
    This class wraps an implementation dependent
    Cursor object, exposing a common API which
    resembles the Python DBAPI 2.0.
    All the underlying library calls are wrapped
    around using a proxy method in order to catch
    and then raise entropy.db.exceptions exceptions.
    """

    def __init__(self, cursor, exceptions):
        self._cur = cursor
        self._excs = exceptions

    def _proxy_call(self, method, *args, **kwargs):
        """
        This method is tricky because it wraps every
        underlying engine call catching all its exceptions
        and respawning them as entropy.db.exceptions.
        This provides optimum abstraction.
        """
        try:
            # do not change the exception handling
            # order, we need to reverse the current
            # hierarchy to avoid catching super
            # classes before their subs.
            return method(*args, **kwargs)
        except self._excs.InterfaceError as err:
            raise InterfaceError(err)

        except self._excs.DataError as err:
            raise DataError(err)
        except self._excs.OperationalError as err:
            raise OperationalError(err)
        except self._excs.IntegrityError as err:
            raise IntegrityError(err)
        except self._excs.InternalError as err:
            raise InternalError(err)
        except self._excs.ProgrammingError as err:
            raise ProgrammingError(err)
        except self._excs.NotSupportedError as err:
            raise NotSupportedError(err)
        except self._excs.DatabaseError as err:
            # this is the parent of all the above
            raise DatabaseError(err)

        except self._excs.Error as err:
            raise Error(err)
        except self._excs.Warning as err:
            raise Warning(err)

    def wrap(self, method, *args, **kwargs):
        return self._proxy_call(method, *args, **kwargs)

    def execute(self, *args, **kwargs):
        raise NotImplementedError()

    def executemany(self, *args, **kwargs):
        raise NotImplementedError()

    def close(self, *args, **kwargs):
        raise NotImplementedError()

    def fetchone(self, *args, **kwargs):
        raise NotImplementedError()

    def fetchall(self, *args, **kwargs):
        raise NotImplementedError()

    def fetchmany(self, *args, **kwargs):
        raise NotImplementedError()

    def executescript(self, *args, **kwargs):
        raise NotImplementedError()

    def callproc(self, *args, **kwargs):
        raise NotImplementedError()

    def nextset(self, *args, **kwargs):
        raise NotImplementedError()

    def __iter__(self):
        raise NotImplementedError()

    def __next__(self):
        raise NotImplementedError()

    def next(self):
        raise NotImplementedError()

    @property
    def lastrowid(self):
        return self._cur.lastrowid

    @property
    def rowcount(self):
        return self._cur.rowcount

    @property
    def description(self):
        return self._cur.description


class EntropySQLRepository(EntropyRepositoryBase):

    """
    EntropySQLRepository partially implements a SQL based repository
    storage.
    """

    class Schema(object):

        def get_init(self):
            data = """
                CREATE TABLE baseinfo (
                    idpackage INTEGER PRIMARY KEY AUTOINCREMENT,
                    atom VARCHAR,
                    category VARCHAR,
                    name VARCHAR,
                    version VARCHAR,
                    versiontag VARCHAR,
                    revision INTEGER,
                    branch VARCHAR,
                    slot VARCHAR,
                    license VARCHAR,
                    etpapi INTEGER,
                    trigger INTEGER
                );

                CREATE TABLE extrainfo (
                    idpackage INTEGER PRIMARY KEY,
                    description VARCHAR,
                    homepage VARCHAR,
                    download VARCHAR,
                    size VARCHAR,
                    chost VARCHAR,
                    cflags VARCHAR,
                    cxxflags VARCHAR,
                    digest VARCHAR,
                    datecreation VARCHAR,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );
                CREATE TABLE content (
                    idpackage INTEGER,
                    file VARCHAR,
                    type VARCHAR,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE contentsafety (
                    idpackage INTEGER,
                    file VARCHAR,
                    mtime FLOAT,
                    sha256 VARCHAR,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE provide (
                    idpackage INTEGER,
                    atom VARCHAR,
                    is_default INTEGER DEFAULT 0,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE dependencies (
                    idpackage INTEGER,
                    iddependency INTEGER,
                    type INTEGER,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE dependenciesreference (
                    iddependency INTEGER PRIMARY KEY AUTOINCREMENT,
                    dependency VARCHAR
                );

                CREATE TABLE conflicts (
                    idpackage INTEGER,
                    conflict VARCHAR,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE mirrorlinks (
                    mirrorname VARCHAR,
                    mirrorlink VARCHAR
                );

                CREATE TABLE sources (
                    idpackage INTEGER,
                    idsource INTEGER,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE sourcesreference (
                    idsource INTEGER PRIMARY KEY AUTOINCREMENT,
                    source VARCHAR
                );

                CREATE TABLE useflags (
                    idpackage INTEGER,
                    idflag INTEGER,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE useflagsreference (
                    idflag INTEGER PRIMARY KEY AUTOINCREMENT,
                    flagname VARCHAR
                );

                CREATE TABLE keywords (
                    idpackage INTEGER,
                    idkeyword INTEGER,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE keywordsreference (
                    idkeyword INTEGER PRIMARY KEY AUTOINCREMENT,
                    keywordname VARCHAR
                );

                CREATE TABLE configprotect (
                    idpackage INTEGER PRIMARY KEY,
                    idprotect INTEGER,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE configprotectmask (
                    idpackage INTEGER PRIMARY KEY,
                    idprotect INTEGER,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE configprotectreference (
                    idprotect INTEGER PRIMARY KEY AUTOINCREMENT,
                    protect VARCHAR
                );

                CREATE TABLE systempackages (
                    idpackage INTEGER PRIMARY KEY,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE injected (
                    idpackage INTEGER PRIMARY KEY,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE installedtable (
                    idpackage INTEGER PRIMARY KEY,
                    repositoryname VARCHAR,
                    source INTEGER,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE sizes (
                    idpackage INTEGER PRIMARY KEY,
                    size INTEGER,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE counters (
                    counter INTEGER,
                    idpackage INTEGER,
                    branch VARCHAR,
                    PRIMARY KEY(idpackage,branch),
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE trashedcounters (
                    counter INTEGER
                );

                CREATE TABLE needed (
                    idpackage INTEGER,
                    idneeded INTEGER,
                    elfclass INTEGER,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE neededreference (
                    idneeded INTEGER PRIMARY KEY AUTOINCREMENT,
                    library VARCHAR
                );

                CREATE TABLE provided_libs (
                    idpackage INTEGER,
                    library VARCHAR,
                    path VARCHAR,
                    elfclass INTEGER,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE treeupdates (
                    repository VARCHAR PRIMARY KEY,
                    digest VARCHAR
                );

                CREATE TABLE treeupdatesactions (
                    idupdate INTEGER PRIMARY KEY AUTOINCREMENT,
                    repository VARCHAR,
                    command VARCHAR,
                    branch VARCHAR,
                    date VARCHAR
                );

                CREATE TABLE licensedata (
                    licensename VARCHAR UNIQUE,
                    text BLOB,
                    compressed INTEGER
                );

                CREATE TABLE licenses_accepted (
                    licensename VARCHAR UNIQUE
                );

                CREATE TABLE triggers (
                    idpackage INTEGER PRIMARY KEY,
                    data BLOB,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE entropy_misc_counters (
                    idtype INTEGER PRIMARY KEY,
                    counter INTEGER
                );

                CREATE TABLE categoriesdescription (
                    category VARCHAR,
                    locale VARCHAR,
                    description VARCHAR
                );

                CREATE TABLE packagesets (
                    setname VARCHAR,
                    dependency VARCHAR
                );

                CREATE TABLE packagechangelogs (
                    category VARCHAR,
                    name VARCHAR,
                    changelog BLOB,
                    PRIMARY KEY (category, name)
                );

                CREATE TABLE automergefiles (
                    idpackage INTEGER,
                    configfile VARCHAR,
                    md5 VARCHAR,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE packagedesktopmime (
                    idpackage INTEGER,
                    name VARCHAR,
                    mimetype VARCHAR,
                    executable VARCHAR,
                    icon VARCHAR,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE packagedownloads (
                    idpackage INTEGER,
                    download VARCHAR,
                    type VARCHAR,
                    size INTEGER,
                    disksize INTEGER,
                    md5 VARCHAR,
                    sha1 VARCHAR,
                    sha256 VARCHAR,
                    sha512 VARCHAR,
                    gpg BLOB,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE provided_mime (
                    mimetype VARCHAR,
                    idpackage INTEGER,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE packagesignatures (
                    idpackage INTEGER PRIMARY KEY,
                    sha1 VARCHAR,
                    sha256 VARCHAR,
                    sha512 VARCHAR,
                    gpg BLOB,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE packagespmphases (
                    idpackage INTEGER PRIMARY KEY,
                    phases VARCHAR,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE packagespmrepository (
                    idpackage INTEGER PRIMARY KEY,
                    repository VARCHAR,
                    FOREIGN KEY(idpackage)
                        REFERENCES baseinfo(idpackage) ON DELETE CASCADE
                );

                CREATE TABLE entropy_branch_migration (
                    repository VARCHAR,
                    from_branch VARCHAR,
                    to_branch VARCHAR,
                    post_migration_md5sum VARCHAR,
                    post_upgrade_md5sum VARCHAR,
                    PRIMARY KEY (repository, from_branch, to_branch)
                );

                CREATE TABLE xpakdata (
                    idpackage INTEGER PRIMARY KEY,
                    data BLOB
                );

                CREATE TABLE settings (
                    setting_name VARCHAR,
                    setting_value VARCHAR,
                    PRIMARY KEY(setting_name)
                );

            """
            return data

    # the "INSERT OR REPLACE" dialect
    # For SQLite3 it's "INSERT OR REPLACE"
    # while for MySQL it's "REPLACE"
    _INSERT_OR_REPLACE = None
    # the "INSERT OR IGNORE" dialect
    _INSERT_OR_IGNORE = None

    ## Optionals

    # If not None, must contain the
    # "UPDATE OR REPLACE" dialect
    _UPDATE_OR_REPLACE = None

    _MAIN_THREAD = _get_main_thread()

    # Generic repository name to use when none is given.
    GENERIC_NAME = "__generic__"

    def __init__(self, db, read_only, skip_checks, indexing,
                 xcache, temporary, name):
        # connection and cursor automatic cleanup support
        self._cleanup_monitor_cache_mutex = threading.Lock()
        self._cleanup_monitor_cache = {}

        self._db = db
        self._indexing = indexing
        self._skip_checks = skip_checks
        self._settings_cache = {}
        self.__connection_pool = {}
        self.__connection_pool_mutex = threading.RLock()
        self.__cursor_pool_mutex = threading.RLock()
        self.__cursor_pool = {}
        if name is None:
            name = self.GENERIC_NAME
        self._live_cacher = EntropyRepositoryCacher()

        EntropyRepositoryBase.__init__(self, read_only, xcache,
                                       temporary, name)

    def _cursor_connection_pool_key(self):
        """
        Return the Cursor and Connection Pool key
        that can be used inside the current thread
        and process (multiprocessing not supported).
        """
        current_thread = threading.current_thread()
        thread_id = current_thread.ident
        pid = os.getpid()
        return self._db, thread_id, pid

    def _cleanup_all(self, _cleanup_main_thread=True):
        """
        Clean all the Cursor and Connection resources
        left open.
        """
        if const_debug_enabled():
            const_debug_write(
                __name__,
                "called _cleanup_all() for %s" % (self,))
        with self._cursor_pool_mutex():
            with self._connection_pool_mutex():
                th_data = set(self._cursor_pool().keys())
                th_data.update(self._connection_pool().keys())
                for c_key in th_data:
                    self._cleanup_killer(
                        c_key,
                        _cleanup_main_thread=_cleanup_main_thread)

    def _cleanup_monitor(self, target_thread, c_key):
        """
        Execute Cursor and Connection resources
        termination.
        """
        # join on thread
        target_thread.join()

        if const_debug_enabled():
            const_debug_write(
                __name__,
                "thread '%s' exited [%s], cleaning: %s" % (
                    target_thread, hex(target_thread.ident),
                    c_key,))
        with self._cleanup_monitor_cache_mutex:
            self._cleanup_monitor_cache.pop(c_key, None)
        self._cleanup_killer(c_key)

    def _start_cleanup_monitor(self, current_thread, c_key):
        """
        Allocate a new thread that monitors the thread object
        passed as "current_thread". Once this thread terminates,
        all its resources are automatically released.
        current_thread is actually joined() and live cursor and
        connections are checked against thread identity value
        clashing (because thread.ident values are recycled).
        For the main thread, this method is a NO-OP.
        The allocated thread is a daemon thread, so it should
        be safe to use join() on daemon threads as well.
        """
        if current_thread is self._MAIN_THREAD:
            const_debug_write(
                __name__,
                "NOT setting up a cleanup monitor for the MainThread")
            # do not install any cleanup monitor then
            return

        with self._cleanup_monitor_cache_mutex:
            mon = self._cleanup_monitor_cache.get(c_key)
            if mon is not None:
                # there is already a monitor for this
                # cache key, quit straight away
                return
            self._cleanup_monitor_cache[c_key] = mon

        if const_debug_enabled():
            const_debug_write(
                __name__,
                "setting up a new cleanup monitor")
        mon = ParallelTask(self._cleanup_monitor,
                           current_thread, c_key)
        mon.name = "CleanupMonitor"
        mon.daemon = True
        mon.start()

    def _cleanup_killer(self, c_key, _cleanup_main_thread=False):
        """
        Cursor and Connection cleanup method.
        """
        db, th_ident, pid = c_key

        with self._cursor_pool_mutex():
            with self._connection_pool_mutex():
                cursor_pool = self._cursor_pool()
                cur = None
                threads = set()

                cur_data = cursor_pool.get(c_key)
                if cur_data is not None:
                    cur, threads = cur_data

                connection_pool = self._connection_pool()
                conn_data = connection_pool.get(c_key)
                conn = None
                if conn_data is not None:
                    conn, _threads = conn_data
                    threads |= _threads

                if not threads:
                    # no threads?
                    return

                # now cleanup threads set() first
                # if it's empty, we can kill both
                # connection and cursor
                _dead_threads = set(
                    (x for x in threads if not x.is_alive()))
                # we need to use the method rather than
                # the operator, because we alter its data in
                # place.
                threads.difference_update(_dead_threads)

                # also remove myself from the list
                current_thread = threading.current_thread()
                threads.discard(current_thread)

                # closing the main thread objects (forcibly)
                # is VERY dangerous, but it turned out
                # that the original version of EntropyRepository.close()
                # did that (that is why we have rwsems encapsulating
                # entropy calls in RigoDaemon and Rigo).
                # Also, one expects that close() really terminates
                # all the connections and releases all the resources.
                if _cleanup_main_thread and threads:
                    threads.discard(self._MAIN_THREAD)

                if threads:
                    if const_debug_enabled():
                        const_debug_write(
                            __name__,
                            "_cleanup_killer: "
                            "there are still alive threads, "
                            "not cleaning up resources, "
                            "alive: %s -- dead: %s" % (
                                threads, _dead_threads,))
                    return

                cursor_pool.pop(c_key, None)
                connection_pool.pop(c_key, None)

            if const_debug_enabled():
                const_debug_write(
                    __name__,
                    "_cleanup_killer: "
                    "all threads sharing the same "
                    "ident are gone, i canz kill thread "
                    "ids: %s." % (hex(th_ident),))

            # WARNING !! BEHAVIOUR CHANGE
            # no more implicit commit()
            # caller has to do it!
            try:
                conn.close()
            except OperationalError as err:
                if const_debug_enabled():
                    const_debug_write(
                        __name__,
                        "_cleanup_killer_1: %s" % (err,))
                try:
                    conn.interrupt()
                    conn.close()
                except OperationalError as err:
                    # heh, unable to close due to
                    # unfinalized statements
                    # interpreter shutdown?
                    if const_debug_enabled():
                        const_debug_write(
                            __name__,
                            "_cleanup_killer_2: %s" % (err,))

    def _concatOperator(self, fields):
        """
        Return the SQL for the CONCAT() function
        of the given field elements.
        For instance, MySQL has CONCAT(el_1, el_2, ...)
        while SQLite3 uses the || n-ary operator.
        So, the output of this method is a string, which
        for MySQL is something like "CONCAT(el_1, el_2, ...)"
        """
        raise NotImplementedError()

    def _isBaseinfoExtrainfo2010(self):
        """
        This method is mainly for old adapters that were
        using a less-optimized more-normalized schema.
        Just return True if you don't know what it does mean.
        """
        return True

    def clearCache(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._live_cacher.clear()
        super(EntropySQLRepository, self).clearCache()
        self._live_cacher.clear()

    def _clearLiveCache(self, key):
        """
        Remove any in-memory cache pointed by key.
        """
        self._live_cacher.clear_key(self._getLiveCacheKey() + key)

    def _discardLiveCache(self):
        """
        Invalidate all the in-memory cache.
        """
        self._live_cacher.discard(self._getLiveCacheKey())

    def _setLiveCache(self, key, value):
        """
        Save a new key -> value pair to the in-memory cache.
        """
        self._live_cacher.set(self._getLiveCacheKey() + key, value)

    def _getLiveCache(self, key):
        """
        Lookup a key value from the in-memory cache.
        """
        return self._live_cacher.get(self._getLiveCacheKey() + key)

    def _getLiveCacheKey(self):
        """
        Reimplemented from EntropySQLRepository.
        """
        return etpConst['systemroot'] + "_" + self._db + "_" + \
            self.name + "_"

    def _connection(self):
        """
        Return a valid Connection object for this thread.
        Must be implemented by subclasses and must return
        a SQLConnectionWrapper object.
        """
        raise NotImplementedError()

    def _cursor(self):
        """
        Return a valid Cursor object for this thread.
        Must be implemented by subclasses and must return
        a SQLCursorWrapper object.
        """
        raise NotImplementedError()

    def _cur2frozenset(self, cur):
        """
        Flatten out a cursor content (usually some kind of list of lists)
        and transform it into an immutable frozenset object.
        """
        content = set()
        for x in cur:
            content |= set(x)
        return frozenset(content)

    def _cur2tuple(self, cur):
        """
        Flatten out a cursor content (usually some kind of list of lists)
        and transform it into an immutable tuple object.
        """
        return tuple(itertools.chain.from_iterable(cur))

    def _connection_pool(self):
        """
        Return the Connection Pool mapping object
        """
        return self.__connection_pool

    def _connection_pool_mutex(self):
        """
        Return the Connection Pool mapping mutex
        """
        return self.__connection_pool_mutex

    def _cursor_pool(self):
        """
        Return the Cursor Pool mapping object
        """
        return self.__cursor_pool

    def _cursor_pool_mutex(self):
        """
        Return the Cursor Pool mapping mutex
        """
        return self.__cursor_pool_mutex

    def _doesTableExist(self, table, temporary = False):
        """
        Return whether a table exists.
        """
        raise NotImplementedError()

    def _doesColumnInTableExist(self, table, column):
        """
        Return whether a column in table exists.
        """
        raise NotImplementedError()

    @staticmethod
    def update(entropy_client, repository_id, force, gpg):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        return EntropyRepositoryBase.update(
            entropy_client, repository_id, force, gpg)

    @staticmethod
    def revision(repository_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        return EntropyRepositoryBase.revision(repository_id)

    @staticmethod
    def remote_revision(repository_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        return EntropyRepositoryBase.remote_revision(repository_id)

    def setIndexing(self, indexing):
        """
        Enable or disable metadata indexing.

