mirror of
https://github.com/psycopg/psycopg2.git
synced 2024-11-14 04:56:33 +03:00
01799e9137
Drop the async kwarg from cursor.execute(), cursors created by asynchronous connections will be asynchronous by default, ones created by synchronous connections will be synchronous. Mind that this might break third party subclasses of psycopg2.extensions.cursor, if they try to chain to the superclass in their execute() implementation and are passing the async kwarg. The example cursors in psycopg2.extras have been fixed no to do that.
488 lines
15 KiB
Python
488 lines
15 KiB
Python
"""Miscellaneous goodies for psycopg2
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This module is a generic place used to hold little helper functions
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and classes untill a better place in the distribution is found.
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"""
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# psycopg/extras.py - miscellaneous extra goodies for psycopg
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#
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# Copyright (C) 2003-2010 Federico Di Gregorio <fog@debian.org>
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#
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# psycopg2 is free software: you can redistribute it and/or modify it
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# under the terms of the GNU Lesser General Public License as published
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# by the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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#
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# In addition, as a special exception, the copyright holders give
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# permission to link this program with the OpenSSL library (or with
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# modified versions of OpenSSL that use the same license as OpenSSL),
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# and distribute linked combinations including the two.
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#
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# You must obey the GNU Lesser General Public License in all respects for
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# all of the code used other than OpenSSL.
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#
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# psycopg2 is distributed in the hope that it will be useful, but WITHOUT
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# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
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# License for more details.
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import os
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import time
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import re as regex
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try:
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import logging
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except:
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logging = None
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from psycopg2 import DATETIME, DataError
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from psycopg2 import extensions as _ext
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from psycopg2.extensions import cursor as _cursor
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from psycopg2.extensions import connection as _connection
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from psycopg2.extensions import adapt as _A
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class DictCursorBase(_cursor):
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"""Base class for all dict-like cursors."""
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def __init__(self, *args, **kwargs):
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if kwargs.has_key('row_factory'):
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row_factory = kwargs['row_factory']
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del kwargs['row_factory']
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else:
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raise NotImplementedError(
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"DictCursorBase can't be instantiated without a row factory.")
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_cursor.__init__(self, *args, **kwargs)
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self._query_executed = 0
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self._prefetch = 0
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self.row_factory = row_factory
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def fetchone(self):
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if self._prefetch:
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res = _cursor.fetchone(self)
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if self._query_executed:
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self._build_index()
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if not self._prefetch:
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res = _cursor.fetchone(self)
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return res
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def fetchmany(self, size=None):
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if self._prefetch:
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res = _cursor.fetchmany(self, size)
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if self._query_executed:
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self._build_index()
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if not self._prefetch:
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res = _cursor.fetchmany(self, size)
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return res
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def fetchall(self):
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if self._prefetch:
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res = _cursor.fetchall(self)
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if self._query_executed:
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self._build_index()
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if not self._prefetch:
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res = _cursor.fetchall(self)
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return res
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def next(self):
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if self._prefetch:
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res = _cursor.fetchone(self)
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if res is None:
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raise StopIteration()
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if self._query_executed:
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self._build_index()
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if not self._prefetch:
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res = _cursor.fetchone(self)
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if res is None:
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raise StopIteration()
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return res
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class DictConnection(_connection):
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"""A connection that uses `DictCursor` automatically."""
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def cursor(self, name=None):
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if name is None:
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return _connection.cursor(self, cursor_factory=DictCursor)
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else:
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return _connection.cursor(self, name, cursor_factory=DictCursor)
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class DictCursor(DictCursorBase):
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"""A cursor that keeps a list of column name -> index mappings."""
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def __init__(self, *args, **kwargs):
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kwargs['row_factory'] = DictRow
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DictCursorBase.__init__(self, *args, **kwargs)
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self._prefetch = 1
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def execute(self, query, vars=None):
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self.index = {}
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self._query_executed = 1
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return _cursor.execute(self, query, vars)
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def callproc(self, procname, vars=None):
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self.index = {}
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self._query_executed = 1
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return _cursor.callproc(self, procname, vars)
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def _build_index(self):
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if self._query_executed == 1 and self.description:
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for i in range(len(self.description)):
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self.index[self.description[i][0]] = i
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self._query_executed = 0
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class DictRow(list):
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"""A row object that allow by-colmun-name access to data."""
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__slots__ = ('_index',)
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def __init__(self, cursor):
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self._index = cursor.index
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self[:] = [None] * len(cursor.description)
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def __getitem__(self, x):
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if type(x) != int:
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x = self._index[x]
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return list.__getitem__(self, x)
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def items(self):
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res = []
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for n, v in self._index.items():
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res.append((n, list.__getitem__(self, v)))
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return res
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def keys(self):
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return self._index.keys()
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def values(self):
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return tuple(self[:])
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def has_key(self, x):
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return self._index.has_key(x)
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def get(self, x, default=None):
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try:
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return self[x]
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except:
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return default
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def iteritems(self):
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for n, v in self._index.items():
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yield n, list.__getitem__(self, v)
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def iterkeys(self):
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return self._index.iterkeys()
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def itervalues(self):
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return list.__iter__(self)
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def copy(self):
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return dict(self.items())
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def __contains__(self, x):
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return self._index.__contains__(x)
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class RealDictConnection(_connection):
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"""A connection that uses `RealDictCursor` automatically."""
