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# -*- coding: utf-8 -*-
# OpenERP, Open Source Management Solution
# Copyright (C) 2004-2009 Tiny SPRL (<http://tiny.be>).
# Copyright (C) 2010-2014 OpenERP s.a. (<http://openerp.com>).
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, 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
# GNU Affero General Public License for more details.
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
The PostgreSQL connector is a connectivity layer between the OpenERP code and
the database, *not* a database abstraction toolkit. Database abstraction is what
the ORM does, in fact.
from contextlib import contextmanager
from functools import wraps
import logging
import urlparse
import uuid
import psycopg2.extras
import psycopg2.extensions
from psycopg2.pool import PoolError
_logger = logging.getLogger(__name__)
types_mapping = {
'date': (1082,),
'time': (1083,),
'datetime': (1114,),
def unbuffer(symb, cr):
if symb is None:
return None
return str(symb)
def undecimalize(symb, cr):
if symb is None:
return None
return float(symb)
for name, typeoid in types_mapping.items():
psycopg2.extensions.register_type(psycopg2.extensions.new_type(typeoid, name, lambda x, cr: x))
psycopg2.extensions.register_type(psycopg2.extensions.new_type((700, 701, 1700,), 'float', undecimalize))
import tools
from tools.func import frame_codeinfo
from datetime import datetime as mdt
from datetime import timedelta
import threading
from inspect import currentframe
import re
re_from = re.compile('.* from "?([a-zA-Z_0-9]+)"? .*$')
re_into = re.compile('.* into "?([a-zA-Z_0-9]+)"? .*$')
sql_counter = 0
class Cursor(object):
"""Represents an open transaction to the PostgreSQL DB backend,
acting as a lightweight wrapper around psycopg2's
``cursor`` objects.
``Cursor`` is the object behind the ``cr`` variable used all
over the OpenERP code.
.. rubric:: Transaction Isolation
One very important property of database transactions is the
level of isolation between concurrent transactions.
The SQL standard defines four levels of transaction isolation,
ranging from the most strict *Serializable* level, to the least
strict *Read Uncommitted* level. These levels are defined in
terms of the phenomena that must not occur between concurrent
transactions, such as *dirty read*, etc.
In the context of a generic business data management software
such as OpenERP, we need the best guarantees that no data
corruption can ever be cause by simply running multiple
transactions in parallel. Therefore, the preferred level would
be the *serializable* level, which ensures that a set of
transactions is guaranteed to produce the same effect as
running them one at a time in some order.
However, most database management systems implement a limited
serializable isolation in the form of
`snapshot isolation <http://en.wikipedia.org/wiki/Snapshot_isolation>`_,
providing most of the same advantages as True Serializability,
with a fraction of the performance cost.
With PostgreSQL up to version 9.0, this snapshot isolation was
the implementation of both the ``REPEATABLE READ`` and
``SERIALIZABLE`` levels of the SQL standard.
As of PostgreSQL 9.1, the previous snapshot isolation implementation
was kept for ``REPEATABLE READ``, while a new ``SERIALIZABLE``
level was introduced, providing some additional heuristics to
detect a concurrent update by parallel transactions, and forcing
one of them to rollback.
OpenERP implements its own level of locking protection
for transactions that are highly likely to provoke concurrent
updates, such as stock reservations or document sequences updates.
Therefore we mostly care about the properties of snapshot isolation,
but we don't really need additional heuristics to trigger transaction
rollbacks, as we are taking care of triggering instant rollbacks
ourselves when it matters (and we can save the additional performance
hit of these heuristics).
As a result of the above, we have selected ``REPEATABLE READ`` as
the default transaction isolation level for OpenERP cursors, as
it will be mapped to the desired ``snapshot isolation`` level for
all supported PostgreSQL version (8.3 - 9.x).
Note: up to psycopg2 v.2.4.2, psycopg2 itself remapped the repeatable
read level to serializable before sending it to the database, so it would
actually select the new serializable mode on PostgreSQL 9.1. Make
sure you use psycopg2 v2.4.2 or newer if you use PostgreSQL 9.1 and
the performance hit is a concern for you.
.. attribute:: cache
Cache dictionary with a "request" (-ish) lifecycle, only lives as
long as the cursor itself does and proactively cleared when the
cursor is closed.
This cache should *only* be used to store repeatable reads as it
ignores rollbacks and savepoints, it should not be used to store
*any* data which may be modified during the life of the cursor.