        @param indexing: True, to enable indexing.
        @type indexing: bool
        """
        self._indexing = bool(indexing)

    def close(self, safe=False):
        """
        Reimplemented from EntropyRepositoryBase.
        Needs to call superclass method. This is a stub,
        please implement the SQL logic.
        """
        super(EntropySQLRepository, self).close(safe=safe)

    def vacuum(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        raise NotImplementedError()

    def commit(self, force = False, no_plugins = False):
        """
        Reimplemented from EntropyRepositoryBase.
        Needs to call superclass method.
        """
        if const_debug_enabled():
            const_debug_write(
                __name__,
                "commit(), "
                "force: %s, no_plugins: %s, readonly: %s | %s" % (
                    force, no_plugins, self.readonly(), self))
        if force or not self.readonly():
            # NOTE: the actual commit MUST be executed before calling
            # the superclass method (that is going to call EntropyRepositoryBase
            # plugins). This to avoid that other connection to the same exact
            # database file are opened and used before data is actually written
            # to disk, causing a tricky race condition hard to exploit.
            # So, FIRST commit changes, then call plugins.
            try:
                self._connection().commit()
            except OperationalError as err:
                # catch stupid sqlite3 error
                # 'cannot commit - no transaction is active'
                # and ignore.
                if str(err.message).find("no transaction is active") == -1:
                    raise

        super(EntropySQLRepository, self).commit(
            force = force, no_plugins = no_plugins)

    def rollback(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._connection().rollback()

    def initializeRepository(self):
        """
        Reimplemented from EntropyRepositoryBase.
        Needs to call superclass method. This is a stub,
        please implement the SQL logic.
        """
        super(EntropySQLRepository, self).initializeRepository()

    def handlePackage(self, pkg_data, revision = None,
                      formattedContent = False):
        """
        Reimplemented from EntropyRepositoryBase. Raises NotImplementedError.
        Subclasses have to reimplement this.
        @raise NotImplementedError: guess what, you need to implement this.
        """
        raise NotImplementedError()

    def _addCompileFlags(self, chost, cflags, cxxflags):
        """
        NOTE: only working with _baseinfo_extrainfo_2010 disabled

        Add package Compiler flags used to repository.
        Return its identifier (idflags).

        @param chost: CHOST string
        @type chost: string
        @param cflags: CFLAGS string
        @type cflags: string
        @param cxxflags: CXXFLAGS string
        @type cxxflags: string
        @return: Compiler flags triple identifier (idflags)
        @rtype: int
        """
        cur = self._cursor().execute("""
        INSERT INTO flags VALUES (NULL,?,?,?)
        """, (chost, cflags, cxxflags,))
        return cur.lastrowid

    def _areCompileFlagsAvailable(self, chost, cflags, cxxflags):
        """
        NOTE: only working with _baseinfo_extrainfo_2010 disabled
        Return whether given Compiler FLAGS are available in repository.

        @param chost: CHOST flag
        @type chost: string
        @param cflags: CFLAGS flag
        @type cflags: string
        @param cxxflags: CXXFLAGS flag
        @type cxxflags: string
        @return: availability (True if available)
        @rtype: bool
        """
        cur = self._cursor().execute("""
        SELECT idflags FROM flags WHERE chost = (?)
        AND cflags = (?) AND cxxflags = (?) LIMIT 1
        """,
            (chost, cflags, cxxflags,)
        )
        result = cur.fetchone()
        if result:
            return result[0]
        return -1

    def _isLicenseAvailable(self, pkglicense):
        """
        NOTE: only working with _baseinfo_extrainfo_2010 disabled

        Return whether license metdatatum (NOT license name) is available
        in repository.

        @param pkglicense: "license" package metadatum (returned by
            retrieveLicense)
        @type pkglicense: string
        @return: "license" metadatum identifier (idlicense)
        @rtype: int
        """
        if not entropy.tools.is_valid_string(pkglicense):
            pkglicense = ' '

        cur = self._cursor().execute("""
        SELECT idlicense FROM licenses WHERE license = (?) LIMIT 1
        """, (pkglicense,))
        result = cur.fetchone()

        if result:
            return result[0]
        return -1

    def _addLicense(self, pkglicense):
        """
        NOTE: only working with _baseinfo_extrainfo_2010 disabled

        Add package license name string to repository.
        Return its identifier (idlicense).

        @param pkglicense: license name string
        @type pkglicense: string
        @return: license name identifier (idlicense)
        @rtype: int
        """
        if not entropy.tools.is_valid_string(pkglicense):
            pkglicense = ' ' # workaround for broken license entries
        cur = self._cursor().execute("""
        INSERT INTO licenses VALUES (NULL,?)
        """, (pkglicense,))
        return cur.lastrowid

    def _isCategoryAvailable(self, category):
        """
        NOTE: only working with _baseinfo_extrainfo_2010 disabled
        Return whether given category is available in repository.

        @param category: category name
        @type category: string
        @return: availability (True if available)
        @rtype: bool
        """
        cur = self._cursor().execute("""
        SELECT idcategory FROM categories WHERE category = (?) LIMIT 1
        """, (category,))
        result = cur.fetchone()
        if result:
            return result[0]
        return -1

    def _addCategory(self, category):
        """
        NOTE: only working with _baseinfo_extrainfo_2010 disabled

        Add package category string to repository. Return its identifier
        (idcategory).

        @param category: name of the category to add
        @type category: string
        @return: category identifier (idcategory)
        @rtype: int
        """
        cur = self._cursor().execute("""
        INSERT INTO categories VALUES (NULL,?)
        """, (category,))
        return cur.lastrowid

    def _addPackage(self, pkg_data, revision = -1, package_id = None,
        formatted_content = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        if revision == -1:
            try:
                revision = int(pkg_data['revision'])
            except (KeyError, ValueError):
                pkg_data['revision'] = 0 # revision not specified
                revision = 0
        elif 'revision' not in pkg_data:
            pkg_data['revision'] = revision

        _baseinfo_extrainfo_2010 = self._isBaseinfoExtrainfo2010()
        catid = None
        licid = None
        idflags = None
        if not _baseinfo_extrainfo_2010:
            # create new category if it doesn't exist
            catid = self._isCategoryAvailable(pkg_data['category'])
            if catid == -1:
                catid = self._addCategory(pkg_data['category'])

            # create new license if it doesn't exist
            licid = self._isLicenseAvailable(pkg_data['license'])
            if licid == -1:
                licid = self._addLicense(pkg_data['license'])

            idflags = self._areCompileFlagsAvailable(pkg_data['chost'],
                pkg_data['cflags'], pkg_data['cxxflags'])
            if idflags == -1:
                idflags = self._addCompileFlags(pkg_data['chost'],
                    pkg_data['cflags'], pkg_data['cxxflags'])

        idprotect = self._isProtectAvailable(pkg_data['config_protect'])
        if idprotect == -1:
            idprotect = self._addProtect(pkg_data['config_protect'])

        idprotect_mask = self._isProtectAvailable(
            pkg_data['config_protect_mask'])
        if idprotect_mask == -1:
            idprotect_mask = self._addProtect(
                pkg_data['config_protect_mask'])

        trigger = 0
        if pkg_data['trigger']:
            trigger = 1

        # baseinfo
        pkgatom = entropy.dep.create_package_atom_string(
            pkg_data['category'], pkg_data['name'], pkg_data['version'],
            pkg_data['versiontag'])
        # add atom metadatum
        pkg_data['atom'] = pkgatom

        if not _baseinfo_extrainfo_2010:
            mybaseinfo_data = (pkgatom, catid, pkg_data['name'],
                pkg_data['version'], pkg_data['versiontag'], revision,
                pkg_data['branch'], pkg_data['slot'],
                licid, pkg_data['etpapi'], trigger,
            )
        else:
            mybaseinfo_data = (pkgatom, pkg_data['category'], pkg_data['name'],
                pkg_data['version'], pkg_data['versiontag'], revision,
                pkg_data['branch'], pkg_data['slot'],
                pkg_data['license'], pkg_data['etpapi'], trigger,
            )

        mypackage_id_string = 'NULL'
        if package_id is not None:

            manual_deps = self.retrieveManualDependencies(package_id,
                resolve_conditional_deps = False)

            # does it exist?
            self.removePackage(package_id, from_add_package = True)
            mypackage_id_string = '?'
            mybaseinfo_data = (package_id,)+mybaseinfo_data

            # merge old manual dependencies
            dep_dict = pkg_data['dependencies']
            for manual_dep in manual_deps:
                if manual_dep in dep_dict:
                    continue
                dep_dict[manual_dep] = \
                    etpConst['dependency_type_ids']['mdepend_id']

        cur = self._cursor().execute("""
        INSERT INTO baseinfo VALUES
        (%s, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)""" % (
            mypackage_id_string,), mybaseinfo_data)
        if package_id is None:
            package_id = cur.lastrowid

        # extrainfo
        if not _baseinfo_extrainfo_2010:
            self._cursor().execute(
                'INSERT INTO extrainfo VALUES (?, ?, ?, ?, ?, ?, ?, ?)',
                (   package_id,
                    pkg_data['description'],
                    pkg_data['homepage'],
                    pkg_data['download'],
                    pkg_data['size'],
                    idflags,
                    pkg_data['digest'],
                    pkg_data['datecreation'],
                )
            )
        else:
            self._cursor().execute(
                'INSERT INTO extrainfo VALUES (?,?,?,?,?,?,?,?,?,?)',
                (   package_id,
                    pkg_data['description'],
                    pkg_data['homepage'],
                    pkg_data['download'],
                    pkg_data['size'],
                    pkg_data['chost'],
                    pkg_data['cflags'],
                    pkg_data['cxxflags'],
                    pkg_data['digest'],
                    pkg_data['datecreation'],
                )
            )
        # baseinfo and extrainfo are tainted
        self.clearCache()
        ### other information iserted below are not as
        ### critical as these above

        # tables using a select
        self._insertNeeded(package_id, pkg_data['needed'])
        self.insertDependencies(package_id, pkg_data['dependencies'])
        self._insertSources(package_id, pkg_data['sources'])
        self._insertUseflags(package_id, pkg_data['useflags'])
        self._insertKeywords(package_id, pkg_data['keywords'])
        self._insertLicenses(pkg_data['licensedata'])
        self._insertMirrors(pkg_data['mirrorlinks'])

        # packages and file association metadata
        desktop_mime = pkg_data.get('desktop_mime')
        if desktop_mime:
            self._insertDesktopMime(package_id, desktop_mime)
        provided_mime = pkg_data.get('provided_mime')
        if provided_mime:
            self._insertProvidedMime(package_id, provided_mime)

        # package ChangeLog
        if pkg_data.get('changelog'):
            self._insertChangelog(pkg_data['category'], pkg_data['name'],
                pkg_data['changelog'])
        # package signatures
        if pkg_data.get('signatures'):
            signatures = pkg_data['signatures']
            sha1, sha256, sha512, gpg = signatures['sha1'], \
                signatures['sha256'], signatures['sha512'], \
                signatures.get('gpg')
            self._insertSignatures(package_id, sha1, sha256, sha512,
                gpg = gpg)

        # extra package download URLs
        if pkg_data.get('extra_download'):
            extra_download = pkg_data['extra_download']
            self._insertExtraDownload(package_id, extra_download)

        if pkg_data.get('provided_libs'):
            self._insertProvidedLibraries(
                package_id, pkg_data['provided_libs'])

        # spm phases
        if pkg_data.get('spm_phases') is not None:
            self._insertSpmPhases(package_id, pkg_data['spm_phases'])

        if pkg_data.get('spm_repository') is not None:
            self._insertSpmRepository(
                package_id, pkg_data['spm_repository'])

        # not depending on other tables == no select done
        self.insertContent(package_id, pkg_data['content'],
            already_formatted = formatted_content)
        # insert content safety metadata (checksum, mtime)
        # if metadatum exists
        content_safety = pkg_data.get('content_safety')
        if content_safety is not None:
            self._insertContentSafety(package_id, content_safety)

        # handle SPM UID<->package_id binding
        pkg_data['counter'] = int(pkg_data['counter'])
        if not pkg_data['injected'] and (pkg_data['counter'] != -1):
            pkg_data['counter'] = self._bindSpmPackageUid(
                package_id, pkg_data['counter'], pkg_data['branch'])

        self._insertOnDiskSize(package_id, pkg_data['disksize'])
        if pkg_data['trigger']:
            self._insertTrigger(package_id, pkg_data['trigger'])
        self._insertConflicts(package_id, pkg_data['conflicts'])

        if "provide_extended" not in pkg_data:
            self._insertProvide(package_id, pkg_data['provide'])
        else:
            self._insertProvide(package_id, pkg_data['provide_extended'])

        self._insertConfigProtect(package_id, idprotect)
        self._insertConfigProtect(package_id, idprotect_mask, mask = True)
        # injected?
        if pkg_data.get('injected'):
            self.setInjected(package_id)
        # is it a system package?
        if pkg_data.get('systempackage'):
            self._setSystemPackage(package_id)

        # this will always be optional !
        # (see entropy.client.interfaces.package)
        original_repository = pkg_data.get('original_repository')
        if original_repository is not None:
            self.storeInstalledPackage(package_id, original_repository)

        # baseinfo and extrainfo are tainted
        # ensure that cache is clear even here
        self.clearCache()

        return package_id

    def addPackage(self, pkg_data, revision = -1, package_id = None,
        formatted_content = False):
        """
        Reimplemented from EntropyRepositoryBase.
        Needs to call superclass method.
        """
        try:
            package_id = self._addPackage(pkg_data, revision = revision,
                package_id = package_id,
                formatted_content = formatted_content)
            super(EntropySQLRepository, self).addPackage(
                pkg_data, revision = revision,
                package_id = package_id,
                formatted_content = formatted_content)
            return package_id
        except:
            self._connection().rollback()
            raise

    def removePackage(self, package_id, from_add_package = False):
        """
        Reimplemented from EntropyRepositoryBase.
        Needs to call superclass method.
        """
        try:
            self.clearCache()
            super(EntropySQLRepository, self).removePackage(
                package_id, from_add_package = from_add_package)
            self.clearCache()

            return self._removePackage(package_id,
                from_add_package = from_add_package)
        except:
            self._connection().rollback()
            raise

    def _removePackage(self, package_id, from_add_package = False):
        """
        Reimplemented from EntropyRepositoryBase.
        This method uses "ON DELETE CASCADE" to implement quick
        and reliable package removal.
        """
        self._cursor().execute(
            "DELETE FROM baseinfo WHERE idpackage = ?", (package_id,))

    def _removeMirrorEntries(self, mirrorname):
        """
        Remove source packages mirror entries from database for the given
        mirror name. This is a representation of Portage's "thirdpartymirrors".

