psycopg2/lib/extensions.py
Federico Di Gregorio 34317dc4c3 Support asynchronous connection building
After calling psycopg2.connect(dsn, async=True) you can poll the
connection that will tell you whether its file descriptor should be
waited on to become writable or readable or that the connection
attempt has succeeded.

Edited commit by Jan to not expose internal state in extensions.py.
2010-04-05 11:30:03 +02:00

120 lines
4.1 KiB
Python

"""psycopg extensions to the DBAPI-2.0
This module holds all the extensions to the DBAPI-2.0 provided by psycopg.
- `connection` -- the new-type inheritable connection class
- `cursor` -- the new-type inheritable cursor class
- `lobject` -- the new-type inheritable large object class
- `adapt()` -- exposes the PEP-246_ compatible adapting mechanism used
by psycopg to adapt Python types to PostgreSQL ones
.. _PEP-246: http://www.python.org/peps/pep-0246.html
"""
# psycopg/extensions.py - DBAPI-2.0 extensions specific to psycopg
#
# Copyright (C) 2003-2010 Federico Di Gregorio <fog@debian.org>
#
# psycopg2 is free software: you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# In addition, as a special exception, the copyright holders give
# permission to link this program with the OpenSSL library (or with
# modified versions of OpenSSL that use the same license as OpenSSL),
# and distribute linked combinations including the two.
#
# You must obey the GNU Lesser General Public License in all respects for
# all of the code used other than OpenSSL.
#
# psycopg2 is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
# License for more details.
from _psycopg import UNICODE, INTEGER, LONGINTEGER, BOOLEAN, FLOAT
from _psycopg import TIME, DATE, INTERVAL
from _psycopg import BINARYARRAY, BOOLEANARRAY, DATEARRAY, DATETIMEARRAY
from _psycopg import DECIMALARRAY, FLOATARRAY, INTEGERARRAY, INTERVALARRAY
from _psycopg import LONGINTEGERARRAY, ROWIDARRAY, STRINGARRAY, TIMEARRAY
from _psycopg import UNICODEARRAY
from _psycopg import Binary, Boolean, Float, QuotedString, AsIs
try:
from _psycopg import DateFromMx, TimeFromMx, TimestampFromMx
from _psycopg import IntervalFromMx
except:
pass
try:
from _psycopg import DateFromPy, TimeFromPy, TimestampFromPy
from _psycopg import IntervalFromPy
except:
pass
from _psycopg import adapt, adapters, encodings, connection, cursor, lobject
from _psycopg import string_types, binary_types, new_type, register_type
from _psycopg import ISQLQuote
from _psycopg import QueryCanceledError, TransactionRollbackError
"""Isolation level values."""
ISOLATION_LEVEL_AUTOCOMMIT = 0
ISOLATION_LEVEL_READ_COMMITTED = 1
ISOLATION_LEVEL_SERIALIZABLE = 2
# PostgreSQL maps the the other standard values to already defined levels
ISOLATION_LEVEL_REPEATABLE_READ = ISOLATION_LEVEL_SERIALIZABLE
ISOLATION_LEVEL_READ_UNCOMMITTED = ISOLATION_LEVEL_READ_COMMITTED
"""psycopg connection status values."""
STATUS_SETUP = 0
STATUS_READY = 1
STATUS_BEGIN = 2
STATUS_SYNC = 3
STATUS_ASYNC = 4
# This is a usefull mnemonic to check if the connection is in a transaction
STATUS_IN_TRANSACTION = STATUS_BEGIN
"""psycopg async connection polling values"""
POLL_READ = 1
POLL_WRITE = 2
POLL_OK = 3
"""Backend transaction status values."""
TRANSACTION_STATUS_IDLE = 0
TRANSACTION_STATUS_ACTIVE = 1
TRANSACTION_STATUS_INTRANS = 2
TRANSACTION_STATUS_INERROR = 3
TRANSACTION_STATUS_UNKNOWN = 4
def register_adapter(typ, callable):
"""Register 'callable' as an ISQLQuote adapter for type 'typ'."""
adapters[(typ, ISQLQuote)] = callable
# The SQL_IN class is the official adapter for tuples starting from 2.0.6.
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 = [adapt(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
__all__ = filter(lambda k: not k.startswith('_'), locals().keys())