Package entropy :: Module cache :: Class EntropyCacher

Class EntropyCacher

Entropy asynchronous and synchronous cache writer and reader. This class is a Singleton and contains a thread doing the cache writes asynchronously, thus it must be stopped before your application is terminated calling the stop() method.

Instance Methods

init_singleton(self)
Singleton overloaded method.

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__del__(self)

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start(self)
This is the method used to start the asynchronous cache writer but also the whole cacher.

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is_started(self)
Return whether start is called or not.

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stop(self)
This method stops the execution of the cacher, which won't accept cache writes anymore.

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sync(self, wait=False)
This method can be called anytime and forces the instance to flush all the cache writes queued to disk.

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discard(self)
This method makes buffered cache to be discarded synchronously.

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None

push(self, key, data, async=True)
This is the place where data is either added to the write queue or written to disk (if async == False) only and only if start() method has been called.

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Python object

pop(self, key)
This is the place where data is retrieved from cache.

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Inherited from core.Singleton: is_destroyed, is_singleton

Inherited from object: __delattr__, __getattribute__, __hash__, __init__, __reduce__, __reduce_ex__, __repr__, __setattr__, __str__

Static Methods
Inherited from `core.Singleton`: `__new__`

Properties
Inherited from `object`: `__class__`

Method Details

init_singleton(self)

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Singleton overloaded method. Equals to __init__. This is the place where all the properties initialization takes place.

start(self)

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This is the method used to start the asynchronous cache writer but also the whole cacher. If this method is not called, the instance will always trash and cache write request.

Returns:: None

is_started(self)

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Return whether start is called or not. This equals to checking if the cacher is running, thus is writing cache to disk.

Returns:: None

stop(self)

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This method stops the execution of the cacher, which won't accept cache writes anymore. The thread responsible of writing to disk is stopped here and the Cacher will be back to being inactive. A watchdog will avoid the thread to freeze the call if the write buffer is overloaded.

Returns:: None

sync(self, wait=False)

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This method can be called anytime and forces the instance to flush all the cache writes queued to disk. If wait == False a watchdog prevents this call to get stuck in case of write buffer overloads.

Parameters:

wait (bool) - indicates if waiting until done (synchronous mode) or not

Returns:

None

discard(self)

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This method makes buffered cache to be discarded synchronously.

Returns:: None

push(self, key, data, async=True)

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This is the place where data is either added to the write queue or written to disk (if async == False) only and only if start() method has been called.

Parameters:

key (basestring) - cache data identifier
data (any picklable object) - picklable object
async (bool) - store cache asynchronously or not

Returns: None

nothing

pop(self, key)

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This is the place where data is retrieved from cache. You must know the cache identifier used when push() was called.

Parameters:

key (basestring) - cache data identifier

Returns: Python object

object stored into the stack or None (if stack is empty)