        @param mirrorname: mirror name
        @type mirrorname: string
        """
        self._cursor().execute("""
        DELETE FROM mirrorlinks WHERE mirrorname = ?
        """, (mirrorname,))

    def _addMirrors(self, mirrorname, mirrorlist):
        """
        Add source package mirror entry to database.
        This is a representation of Portage's "thirdpartymirrors".

        @param mirrorname: name of the mirror from which "mirrorlist" belongs
        @type mirrorname: string
        @param mirrorlist: list of URLs belonging to the given mirror name
        @type mirrorlist: list
        """
        self._cursor().executemany("""
        INSERT INTO mirrorlinks VALUES (?, ?)
        """, [(mirrorname, x,) for x in mirrorlist])

    def _addProtect(self, protect):
        """
        Add a single, generic CONFIG_PROTECT (not defined as _MASK/whatever
        here) path. Return its identifier (idprotect).

        @param protect: CONFIG_PROTECT path to add
        @type protect: string
        @return: protect identifier (idprotect)
        @rtype: int
        """
        cur = self._cursor().execute("""
        INSERT INTO configprotectreference VALUES (NULL, ?)
        """, (protect,))
        return cur.lastrowid

    def _addSource(self, source):
        """
        Add source code package download path to repository. Return its
        identifier (idsource).

        @param source: source package download path
        @type source: string
        @return: source identifier (idprotect)
        @rtype: int
        """
        cur = self._cursor().execute("""
        INSERT INTO sourcesreference VALUES (NULL, ?)
        """, (source,))
        return cur.lastrowid

    def _addDependency(self, dependency):
        """
        Add dependency string to repository. Return its identifier
        (iddependency).

        @param dependency: dependency string
        @type dependency: string
        @return: dependency identifier (iddependency)
        @rtype: int
        """
        cur = self._cursor().execute("""
        INSERT INTO dependenciesreference VALUES (NULL, ?)
        """, (dependency,))
        return cur.lastrowid

    def _addKeyword(self, keyword):
        """
        Add package SPM keyword string to repository.
        Return its identifier (idkeyword).

        @param keyword: keyword string
        @type keyword: string
        @return: keyword identifier (idkeyword)
        @rtype: int
        """
        cur = self._cursor().execute("""
        INSERT INTO keywordsreference VALUES (NULL, ?)
        """, (keyword,))
        return cur.lastrowid

    def _addUseflag(self, useflag):
        """
        Add package USE flag string to repository.
        Return its identifier (iduseflag).

        @param useflag: useflag string
        @type useflag: string
        @return: useflag identifier (iduseflag)
        @rtype: int
        """
        cur = self._cursor().execute("""
        INSERT INTO useflagsreference VALUES (NULL, ?)
        """, (useflag,))
        return cur.lastrowid

    def _addNeeded(self, needed):
        """
        Add package libraries' ELF object NEEDED string to repository.
        Return its identifier (idneeded).

        @param needed: NEEDED string (as shown in `readelf -d elf.so`)
        @type needed: string
        @return: needed identifier (idneeded)
        @rtype: int
        """
        cur = self._cursor().execute("""
        INSERT INTO neededreference VALUES (NULL, ?)
        """, (needed,))
        return cur.lastrowid

    def _setSystemPackage(self, package_id):
        """
        Mark a package as system package, which means that entropy.client
        will deny its removal.

        @param package_id: package identifier
        @type package_id: int
        """
        self._cursor().execute("""
        INSERT INTO systempackages VALUES (?)
        """, (package_id,))

    def setInjected(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        if not self.isInjected(package_id):
            self._cursor().execute("""
            INSERT INTO injected VALUES (?)
            """, (package_id,))

    def setCreationDate(self, package_id, date):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        UPDATE extrainfo SET datecreation = ? WHERE idpackage = ?
        """, (str(date), package_id,))

    def setDigest(self, package_id, digest):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        UPDATE extrainfo SET digest = ? WHERE idpackage = ?
        """, (digest, package_id,))

    def setSignatures(self, package_id, sha1, sha256, sha512, gpg = None):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        UPDATE packagesignatures SET sha1 = ?, sha256 = ?, sha512 = ?,
        gpg = ? WHERE idpackage = ?
        """, (sha1, sha256, sha512, gpg, package_id))

    def setDownloadURL(self, package_id, url):
        """
        Set download URL prefix for package.

        @param package_id: package indentifier
        @type package_id: int
        @param url: URL prefix to set
        @type url: string
        """
        self._cursor().execute("""
        UPDATE extrainfo SET download = ? WHERE idpackage = ?
        """, (url, package_id,))

    def setCategory(self, package_id, category):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        UPDATE baseinfo SET category = ? WHERE idpackage = ?
        """, (category, package_id,))

    def setCategoryDescription(self, category, description_data):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        DELETE FROM categoriesdescription WHERE category = ?
        """, (category,))
        for locale in description_data:
            mydesc = description_data[locale]
            self._cursor().execute("""
            INSERT INTO categoriesdescription VALUES (?, ?, ?)
            """, (category, locale, mydesc,))

    def setName(self, package_id, name):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        UPDATE baseinfo SET name = ? WHERE idpackage = ?
        """, (name, package_id,))

    def setDependency(self, iddependency, dependency):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        UPDATE dependenciesreference SET dependency = ?
        WHERE iddependency = ?
        """, (dependency, iddependency,))

    def setAtom(self, package_id, atom):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        UPDATE baseinfo SET atom = ? WHERE idpackage = ?
        """, (atom, package_id,))

    def setSlot(self, package_id, slot):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        UPDATE baseinfo SET slot = ? WHERE idpackage = ?
        """, (slot, package_id,))

    def setRevision(self, package_id, revision):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        UPDATE baseinfo SET revision = ? WHERE idpackage = ?
        """, (revision, package_id,))

    def removeDependencies(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        DELETE FROM dependencies WHERE idpackage = ?
        """, (package_id,))

    def insertDependencies(self, package_id, depdata):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        dcache = set()
        add_dep = self._addDependency
        is_dep_avail = self._isDependencyAvailable

        deps = []
        for dep in depdata:
            if dep in dcache:
                continue
            iddep = is_dep_avail(dep)
            if iddep == -1:
                iddep = add_dep(dep)

            deptype = 0
            if isinstance(depdata, dict):
                deptype = depdata[dep]

            dcache.add(dep)
            deps.append((package_id, iddep, deptype,))

        del dcache

        self._cursor().executemany("""
        INSERT INTO dependencies VALUES (?, ?, ?)
        """, deps)

    def insertContent(self, package_id, content, already_formatted = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        # respect iterators, so that if they're true iterators
        # we save a lot of memory.
        class MyIter:

            def __init__(self, _package_id, _content, _already_fmt):
                self._package_id = _package_id
                self._content = _content
                self._already_fmt = _already_fmt
                self._iter = iter(self._content)

            def __iter__(self):
                # reinit iter
                self._iter = iter(self._content)
                return self

            def __next__(self):
                if self._already_fmt:
                    a, x, y = next(self._iter)
                    return self._package_id, x, y
                else:
                    x = next(self._iter)
                    return self._package_id, x, self._content[x]

            def next(self):
                if self._already_fmt:
                    a, x, y = self._iter.next()
                    return self._package_id, x, y
                else:
                    x = self._iter.next()
                    return self._package_id, x, self._content[x]

        if already_formatted:
            self._cursor().executemany("""
            INSERT INTO content VALUES (?, ?, ?)
            """, MyIter(package_id, content, already_formatted))
        else:
            self._cursor().executemany("""
            INSERT INTO content VALUES (?, ?, ?)
            """, MyIter(package_id, content, already_formatted))

    def _insertContentSafety(self, package_id, content_safety):
        """
        Currently supported: sha256, mtime.
        Insert into contentsafety table package files sha256sum and mtime.
        """
        if isinstance(content_safety, dict):
            self._cursor().executemany("""
            INSERT INTO contentsafety VALUES (?, ?, ?, ?)
            """, [(package_id, k, v['mtime'], v['sha256']) \
                      for k, v in content_safety.items()])
        else:
            # support for iterators containing tuples like this:
            # (path, sha256, mtime)
            class MyIterWrapper:
                def __init__(self, _iter):
                    self._iter = iter(_iter)

                def __iter__(self):
                    # reinit iter
                    self._iter = iter(self._iter)
                    return self

                def __next__(self):
                    path, sha256, mtime = next(self._iter)
                    # this is the insert order, with mtime
                    # and sha256 swapped.
                    return package_id, path, mtime, sha256

                def next(self):
                    path, sha256, mtime = self._iter.next()
                    # this is the insert order, with mtime
                    # and sha256 swapped.
                    return package_id, path, mtime, sha256

            self._cursor().executemany("""
            INSERT INTO contentsafety VALUES (?, ?, ?, ?)
            """, MyIterWrapper(content_safety))

    def _insertProvidedLibraries(self, package_id, libs_metadata):
        """
        Insert library metadata owned by package.

        @param package_id: package indentifier
        @type package_id: int
        @param libs_metadata: provided library metadata composed by list of
            tuples of length 3 containing library name, path and ELF class.
        @type libs_metadata: list
        """
        self._cursor().executemany("""
        INSERT INTO provided_libs VALUES (?, ?, ?, ?)
        """, [(package_id, x, y, z,) for x, y, z in libs_metadata])

    def insertAutomergefiles(self, package_id, automerge_data):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().executemany("""
        INSERT INTO automergefiles VALUES (?, ?, ?)""",
            [(package_id, x, y,) for x, y in automerge_data])

    def _insertChangelog(self, category, name, changelog_txt):
        """
        Insert package changelog for package (in this case using category +
        name as key).

        @param category: package category
        @type category: string
        @param name: package name
        @type name: string
        @param changelog_txt: changelog text
        @type changelog_txt: string
        """
        mytxt = changelog_txt.encode('raw_unicode_escape')

        self._cursor().execute("""
        DELETE FROM packagechangelogs WHERE category = ? AND name = ?
        """, (category, name,))

        self._cursor().execute("""
        INSERT INTO packagechangelogs VALUES (?, ?, ?)
        """, (category, name, const_get_buffer()(mytxt),))

    def _insertLicenses(self, licenses_data):
        """
        insert license data (license names and text) into repository.

        @param licenses_data: dictionary containing license names as keys and
            text as values
        @type licenses_data: dict
        """

        mylicenses = list(licenses_data.keys())
        def my_mf(mylicense):
            return not self.isLicenseDataKeyAvailable(mylicense)

        def my_mm(mylicense):

            lic_data = licenses_data.get(mylicense, '')

            # support both utf8 and str input
            if const_isunicode(lic_data): # encode to str
                try:
                    lic_data = lic_data.encode('raw_unicode_escape')
                except (UnicodeDecodeError,):
                    lic_data = lic_data.encode('utf-8')

            return (mylicense, const_get_buffer()(lic_data), 0,)

        # set() used after filter to remove duplicates
        self._cursor().executemany("""
        %s INTO licensedata VALUES (?, ?, ?)
        """ % (self._INSERT_OR_REPLACE,),
        list(map(my_mm, set(filter(my_mf, mylicenses)))))

    def _insertConfigProtect(self, package_id, idprotect, mask = False):
        """
        Insert CONFIG_PROTECT (configuration files protection) entry identifier
        for package. This entry is usually a space separated string of directory
        and files which are used to handle user-protected configuration files
        or directories, those that are going to be stashed in separate paths
        waiting for user merge decisions.

        @param package_id: package indentifier
        @type package_id: int
        @param idprotect: configuration files protection identifier
        @type idprotect: int
        @keyword mask: if True, idproctect will be considered a "mask" entry,
            meaning that configuration files starting with paths referenced
            by idprotect will be forcefully merged.
        @type mask: bool
        """

        mytable = 'configprotect'
        if mask:
            mytable += 'mask'
        self._cursor().execute("""
        INSERT INTO %s VALUES (?, ?)
        """ % (mytable,), (package_id, idprotect,))

    def _insertMirrors(self, mirrors):
        """
        Insert list of "mirror name" and "mirror list" into repository.
        The term "mirror" in this case references to Source Package Manager
        package download mirrors.
        Argument format is like this for historical reasons and may change in
        future.

        @todo: change argument format
        @param mirrors: list of tuples of length 2 containing string as first
            item and list as second.
            [('openoffice', ['http://openoffice1', 'http://..."],), ...]
        @type mirrors: list
        """

        for mirrorname, mirrorlist in mirrors:
            # remove old
            self._removeMirrorEntries(mirrorname)
            # add new
            self._addMirrors(mirrorname, mirrorlist)

    def _insertKeywords(self, package_id, keywords):
        """
        Insert keywords for package. Keywords are strings contained in package
        metadata stating what architectures or subarchitectures are supported
        by package. It is historically used also for masking packages (making
        them not available).

        @param package_id: package indentifier
        @type package_id: int
        @param keywords: list of keywords
        @type keywords: list
        """

        def mymf(key):
            idkeyword = self._isKeywordAvailable(key)
            if idkeyword == -1:
                # create category
                idkeyword = self._addKeyword(key)
            return (package_id, idkeyword,)

        self._cursor().executemany("""
        INSERT INTO keywords VALUES (?, ?)
        """, list(map(mymf, keywords)))

    def _insertUseflags(self, package_id, useflags):
        """
        Insert Source Package Manager USE (components build) flags for package.

        @param package_id: package indentifier
        @type package_id: int
        @param useflags: list of use flags strings
        @type useflags: list
        """

        def mymf(flag):
            iduseflag = self._isUseflagAvailable(flag)
            if iduseflag == -1:
                # create category
                iduseflag = self._addUseflag(flag)
            return (package_id, iduseflag,)

        self._cursor().executemany("""
        INSERT INTO useflags VALUES (?, ?)
        """, list(map(mymf, useflags)))

    def _insertSignatures(self, package_id, sha1, sha256, sha512, gpg = None):
        """
        Insert package file extra hashes (sha1, sha256, sha512) for package.

        @param package_id: package indentifier
        @type package_id: int
        @param sha1: SHA1 hash for package file
        @type sha1: string
        @param sha256: SHA256 hash for package file
        @type sha256: string
        @param sha512: SHA512 hash for package file
        @type sha512: string
        @keyword gpg: GPG signature file content
        @type gpg: string
        """
        self._cursor().execute("""
        INSERT INTO packagesignatures VALUES (?, ?, ?, ?, ?)
        """, (package_id, sha1, sha256, sha512, gpg))

    def _insertExtraDownload(self, package_id, package_downloads_data):
        """
        Insert extra package files download objects to repository.

        @param package_id: package indentifier
        @type package_id: int
        @param package_downloads_data: list of dict composed by
            (download, type, size, md5, sha1, sha256, sha512, gpg) as keys
        @type package_downloads_data: list
        """
        self._cursor().executemany("""
        INSERT INTO packagedownloads VALUES
        (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
        """, [(package_id, edw['download'], edw['type'], edw['size'],
                edw['disksize'], edw['md5'], edw['sha1'], edw['sha256'],
                edw['sha512'], edw['gpg']) for edw in \
                    package_downloads_data])

    def _insertDesktopMime(self, package_id, metadata):
        """
        Insert file association information for package.

        @param package_id: package indentifier
        @type package_id: int
        @param metadata: list of dict() containing file association metadata
        @type metadata: list
        """
        mime_data = [(package_id, x['name'],
                      x['mimetype'], x['executable'],
                      x['icon']) for x in metadata]
        self._cursor().executemany("""
        INSERT INTO packagedesktopmime VALUES (?, ?, ?, ?, ?)
        """, mime_data)

    def _insertProvidedMime(self, package_id, mimetypes):
        """
        Insert file association information for package in a way useful for
        making direct and inverse queries (having a mimetype or having a
        package identifier)

        @param package_id: package indentifier
        @type package_id: int
        @param mimetypes: list of mimetypes supported by package
        @type mimetypes: list
        """
        self._cursor().executemany("""
        INSERT INTO provided_mime VALUES (?, ?)""",
            [(x, package_id) for x in mimetypes])

    def _insertSpmPhases(self, package_id, phases):
        """
        Insert Source Package Manager phases for package.
        Entropy can call several Source Package Manager (the PM which Entropy
        relies on) package installation/removal phases.
        Such phase names are listed here.

        @param package_id: package indentifier
        @type package_id: int
        @param phases: list of available Source Package Manager phases
        @type phases: list
        """
        self._cursor().execute("""
        INSERT INTO packagespmphases VALUES (?, ?)
        """, (package_id, phases,))

    def _insertSpmRepository(self, package_id, repository):
        """
        Insert Source Package Manager repository for package.
        This medatatum describes the source repository where package has
        been compiled from.

        @param package_id: package indentifier
        @type package_id: int
        @param repository: Source Package Manager repository
        @type repository: string
        """
        self._cursor().execute("""
        INSERT INTO packagespmrepository VALUES (?, ?)
        """, (package_id, repository,))

    def _insertSources(self, package_id, sources):
        """
        Insert source code package download URLs for package_id.

        @param package_id: package indentifier
        @type package_id: int
        @param sources: list of source URLs
        @type sources: list
        """
        def mymf(source):

            if (not source) or \
            (not entropy.tools.is_valid_string(source)):
                return 0

            idsource = self._isSourceAvailable(source)
            if idsource == -1:
                idsource = self._addSource(source)

            return (package_id, idsource,)

        self._cursor().executemany("""
        INSERT INTO sources VALUES (?, ?)
        """, [x for x in map(mymf, sources) if x != 0])

    def _insertConflicts(self, package_id, conflicts):
        """
        Insert dependency conflicts for package.

