[entropy.server] automatically cleanup the list of trashed SPM UIDs

This commit tries to safely reduce the amount of entries inside the
Trashed SPM UIDs table. At least, the entries are now kept under
control.

lib/entropy/server/interfaces/db.py

@@ -1096,6 +1096,36 @@ Name:    %s
             pkg_f.flush()
         os.rename(tmp_extra_pkglist_file, extra_pkglist_file)
 
+    def _cleanup_trashed_spm_uids(self, entropy_repository):
+        """
+        Cleanup the list of SPM package UIDs marked as trashed.
+        """
+        # generate in-memory map
+        uids_map = {}
+        spm = self._entropy.Spm()
+        spm_packages = spm.get_installed_packages()
+        for pkg in spm_packages:
+            try:
+                uid = spm.resolve_spm_package_uid(pkg)
+            except KeyError:
+                uid = None
+            uids_map[uid] = pkg
+
+        uids_map_keys = set(uids_map.keys())
+        dead_uids = entropy_repository.listAllTrashedSpmUids()
+        really_dead = dead_uids - uids_map_keys
+
+        # then cycle all the repositories looking for
+        # uids still alive
+        spm_uids = set()
+        for repository_id in self._entropy.repositories():
+            repo = self._entropy.open_repository(repository_id)
+            spm_uids |= set([x for x, y in repo.listAllSpmUids()])
+        really_dead -= spm_uids
+
+        if really_dead:
+            entropy_repository.removeTrashedUids(really_dead)
+
     def _rewrite_treeupdates(self, entropy_repository):
         """
         Rewrite (and sync) packages category and name update metadata
@@ -1456,6 +1486,7 @@ Name:    %s
         dbconn = self._entropy.open_server_repository(self._repository_id,
             read_only = False, no_upload = True, do_treeupdates = False)
         self._rewrite_treeupdates(dbconn)
+        self._cleanup_trashed_spm_uids(dbconn)
         self._entropy._update_package_sets(self._repository_id, dbconn)
         # Package Sets info
         self._show_package_sets_messages()