IN_MAX = 1000 # decent limit on size of IN queries - guideline = Oracle limit
def check(f):
def wrapper(self, *args, **kwargs):
if self._closed:
msg = 'Unable to use a closed cursor.'
if self.__closer:
msg += ' It was closed at %s, line %s' % self.__closer
raise psycopg2.OperationalError(msg)
return f(self, *args, **kwargs)
return wrapper
def __init__(self, pool, dbname, dsn, serialized=True):
self.sql_from_log = {}
self.sql_into_log = {}
# default log level determined at cursor creation, could be
# overridden later for debugging purposes
self.sql_log = _logger.isEnabledFor(logging.DEBUG)
self.sql_log_count = 0
# avoid the call of close() (by __del__) if an exception
# is raised by any of the following initialisations
self._closed = True
self.__pool = pool
self.dbname = dbname
# Whether to enable snapshot isolation level for this cursor.
# see also the docstring of Cursor.
self._serialized = serialized
self._cnx = pool.borrow(dsn)
self._obj = self._cnx.cursor()
if self.sql_log:
self.__caller = frame_codeinfo(currentframe(), 2)
self.__caller = False
self._closed = False # real initialisation value
self.__closer = False
self._default_log_exceptions = True
self.cache = {}
def __build_dict(self, row):
return {d.name: row[i] for i, d in enumerate(self._obj.description)}
def dictfetchone(self):
row = self._obj.fetchone()
return row and self.__build_dict(row)
def dictfetchmany(self, size):
return map(self.__build_dict, self._obj.fetchmany(size))
def dictfetchall(self):
return map(self.__build_dict, self._obj.fetchall())
def __del__(self):
if not self._closed and not self._cnx.closed:
# Oops. 'self' has not been closed explicitly.
# The cursor will be deleted by the garbage collector,
# but the database connection is not put back into the connection
# pool, preventing some operation on the database like dropping it.
# This can also lead to a server overload.
msg = "Cursor not closed explicitly\n"
if self.__caller:
msg += "Cursor was created at %s:%s" % self.__caller
msg += "Please enable sql debugging to trace the caller."
def execute(self, query, params=None, log_exceptions=None):
if '%d' in query or '%f' in query:
_logger.warning("SQL queries cannot contain %d or %f anymore. Use only %s")
if params and not isinstance(params, (tuple, list, dict)):
_logger.error("SQL query parameters should be a tuple, list or dict; got %r", params)
raise ValueError("SQL query parameters should be a tuple, list or dict; got %r" % (params,))
if self.sql_log:
now = mdt.now()
params = params or None
res = self._obj.execute(query, params)
except psycopg2.ProgrammingError, pe:
if self._default_log_exceptions if log_exceptions is None else log_exceptions:
_logger.error("Programming error: %s, in query %s", pe, query)
except Exception:
if self._default_log_exceptions if log_exceptions is None else log_exceptions:
_logger.exception("bad query: %s", self._obj.query or query)
# simple query count is always computed
self.sql_log_count += 1
# advanced stats only if sql_log is enabled
if self.sql_log:
delay = mdt.now() - now
delay = delay.seconds * 1E6 + delay.microseconds
_logger.debug("query: %s", self._obj.query)
res_from = re_from.match(query.lower())
if res_from:
self.sql_from_log.setdefault(res_from.group(1), [0, 0])
self.sql_from_log[res_from.group(1)][0] += 1
self.sql_from_log[res_from.group(1)][1] += delay
res_into = re_into.match(query.lower())
if res_into:
self.sql_into_log.setdefault(res_into.group(1), [0, 0])
self.sql_into_log[res_into.group(1)][0] += 1
self.sql_into_log[res_into.group(1)][1] += delay
return res
def split_for_in_conditions(self, ids):
"""Split a list of identifiers into one or more smaller tuples
safe for IN conditions, after uniquifying them."""