        @param package_id: package indentifier
        @type package_id: int
        @param conflicts: list of dep. conflicts
        @type conflicts: list
        """
        self._cursor().executemany("""
        INSERT INTO conflicts VALUES (?, ?)
        """, [(package_id, x,) for x in conflicts])

    def _insertProvide(self, package_id, provides):
        """
        Insert PROVIDE metadata for package_id.
        This has been added for supporting Portage Source Package Manager
        old-style meta-packages support.
        Packages can provide extra atoms, you can see it like aliases, where
        these can be given by multiple packages. This allowed to make available
        multiple applications providing the same functionality which depending
        packages can reference, without forcefully being bound to a single
        package.

        @param package_id: package indentifier
        @type package_id: int
        @param provides: list of atom strings
        @type provides: list
        """
        default_provides = [x for x in provides if x[1]]

        self._cursor().executemany("""
        INSERT INTO provide VALUES (?, ?, ?)
        """, [(package_id, x, y,) for x, y in provides])

        if default_provides:
            # reset previously set default provides
            self._cursor().executemany("""
            UPDATE provide SET is_default=0 WHERE atom = ? AND
            idpackage != ?
            """, default_provides)

    def _insertNeeded(self, package_id, neededs):
        """
        Insert package libraries' ELF object NEEDED string for package.
        Return its identifier (idneeded).

        @param package_id: package indentifier
        @type package_id: int
        @param neededs: list of NEEDED string (as shown in `readelf -d elf.so`)
        @type neededs: string
        """
        def mymf(needed_data):
            needed, elfclass = needed_data
            idneeded = self.isNeededAvailable(needed)
            if idneeded == -1:
                idneeded = self._addNeeded(needed)
            return (package_id, idneeded, elfclass,)

        self._cursor().executemany("""
        INSERT INTO needed VALUES (?, ?, ?)
        """, list(map(mymf, neededs)))

    def _insertOnDiskSize(self, package_id, mysize):
        """
        Insert on-disk size (bytes) for package.

        @param package_id: package indentifier
        @type package_id: int
        @param mysize: package size (bytes)
        @type mysize: int
        """
        self._cursor().execute("""
        INSERT INTO sizes VALUES (?, ?)
        """, (package_id, mysize,))

    def _insertTrigger(self, package_id, trigger):
        """
        Insert built-in trigger script for package, containing
        pre-install, post-install, pre-remove, post-remove hooks.
        This feature should be considered DEPRECATED, and kept for convenience.
        Please use Source Package Manager features if possible.

        @param package_id: package indentifier
        @type package_id: int
        @param trigger: trigger file dump
        @type trigger: string
        """
        self._cursor().execute("""
        INSERT INTO triggers VALUES (?, ?)
        """, (package_id, const_get_buffer()(trigger),))

    def insertBranchMigration(self, repository, from_branch, to_branch,
        post_migration_md5sum, post_upgrade_md5sum):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        %s INTO entropy_branch_migration VALUES (?,?,?,?,?)
        """ % (self._INSERT_OR_REPLACE,), (
                repository, from_branch,
                to_branch, post_migration_md5sum,
                post_upgrade_md5sum,
            )
        )

    def setBranchMigrationPostUpgradeMd5sum(self, repository, from_branch,
        to_branch, post_upgrade_md5sum):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        UPDATE entropy_branch_migration SET post_upgrade_md5sum = ? WHERE
        repository = ? AND from_branch = ? AND to_branch = ?
        """, (post_upgrade_md5sum, repository, from_branch, to_branch,))

    def _bindSpmPackageUid(self, package_id, spm_package_uid, branch):
        """
        Bind Source Package Manager package identifier ("COUNTER" metadata
        for Portage) to Entropy package.
        If uid <= -2, a new negative UID will be allocated and returned.
        Negative UIDs are considered auto-allocated by Entropy.
        This is mainly used for binary packages not belonging to any SPM
        packages which are just "injected" inside the repository.

        @param package_id: package indentifier
        @type package_id: int
        @param spm_package_uid: Source package Manager unique package identifier
        @type spm_package_uid: int
        @param branch: current running Entropy branch
        @type branch: string
        @return: uid set
        @rtype: int
        """
        my_uid = spm_package_uid
        if my_uid <= -2:
            # special cases
            my_uid = self.getFakeSpmUid()

        self._cursor().execute("""
        INSERT INTO counters VALUES (?, ?, ?)
        """, (my_uid, package_id, branch,))

        return my_uid

    def insertSpmUid(self, package_id, spm_package_uid):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        branch = self._settings['repositories']['branch']

        self._cursor().execute("""
        DELETE FROM counters WHERE counter = ?
        AND branch = ?
        """, (spm_package_uid, branch,))
        # the "OR REPLACE" clause handles the UPDATE
        # of the counter value in case of clashing
        self._cursor().execute("""
        %s INTO counters VALUES (?, ?, ?);
        """ % (self._INSERT_OR_REPLACE,),
        (spm_package_uid, package_id, branch,))

    def removeTrashedUids(self, spm_package_uids):
        """
        Remove given Source Package Manager unique package identifiers from
        the "trashed" list. This is only used by Entropy Server.
        """
        self._cursor().executemany("""
        DELETE FROM trashedcounters WHERE counter = ?
        """, [(x,) for x in spm_package_uids])

    def setTrashedUid(self, spm_package_uid):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        %s INTO trashedcounters VALUES (?)
        """ % (self._INSERT_OR_REPLACE,), (spm_package_uid,))

    def setSpmUid(self, package_id, spm_package_uid, branch = None):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        branchstring = ''
        insertdata = (spm_package_uid, package_id)
        if branch:
            branchstring = ', branch = (?)'
            insertdata += (branch,)

        if self._UPDATE_OR_REPLACE is not None:
            self._cursor().execute("""
            %s counters SET counter = (?) %s
            WHERE idpackage = (?)""" % (
                    self._UPDATE_OR_REPLACE,
                    branchstring,), insertdata)
        else:
            try:
                cur = self._cursor().execute("""
                UPDATE counters SET counter = ? %s
                WHERE idpackage = ?""" % (branchstring,), insertdata)
            except IntegrityError as err:
                # this was used by MySQL
                # errno = self.ModuleProxy.errno()
                # if err.args[0].errno != errno['ER_DUP_ENTRY']:
                #     raise
                # fallback to replace
                cur = self._cursor().execute("""
                %s INTO counters SET counter = ? %s
                WHERE idpackage = ?""" % (
                        self._INSERT_OR_REPLACE,
                        branchstring,), insertdata)

    def setContentSafety(self, package_id, content_safety):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        DELETE FROM contentsafety where idpackage = ?
        """, (package_id,))
        self._insertContentSafety(package_id, content_safety)

    def contentDiff(self, package_id, dbconn, dbconn_package_id,
                    extended = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        # setup random table name
        random_str = "%svs%s_%s" % (package_id, id(dbconn),
            dbconn_package_id)
        if const_is_python3():
            random_str = const_convert_to_rawstring(random_str)
        randomtable = "cdiff%s" % (hashlib.md5(random_str).hexdigest(),)

        # create random table
        self._cursor().executescript("""
            DROP TABLE IF EXISTS `%s`;
            CREATE TEMPORARY TABLE `%s` (
                file VARCHAR(75), ftype VARCHAR(3) );
            """ % (randomtable, randomtable,)
        )

        try:

            content_iter = dbconn.retrieveContentIter(dbconn_package_id)
            self._cursor().executemany("""
            INSERT INTO `%s` VALUES (?, ?)""" % (randomtable,),
                content_iter)

            # remove this when the one in retrieveContent will be removed
            self._connection().unicode()

            # now compare
            ftype_str = ""
            if extended:
                ftype_str = ", type"
            cur = self._cursor().execute("""
            SELECT file%s FROM content
            WHERE content.idpackage = ? AND
            content.file NOT IN (SELECT file from `%s`)""" % (
                    ftype_str, randomtable,), (package_id,))

            # suck back
            if extended:
                return tuple(cur)
            return self._cur2frozenset(cur)

        finally:
            self._cursor().execute('DROP TABLE IF EXISTS `%s`' % (
                    randomtable,))

    def clean(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cleanupUseflags()
        self._cleanupSources()
        self._cleanupNeeded()
        self._cleanupDependencies()
        self._cleanupChangelogs()

    def _cleanupChangelogs(self):
        """
        Cleanup "changelog" metadata unused references to save space.
        """
        concat = self._concatOperator(("category", "'/'", "name"))
        concat_sub = self._concatOperator(
            ("baseinfo.category", "'/'", "baseinfo.name"))
        self._cursor().execute("""
        DELETE FROM packagechangelogs
        WHERE %s NOT IN
        ( SELECT %s FROM baseinfo)
        """ % (concat, concat_sub,))

    def _cleanupUseflags(self):
        """
        Cleanup "USE flags" metadata unused references to save space.
        """
        self._cursor().execute("""
        DELETE FROM useflagsreference
        WHERE idflag NOT IN (SELECT idflag FROM useflags)""")

    def _cleanupSources(self):
        """
        Cleanup "sources" metadata unused references to save space.
        """
        self._cursor().execute("""
        DELETE FROM sourcesreference
        WHERE idsource NOT IN (SELECT idsource FROM sources)""")

    def _cleanupNeeded(self):
        """
        Cleanup "needed" metadata unused references to save space.
        """
        self._cursor().execute("""
        DELETE FROM neededreference
        WHERE idneeded NOT IN (SELECT idneeded FROM needed)""")

    def _cleanupDependencies(self):
        """
        Cleanup "dependencies" metadata unused references to save space.
        """
        self._cursor().execute("""
        DELETE FROM dependenciesreference
        WHERE iddependency NOT IN (SELECT iddependency FROM dependencies)
        """)

    def getFakeSpmUid(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        try:
            cur = self._cursor().execute("""
            SELECT min(counter) FROM counters LIMIT 1
            """)
            dbcounter = cur.fetchone()
        except Error:
            # first available counter
            return -2

        counter = 0
        if dbcounter:
            counter = dbcounter[0]

        if (counter >= -1) or (counter is None):
            counter = -2
        else:
            counter -= 1

        return counter

    def getApi(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT max(etpapi) FROM baseinfo LIMIT 1
        """)
        api = cur.fetchone()
        if api:
            return api[0]
        return -1

    def getDependency(self, iddependency):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT dependency FROM dependenciesreference
        WHERE iddependency = ? LIMIT 1
        """, (iddependency,))
        dep = cur.fetchone()
        if dep:
            return dep[0]

    def getPackageIds(self, atom):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT idpackage FROM baseinfo WHERE atom = ?
        """, (atom,))
        return self._cur2frozenset(cur)

    def getPackageIdFromDownload(self, download_relative_path,
        endswith = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        if endswith:
            cur = self._cursor().execute("""
            SELECT baseinfo.idpackage FROM baseinfo,extrainfo
            WHERE extrainfo.download LIKE ? AND
            baseinfo.idpackage = extrainfo.idpackage
            LIMIT 1
            """, ("%"+download_relative_path,))
        else:
            cur = self._cursor().execute("""
            SELECT baseinfo.idpackage FROM baseinfo,extrainfo
            WHERE extrainfo.download = ? AND
            baseinfo.idpackage = extrainfo.idpackage
            LIMIT 1
            """, (download_relative_path,))

        package_id = cur.fetchone()
        if package_id:
            return package_id[0]
        return -1

    def getVersioningData(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT version, versiontag, revision FROM baseinfo
        WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        return cur.fetchone()

    def getStrictData(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        concat = self._concatOperator(("category", "'/'", "name"))
        cur = self._cursor().execute("""
        SELECT %s, slot, version, versiontag, revision, atom
        FROM baseinfo
        WHERE idpackage = ? LIMIT 1
        """ % (concat,), (package_id,))
        return cur.fetchone()

    def getStrictScopeData(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT atom, slot, revision FROM baseinfo
        WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        return cur.fetchone()

    def getScopeData(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT atom, category, name, version, slot, versiontag,
            revision, branch, etpapi FROM baseinfo
        WHERE baseinfo.idpackage = ? LIMIT 1
        """, (package_id,))
        return cur.fetchone()

    def getBaseData(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        sql = """
        SELECT
            baseinfo.atom,
            baseinfo.name,
            baseinfo.version,
            baseinfo.versiontag,
            extrainfo.description,
            baseinfo.category,
            extrainfo.chost,
            extrainfo.cflags,
            extrainfo.cxxflags,
            extrainfo.homepage,
            baseinfo.license,
            baseinfo.branch,
            extrainfo.download,
            extrainfo.digest,
            baseinfo.slot,
            baseinfo.etpapi,
            extrainfo.datecreation,
            extrainfo.size,
            baseinfo.revision
        FROM
            baseinfo,
            extrainfo
        WHERE
            baseinfo.idpackage = ?
            AND baseinfo.idpackage = extrainfo.idpackage
        LIMIT 1
        """
        cur = self._cursor().execute(sql, (package_id,))
        return cur.fetchone()

    def retrieveRepositoryUpdatesDigest(self, repository):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT digest FROM treeupdates WHERE repository = ? LIMIT 1
        """, (repository,))

        mydigest = cur.fetchone()
        if mydigest:
            return mydigest[0]
        return -1

    def listAllTreeUpdatesActions(self, no_ids_repos = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        if no_ids_repos:
            cur = self._cursor().execute("""
            SELECT command, branch, date FROM treeupdatesactions
            ORDER BY CAST(date AS FLOAT)
            """)
        else:
            cur = self._cursor().execute("""
            SELECT idupdate, repository, command, branch, date
            FROM treeupdatesactions ORDER BY CAST(date AS FLOAT)
            """)
        return tuple(cur)

    def retrieveTreeUpdatesActions(self, repository):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        params = (repository,)

        cur = self._cursor().execute("""
        SELECT command FROM treeupdatesactions WHERE
        repository = ? ORDER BY CAST(date AS FLOAT)""", params)
        return self._cur2tuple(cur)

    def bumpTreeUpdatesActions(self, updates):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute('DELETE FROM treeupdatesactions')
        self._cursor().executemany("""
        INSERT INTO treeupdatesactions VALUES (?, ?, ?, ?, ?)
        """, updates)

    def removeTreeUpdatesActions(self, repository):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        DELETE FROM treeupdatesactions WHERE repository = ?
        """, (repository,))

    def insertTreeUpdatesActions(self, updates, repository):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        myupdates = [[repository]+list(x) for x in updates]
        self._cursor().executemany("""
        INSERT INTO treeupdatesactions VALUES (NULL, ?, ?, ?, ?)
        """, myupdates)

    def setRepositoryUpdatesDigest(self, repository, digest):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        DELETE FROM treeupdates where repository = ?
        """, (repository,))
        self._cursor().execute("""
        INSERT INTO treeupdates VALUES (?, ?)
        """, (repository, digest,))

    def addRepositoryUpdatesActions(self, repository, actions, branch):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        mytime = str(time.time())
        myupdates = [
            (repository, x, branch, mytime,) for x in actions \
            if not self._doesTreeupdatesActionExist(repository, x, branch)
        ]
        self._cursor().executemany("""
        INSERT INTO treeupdatesactions VALUES (NULL, ?, ?, ?, ?)
        """, myupdates)

    def _doesTreeupdatesActionExist(self, repository, command, branch):
        """
        This method should be considered internal and not suited for general
        audience.
        Return whether provided "treeupdates" action in repository with
        provided branch exists.

