59 lines
1.7 KiB
ReStructuredText
59 lines
1.7 KiB
ReStructuredText
.. _ref-cache:
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.. module:: trytond.cache
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=====
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Cache
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=====
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.. class:: Cache(name[, size_limit[, duration[, context]]])
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The class is used to cache values between server requests. The `name` should be
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unique and it's used to identify the cache. We usually use
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`<class_name>.<content_name>` to make it unique. The `size_limit` parameter can
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be used to limit the number of values cached and it has 1024 as the default
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value. The `duration` parameter defines how long a cached value stays valid
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but if it is not set the value remains valid until it is cleared. And the
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`context` parameter is used to indicate if the cache depends on the user
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context and is true by default. The cache is cleaned on :class:`Transaction`
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starts and resets on :class:`Transaction` commit or rollback.
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.. warning::
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As there is no deepcopy of the values cached, they must never be mutated
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after being set in or retrieved from the cache.
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..
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.. method:: get(key[, default])
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Retrieve the value of the key in the cache. If a `default` is specified it
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will be returned when the key is missing otherwise it will return `None`.
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.. method:: set(key, value)
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Sets the `value` of the `key` in the cache.
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.. method:: clear()
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Clears all the keys in the cache.
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.. classmethod:: sync(transaction)
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Synchronize cache instances using transaction.
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.. classmethod:: commit(transaction)
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Apply cache changes from transaction.
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.. classmethod:: rollback(transaction)
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Remove cache changes from transaction.
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.. staticmethod:: drop(dbname)
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Drops all the caches for database `dbname`
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.. note::
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By default Tryton uses a MemoryCache, but this behaviour can be overridden
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by setting a fully qualified name of an alternative class defined in the
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configuration `class` of the `cache` section.
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..
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