return tools.misc.split_every(self.IN_MAX, ids)
def print_log(self):
global sql_counter
if not self.sql_log:
def process(type):
sqllogs = {'from': self.sql_from_log, 'into': self.sql_into_log}
sum = 0
if sqllogs[type]:
sqllogitems = sqllogs[type].items()
sqllogitems.sort(key=lambda k: k[1][1])
_logger.debug("SQL LOG %s:", type)
sqllogitems.sort(lambda x, y: cmp(x[1][0], y[1][0]))
for r in sqllogitems:
delay = timedelta(microseconds=r[1][1])
_logger.debug("table: %s: %s/%s", r[0], delay, r[1][0])
sum += r[1][1]
sum = timedelta(microseconds=sum)
_logger.debug("SUM %s:%s/%d [%d]", type, sum, self.sql_log_count, sql_counter)
self.sql_log_count = 0
self.sql_log = False
def close(self):
return self._close(False)
def _close(self, leak=False):
global sql_counter
if not self._obj:
del self.cache
if self.sql_log:
self.__closer = frame_codeinfo(currentframe(), 3)
# simple query count is always computed
sql_counter += self.sql_log_count
# advanced stats only if sql_log is enabled
# This force the cursor to be freed, and thus, available again. It is
# important because otherwise we can overload the server very easily
# because of a cursor shortage (because cursors are not garbage
# collected as fast as they should). The problem is probably due in
# part because browse records keep a reference to the cursor.
del self._obj
self._closed = True
# Clean the underlying connection.
if leak:
self._cnx.leaked = True
chosen_template = tools.config['db_template']
templates_list = tuple(set(['template0', 'template1', 'postgres', chosen_template]))
keep_in_pool = self.dbname not in templates_list
self.__pool.give_back(self._cnx, keep_in_pool=keep_in_pool)
def autocommit(self, on):
if on:
# If a serializable cursor was requested, we
# use the appropriate PotsgreSQL isolation level
# that maps to snaphsot isolation.
# For all supported PostgreSQL versions (8.3-9.x),
# this is currently the ISOLATION_REPEATABLE_READ.
# See also the docstring of this class.
# NOTE: up to psycopg 2.4.2, repeatable read
# is remapped to serializable before being
# sent to the database, so it is in fact
# unavailable for use with pg 9.1.
isolation_level = \
if self._serialized \
def commit(self):
""" Perform an SQL `COMMIT`
return self._cnx.commit()
def rollback(self):
""" Perform an SQL `ROLLBACK`
return self._cnx.rollback()
def __enter__(self):
""" Using the cursor as a contextmanager automatically commits and
closes it::
with cr:
# cr is committed if no failure occurred
# cr is closed in any case
return self
def __exit__(self, exc_type, exc_value, traceback):
if exc_type is None:
def savepoint(self):
"""context manager entering in a new savepoint"""
name = uuid.uuid1().hex
self.execute('SAVEPOINT "%s"' % name)
self.execute('RELEASE SAVEPOINT "%s"' % name)
self.execute('ROLLBACK TO SAVEPOINT "%s"' % name)
def __getattr__(self, name):
return getattr(self._obj, name)
def closed(self):
return self._closed
class TestCursor(Cursor):
""" A cursor to be used for tests. It keeps the transaction open across
several requests, and simulates committing, rolling back, and closing.
def __init__(self, *args, **kwargs):
super(TestCursor, self).__init__(*args, **kwargs)
# in order to simulate commit and rollback, the cursor maintains a
# savepoint at its last commit
self.execute("SAVEPOINT test_cursor")
# we use a lock to serialize concurrent requests
self._lock = threading.RLock()
def acquire(self):
def release(self):
def force_close(self):
super(TestCursor, self).close()
def close(self):
if not self._closed:
self.rollback() # for stuff that has not been committed
def autocommit(self, on):
_logger.debug("TestCursor.autocommit(%r) does nothing", on)
def commit(self):
self.execute("RELEASE SAVEPOINT test_cursor")
self.execute("SAVEPOINT test_cursor")
def rollback(self):
self.execute("ROLLBACK TO SAVEPOINT test_cursor")
self.execute("SAVEPOINT test_cursor")
class PsycoConnection(psycopg2.extensions.connection):
class ConnectionPool(object):
""" The pool of connections to database(s)
Keep a set of connections to pg databases open, and reuse them
to open cursors for all transactions.
The connections are *not* automatically closed. Only a close_db()
can trigger that.