        @param repository: repository identifier
        @type repository: string
        @param command: treeupdates command
        @type command: string
        @param branch: branch metadata bound to command argument value given
        @type branch: string
        @return: if True, provided treeupdates action already exists
        @rtype: bool
        """
        cur = self._cursor().execute("""
        SELECT idupdate FROM treeupdatesactions
        WHERE repository = ? and command = ?
        and branch = ? LIMIT 1
        """, (repository, command, branch,))

        result = cur.fetchone()
        if result:
            return True
        return False

    def clearPackageSets(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute('DELETE FROM packagesets')

    def insertPackageSets(self, sets_data):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        mysets = []
        for setname in sorted(sets_data):
            for dependency in sorted(sets_data[setname]):
                try:
                    mysets.append((const_convert_to_unicode(setname),
                        const_convert_to_unicode(dependency),))
                except (UnicodeDecodeError, UnicodeEncodeError,):
                    continue

        self._cursor().executemany("""
        INSERT INTO packagesets VALUES (?, ?)
        """, mysets)

    def retrievePackageSets(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT setname, dependency FROM packagesets
        """)
        sets = {}
        for setname, dependency in cur:
            obj = sets.setdefault(setname, set())
            obj.add(dependency)
        return sets

    def retrievePackageSet(self, setname):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT dependency FROM packagesets WHERE setname = ?""",
            (setname,))
        return self._cur2frozenset(cur)

    def retrieveAtom(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT atom FROM baseinfo WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        atom = cur.fetchone()
        if atom:
            return atom[0]

    def retrieveBranch(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT branch FROM baseinfo WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        branch = cur.fetchone()
        if branch:
            return branch[0]

    def retrieveTrigger(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT data FROM triggers WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        trigger = cur.fetchone()
        if not trigger:
            # backward compatibility with <=0.52.x
            return const_convert_to_rawstring('')
        return const_convert_to_rawstring(trigger[0])

    def retrieveDownloadURL(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT download FROM extrainfo WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        download = cur.fetchone()
        if download:
            return download[0]

    def retrieveDescription(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT description FROM extrainfo WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        description = cur.fetchone()
        if description:
            return description[0]

    def retrieveHomepage(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT homepage FROM extrainfo WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        home = cur.fetchone()
        if home:
            return home[0]

    def retrieveSpmUid(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT counters.counter FROM counters,baseinfo
        WHERE counters.idpackage = ? AND
        baseinfo.idpackage = counters.idpackage AND
        baseinfo.branch = counters.branch LIMIT 1
        """, (package_id,))
        mycounter = cur.fetchone()
        if mycounter:
            return mycounter[0]
        return -1

    def retrieveSize(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT size FROM extrainfo WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        size = cur.fetchone()
        if size:
            try:
                return int(size[0])
            except ValueError: # wtf?
                return 0

    def retrieveOnDiskSize(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT size FROM sizes WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        size = cur.fetchone()
        if size:
            return size[0]
        return 0

    def retrieveDigest(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT digest FROM extrainfo WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        digest = cur.fetchone()
        if digest:
            return digest[0]
        return None

    def retrieveSignatures(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT sha1, sha256, sha512, gpg FROM packagesignatures
        WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        data = cur.fetchone()

        if data:
            return data
        return None, None, None, None

    def retrieveExtraDownload(self, package_id, down_type = None):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        down_type_str = ""
        params = [package_id]
        if down_type is not None:
            down_type_str = " AND down_type = ?"
            params.append(down_type)

        cur = self._cursor().execute("""
        SELECT download, type, size, disksize, md5, sha1,
            sha256, sha512, gpg
        FROM packagedownloads WHERE idpackage = ?
        """ + down_type_str, params)

        result = []
        for download, d_type, size, d_size, md5, sha1, sha256, sha512, gpg in \
                cur:
            result.append({
                "download": download,
                "type": d_type,
                "size": size,
                "disksize": d_size,
                "md5": md5,
                "sha1": sha1,
                "sha256": sha256,
                "sha512": sha512,
                "gpg": gpg,
            })
        return tuple(result)

    def retrieveName(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT name FROM baseinfo WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        name = cur.fetchone()
        if name:
            return name[0]

    def retrieveKeySplit(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT category, name FROM baseinfo
        WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        return cur.fetchone()

    def retrieveKeySlot(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        concat = self._concatOperator(("category", "'/'", "name"))
        cur = self._cursor().execute("""
        SELECT %s, slot FROM baseinfo
        WHERE idpackage = ? LIMIT 1
        """ % (concat,), (package_id,))
        return cur.fetchone()

    def retrieveKeySlotAggregated(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        concat = self._concatOperator(
            ("category",
             "'/'",
             "name",
             "'%s'" % (etpConst['entropyslotprefix'],),
             "slot"))
        cur = self._cursor().execute("""
        SELECT %s FROM baseinfo
        WHERE idpackage = ? LIMIT 1
        """ % (concat,), (package_id,))
        keyslot = cur.fetchone()
        if keyslot:
            return keyslot[0]
        return None

    def retrieveKeySlotTag(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        concat = self._concatOperator(("category", "'/'", "name"))
        cur = self._cursor().execute("""
        SELECT %s, slot, versiontag
        FROM baseinfo WHERE
        idpackage = ? LIMIT 1
        """ % (concat,), (package_id,))
        return cur.fetchone()

    def retrieveVersion(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT version FROM baseinfo
        WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        version = cur.fetchone()
        if version:
            return version[0]
        return None

    def retrieveRevision(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT revision FROM baseinfo
        WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        rev = cur.fetchone()
        if rev:
            return rev[0]
        return None

    def retrieveCreationDate(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT datecreation FROM extrainfo WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        date = cur.fetchone()
        if date:
            return date[0]

    def retrieveApi(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT etpapi FROM baseinfo WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        api = cur.fetchone()
        if api:
            return api[0]

    def retrieveUseflags(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT useflagsreference.flagname
        FROM useflags, useflagsreference
        WHERE useflags.idpackage = ?
        AND useflags.idflag = useflagsreference.idflag
        """, (package_id,))
        return self._cur2frozenset(cur)

    def retrieveSpmPhases(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT phases FROM packagespmphases WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        spm_phases = cur.fetchone()

        if spm_phases:
            return spm_phases[0]

    def retrieveSpmRepository(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT repository FROM packagespmrepository
        WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        spm_repo = cur.fetchone()

        if spm_repo:
            return spm_repo[0]

    def retrieveDesktopMime(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT name, mimetype, executable, icon FROM packagedesktopmime
        WHERE idpackage = ?""", (package_id,))
        data = []
        for row in cur:
            item = {}
            item['name'], item['mimetype'], item['executable'], \
                item['icon'] = row
            data.append(item)
        return data

    def retrieveProvidedMime(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT mimetype FROM provided_mime WHERE idpackage = ?
        """, (package_id,))
        return self._cur2frozenset(cur)

    def retrieveNeededRaw(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT library FROM needed,neededreference
        WHERE needed.idpackage = ? AND
        needed.idneeded = neededreference.idneeded""", (package_id,))
        return self._cur2frozenset(cur)

    def retrieveNeeded(self, package_id, extended = False, formatted = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        if extended:

            cur = self._cursor().execute("""
            SELECT library,elfclass FROM needed,neededreference
            WHERE needed.idpackage = ? AND
            needed.idneeded = neededreference.idneeded ORDER BY library
            """, (package_id,))
            needed = tuple(cur)

        else:

            cur = self._cursor().execute("""
            SELECT library FROM needed,neededreference
            WHERE needed.idpackage = ? AND
            needed.idneeded = neededreference.idneeded ORDER BY library
            """, (package_id,))
            needed = self._cur2tuple(cur)

        if extended and formatted:
            return dict((lib, elfclass,) for lib, elfclass in needed)
        return needed

    def retrieveProvidedLibraries(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT library, path, elfclass FROM provided_libs
        WHERE idpackage = ?
        """, (package_id,))
        return frozenset(cur)

    def retrieveConflicts(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT conflict FROM conflicts WHERE idpackage = ?
        """, (package_id,))
        return self._cur2frozenset(cur)

    def retrieveProvide(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT atom, is_default FROM provide WHERE idpackage = ?
        """, (package_id,))
        return frozenset(cur)

    def retrieveDependenciesList(self, package_id, exclude_deptypes = None,
        resolve_conditional_deps = True):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        excluded_deptypes_query = ""
        if exclude_deptypes is not None:
            for dep_type in exclude_deptypes:
                excluded_deptypes_query += \
                    " AND dependencies.type != %d" % (dep_type,)

        concat = self._concatOperator(
            ("'!'", "conflict"))
        cur = self._cursor().execute("""
        SELECT dependenciesreference.dependency
        FROM dependencies, dependenciesreference
        WHERE dependencies.idpackage = (?) AND
        dependencies.iddependency = dependenciesreference.iddependency %s
        UNION SELECT %s FROM conflicts
        WHERE idpackage = (?)""" % (excluded_deptypes_query, concat,),
        (package_id, package_id,))
        if resolve_conditional_deps:
            return frozenset(entropy.dep.expand_dependencies(cur, [self]))
        else:
            return self._cur2frozenset(cur)

    def retrieveBuildDependencies(self, package_id, extended = False,
        resolve_conditional_deps = True):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        return self.retrieveDependencies(package_id, extended = extended,
            deptype = etpConst['dependency_type_ids']['bdepend_id'],
            resolve_conditional_deps = resolve_conditional_deps)

    def retrieveRuntimeDependencies(self, package_id, extended = False,
        resolve_conditional_deps = True):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        return self.retrieveDependencies(package_id, extended = extended,
            deptype = etpConst['dependency_type_ids']['rdepend_id'],
            resolve_conditional_deps = resolve_conditional_deps)

    def retrievePostDependencies(self, package_id, extended = False,
        resolve_conditional_deps = True):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        return self.retrieveDependencies(package_id, extended = extended,
            deptype = etpConst['dependency_type_ids']['pdepend_id'],
            resolve_conditional_deps = resolve_conditional_deps)

    def retrieveManualDependencies(self, package_id, extended = False,
        resolve_conditional_deps = True):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        return self.retrieveDependencies(package_id, extended = extended,
            deptype = etpConst['dependency_type_ids']['mdepend_id'],
            resolve_conditional_deps = resolve_conditional_deps)

    def retrieveDependencies(self, package_id, extended = False,
        deptype = None, exclude_deptypes = None,
        resolve_conditional_deps = True):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        searchdata = (package_id,)

        depstring = ''
        if deptype is not None:
            depstring = 'and dependencies.type = ?'
            searchdata += (deptype,)

        excluded_deptypes_query = ""
        if exclude_deptypes is not None:
            for dep_type in exclude_deptypes:
                excluded_deptypes_query += " AND dependencies.type != %d" % (
                    dep_type,)

        cur = None
        iter_obj = None
        if extended:
            cur = self._cursor().execute("""
            SELECT dependenciesreference.dependency,dependencies.type
            FROM dependencies,dependenciesreference
            WHERE dependencies.idpackage = ? AND
            dependencies.iddependency =
            dependenciesreference.iddependency %s %s""" % (
                depstring, excluded_deptypes_query,), searchdata)
            iter_obj = tuple
        else:
            cur = self._cursor().execute("""
            SELECT dependenciesreference.dependency
            FROM dependencies,dependenciesreference
            WHERE dependencies.idpackage = ? AND
            dependencies.iddependency =
            dependenciesreference.iddependency %s %s""" % (
                depstring, excluded_deptypes_query,), searchdata)
            iter_obj = frozenset

        if resolve_conditional_deps:
            return iter_obj(entropy.dep.expand_dependencies(
                    cur, [self]))
        return iter_obj(cur)

    def retrieveKeywords(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT keywordname FROM keywords,keywordsreference
        WHERE keywords.idpackage = ? AND
        keywords.idkeyword = keywordsreference.idkeyword""", (package_id,))
        return self._cur2frozenset(cur)

    def retrieveProtect(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT protect FROM configprotect,configprotectreference
        WHERE configprotect.idpackage = ? AND
        configprotect.idprotect = configprotectreference.idprotect
        LIMIT 1
        """, (package_id,))

        protect = cur.fetchone()
        if protect:
            return protect[0]
        return ''

    def retrieveProtectMask(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT protect FROM configprotectmask,configprotectreference
        WHERE idpackage = ? AND
        configprotectmask.idprotect = configprotectreference.idprotect
        LIMIT 1
        """, (package_id,))

        protect = cur.fetchone()
        if protect:
            return protect[0]
        return ''

    def retrieveSources(self, package_id, extended = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT sourcesreference.source FROM sources, sourcesreference
        WHERE idpackage = ? AND
        sources.idsource = sourcesreference.idsource
        """, (package_id,))
        sources = self._cur2frozenset(cur)
        if not extended:
            return sources

        source_data = {}
        mirror_str = "mirror://"
        for source in sources:

            source_data[source] = set()
            if source.startswith(mirror_str):

                mirrorname = source.split("/")[2]
                # avoid leading "/"
                mirror_url =  source.split("/", 3)[3:][0].lstrip("/")
                source_data[source] |= set(
                    [url.rstrip("/") + "/" + mirror_url for url in \
                        self.retrieveMirrorData(mirrorname)])

            else:
                source_data[source].add(source)

        return source_data

    def retrieveAutomergefiles(self, package_id, get_dict = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        # like portage does
        self._connection().unicode()

        cur = self._cursor().execute("""
        SELECT configfile, md5 FROM automergefiles WHERE idpackage = ?
        """, (package_id,))
        data = frozenset(cur)

        if get_dict:
            data = dict(((x, y,) for x, y in data))
        return data

    def retrieveContent(self, package_id, extended = False,
        formatted = False, insert_formatted = False, order_by = None):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        extstring = ''
        if extended:
            extstring = ",type"
        extstring_package_id = ''
        if insert_formatted:
            extstring_package_id = 'idpackage,'

        searchkeywords = (package_id,)
        order_by_string = ''
        if order_by is not None:
            if order_by not in ("package_id", "idpackage", "file", "type",):
                raise AttributeError("invalid order_by argument")
            if order_by == "package_id":
                order_by = "idpackage"
            order_by_string = ' order by %s' % (order_by,)

        cur = self._cursor().execute("""
        SELECT %s file%s FROM content WHERE idpackage = ? %s""" % (
            extstring_package_id, extstring, order_by_string,),
            searchkeywords)

        if extended and insert_formatted:
            fl = tuple(cur)

        elif extended and formatted:
            fl = {}
            items = cur.fetchone()
            while items:
                fl[items[0]] = items[1]
                items = cur.fetchone()

        elif extended:
            fl = tuple(cur)

        else:
            if order_by:
                fl = self._cur2tuple(cur)
            else:
                fl = self._cur2frozenset(cur)

        return fl

    def retrieveContentIter(self, package_id, order_by = None,
                            reverse = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        class MyIter:

            def __init__(self, db, query, keywords):
                self._cur = None
                self._db = db
                self._query = query
                self._keywords = keywords
                self._init_cur()

            def _init_cur(self):
                self._cur = self._db._cursor().execute(
                    self._query, self._keywords)

            def __iter__(self):
                self._init_cur()
                return self

            def __next__(self):
                return next(self._cur)

            def next(self):
                return self._cur.next()

        searchkeywords = (package_id,)
        order_by_string = ''
        if order_by is not None:
            if order_by not in ("package_id", "idpackage", "file", "type",):
                raise AttributeError("invalid order_by argument")
            if order_by == "package_id":
                order_by = "idpackage"
            ordering_term = "ASC"
            if reverse:
                ordering_term = "DESC"
            order_by_string = " order by %s %s" % (
                order_by, ordering_term)

        query = """
        SELECT file, type FROM content WHERE idpackage = ? %s""" % (
            order_by_string,)
        return MyIter(self, query, searchkeywords)

    def retrieveContentSafety(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT file, sha256, mtime from contentsafety WHERE idpackage = ?
        """, (package_id,))
        return dict((path, {'sha256': sha256, 'mtime': mtime}) for path, \
            sha256, mtime in cur)

    def retrieveContentSafetyIter(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        class MyIter:

            def __init__(self, db, query, keywords):
                self._cur = None
                self._db = db
                self._query = query
                self._keywords = keywords
                self._init_cur()

            def _init_cur(self):
                self._cur = self._db._cursor().execute(
                    self._query, self._keywords)

            def __iter__(self):
                self._init_cur()
                return self

            def __next__(self):
                return next(self._cur)

            def next(self):
                return self._cur.next()

        query = """
        SELECT file, sha256, mtime from contentsafety WHERE idpackage = ?
        """
        return MyIter(self, query, (package_id,))

    def retrieveChangelog(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT packagechangelogs.changelog
        FROM packagechangelogs, baseinfo
        WHERE baseinfo.idpackage = ? AND
        packagechangelogs.category = baseinfo.category AND
        packagechangelogs.name = baseinfo.name
        LIMIT 1
        """, (package_id,))
        changelog = cur.fetchone()
        if changelog:
            changelog = changelog[0]
            try:
                return const_convert_to_unicode(changelog)
            except UnicodeDecodeError:
                return const_convert_to_unicode(
                    changelog, enctype = 'utf-8')

    def retrieveChangelogByKey(self, category, name):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._connection().unicode()

        cur = self._cursor().execute("""
        SELECT changelog FROM packagechangelogs WHERE category = ? AND
        name = ? LIMIT 1
        """, (category, name,))

        changelog = cur.fetchone()
        if changelog:
            return const_convert_to_unicode(changelog[0])

    def retrieveSlot(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT slot FROM baseinfo
        WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        slot = cur.fetchone()
        if slot:
            return slot[0]
        return None

    def retrieveTag(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT versiontag FROM baseinfo
        WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        tag = cur.fetchone()
        if tag:
            return tag[0]
        return None

    def retrieveMirrorData(self, mirrorname):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT mirrorlink FROM mirrorlinks WHERE mirrorname = ?
        """, (mirrorname,))
        return self._cur2frozenset(cur)

    def retrieveCategory(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT category FROM baseinfo
        WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        category = cur.fetchone()
        if category:
            return category[0]
        return None

    def retrieveCategoryDescription(self, category):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT description, locale FROM categoriesdescription
        WHERE category = ?
        """, (category,))

        return dict((locale, desc,) for desc, locale in cur)

    def retrieveLicenseData(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        licenses = self.retrieveLicense(package_id)
        if licenses is None:
            return {}

        licdata = {}
        for licname in licenses.split():

            if not licname.strip():
                continue

            if not entropy.tools.is_valid_string(licname):
                continue

            cur = self._cursor().execute("""
            SELECT text FROM licensedata WHERE licensename = ? LIMIT 1
            """, (licname,))
            lictext = cur.fetchone()
            if lictext is not None:
                lictext = lictext[0]
                try:
                    licdata[licname] = const_convert_to_unicode(lictext)
                except UnicodeDecodeError:
                    licdata[licname] = \
                        const_convert_to_unicode(
                            lictext, enctype = 'utf-8')

        return licdata

    def retrieveLicenseDataKeys(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        licenses = self.retrieveLicense(package_id)
        if licenses is None:
            return frozenset()

        licdata = set()
        for licname in licenses.split():

            if not licname.strip():
                continue

            if not entropy.tools.is_valid_string(licname):
                continue

            cur = self._cursor().execute("""
            SELECT licensename FROM licensedata WHERE licensename = ?
            LIMIT 1
            """, (licname,))
            lic_id = cur.fetchone()
            if lic_id:
                licdata.add(lic_id[0])

        return frozenset(licdata)

    def retrieveLicenseText(self, license_name):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._connection().unicode()

        cur = self._cursor().execute("""
        SELECT text FROM licensedata WHERE licensename = ? LIMIT 1
        """, (license_name,))

        text = cur.fetchone()
        if text:
            return const_convert_to_rawstring(text[0])

    def retrieveLicense(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT license FROM baseinfo
        WHERE idpackage = ? LIMIT 1
        """, (package_id,))

        licname = cur.fetchone()
        if licname:
            return licname[0]

    def retrieveCompileFlags(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT chost, cflags, cxxflags FROM extrainfo
        WHERE extrainfo.idpackage = ? LIMIT 1""", (package_id,))
        flags = cur.fetchone()
        if not flags:
            flags = ("N/A", "N/A", "N/A",)
        return flags

    def retrieveReverseDependencies(self, package_id, atoms = False,
        key_slot = False, exclude_deptypes = None, extended = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cached = self._getLiveCache("reverseDependenciesMetadata")
        if cached is None:
            cached = self._generateReverseDependenciesMetadata()

        dep_ids = set((k for k, v in cached.items() if package_id in v))
        if not dep_ids:
            # avoid python3.x memleak
            del cached
            if key_slot:
                return tuple()
            return frozenset()

        dep_ids_str = ', '.join((str(x) for x in dep_ids))
        excluded_deptypes_query = ""
        if exclude_deptypes is not None:
            for dep_type in exclude_deptypes:
                excluded_deptypes_query += " AND dependencies.type != %d" % (
                    dep_type,)

        if atoms:
            if extended:
                cur = self._cursor().execute("""
                SELECT baseinfo.atom, dependenciesreference.dependency
                FROM dependencies, baseinfo, dependenciesreference
                WHERE baseinfo.idpackage = dependencies.idpackage %s AND
                dependencies.iddependency =
                    dependenciesreference.iddependency AND
                dependencies.iddependency IN ( %s )""" % (
                    excluded_deptypes_query, dep_ids_str,))
                result = tuple(cur)
            else:
                cur = self._cursor().execute("""
                SELECT baseinfo.atom FROM dependencies, baseinfo
                WHERE baseinfo.idpackage = dependencies.idpackage %s AND
                dependencies.iddependency IN ( %s )""" % (
                    excluded_deptypes_query, dep_ids_str,))
                result = self._cur2frozenset(cur)
        elif key_slot:
            if self._isBaseinfoExtrainfo2010():
                concat = self._concatOperator(
                    ("baseinfo.category", "'/'", "baseinfo.name"))
                if extended:
                    cur = self._cursor().execute("""
                    SELECT %s,
                        baseinfo.slot, dependenciesreference.dependency
                    FROM baseinfo, dependencies, dependenciesreference
                    WHERE baseinfo.idpackage = dependencies.idpackage %s AND
                    dependencies.iddependency =
                        dependenciesreference.iddependency AND
                    dependencies.iddependency IN ( %s )""" % (
                        concat, excluded_deptypes_query, dep_ids_str,))
                else:
                    cur = self._cursor().execute("""
                    SELECT %s, baseinfo.slot
                    FROM baseinfo, dependencies
                    WHERE baseinfo.idpackage = dependencies.idpackage %s AND
                    dependencies.iddependency IN ( %s )""" % (
                        concat, excluded_deptypes_query, dep_ids_str,))
            else:
                concat = self._concatOperator(
                    ("categories.category", "'/'", "baseinfo.name"))
                if extended:
                    cur = self._cursor().execute("""
                    SELECT %s,
                        baseinfo.slot, dependenciesreference.dependency
                    FROM baseinfo, categories,
                        dependencies, dependenciesreference
                    WHERE baseinfo.idpackage = dependencies.idpackage AND
                    dependencies.iddependency =
                        dependenciesreference.iddependency AND
                    categories.idcategory = baseinfo.idcategory %s AND
                    dependencies.iddependency IN ( %s )""" % (
                        concat, excluded_deptypes_query, dep_ids_str,))
                else:
                    cur = self._cursor().execute("""
                    SELECT %s, baseinfo.slot
                    FROM baseinfo, categories, dependencies
                    WHERE baseinfo.idpackage = dependencies.idpackage AND
                    categories.idcategory = baseinfo.idcategory %s AND
                    dependencies.iddependency IN ( %s )""" % (
                        concat, excluded_deptypes_query, dep_ids_str,))
            result = tuple(cur)
        elif excluded_deptypes_query:
            if extended:
                cur = self._cursor().execute("""
                SELECT dependencies.idpackage, dependenciesreference.dependency
                FROM dependencies, dependenciesreference
                WHERE %s AND
                dependencies.iddependency =
                    dependenciesreference.iddependency AND
                dependencies.iddependency IN ( %s )""" % (
                    excluded_deptypes_query.lstrip("AND "), dep_ids_str,))
                result = tuple(cur)
            else:
                cur = self._cursor().execute("""
                SELECT dependencies.idpackage FROM dependencies
                WHERE %s AND dependencies.iddependency IN ( %s )""" % (
                    excluded_deptypes_query.lstrip("AND "), dep_ids_str,))
                result = self._cur2frozenset(cur)
        else:
            if extended:
                cur = self._cursor().execute("""
                SELECT dependencies.idpackage, dependenciesreference.dependency
                FROM dependencies, dependenciesreference
                WHERE
                dependencies.iddependency =
                    dependenciesreference.iddependency AND
                dependencies.iddependency IN ( %s )""" % (dep_ids_str,))
                result = tuple(cur)
            else:
                cur = self._cursor().execute("""
                SELECT dependencies.idpackage FROM dependencies
                WHERE dependencies.iddependency IN ( %s )""" % (dep_ids_str,))
                result = self._cur2frozenset(cur)

        # avoid python3.x memleak
        del cached
        return result

    def retrieveUnusedPackageIds(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cached = self._getLiveCache("reverseDependenciesMetadata")
        if cached is None:
            cached = self._generateReverseDependenciesMetadata()

        pkg_ids = set()
        for v in cached.values():
            pkg_ids |= v
        if not pkg_ids:
            # avoid python3.x memleak
            del cached
            return tuple()
        pkg_ids_str = ', '.join((str(x) for x in pkg_ids))

        cur = self._cursor().execute("""
        SELECT idpackage FROM baseinfo
        WHERE idpackage NOT IN ( %s )
        ORDER BY atom
        """ % (pkg_ids_str,))
        # avoid python3.x memleak
        del cached
        return self._cur2tuple(cur)

    def arePackageIdsAvailable(self, package_ids):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        sql = """SELECT count(idpackage) FROM baseinfo
        WHERE idpackage IN (%s) LIMIT 1""" % (','.join(
            [str(x) for x in set(package_ids)]),
        )
        cur = self._cursor().execute(sql)
        count = cur.fetchone()[0]
        if count != len(package_ids):
            return False
        return True

    def isPackageIdAvailable(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT idpackage FROM baseinfo WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        result = cur.fetchone()
        if not result:
            return False
        return True

    def _isProtectAvailable(self, protect):
        """
        Return whether given CONFIG_PROTECT* entry is available in repository.

        @param protect: CONFIG_PROTECT* entry (path to a protected directory
            or file that won't be overwritten by Entropy Client during
            package merge)
        @type protect: string
        @return: availability (True if available)
        @rtype: bool
        """
        cur = self._cursor().execute("""
        SELECT idprotect FROM configprotectreference WHERE protect = ?
        LIMIT 1
        """, (protect,))
        result = cur.fetchone()
        if result:
            return result[0]
        return -1

    def isFileAvailable(self, path, get_id = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT idpackage FROM content WHERE file = ?""", (path,))
        result = self._cur2frozenset(cur)
        if get_id:
            return result
        elif result:
            return True
        return False

    def resolveNeeded(self, needed, elfclass = -1, extended = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        args = (needed,)
        elfclass_txt = ''
        if elfclass != -1:
            elfclass_txt = ' AND provided_libs.elfclass = ?'
            args = (needed, elfclass,)

        if extended:
            cur = self._cursor().execute("""
            SELECT idpackage, path FROM provided_libs
            WHERE library = ?""" + elfclass_txt, args)
            return frozenset(cur)

        cur = self._cursor().execute("""
        SELECT idpackage FROM provided_libs
        WHERE library = ?""" + elfclass_txt, args)
        return self._cur2frozenset(cur)

    def _isSourceAvailable(self, source):
        """
        Return whether given source package URL is available in repository.
        Returns source package URL identifier (idsource).

        @param source: source package URL
        @type source: string
        @return: source package URL identifier (idsource) or -1 if not found
        @rtype: int
        """
        cur = self._cursor().execute("""
        SELECT idsource FROM sourcesreference WHERE source = ? LIMIT 1
        """, (source,))
        result = cur.fetchone()
        if result:
            return result[0]
        return -1

    def _isDependencyAvailable(self, dependency):
        """
        Return whether given dependency string is available in repository.
        Returns dependency identifier (iddependency).

        @param dependency: dependency string
        @type dependency: string
        @return: dependency identifier (iddependency) or -1 if not found
        @rtype: int
        """
        cur = self._cursor().execute("""
        SELECT iddependency FROM dependenciesreference WHERE dependency = ?
        LIMIT 1
        """, (dependency,))
        result = cur.fetchone()
        if result:
            return result[0]
        return -1

    def _isKeywordAvailable(self, keyword):
        """
        Return whether keyword string is available in repository.
        Returns keyword identifier (idkeyword)

        @param keyword: keyword string
        @type keyword: string
        @return: keyword identifier (idkeyword) or -1 if not found
        @rtype: int
        """
        cur = self._cursor().execute("""
        SELECT idkeyword FROM keywordsreference WHERE keywordname = ? LIMIT 1
        """, (keyword,))
        result = cur.fetchone()
        if result:
            return result[0]
        return -1

    def _isUseflagAvailable(self, useflag):
        """
        Return whether USE flag name is available in repository.
        Returns USE flag identifier (idflag).

        @param useflag: USE flag name
        @type useflag: string
        @return: USE flag identifier or -1 if not found
        @rtype: int
        """
        cur = self._cursor().execute("""
        SELECT idflag FROM useflagsreference WHERE flagname = ? LIMIT 1
        """, (useflag,))
        result = cur.fetchone()
        if result:
            return result[0]
        return -1

    def isNeededAvailable(self, needed):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT idneeded FROM neededreference WHERE library = ? LIMIT 1
        """, (needed,))
        result = cur.fetchone()
        if result:
            return result[0]
        return -1

    def isSpmUidAvailable(self, spm_uid):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT counter FROM counters WHERE counter = ? LIMIT 1
        """, (spm_uid,))
        result = cur.fetchone()
        if result:
            return True
        return False

    def isSpmUidTrashed(self, spm_uid):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT counter FROM trashedcounters WHERE counter = ? LIMIT 1
        """, (spm_uid,))
        result = cur.fetchone()
        if result:
            return True
        return False

    def isLicenseDataKeyAvailable(self, license_name):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT licensename FROM licensedata WHERE licensename = ? LIMIT 1
        """, (license_name,))
        result = cur.fetchone()
        if not result:
            return False
        return True

    def isLicenseAccepted(self, license_name):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT licensename FROM licenses_accepted WHERE licensename = ?
        LIMIT 1
        """, (license_name,))
        result = cur.fetchone()
        if not result:
            return False
        return True

    def isSystemPackage(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT idpackage FROM systempackages WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        result = cur.fetchone()
        if result:
            return True
        return False

    def isInjected(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT idpackage FROM injected WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        result = cur.fetchone()
        if result:
            return True
        return False

    def searchBelongs(self, bfile, like = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        if like:
            cur = self._cursor().execute("""
            SELECT content.idpackage FROM content,baseinfo
            WHERE file LIKE ? AND
            content.idpackage = baseinfo.idpackage""", (bfile,))
        else:
            cur = self._cursor().execute("""
            SELECT content.idpackage
            FROM content, baseinfo WHERE file = ?
            AND content.idpackage = baseinfo.idpackage""", (bfile,))

        return self._cur2frozenset(cur)

    def searchContentSafety(self, sfile):
        """
        Search content safety metadata (usually, sha256 and mtime) related to
        given file path. A list of dictionaries is returned, each dictionary
        item contains at least the following fields "path", "sha256", "mtime").

        @param sfile: file path to search
        @type sfile: string
        @return: content safety metadata list
        @rtype: tuple
        """
        cur = self._cursor().execute("""
        SELECT idpackage, file, sha256, mtime
        FROM contentsafety WHERE file = ?""", (sfile,))
        return tuple(({'package_id': x, 'path': y, 'sha256': z, 'mtime': m} for
            x, y, z, m in cur))

    def searchTaggedPackages(self, tag, atoms = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        if atoms:
            cur = self._cursor().execute("""
            SELECT atom, idpackage FROM baseinfo WHERE versiontag = ?
            """, (tag,))
            return frozenset(cur)

        cur = self._cursor().execute("""
        SELECT idpackage FROM baseinfo WHERE versiontag = ?
        """, (tag,))
        return self._cur2frozenset(cur)

    def searchRevisionedPackages(self, revision):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT idpackage FROM baseinfo WHERE revision = ?
        """, (revision,))
        return self._cur2frozenset(cur)

    def acceptLicense(self, license_name):
        """
        Reimplemented from EntropyRepositoryBase.
        Needs to call superclass method.
        """
        super(EntropySQLRepository, self).acceptLicense(license_name)

        self._cursor().execute("""
        %s INTO licenses_accepted VALUES (?)
        """ % (self._INSERT_OR_IGNORE,), (license_name,))

    def searchLicense(self, keyword, just_id = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        if not entropy.tools.is_valid_string(keyword):
            return frozenset()

        if just_id:
            cur = self._cursor().execute("""
            SELECT baseinfo.idpackage FROM
            baseinfo WHERE LOWER(baseinfo.license) LIKE ?
            """, ("%"+keyword+"%".lower(),))
            return self._cur2frozenset(cur)
        else:
            cur = self._cursor().execute("""
            SELECT baseinfo.atom, baseinfo.idpackage FROM
            baseinfo WHERE LOWER(baseinfo.license) LIKE ?
            """, ("%"+keyword+"%".lower(),))
            return frozenset(cur)

    def searchSlotted(self, keyword, just_id = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        if just_id:
            cur = self._cursor().execute("""
            SELECT idpackage FROM baseinfo WHERE slot = ?""", (keyword,))
            return self._cur2frozenset(cur)
        else:
            cur = self._cursor().execute("""
            SELECT atom, idpackage FROM baseinfo WHERE slot = ?
            """, (keyword,))
            return frozenset(cur)

    def searchKeySlot(self, key, slot):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        concat = self._concatOperator(("category", "'/'", "name"))
        cur = self._cursor().execute("""
        SELECT idpackage FROM baseinfo
        WHERE %s = ? AND slot = ?
        """ % (concat,), (key, slot,))
        return self._cur2frozenset(cur)

    def searchKeySlotTag(self, key, slot, tag):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        concat = self._concatOperator(("category", "'/'", "name"))
        cur = self._cursor().execute("""
        SELECT idpackage FROM baseinfo
        WHERE %s = ? AND slot = ?
        AND tag = ?
        """ % (concat,), (key, slot, tag))
        return self._cur2frozenset(cur)

    def searchNeeded(self, needed, elfclass = -1, like = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        if like:
            needed = needed.replace("*", "%")
        elfsearch = ''
        search_args = (needed,)
        if elfclass != -1:
            elfsearch = ' AND needed.elfclass = ?'
            search_args = (needed, elfclass,)

        if like:
            cur = self._cursor().execute("""
            SELECT needed.idpackage FROM needed,neededreference
            WHERE library LIKE ? %s AND
            needed.idneeded = neededreference.idneeded
            """ % (elfsearch,), search_args)
        else:
            cur = self._cursor().execute("""
            SELECT needed.idpackage FROM needed,neededreference
            WHERE library = ? %s AND
            needed.idneeded = neededreference.idneeded
            """ % (elfsearch,), search_args)

        return self._cur2frozenset(cur)

    def searchConflict(self, conflict, strings = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        keyword = "%"+conflict+"%"
        if strings:
            cur = self._cursor().execute("""
            SELECT conflict FROM conflicts WHERE conflict LIKE ?
            """, (keyword,))
            return self._cur2tuple(cur)

        cur = self._cursor().execute("""
        SELECT idpackage, conflict FROM conflicts WHERE conflict LIKE ?
        """, (keyword,))
        return tuple(cur)

    def searchDependency(self, dep, like = False, multi = False,
        strings = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        sign = "="
        limit = ""
        if like:
            sign = "LIKE"
            dep = "%"+dep+"%"
        item = 'iddependency'
        if strings:
            item = 'dependency'
        if not multi:
            limit = "LIMIT 1"

        cur = self._cursor().execute("""
        SELECT %s FROM dependenciesreference WHERE dependency %s ? %s
        """ % (item, sign, limit), (dep,))

        if multi:
            return self._cur2frozenset(cur)
        iddep = cur.fetchone()

        if iddep:
            return iddep[0]
        return -1

    def searchPackageIdFromDependencyId(self, dependency_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT idpackage FROM dependencies WHERE iddependency = ?
        """, (dependency_id,))
        return self._cur2frozenset(cur)

    def searchSets(self, keyword):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT DISTINCT(setname) FROM packagesets WHERE setname LIKE ?
        """, ("%"+keyword+"%",))

        return self._cur2frozenset(cur)

    def searchProvidedMime(self, mimetype):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT provided_mime.idpackage FROM provided_mime, baseinfo
        WHERE provided_mime.mimetype = ?
        AND baseinfo.idpackage = provided_mime.idpackage
        ORDER BY baseinfo.atom""",
        (mimetype,))
        return self._cur2tuple(cur)

    def searchSimilarPackages(self, keyword, atom = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        s_item = 'name'
        if atom:
            s_item = 'atom'
        cur = self._cursor().execute("""
        SELECT idpackage FROM baseinfo
        WHERE soundex(%s) = soundex(?) ORDER BY %s
        """ % (s_item, s_item,), (keyword,))

        return self._cur2tuple(cur)

    def searchPackages(self, keyword, sensitive = False, slot = None,
            tag = None, order_by = None, just_id = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        like_keyword = "%"+keyword+"%"
        if not sensitive:
            like_keyword = like_keyword.lower()
        searchkeywords = (like_keyword, like_keyword)

        slotstring = ''
        if slot:
            searchkeywords += (slot,)
            slotstring = ' AND slot = ?'

