88 lines
2.7 KiB
ReStructuredText
88 lines
2.7 KiB
ReStructuredText
Usage
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=====
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Installation
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------------
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Default installation option is to use pip+git
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.. code-block:: console
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(venv) $ pip install git+https://gitea.parrrate.ru/PTV/ptvp35.git
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Basic functionality
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-------------------
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.. autoclass:: ptvp35.DbFactory
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:code:`DbFactory` class provides context management for database connections (:code:`DbConnection`) via :code:`async with` statement.
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The connection isn't just a "connection", it's also the MMDB itself, so **using two connections to one database is an undefined behaviour**.
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Also, that means that each connection start/shutdown is quite time expensive.
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These two facts together tell that, if you intend on using the connection, you should probably wrap the main program in an :code:`async with` block.
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.. code-block:: python3
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import pathlib
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from ptvp35 import DbFactory, KVJson
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async def main():
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async with DbFactory(pathlib.Path('example.db'), kvfactory=KVJson()) as connection:
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await _main(connection)
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Different ways to get/set a value:
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.. code-block:: python3
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from ptvp35 import DbConnection
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async def _main(connection: DbConnection):
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value0 = connection.get('increment-0', 0)
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await connection.set('increment-0', value0 + 1)
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value1 = connection.get('increment-1', 0)
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connection.set_nowait('increment-1', value1 + 1)
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await connection.commit()
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async with connection.transaction() as transaction:
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value2 = transaction.get('increment-2', 0)
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transaction.set_nowait('increment-2', value2 + 1)
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async with connection.transaction() as transaction:
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value3 = transaction.get('increment-3', 0)
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transaction.set_nowait('increment-3', value3 + 1)
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await transaction.commit()
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with connection.transaction() as transaction:
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value4 = transaction.get('increment-4', 0)
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transaction.set_nowait('increment-4', value4 + 1)
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await transaction.commit()
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with connection.transaction() as transaction:
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value5 = transaction.get('increment-5', 0)
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transaction.set_nowait('increment-5', value5 + 1)
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await connection.commit()
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.. autoclass:: ptvp35.DbConnection
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.. automethod:: get
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this method is instant.
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.. automethod:: set
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this method may take time to run.
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ordering may not be guaranteed (depends on event loop implementation).
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.. automethod:: set_nowait
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this method is instant.
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ordering is guaranteed.
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.. automethod:: commit
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this method may take time to run.
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respects the ordering of previously called :code:`set_nowait` methods.
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will, under most circumstances, also execute later changes.
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.. automethod:: transaction
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