Class s.p.PersistentDict(PersistentDictBase):

I am a database-persistent dictionary-like object with memory caching of items and lazy writing.

Getting, setting, or deleting my items returns Deferred objects of the Twisted asynchronous framework that fire when the underlying database accesses are completed. Returning a deferred value avoids forcing the client code to block while the real value is being read from the database.

Instance Variables data The in-memory dictionary that each instance of me uses to cache values for a given ID.

Method	__getitem__	Returns a `Deferred` to the value of item name or the value itself
Method	__setitem__	Sets item name to value, saving it to the database if there
Method	__delitem__	Deletes item name, removing its entry from both the in-memory
Method	__contains__	Indicates if I contain item key.
Method	keys	Returns an immediate or deferred list of the names of all my items in
Method	has_key	Returns an immediate or deferred Boolean indicating whether the key is
Method	clear	Clears the in-memory dictionary of all items and deletes all their
Method	iteritems	Only for preload mode: Iterate over all my items.
Method	iterkeys	Only for preload mode: Iterate over all my keys.
Method	itervalues	Only for preload mode: Iterate over all my values.
Method	items	Returns an immediate or deferred sequence of (name, value) tuples
Method	values	Returns an immediate or deferred sequence of all my values.
Method	get	Returns an immediate or deferred value of the value for the key
Method	setdefault	Sets my item specified by key to value if it doesn't exist
Method	copy	Returns an immediate or deferred copy of me that is a conventional

Inherited from PersistentDictBase:

Method	__init__	Instantiates me with an item store keyed to the supplied hashable
Method	preload	This method preloads all my items from the database (which may take a
Method	shutdown	Shuts down my database `Transactor` and its synchronous task queue.
Method	loadAll	Loads all items from the database, setting my in-memory dict and key
Method	deferToWrites	`@see: L{DeferredTracker.deferToAll}`

def __getitem__(self, name):

Returns a Deferred to the value of item name or the value itself if in preload mode.

The value is only loaded from the database if it isn't already in the in-memory dictionary.

def __setitem__(self, name, value):

Sets item name to value, saving it to the database if there isn't already an in-memory dictionary item with that exact value.

def __delitem__(self, name):

Deletes item name, removing its entry from both the in-memory dictionary and the database

def __contains__(self, key):

Indicates if I contain item key.

In preload mode, returns True if the item is present in my in-memory dictionary and False if not.

In normal mode, returns an immediate Deferred firing with True without a transaction if the item is already present in my in-memory dictionary. If it isn't, tries to load the item (it will probably be requested soon anyhow) and returns a Deferred that will ultimately fire with True unless the load resulted in a Missing object. In that case, deletes the loaded Missing object from my in-memory dictionary and fires the deferred with False.

Using the <key> in <dict> Python construct doesn't seem to work in normal mode. Use has_key instead.

def keys(self):

Returns an immediate or deferred list of the names of all my items in the database.

def has_key(self, key):

Returns an immediate or deferred Boolean indicating whether the key is present.

def clear(self):

Clears the in-memory dictionary of all items and deletes all their database entries.

def iteritems(self):

Only for preload mode: Iterate over all my items.

def iterkeys(self):

Only for preload mode: Iterate over all my keys.

def itervalues(self):

Only for preload mode: Iterate over all my values.

def items(self):

Returns an immediate or deferred sequence of (name, value) tuples representing all my items.

def values(self):

Returns an immediate or deferred sequence of all my values.

def get(self, *args):

Returns an immediate or deferred value of the value for the key specified as the first argument, or a default value if specified as an optional second argument. If the item is not present and no default value is supplied, raises the appropriate exception.

def setdefault(self, key, value):

Sets my item specified by key to value if it doesn't exist already. Returns an immediate or deferred reference to the item's value after its new value (if any) is set.

def copy(self):

Returns an immediate or deferred copy of me that is a conventional (non-persisted) dictionary.

API Documentation for sAsync, generated by pydoctor.