        tagstring = ''
        if tag:
            searchkeywords += (tag,)
            tagstring = ' AND versiontag = ?'

        order_by_string = ''
        if order_by is not None:
            valid_order_by = ("atom", "idpackage", "package_id", "branch",
                "name", "version", "versiontag", "revision", "slot")
            if order_by not in valid_order_by:
                raise AttributeError("invalid order_by argument")
            if order_by == "package_id":
                order_by = "idpackage"
            order_by_string = ' ORDER BY %s' % (order_by,)

        # atom idpackage branch
        # idpackage
        search_elements_all = """\
        t.atom AS atom, t.idpackage AS idpackage, t.branch AS branch,
        t.name AS name, t.version AS version, t.versiontag AS versiontag,
        t.revision AS revision, t.slot AS slot"""
        search_elements_provide_all = """\
        d.atom AS atom, d.idpackage AS idpackage, d.branch AS branch,
        d.name AS name, d.version AS version, d.versiontag AS versiontag,
        d.revision AS revision, d.slot AS slot"""

        search_elements = 'atom, idpackage, branch'
        if just_id:
            search_elements = 'idpackage'

        if sensitive:
            cur = self._cursor().execute("""
            SELECT DISTINCT %s FROM (
                SELECT %s FROM baseinfo t
                    WHERE t.atom LIKE ?
                UNION ALL
                SELECT %s FROM baseinfo d, provide as p
                    WHERE d.idpackage = p.idpackage
                    AND p.atom LIKE ?
            ) WHERE 1=1 %s %s %s
            """ % (search_elements, search_elements_all,
                search_elements_provide_all, slotstring, tagstring,
                order_by_string), searchkeywords)
        else:
            cur = self._cursor().execute("""
            SELECT DISTINCT %s FROM (
                SELECT %s FROM baseinfo t
                    WHERE LOWER(t.atom) LIKE ?
                UNION ALL
                SELECT %s FROM baseinfo d, provide as p
                    WHERE d.idpackage = p.idpackage
                    AND LOWER(p.atom) LIKE ?
            ) WHERE 1=1 %s %s %s
            """ % (search_elements, search_elements_all,
                search_elements_provide_all, slotstring, tagstring,
                order_by_string), searchkeywords)

        if just_id:
            return self._cur2tuple(cur)
        return tuple(cur)

    def searchProvidedVirtualPackage(self, keyword):
        """
        Search in old-style Portage PROVIDE metadata.
        @todo: rewrite docstring :-)

        @param keyword: search term
        @type keyword: string
        @return: found PROVIDE metadata
        @rtype: list
        """
        cur = self._cursor().execute("""
        SELECT baseinfo.idpackage, provide.is_default
        FROM baseinfo, provide
        WHERE provide.atom = ? AND
        provide.idpackage = baseinfo.idpackage
        """, (keyword,))
        return tuple(cur)

    def searchDescription(self, keyword, just_id = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        keyword_split = keyword.split()
        query_str_list = []
        query_args = []
        for sub_keyword in keyword_split:
            query_str_list.append("LOWER(extrainfo.description) LIKE ?")
            query_args.append("%" + sub_keyword + "%")
        query_str = " AND ".join(query_str_list)
        if just_id:
            cur = self._cursor().execute("""
            SELECT baseinfo.idpackage FROM extrainfo, baseinfo
            WHERE %s AND
            baseinfo.idpackage = extrainfo.idpackage
            """ % (query_str,), query_args)
            return self._cur2frozenset(cur)
        else:
            cur = self._cursor().execute("""
            SELECT baseinfo.atom, baseinfo.idpackage FROM extrainfo, baseinfo
            WHERE %s AND
            baseinfo.idpackage = extrainfo.idpackage
            """ % (query_str,), query_args)
            return frozenset(cur)

    def searchUseflag(self, keyword, just_id = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        if just_id:
            cur = self._cursor().execute("""
            SELECT useflags.idpackage FROM useflags, useflagsreference
            WHERE useflags.idflag = useflagsreference.idflag
            AND useflagsreference.flagname = ?
            """, (keyword,))
            return self._cur2frozenset(cur)
        else:
            cur = self._cursor().execute("""
            SELECT baseinfo.atom, useflags.idpackage
            FROM baseinfo, useflags, useflagsreference
            WHERE useflags.idflag = useflagsreference.idflag
            AND baseinfo.idpackage = useflags.idpackage
            AND useflagsreference.flagname = ?
            """, (keyword,))
            return frozenset(cur)

    def searchHomepage(self, keyword, just_id = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        if just_id:
            cur = self._cursor().execute("""
            SELECT baseinfo.idpackage FROM extrainfo, baseinfo
            WHERE LOWER(extrainfo.homepage) LIKE ? AND
            baseinfo.idpackage = extrainfo.idpackage
            """, ("%"+keyword.lower()+"%",))
            return self._cur2frozenset(cur)
        else:
            cur = self._cursor().execute("""
            SELECT baseinfo.atom, baseinfo.idpackage FROM extrainfo, baseinfo
            WHERE LOWER(extrainfo.homepage) LIKE ? AND
            baseinfo.idpackage = extrainfo.idpackage
            """, ("%"+keyword.lower()+"%",))
            return frozenset(cur)

    def searchName(self, keyword, sensitive = False, just_id = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        atomstring = ''
        if not just_id:
            atomstring = 'atom,'

        if sensitive:
            cur = self._cursor().execute("""
            SELECT %s idpackage FROM baseinfo
            WHERE name = ?
            """ % (atomstring,), (keyword,))
        else:
            cur = self._cursor().execute("""
            SELECT %s idpackage FROM baseinfo
            WHERE LOWER(name) = ?
            """ % (atomstring,), (keyword.lower(),))

        if just_id:
            return self._cur2tuple(cur)
        return frozenset(cur)


    def searchCategory(self, keyword, like = False, just_id = True):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        like_string = "= ?"
        if like:
            like_string = "LIKE ?"

        if just_id:
            cur = self._cursor().execute("""
            SELECT idpackage FROM baseinfo
            WHERE baseinfo.category %s
            """ % (like_string,), (keyword,))
        else:
            cur = self._cursor().execute("""
            SELECT atom, idpackage FROM baseinfo
            WHERE baseinfo.category %s
            """ % (like_string,), (keyword,))

        if just_id:
            return self._cur2frozenset(cur)
        return frozenset(cur)

    def searchNameCategory(self, name, category, just_id = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        if just_id:
            cur = self._cursor().execute("""
            SELECT idpackage FROM baseinfo
            WHERE name = ? AND category = ?
            """, (name, category))
            return self._cur2frozenset(cur)

        cur = self._cursor().execute("""
        SELECT atom, idpackage FROM baseinfo
        WHERE name = ? AND category = ?
        """, (name, category))
        return tuple(cur)

    def isPackageScopeAvailable(self, atom, slot, revision):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        searchdata = (atom, slot, revision,)
        cur = self._cursor().execute("""
        SELECT idpackage FROM baseinfo
        where atom = ?  AND slot = ? AND revision = ? LIMIT 1
        """, searchdata)
        rslt = cur.fetchone()

        if rslt: # check if it's masked
            return self.maskFilter(rslt[0])
        return -1, 0

    def isBranchMigrationAvailable(self, repository, from_branch, to_branch):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT post_migration_md5sum, post_upgrade_md5sum
        FROM entropy_branch_migration
        WHERE repository = ? AND from_branch = ? AND to_branch = ? LIMIT 1
        """, (repository, from_branch, to_branch,))
        return cur.fetchone()

    def listPackageIdsInCategory(self, category, order_by = None):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        order_by_string = ''
        if order_by is not None:
            valid_order_by = ("atom", "idpackage", "package_id", "branch",
                "name", "version", "versiontag", "revision", "slot")
            if order_by not in valid_order_by:
                raise AttributeError("invalid order_by argument")
            if order_by == "package_id":
                order_by = "idpackage"
            order_by_string = ' order by %s' % (order_by,)

        cur = self._cursor().execute("""
        SELECT idpackage FROM baseinfo where category = ?
        """ + order_by_string, (category,))
        return self._cur2frozenset(cur)

    def listAllPackages(self, get_scope = False, order_by = None):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        order_by_string = ''
        if order_by is not None:
            valid_order_by = ("atom", "idpackage", "package_id", "branch",
                "name", "version", "versiontag", "revision", "slot")
            if order_by not in valid_order_by:
                raise AttributeError("invalid order_by argument")
            if order_by == "package_id":
                order_by = "idpackage"
            order_by_string = ' order by %s' % (order_by,)

        if get_scope:
            cur = self._cursor().execute("""
            SELECT idpackage,atom,slot,revision FROM baseinfo
            """ + order_by_string)
        else:
            cur = self._cursor().execute("""
            SELECT atom,idpackage,branch FROM baseinfo
            """ + order_by_string)

        return tuple(cur)

    def listAllSpmUids(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT counter, idpackage FROM counters
        """)
        return tuple(cur)

    def listAllTrashedSpmUids(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT counter FROM trashedcounters
        """)
        return self._cur2frozenset(cur)

    def listAllPackageIds(self, order_by = None):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        order_by_string = ''
        if order_by is not None:
            valid_order_by = ("atom", "idpackage", "package_id", "branch",
                "name", "version", "versiontag", "revision", "slot", "date")
            if order_by not in valid_order_by:
                raise AttributeError("invalid order_by argument")
            if order_by == "package_id":
                order_by = "idpackage"
            order_by_string = ' order by %s' % (order_by,)

        if order_by == "date":
            cur = self._cursor().execute("""
            SELECT baseinfo.idpackage FROM baseinfo, extrainfo
            WHERE baseinfo.idpackage = extrainfo.idpackage
            ORDER BY extrainfo.datecreation DESC""")
        else:
            cur = self._cursor().execute("""
            SELECT idpackage FROM baseinfo""" + order_by_string)

        try:
            if order_by:
                return self._cur2tuple(cur)
            return self._cur2frozenset(cur)
        except OperationalError:
            if order_by:
                return tuple()
            return frozenset()

    def listAllInjectedPackageIds(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("SELECT idpackage FROM injected")
        return self._cur2frozenset(cur)

    def listAllSystemPackageIds(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("SELECT idpackage FROM systempackages")
        return self._cur2frozenset(cur)

    def listAllDependencies(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT iddependency, dependency FROM dependenciesreference
        """)
        return tuple(cur)

    def listAllDownloads(self, do_sort = True, full_path = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        order_string = ''
        if do_sort:
            order_string = 'ORDER BY extrainfo.download'

        cur = self._cursor().execute("""
        SELECT extrainfo.download FROM baseinfo, extrainfo
        WHERE baseinfo.idpackage = extrainfo.idpackage %s
        """ % (order_string,))

        if do_sort:
            results = self._cur2tuple(cur)
        else:
            results = self._cur2frozenset(cur)

        if not full_path:
            results = tuple((os.path.basename(x) for x in results))

        return results

    def listAllExtraDownloads(self, do_sort = True):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        order_string = ''
        if do_sort:
            order_string = ' ORDER BY download'
        cur = self._cursor().execute("""
        SELECT download FROM packagedownloads
        """ + order_string)

        if do_sort:
            results = self._cur2tuple(cur)
        else:
            results = self._cur2frozenset(cur)
        return results

    def listAllFiles(self, clean = False, count = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._connection().unicode()

        if count:
            cur = self._cursor().execute("""
            SELECT count(file) FROM content LIMIT 1
            """)
        else:
            cur = self._cursor().execute("""
            SELECT file FROM content
            """)

        if count:
            return cur.fetchone()[0]
        if clean:
            return self._cur2frozenset(cur)
        return self._cur2tuple(cur)

    def listAllCategories(self, order_by = None):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        order_by_string = ''
        if order_by is not None:
            valid_order_by = ("category",)
            if order_by not in valid_order_by:
                raise AttributeError("invalid order_by argument")
            order_by_string = 'ORDER BY %s' % (order_by,)

        cur = self._cursor().execute(
            "SELECT DISTINCT category FROM baseinfo %s" % (
                order_by_string,))
        return self._cur2frozenset(cur)

    def listConfigProtectEntries(self, mask = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        mask_t = ''
        if mask:
            mask_t = 'mask'
        dirs = set()

        cur = self._cursor().execute("""
        SELECT protect FROM configprotectreference WHERE idprotect IN
            (SELECT distinct(idprotect) FROM configprotect%s)
        """ % (mask_t,))

        for mystr in self._cur2frozenset(cur):
            dirs.update(mystr.split())

        return sorted(dirs)

    def switchBranch(self, package_id, tobranch):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        UPDATE baseinfo SET branch = ?
        WHERE idpackage = ?""", (tobranch, package_id,))
        self.clearCache()

    def getSetting(self, setting_name):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cached = self._settings_cache.get(setting_name)
        if isinstance(cached, KeyError):
            raise cached
        elif cached is not None:
            return cached

        try:
            cur = self._cursor().execute("""
            SELECT setting_value FROM settings WHERE setting_name = ?
            LIMIT 1
            """, (setting_name,))
        except Error:
            obj = KeyError("cannot find setting_name '%s'" % (
                    setting_name,))
            self._settings_cache[setting_name] = obj
            raise obj

        setting = cur.fetchone()
        if setting is None:
            obj = KeyError("setting unavaliable '%s'" % (setting_name,))
            self._settings_cache[setting_name] = obj
            raise obj

        obj = setting[0]
        self._settings_cache[setting_name] = obj
        return obj

    def _setSetting(self, setting_name, setting_value):
        """
        Internal method, set new setting for setting_name with value
        setting_value.
        """
        # Always force const_convert_to_unicode() to setting_value
        # and setting_name or "OR REPLACE" won't work (sqlite3 bug?)
        cur = self._cursor().execute("""
        %s INTO settings VALUES (?, ?)
        """ % (self._INSERT_OR_REPLACE,),
        (const_convert_to_unicode(setting_name),
            const_convert_to_unicode(setting_value),))
        self._settings_cache.clear()

    def _setupInitialSettings(self):
        """
        Not implemented, subclasses must implement this.
        """
        raise NotImplementedError()

    def _databaseStructureUpdates(self):
        """
        Not implemented, subclasses must implement this.
        """
        raise NotImplementedError()

    def integrity_check(self):
        """
        Not implemented, subclasses must implement this.
        """
        raise NotImplementedError()

    def validate(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cached = self._getLiveCache("validate")
        if cached is not None:
            # avoid python3.x memleak
            del cached
            return
        self._setLiveCache("validate", True)
        # avoid python3.x memleak
        del cached

        mytxt = "Repository is corrupted, missing SQL tables!"
        if not (self._doesTableExist("extrainfo") and \
                    self._doesTableExist("baseinfo") and \
                    self._doesTableExist("keywords")):
            raise SystemDatabaseError(mytxt)

        # execute checksum
        try:
            self.checksum()
        except (OperationalError, DatabaseError,) as err:
            mytxt = "Repository is corrupted, checksum error"
            raise SystemDatabaseError("%s: %s" % (mytxt, err,))

    @staticmethod
    def importRepository(dumpfile, db, data = None):
        """
        Not implemented, subclasses must implement this.
        """
        raise NotImplementedError()

    def exportRepository(self, dumpfile):
        """
        Not implemented, subclasses must implement this.
        """
        raise NotImplementedError()

    def _listAllTables(self):
        """
        Not implemented, subclasses must implement this.
        """
        raise NotImplementedError()

    def mtime(self):
        """
        Not implemented, subclasses must implement this.
        """
        raise NotImplementedError()

    def checksum(self, do_order = False, strict = True,
                 include_signatures = False,
                 include_dependencies = False):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cache_key = "checksum_%s_%s_True_%s_%s" % (
            do_order, strict, include_signatures, include_dependencies)
        cached = self._getLiveCache(cache_key)
        if cached is not None:
            return cached
        # avoid memleak with python3.x
        del cached

        package_id_order = ""
        depenenciesref_order = ""
        dependencies_order = ""
        if do_order:
            package_id_order = "order by idpackage"
            dependenciesref_order = "order by iddependency"
            dependencies_order = "order by idpackage"

        def do_update_hash(m, cursor):
            # this could slow things down a lot, so be careful
            # NOTE: this function must guarantee platform, architecture,
            # interpreter independent results. Cannot use hash() then.
            # Even repr() might be risky! But on the other hand, the
            # conversion to string cannot take forever.
            if const_is_python3():
                for record in cursor:
                    m.update(repr(record).encode("utf-8"))
            else:
                for record in cursor:
                    m.update(repr(record))

        m = hashlib.sha1()

        if not self._doesTableExist("baseinfo"):
            m.update(const_convert_to_rawstring("~empty~"))
            return m.hexdigest()

        if strict:
            cur = self._cursor().execute("""
            SELECT * FROM baseinfo
            %s""" % (package_id_order,))
        else:
            cur = self._cursor().execute("""
            SELECT idpackage, atom, name, version, versiontag, revision,
            branch, slot, etpapi, `trigger` FROM baseinfo
            %s""" % (package_id_order,))

        do_update_hash(m, cur)

        if strict:
            cur = self._cursor().execute("""
            SELECT * FROM extrainfo %s
            """ % (package_id_order,))
        else:
            cur = self._cursor().execute("""
            SELECT idpackage, description, homepage, download, size,
            digest, datecreation FROM extrainfo %s
            """ % (package_id_order,))

        do_update_hash(m, cur)

        if include_signatures:
            # be optimistic and delay if condition,
            # _doesColumnInTableExist
            # is really slow
            cur = self._cursor().execute("""
            SELECT idpackage, sha1, gpg FROM
            packagesignatures %s""" % (package_id_order,))
            do_update_hash(m, cur)

        if include_dependencies:
            cur = self._cursor().execute("""
            SELECT * from dependenciesreference %s
            """ % (dependenciesref_order,))
            do_update_hash(m, cur)

            cur = self._cursor().execute("""
            SELECT * from dependencies %s
            """ % (dependencies_order,))
            do_update_hash(m, cur)

        result = m.hexdigest()
        self._setLiveCache(cache_key, result)

        return result

    def storeInstalledPackage(self, package_id, repoid, source = 0):
        """
        Reimplemented from EntropySQLRepository.
        """
        self._cursor().execute("""
        %s INTO installedtable VALUES (?,?,?)
        """ % (self._INSERT_OR_REPLACE,),
        (package_id, repoid, source,))

    def getInstalledPackageRepository(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT repositoryname FROM installedtable
        WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        repo = cur.fetchone()
        if repo:
            return repo[0]
        return None

    def getInstalledPackageSource(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        # be optimistic, delay _doesColumnInTableExist as much as
        # possible
        cur = self._cursor().execute("""
        SELECT source FROM installedtable
        WHERE idpackage = ? LIMIT 1
        """, (package_id,))
        source = cur.fetchone()
        if source:
            return source[0]
        return None

    def dropInstalledPackageFromStore(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        DELETE FROM installedtable
        WHERE idpackage = ?""", (package_id,))

    def storeSpmMetadata(self, package_id, blob):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        INSERT INTO xpakdata VALUES (?, ?)
        """, (package_id, const_get_buffer()(blob),))

    def retrieveSpmMetadata(self, package_id):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT data from xpakdata where idpackage = ? LIMIT 1
        """, (package_id,))
        mydata = cur.fetchone()
        if not mydata:
            buf = const_get_buffer()
            return buf("")
        return mydata[0]

    def retrieveBranchMigration(self, to_branch):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        cur = self._cursor().execute("""
        SELECT repository, from_branch, post_migration_md5sum,
        post_upgrade_md5sum FROM entropy_branch_migration
        WHERE to_branch = ?
        """, (to_branch,))

        meta = {}
        for repo, from_branch, post_migration_md5, post_upgrade_md5 in cur:
            obj = meta.setdefault(repo, {})
            obj[from_branch] = (post_migration_md5, post_upgrade_md5,)
        return meta

    def dropContent(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute('DELETE FROM content')
        self.dropContentSafety()

    def dropContentSafety(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute('DELETE FROM contentsafety')

    def dropChangelog(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute('DELETE FROM packagechangelogs')

    def dropGpgSignatures(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute('UPDATE packagesignatures set gpg = NULL')

    def dropAllIndexes(self):
        """
        Not implemented, subclasses must implement this.
        """
        raise NotImplementedError()

    def createAllIndexes(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        if not self._indexing:
            return

        self._createTrashedCountersIndex()
        self._createMirrorlinksIndex()
        self._createContentIndex()
        self._createBaseinfoIndex()
        self._createKeywordsIndex()
        self._createDependenciesIndex()
        self._createProvideIndex()
        self._createConflictsIndex()
        self._createExtrainfoIndex()
        self._createNeededIndex()
        self._createUseflagsIndex()
        self._createLicensedataIndex()
        self._createConfigProtectReferenceIndex()
        self._createSourcesIndex()
        self._createCountersIndex()
        self._createPackagesetsIndex()
        self._createAutomergefilesIndex()
        self._createProvidedLibsIndex()
        self._createDesktopMimeIndex()
        self._createProvidedMimeIndex()
        self._createPackageDownloadsIndex()

    def _createTrashedCountersIndex(self):
        try:
            self._cursor().execute("""
            CREATE INDEX trashedcounters_counter
            ON trashedcounters ( counter )""")
        except OperationalError:
            pass

    def _createMirrorlinksIndex(self):
        try:
            self._cursor().execute("""
            CREATE INDEX mirrorlinks_mirrorname
            ON mirrorlinks ( mirrorname )""")
        except OperationalError:
            pass

    def _createDesktopMimeIndex(self):
        try:
            self._cursor().execute("""
            CREATE INDEX packagedesktopmime_idpackage
            ON packagedesktopmime ( idpackage )""")
        except OperationalError:
            pass

    def _createProvidedMimeIndex(self):
        try:
            self._cursor().execute("""
            CREATE INDEX provided_mime_idpackage
            ON provided_mime ( idpackage )""")
        except OperationalError:
            pass

        try:
            self._cursor().execute("""
            CREATE INDEX provided_mime_mimetype
            ON provided_mime ( mimetype )""")
        except OperationalError:
            pass

    def _createPackagesetsIndex(self):
        try:
            self._cursor().execute("""
            CREATE INDEX packagesetsindex
            ON packagesets ( setname )""")
        except OperationalError:
            pass

    def _createProvidedLibsIndex(self):
        try:
            self._cursor().execute("""
                CREATE INDEX provided_libs_idpackage
                ON provided_libs ( idpackage );
            """)
        except OperationalError:
            pass

        try:
            self._cursor().execute("""
                CREATE INDEX provided_libs_lib_elf
                ON provided_libs ( library, elfclass );
            """)
        except OperationalError:
            pass

    def _createAutomergefilesIndex(self):
        try:
            self._cursor().execute("""
                CREATE INDEX automergefiles_idpackage
                ON automergefiles ( idpackage );
            """)
        except OperationalError:
            pass

        try:
            self._cursor().execute("""
                CREATE INDEX automergefiles_file_md5
                ON automergefiles ( configfile, md5 );
            """)
        except OperationalError:
            pass

    def _createPackageDownloadsIndex(self):
        try:
            self._cursor().execute("""
                CREATE INDEX packagedownloads_idpackage_type
                ON packagedownloads ( idpackage, type );
            """)
        except OperationalError:
            pass

    def _createNeededIndex(self):
        try:
            self._cursor().execute("""
                CREATE INDEX neededindex ON neededreference
                    ( library );
            """)
        except OperationalError:
            pass

        try:
            self._cursor().execute("""
                CREATE INDEX neededindex_idpk_idneeded ON needed
                    ( idpackage, idneeded );
            """)
        except OperationalError:
            pass

        try:
            self._cursor().execute("""
                CREATE INDEX neededindex_idn_elfclass ON needed
                    ( idneeded, elfclass );
            """)
        except OperationalError:
            pass

    def _createUseflagsIndex(self):
        try:
            self._cursor().execute("""
            CREATE INDEX useflagsindex_useflags_idpackage
                ON useflags ( idpackage );
            """)
        except OperationalError:
            pass

        try:
            self._cursor().execute("""
            CREATE INDEX useflagsindex_useflags_idflag
                ON useflags ( idflag );
            """)
        except OperationalError:
            pass

        try:
            self._cursor().execute("""
            CREATE INDEX useflagsindex_useflags_idflag_idpk
                ON useflags ( idflag, idpackage );
            """)
        except OperationalError:
            pass

        try:
            self._cursor().execute("""
            CREATE INDEX useflagsindex
                ON useflagsreference ( flagname );
            """)
        except OperationalError:
            pass

    def _createContentIndex(self):
        try:
            self._cursor().execute("""
                CREATE INDEX contentindex_couple
                    ON content ( idpackage );
            """)
        except OperationalError:
            pass
        try:
            self._cursor().execute("""
                CREATE INDEX contentindex_file
                    ON content ( file );
            """)
        except OperationalError:
            pass

    def _createConfigProtectReferenceIndex(self):
        try:
            self._cursor().execute("""
            CREATE INDEX configprotectreferenceindex
                ON configprotectreference ( protect )
            """)
        except OperationalError:
            pass

    def _createBaseinfoIndex(self):
        try:
            self._cursor().execute("""
            CREATE INDEX baseindex_atom
                ON baseinfo ( atom );
            """)
        except OperationalError:
            pass
        try:
            self._cursor().execute("""
            CREATE INDEX baseindex_branch_name
                ON baseinfo ( name, branch );
            """)
        except OperationalError:
            pass

        try:
            self._cursor().execute("""
            CREATE INDEX baseindex_branch_name_category
                ON baseinfo ( name, category, branch );
            """)
        except OperationalError:
            pass
        try:
            self._cursor().execute("""
            CREATE INDEX baseindex_category
                ON baseinfo ( category );
            """)
        except OperationalError:
            pass

    def _createLicensedataIndex(self):
        try:
            self._cursor().execute("""
            CREATE INDEX licensedataindex
                ON licensedata ( licensename )
            """)
        except OperationalError:
            pass

    def _createKeywordsIndex(self):
        try:
            self._cursor().execute("""
            CREATE INDEX keywordsreferenceindex
                ON keywordsreference ( keywordname );
            """)
        except OperationalError:
            pass
        try:
            self._cursor().execute("""
            CREATE INDEX keywordsindex_idpackage_idkw
                ON keywords ( idpackage, idkeyword );
            """)
        except OperationalError:
            pass

    def _createDependenciesIndex(self):
        try:
            self._cursor().execute("""
            CREATE INDEX dependenciesindex_idpk_iddp_type
                ON dependencies ( idpackage, iddependency, type );
            """)
        except OperationalError:
            pass
        try:
            self._cursor().execute("""
            CREATE INDEX dependenciesreferenceindex_dependency
                ON dependenciesreference ( dependency );
            """)
        except OperationalError:
            pass

    def _createCountersIndex(self):
        try:
            self._cursor().execute("""
            CREATE INDEX countersindex_counter_branch_idpk
                ON counters ( counter, branch, idpackage );
            """)
        except OperationalError:
            pass

    def _createSourcesIndex(self):
        try:
            self._cursor().execute("""
            CREATE INDEX sourcesindex_idpk_idsource
                ON sources ( idpackage, idsource );
            """)
        except OperationalError:
            pass
        try:
            self._cursor().execute("""
            CREATE INDEX sourcesindex_idsource
                ON sources ( idsource );
            """)
        except OperationalError:
            pass
        try:
            self._cursor().execute("""
            CREATE INDEX sourcesreferenceindex_source
                ON sourcesreference ( source );
            """)
        except OperationalError:
            pass

    def _createProvideIndex(self):
        try:
            self._cursor().execute("""
            CREATE INDEX provideindex_idpk_atom
                ON provide ( idpackage, atom );
            """)
        except OperationalError:
            pass

    def _createConflictsIndex(self):
        try:
            self._cursor().execute("""
            CREATE INDEX conflictsindex_idpackage
                ON conflicts ( idpackage );
            """)
        except OperationalError:
            pass

    def _createExtrainfoIndex(self):
        # no indexes set. However, we may need two of them on
        # datecreation and download (two separate I mean)
        # to speed up ORDER BY datecreation and ORDER BY download.
        # Even though, listAllPackageIds(order_by="date") and
        # listAllDownloads(do_sort=True) are not critical
        # functions.
        pass

    def regenerateSpmUidMapping(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        spm = get_spm(self)

        # this is necessary now, counters table should be empty
        self._cursor().executescript("""
        DROP TABLE IF EXISTS counters_regen;
        CREATE TEMPORARY TABLE counters_regen (
            counter INTEGER,
            idpackage INTEGER,
            branch VARCHAR,
            PRIMARY KEY(idpackage, branch)
        );
        """)
        insert_data = []
        for myid in self.listAllPackageIds():

            try:
                spm_uid = spm.resolve_package_uid(self, myid)
            except SPMError as err:
                mytxt = "%s: %s: %s" % (
                    bold(_("ATTENTION")),
                    red(_("Spm error occured")),
                    str(err),
                )
                self.output(
                    mytxt,
                    importance = 1,
                    level = "warning"
                )
                continue

            if spm_uid is None:
                mytxt = "%s: %s: %s" % (
                    bold(_("ATTENTION")),
                    red(_("Spm Unique Identifier not found for")),
                    self.retrieveAtom(myid),
                )
                self.output(
                    mytxt,
                    importance = 1,
                    level = "warning"
                )
                continue

            mybranch = self.retrieveBranch(myid)
            insert_data.append((spm_uid, myid, mybranch))

        self._cursor().executemany("""
        %s INTO counters_regen VALUES (?,?,?)
        """ % (self._INSERT_OR_REPLACE,), insert_data)

        self._cursor().executescript("""
        DELETE FROM counters;
        INSERT INTO counters (counter, idpackage, branch)
            SELECT counter, idpackage, branch FROM counters_regen;
        """)

    def clearTreeupdatesEntries(self, repository):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        DELETE FROM treeupdates WHERE repository = ?
        """, (repository,))

    def resetTreeupdatesDigests(self):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        UPDATE treeupdates SET digest = '-1'
        """)

    def _generateReverseDependenciesMetadata(self):
        """
        Reverse dependencies dynamic metadata generation.
        """
        checksum = self.checksum()
        try:
            mtime = repr(self.mtime())
        except (OSError, IOError):
            mtime = "0.0"
        hash_str = "%s|%s|%s|%s|%s" % (
            repr(self._db),
            repr(etpConst['systemroot']),
            repr(self.name),
            repr(checksum),
            mtime,
        )
        if const_is_python3():
            hash_str = hash_str.encode("utf-8")
        sha = hashlib.sha1()
        sha.update(hash_str)
        cache_key = "__generateReverseDependenciesMetadata2_" + \
            sha.hexdigest()
        rev_deps_data = self._cacher.pop(cache_key)
        if rev_deps_data is not None:
            self._setLiveCache("reverseDependenciesMetadata",
                rev_deps_data)
            return rev_deps_data

        dep_data = {}
        for iddep, atom in self.listAllDependencies():

            if iddep == -1:
                continue

            if atom.endswith(etpConst['entropyordepquestion']):
                or_atoms = atom[:-1].split(etpConst['entropyordepsep'])
                for or_atom in or_atoms:
                    # not safe to use cache here, people messing with multiple
                    # instances can make this crash
                    package_id, rc = self.atomMatch(or_atom, useCache = False)
                    if package_id != -1:
                        obj = dep_data.setdefault(iddep, set())
                        obj.add(package_id)
            else:
                # not safe to use cache here, people messing with multiple
                # instances can make this crash
                package_id, rc = self.atomMatch(atom, useCache = False)
                if package_id != -1:
                    obj = dep_data.setdefault(iddep, set())
                    obj.add(package_id)

        self._setLiveCache("reverseDependenciesMetadata", dep_data)
        try:
            self._cacher.save(cache_key, dep_data)
        except IOError:
            # race condition, ignore
            pass
        return dep_data

    def moveSpmUidsToBranch(self, to_branch):
        """
        Reimplemented from EntropyRepositoryBase.
        """
        self._cursor().execute("""
        UPDATE counters SET branch = ?
        """, (to_branch,))
        self.clearCache()