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def cursor(self, name=None):
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if name is None:
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return _connection.cursor(self, cursor_factory=RealDictCursor)
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else:
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return _connection.cursor(self, name, cursor_factory=RealDictCursor)
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class RealDictCursor(DictCursorBase):
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"""A cursor that uses a real dict as the base type for rows.
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Note that this cursor is extremely specialized and does not allow
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the normal access (using integer indices) to fetched data. If you need
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to access database rows both as a dictionary and a list, then use
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the generic `DictCursor` instead of `!RealDictCursor`.
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"""
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def __init__(self, *args, **kwargs):
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kwargs['row_factory'] = RealDictRow
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DictCursorBase.__init__(self, *args, **kwargs)
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self._prefetch = 0
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def execute(self, query, vars=None):
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self.column_mapping = []
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self._query_executed = 1
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return _cursor.execute(self, query, vars)
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def callproc(self, procname, vars=None):
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self.column_mapping = []
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self._query_executed = 1
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return _cursor.callproc(self, procname, vars)
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def _build_index(self):
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if self._query_executed == 1 and self.description:
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for i in range(len(self.description)):
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self.column_mapping.append(self.description[i][0])
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self._query_executed = 0
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class RealDictRow(dict):
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"""A ``dict`` subclass representing a data record."""
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__slots__ = ('_column_mapping')
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def __init__(self, cursor):
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dict.__init__(self)
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self._column_mapping = cursor.column_mapping
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def __setitem__(self, name, value):
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if type(name) == int:
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name = self._column_mapping[name]
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return dict.__setitem__(self, name, value)
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class LoggingConnection(_connection):
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"""A connection that logs all queries to a file or logger__ object.
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.. __: http://docs.python.org/library/logging.html
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"""
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def initialize(self, logobj):
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"""Initialize the connection to log to ``logobj``.
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The ``logobj`` parameter can be an open file object or a Logger
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instance from the standard logging module.
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"""
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self._logobj = logobj
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if logging and isinstance(logobj, logging.Logger):
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self.log = self._logtologger
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else:
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self.log = self._logtofile
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def filter(self, msg, curs):
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"""Filter the query before logging it.
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This is the method to overwrite to filter unwanted queries out of the
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log or to add some extra data to the output. The default implementation
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just does nothing.
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"""
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return msg
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def _logtofile(self, msg, curs):
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msg = self.filter(msg, curs)
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if msg: self._logobj.write(msg + os.linesep)
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def _logtologger(self, msg, curs):
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msg = self.filter(msg, curs)
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if msg: self._logobj.debug(msg)
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def _check(self):
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if not hasattr(self, '_logobj'):
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raise self.ProgrammingError(
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"LoggingConnection object has not been initialize()d")
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def cursor(self, name=None):
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self._check()
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if name is None:
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return _connection.cursor(self, cursor_factory=LoggingCursor)
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else:
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return _connection.cursor(self, name, cursor_factory=LoggingCursor)
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class LoggingCursor(_cursor):
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"""A cursor that logs queries using its connection logging facilities."""
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def execute(self, query, vars=None):
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try:
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return _cursor.execute(self, query, vars)
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finally:
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self.connection.log(self.query, self)
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def callproc(self, procname, vars=None):
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try:
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return _cursor.callproc(self, procname, vars)
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finally:
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self.connection.log(self.query, self)
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class MinTimeLoggingConnection(LoggingConnection):
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"""A connection that logs queries based on execution time.
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This is just an example of how to sub-class `LoggingConnection` to
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provide some extra filtering for the logged queries. Both the
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`inizialize()` and `filter()` methods are overwritten to make sure
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that only queries executing for more than ``mintime`` ms are logged.
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Note that this connection uses the specialized cursor
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`MinTimeLoggingCursor`.
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"""
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def initialize(self, logobj, mintime=0):
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LoggingConnection.initialize(self, logobj)
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self._mintime = mintime
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def filter(self, msg, curs):
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t = (time.time() - curs.timestamp) * 1000
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if t > self._mintime:
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return msg + os.linesep + " (execution time: %d ms)" % t
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def cursor(self, name=None):
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self._check()
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if name is None:
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return _connection.cursor(self, cursor_factory=MinTimeLoggingCursor)
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else:
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return _connection.cursor(self, name, cursor_factory=MinTimeLoggingCursor)
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class MinTimeLoggingCursor(LoggingCursor):
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"""The cursor sub-class companion to `MinTimeLoggingConnection`."""
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def execute(self, query, vars=None):
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self.timestamp = time.time()
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return LoggingCursor.execute(self, query, vars)
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def callproc(self, procname, vars=None):
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self.timestamp = time.time()
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return LoggingCursor.execute(self, procname, vars)
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# a dbtype and adapter for Python UUID type
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try:
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import uuid
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class UUID_adapter(object):
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"""Adapt Python's uuid.UUID__ type to PostgreSQL's uuid__.
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.. __: http://docs.python.org/library/uuid.html
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.. __: http://www.postgresql.org/docs/8.4/static/datatype-uuid.html
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"""
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def __init__(self, uuid):
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self._uuid = uuid
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def prepare(self, conn):
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pass
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def getquoted(self):
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return "'"+str(self._uuid)+"'::uuid"
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__str__ = getquoted
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def register_uuid(oids=None, conn_or_curs=None):
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"""Create the UUID type and an uuid.UUID adapter."""
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if not oids:
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oid1 = 2950
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oid2 = 2951
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elif type(oids) == list:
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oid1, oid2 = oids
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else:
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oid1 = oids
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oid2 = 2951
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def parseUUIDARRAY(data, cursor):
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if data is None:
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return None
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elif data == '{}':
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return []
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else:
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return [((len(x) > 0 and x != 'NULL') and uuid.UUID(x) or None)
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for x in data[1:-1].split(',')]
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_ext.UUID = _ext.new_type((oid1, ), "UUID",
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lambda data, cursor: data and uuid.UUID(data) or None)
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_ext.UUIDARRAY = _ext.new_type((oid2,), "UUID[]", parseUUIDARRAY)
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_ext.register_type(_ext.UUID, conn_or_curs)
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_ext.register_type(_ext.UUIDARRAY, conn_or_curs)
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_ext.register_adapter(uuid.UUID, UUID_adapter)
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return _ext.UUID
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except ImportError, e:
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def register_uuid(oid=None):
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"""Create the UUID type and an uuid.UUID adapter.
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This is a fake function that will always raise an error because the
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import of the uuid module failed.
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"""
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raise e
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# a type, dbtype and adapter for PostgreSQL inet type
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class Inet(object):
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"""Wrap a string to allow for correct SQL-quoting of inet values.
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Note that this adapter does NOT check the passed value to make
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sure it really is an inet-compatible address but DOES call adapt()
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on it to make sure it is impossible to execute an SQL-injection
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by passing an evil value to the initializer.
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"""
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def __init__(self, addr):
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self.addr = addr
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def __repr__(self):
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return "%s(%r)" % (self.__class__.__name__, self.addr)
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def prepare(self, conn):
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self._conn = conn
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def getquoted(self):
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obj = _A(self.addr)
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if hasattr(obj, 'prepare'):
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obj.prepare(self._conn)
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return obj.getquoted()+"::inet"
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def __str__(self):
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return str(self.addr)
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def register_inet(oid=None, conn_or_curs=None):
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"""Create the INET type and an Inet adapter."""
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if not oid: oid = 869
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_ext.INET = _ext.new_type((oid, ), "INET",
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lambda data, cursor: data and Inet(data) or None)
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_ext.register_type(_ext.INET, conn_or_curs)
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_ext.register_adapter(Inet, lambda x: x)
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return _ext.INET
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# safe management of times with a non-standard time zone
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def _convert_tstz_w_secs(s, cursor):
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try:
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return DATETIME(s, cursor)
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except (DataError,), exc:
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if exc.message != "unable to parse time":
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raise
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if regex.match('(\+|-)\d\d:\d\d:\d\d', s[-9:]) is None:
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raise
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# parsing doesn't succeed even if seconds are ":00" so truncate in
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# any case
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return DATETIME(s[:-3], cursor)
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def register_tstz_w_secs(oids=None, conn_or_curs=None):
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"""Register alternate type caster for :sql:`TIMESTAMP WITH TIME ZONE`.
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The Python datetime module cannot handle time zones with
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seconds in the UTC offset. There are, however, historical
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"time zones" which contain such offsets, eg. "Asia/Calcutta".
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In many cases those offsets represent true local time.
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If you encounter "unable to parse time" on a perfectly valid
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timestamp you likely want to try this type caster. It truncates
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the seconds from the time zone data and retries casting
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the timestamp. Note that this will generate timestamps
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which are **inaccurate** by the number of seconds truncated
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(unless the seconds were 00).
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:param oids:
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which OIDs to use this type caster for,
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defaults to :sql:`TIMESTAMP WITH TIME ZONE`
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:param conn_or_curs:
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a cursor or connection if you want to attach
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this type caster to that only, defaults to
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``None`` meaning all connections and cursors
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"""
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if oids is None:
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oids = (1184,) # hardcoded from PostgreSQL headers
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_ext.TSTZ_W_SECS = _ext.new_type(oids, 'TSTZ_W_SECS', _convert_tstz_w_secs)
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_ext.register_type(_ext.TSTZ_W_SECS, conn_or_curs)
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return _ext.TSTZ_W_SECS
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__all__ = filter(lambda k: not k.startswith('_'), locals().keys())
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