--- /dev/null
+"""Miscellaneous goodies for psycopg2
+
+This module is a generic place used to hold little helper functions
+and classes untill a better place in the distribution is found.
+"""
+# psycopg/extras.py - miscellaneous extra goodies for psycopg
+#
+# Copyright (C) 2003-2004 Federico Di Gregorio <fog@debian.org>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by the
+# Free Software Foundation; either version 2, or (at your option) any later
+# version.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTIBILITY
+# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+# for more details.
+
+import os
+import time
+
+try:
+ import logging
+except:
+ logging = None
+
+from psycopg2.extensions import cursor as _cursor
+from psycopg2.extensions import connection as _connection
+from psycopg2.extensions import register_adapter as _RA
+from psycopg2.extensions import adapt as _A
+
+
+class DictConnection(_connection):
+ """A connection that uses DictCursor automatically."""
+ def cursor(self):
+ return _connection.cursor(self, cursor_factory=DictCursor)
+
+class DictCursor(_cursor):
+ """A cursor that keeps a list of column name -> index mappings."""
+
+ __query_executed = 0
+
+ def execute(self, query, vars=None, async=0):
+ self.row_factory = DictRow
+ self.index = {}
+ self.__query_executed = 1
+ return _cursor.execute(self, query, vars, async)
+
+ def callproc(self, procname, vars=None):
+ self.row_factory = DictRow
+ self.index = {}
+ self.__query_executed = 1
+ return _cursor.callproc(self, procname, vars)
+
+ def _build_index(self):
+ if self.__query_executed == 1 and self.description:
+ for i in range(len(self.description)):
+ self.index[self.description[i][0]] = i
+ self.__query_executed = 0
+
+ def fetchone(self):
+ res = _cursor.fetchone(self)
+ if self.__query_executed:
+ self._build_index()
+ return res
+
+ def fetchmany(self, size=None):
+ res = _cursor.fetchmany(self, size)
+ if self.__query_executed:
+ self._build_index()
+ return res
+
+ def fetchall(self):
+ res = _cursor.fetchall(self)
+ if self.__query_executed:
+ self._build_index()
+ return res
+
+ def next(self):
+ res = _cursor.fetchone(self)
+ if res is None:
+ raise StopIteration()
+ if self.__query_executed:
+ self._build_index()
+ return res
+
+class DictRow(list):
+ """A row object that allow by-colun-name access to data."""
+
+ def __init__(self, cursor):
+ self._index = cursor.index
+ self[:] = [None] * len(cursor.description)
+
+ def __getitem__(self, x):
+ if type(x) != int:
+ x = self._index[x]
+ return list.__getitem__(self, x)
+
+ def items(self):
+ res = []
+ for n, v in self._index.items():
+ res.append((n, list.__getitem__(self, v)))
+ return res
+
+ def keys(self):
+ return self._index.keys()
+
+ def values(self):
+ return tuple(self[:])
+
+ def has_key(self, x):
+ return self._index.has_key(x)
+
+ def get(self, x, default=None):
+ try:
+ return self[x]
+ except:
+ return default
+
+
+class SQL_IN(object):
+ """Adapt any iterable to an SQL quotable object."""
+
+ def __init__(self, seq):
+ self._seq = seq
+
+ def prepare(self, conn):
+ self._conn = conn
+
+ def getquoted(self):
+ # this is the important line: note how every object in the
+ # list is adapted and then how getquoted() is called on it
+ pobjs = [_A(o) for o in self._seq]
+ for obj in pobjs:
+ if hasattr(obj, 'prepare'):
+ obj.prepare(self._conn)
+ qobjs = [str(o.getquoted()) for o in pobjs]
+ return '(' + ', '.join(qobjs) + ')'
+
+ __str__ = getquoted
+
+_RA(tuple, SQL_IN)
+
+
+class LoggingConnection(_connection):
+ """A connection that logs all queries to a file or logger object."""
+
+ def initialize(self, logobj):
+ """Initialize the connection to log to `logobj`.
+
+ The `logobj` parameter can be an open file object or a Logger instance
+ from the standard logging module.
+ """
+ self._logobj = logobj
+ if logging and isinstance(logobj, logging.Logger):
+ self.log = self._logtologger
+ else:
+ self.log = self._logtofile
+
+ def filter(self, msg, curs):
+ """Filter the query before logging it.
+
+ This is the method to overwrite to filter unwanted queries out of the
+ log or to add some extra data to the output. The default implementation
+ just does nothing.
+ """
+ return msg
+
+ def _logtofile(self, msg, curs):
+ msg = self.filter(msg, curs)
+ if msg: self._logobj.write(msg + os.linesep)
+
+ def _logtologger(self, msg, curs):
+ msg = self.filter(msg, curs)
+ if msg: self._logobj.debug(msg)
+
+ def _check(self):
+ if not hasattr(self, '_logobj'):
+ raise self.ProgrammingError(
+ "LoggingConnection object has not been initialize()d")
+
+ def cursor(self):
+ self._check()
+ return _connection.cursor(self, cursor_factory=LoggingCursor)
+
+class LoggingCursor(_cursor):
+ """A cursor that logs queries using its connection logging facilities."""
+
+ def execute(self, query, vars=None, async=0):
+ try:
+ return _cursor.execute(self, query, vars, async)
+ finally:
+ self.connection.log(self.query, self)
+
+ def callproc(self, procname, vars=None):
+ try:
+ return _cursor.callproc(self, procname, vars)
+ finally:
+ self.connection.log(self.query, self)
+
+
+class MinTimeLoggingConnection(LoggingConnection):
+ """A connection that logs queries based on execution time.
+
+ This is just an example of how to sub-class LoggingConnection to provide
+ some extra filtering for the logged queries. Both the `.inizialize()` and
+ `.filter()` methods are overwritten to make sure that only queries
+ executing for more than `mintime` ms are logged.
+
+ Note that this connection uses the specialized cursor MinTimeLoggingCursor.
+ """
+ def initialize(self, logobj, mintime=0):
+ LoggingConnection.initialize(self, logobj)
+ self._mintime = mintime
+
+ def filter(self, msg, curs):
+ t = (time.time() - curs.timestamp) * 1000
+ if t > self._mintime:
+ return msg + os.linesep + " (execution time: %d ms)" % t
+
+ def cursor(self):
+ self._check()
+ return _connection.cursor(self, cursor_factory=MinTimeLoggingCursor)
+
+class MinTimeLoggingCursor(LoggingCursor):
+ """The cursor sub-class companion to MinTimeLoggingConnection."""
+
+ def execute(self, query, vars=None, async=0):
+ self.timestamp = time.time()
+ return LoggingCursor.execute(self, query, vars, async)
+
+ def callproc(self, procname, vars=None):
+ self.timestamp = time.time()
+ return LoggingCursor.execute(self, procname, var)
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