def locked(fun):
def _locked(self, *args, **kwargs):
return fun(self, *args, **kwargs)
return _locked
def __init__(self, maxconn=64):
self._connections = []
self._maxconn = max(maxconn, 1)
self._lock = threading.Lock()
def __repr__(self):
used = len([1 for c, u in self._connections[:] if u])
count = len(self._connections)
return "ConnectionPool(used=%d/count=%d/max=%d)" % (used, count, self._maxconn)
def _debug(self, msg, *args):
_logger.debug(('%r ' + msg), self, *args)
def borrow(self, dsn):
# free dead and leaked connections
for i, (cnx, _) in tools.reverse_enumerate(self._connections):
if cnx.closed:
self._debug('Removing closed connection at index %d: %r', i, cnx.dsn)
if getattr(cnx, 'leaked', False):
delattr(cnx, 'leaked')
self._connections.append((cnx, False))
_logger.warning('%r: Free leaked connection to %r', self, cnx.dsn)
for i, (cnx, used) in enumerate(self._connections):
if not used and cnx._original_dsn == dsn:
except psycopg2.OperationalError:
self._debug('Cannot reset connection at index %d: %r', i, cnx.dsn)
# psycopg2 2.4.4 and earlier do not allow closing a closed connection
if not cnx.closed:
self._connections.append((cnx, True))
self._debug('Borrow existing connection to %r at index %d', cnx.dsn, i)
return cnx
if len(self._connections) >= self._maxconn:
# try to remove the oldest connection not used
for i, (cnx, used) in enumerate(self._connections):
if not used:
if not cnx.closed:
self._debug('Removing old connection at index %d: %r', i, cnx.dsn)
# note: this code is called only if the for loop has completed (no break)
raise PoolError('The Connection Pool Is Full')
result = psycopg2.connect(dsn=dsn, connection_factory=PsycoConnection)
except psycopg2.Error:
_logger.exception('Connection to the database failed')
result._original_dsn = dsn
self._connections.append((result, True))
self._debug('Create new connection')
return result
def give_back(self, connection, keep_in_pool=True):
self._debug('Give back connection to %r', connection.dsn)
for i, (cnx, used) in enumerate(self._connections):
if cnx is connection:
if keep_in_pool:
self._connections.append((cnx, False))
self._debug('Put connection to %r in pool', cnx.dsn)
self._debug('Forgot connection to %r', cnx.dsn)
raise PoolError('This connection does not below to the pool')
def close_all(self, dsn=None):
count = 0
last = None
for i, (cnx, used) in tools.reverse_enumerate(self._connections):
if dsn is None or cnx._original_dsn == dsn:
last = self._connections.pop(i)[0]
count += 1
_logger.info('%r: Closed %d connections %s', self, count,
(dsn and last and 'to %r' % last.dsn) or '')
class Connection(object):
""" A lightweight instance of a connection to postgres
def __init__(self, pool, dbname, dsn):
self.dbname = dbname
self.dsn = dsn
self.__pool = pool
def cursor(self, serialized=True):
cursor_type = serialized and 'serialized ' or ''
_logger.debug('create %scursor to %r', cursor_type, self.dsn)
return Cursor(self.__pool, self.dbname, self.dsn, serialized=serialized)
def test_cursor(self, serialized=True):
cursor_type = serialized and 'serialized ' or ''
_logger.debug('create test %scursor to %r', cursor_type, self.dsn)
return TestCursor(self.__pool, self.dbname, self.dsn, serialized=serialized)
# serialized_cursor is deprecated - cursors are serialized by default
serialized_cursor = cursor
def __nonzero__(self):
"""Check if connection is possible"""
_logger.warning("__nonzero__() is deprecated. (It is too expensive to test a connection.)")
cr = self.cursor()
return True
except Exception:
return False
def dsn(db_or_uri):
"""parse the given `db_or_uri` and return a 2-tuple (dbname, uri)"""
if db_or_uri.startswith(('postgresql://', 'postgres://')):
# extract db from uri
us = urlparse.urlsplit(db_or_uri)
if len(us.path) > 1:
db_name = us.path[1:]
elif us.username:
db_name = us.username
db_name = us.hostname
return db_name, db_or_uri
_dsn = ''
for p in ('host', 'port', 'user', 'password'):
cfg = tools.config['db_' + p]
if cfg:
_dsn += '%s=%s ' % (p, cfg)
return db_or_uri, '%sdbname=%s' % (_dsn, db_or_uri)
_Pool = None
def db_connect(to, allow_uri=False):
global _Pool
if _Pool is None:
_Pool = ConnectionPool(int(tools.config['db_maxconn']))
db, uri = dsn(to)
if not allow_uri and db != to:
raise ValueError('URI connections not allowed')
return Connection(_Pool, db, uri)
def close_db(db_name):
""" You might want to call openerp.modules.registry.RegistryManager.delete(db_name) along this function."""
global _Pool
if _Pool:
def close_all():
global _Pool
if _Pool:
# vim:expandtab:smartindent:tabstop=4:softtabstop=4:shiftwidth=4: