726 lines
26 KiB
Python
726 lines
26 KiB
Python
# postgresql/psycopg2.py
|
|
# Copyright (C) 2005-2015 the SQLAlchemy authors and contributors
|
|
# <see AUTHORS file>
|
|
#
|
|
# This module is part of SQLAlchemy and is released under
|
|
# the MIT License: http://www.opensource.org/licenses/mit-license.php
|
|
|
|
"""
|
|
.. dialect:: postgresql+psycopg2
|
|
:name: psycopg2
|
|
:dbapi: psycopg2
|
|
:connectstring: postgresql+psycopg2://user:password@host:port/dbname\
|
|
[?key=value&key=value...]
|
|
:url: http://pypi.python.org/pypi/psycopg2/
|
|
|
|
psycopg2 Connect Arguments
|
|
-----------------------------------
|
|
|
|
psycopg2-specific keyword arguments which are accepted by
|
|
:func:`.create_engine()` are:
|
|
|
|
* ``server_side_cursors``: Enable the usage of "server side cursors" for SQL
|
|
statements which support this feature. What this essentially means from a
|
|
psycopg2 point of view is that the cursor is created using a name, e.g.
|
|
``connection.cursor('some name')``, which has the effect that result rows
|
|
are not immediately pre-fetched and buffered after statement execution, but
|
|
are instead left on the server and only retrieved as needed. SQLAlchemy's
|
|
:class:`~sqlalchemy.engine.ResultProxy` uses special row-buffering
|
|
behavior when this feature is enabled, such that groups of 100 rows at a
|
|
time are fetched over the wire to reduce conversational overhead.
|
|
Note that the ``stream_results=True`` execution option is a more targeted
|
|
way of enabling this mode on a per-execution basis.
|
|
* ``use_native_unicode``: Enable the usage of Psycopg2 "native unicode" mode
|
|
per connection. True by default.
|
|
|
|
.. seealso::
|
|
|
|
:ref:`psycopg2_disable_native_unicode`
|
|
|
|
* ``isolation_level``: This option, available for all PostgreSQL dialects,
|
|
includes the ``AUTOCOMMIT`` isolation level when using the psycopg2
|
|
dialect.
|
|
|
|
.. seealso::
|
|
|
|
:ref:`psycopg2_isolation_level`
|
|
|
|
* ``client_encoding``: sets the client encoding in a libpq-agnostic way,
|
|
using psycopg2's ``set_client_encoding()`` method.
|
|
|
|
.. seealso::
|
|
|
|
:ref:`psycopg2_unicode`
|
|
|
|
Unix Domain Connections
|
|
------------------------
|
|
|
|
psycopg2 supports connecting via Unix domain connections. When the ``host``
|
|
portion of the URL is omitted, SQLAlchemy passes ``None`` to psycopg2,
|
|
which specifies Unix-domain communication rather than TCP/IP communication::
|
|
|
|
create_engine("postgresql+psycopg2://user:password@/dbname")
|
|
|
|
By default, the socket file used is to connect to a Unix-domain socket
|
|
in ``/tmp``, or whatever socket directory was specified when PostgreSQL
|
|
was built. This value can be overridden by passing a pathname to psycopg2,
|
|
using ``host`` as an additional keyword argument::
|
|
|
|
create_engine("postgresql+psycopg2://user:password@/dbname?\
|
|
host=/var/lib/postgresql")
|
|
|
|
See also:
|
|
|
|
`PQconnectdbParams <http://www.postgresql.org/docs/9.1/static/\
|
|
libpq-connect.html#LIBPQ-PQCONNECTDBPARAMS>`_
|
|
|
|
.. _psycopg2_execution_options:
|
|
|
|
Per-Statement/Connection Execution Options
|
|
-------------------------------------------
|
|
|
|
The following DBAPI-specific options are respected when used with
|
|
:meth:`.Connection.execution_options`, :meth:`.Executable.execution_options`,
|
|
:meth:`.Query.execution_options`, in addition to those not specific to DBAPIs:
|
|
|
|
* ``isolation_level`` - Set the transaction isolation level for the lifespan of a
|
|
:class:`.Connection` (can only be set on a connection, not a statement
|
|
or query). See :ref:`psycopg2_isolation_level`.
|
|
|
|
* ``stream_results`` - Enable or disable usage of psycopg2 server side cursors -
|
|
this feature makes use of "named" cursors in combination with special
|
|
result handling methods so that result rows are not fully buffered.
|
|
If ``None`` or not set, the ``server_side_cursors`` option of the
|
|
:class:`.Engine` is used.
|
|
|
|
* ``max_row_buffer`` - when using ``stream_results``, an integer value that
|
|
specifies the maximum number of rows to buffer at a time. This is
|
|
interpreted by the :class:`.BufferedRowResultProxy`, and if omitted the
|
|
buffer will grow to ultimately store 1000 rows at a time.
|
|
|
|
.. versionadded:: 1.0.6
|
|
|
|
.. _psycopg2_unicode:
|
|
|
|
Unicode with Psycopg2
|
|
----------------------
|
|
|
|
By default, the psycopg2 driver uses the ``psycopg2.extensions.UNICODE``
|
|
extension, such that the DBAPI receives and returns all strings as Python
|
|
Unicode objects directly - SQLAlchemy passes these values through without
|
|
change. Psycopg2 here will encode/decode string values based on the
|
|
current "client encoding" setting; by default this is the value in
|
|
the ``postgresql.conf`` file, which often defaults to ``SQL_ASCII``.
|
|
Typically, this can be changed to ``utf8``, as a more useful default::
|
|
|
|
# postgresql.conf file
|
|
|
|
# client_encoding = sql_ascii # actually, defaults to database
|
|
# encoding
|
|
client_encoding = utf8
|
|
|
|
A second way to affect the client encoding is to set it within Psycopg2
|
|
locally. SQLAlchemy will call psycopg2's
|
|
:meth:`psycopg2:connection.set_client_encoding` method
|
|
on all new connections based on the value passed to
|
|
:func:`.create_engine` using the ``client_encoding`` parameter::
|
|
|
|
# set_client_encoding() setting;
|
|
# works for *all* Postgresql versions
|
|
engine = create_engine("postgresql://user:pass@host/dbname",
|
|
client_encoding='utf8')
|
|
|
|
This overrides the encoding specified in the Postgresql client configuration.
|
|
When using the parameter in this way, the psycopg2 driver emits
|
|
``SET client_encoding TO 'utf8'`` on the connection explicitly, and works
|
|
in all Postgresql versions.
|
|
|
|
Note that the ``client_encoding`` setting as passed to :func:`.create_engine`
|
|
is **not the same** as the more recently added ``client_encoding`` parameter
|
|
now supported by libpq directly. This is enabled when ``client_encoding``
|
|
is passed directly to ``psycopg2.connect()``, and from SQLAlchemy is passed
|
|
using the :paramref:`.create_engine.connect_args` parameter::
|
|
|
|
# libpq direct parameter setting;
|
|
# only works for Postgresql **9.1 and above**
|
|
engine = create_engine("postgresql://user:pass@host/dbname",
|
|
connect_args={'client_encoding': 'utf8'})
|
|
|
|
# using the query string is equivalent
|
|
engine = create_engine("postgresql://user:pass@host/dbname?client_encoding=utf8")
|
|
|
|
The above parameter was only added to libpq as of version 9.1 of Postgresql,
|
|
so using the previous method is better for cross-version support.
|
|
|
|
.. _psycopg2_disable_native_unicode:
|
|
|
|
Disabling Native Unicode
|
|
^^^^^^^^^^^^^^^^^^^^^^^^
|
|
|
|
SQLAlchemy can also be instructed to skip the usage of the psycopg2
|
|
``UNICODE`` extension and to instead utilize its own unicode encode/decode
|
|
services, which are normally reserved only for those DBAPIs that don't
|
|
fully support unicode directly. Passing ``use_native_unicode=False`` to
|
|
:func:`.create_engine` will disable usage of ``psycopg2.extensions.UNICODE``.
|
|
SQLAlchemy will instead encode data itself into Python bytestrings on the way
|
|
in and coerce from bytes on the way back,
|
|
using the value of the :func:`.create_engine` ``encoding`` parameter, which
|
|
defaults to ``utf-8``.
|
|
SQLAlchemy's own unicode encode/decode functionality is steadily becoming
|
|
obsolete as most DBAPIs now support unicode fully.
|
|
|
|
Bound Parameter Styles
|
|
----------------------
|
|
|
|
The default parameter style for the psycopg2 dialect is "pyformat", where
|
|
SQL is rendered using ``%(paramname)s`` style. This format has the limitation
|
|
that it does not accommodate the unusual case of parameter names that
|
|
actually contain percent or parenthesis symbols; as SQLAlchemy in many cases
|
|
generates bound parameter names based on the name of a column, the presence
|
|
of these characters in a column name can lead to problems.
|
|
|
|
There are two solutions to the issue of a :class:`.schema.Column` that contains
|
|
one of these characters in its name. One is to specify the
|
|
:paramref:`.schema.Column.key` for columns that have such names::
|
|
|
|
measurement = Table('measurement', metadata,
|
|
Column('Size (meters)', Integer, key='size_meters')
|
|
)
|
|
|
|
Above, an INSERT statement such as ``measurement.insert()`` will use
|
|
``size_meters`` as the parameter name, and a SQL expression such as
|
|
``measurement.c.size_meters > 10`` will derive the bound parameter name
|
|
from the ``size_meters`` key as well.
|
|
|
|
.. versionchanged:: 1.0.0 - SQL expressions will use :attr:`.Column.key`
|
|
as the source of naming when anonymous bound parameters are created
|
|
in SQL expressions; previously, this behavior only applied to
|
|
:meth:`.Table.insert` and :meth:`.Table.update` parameter names.
|
|
|
|
The other solution is to use a positional format; psycopg2 allows use of the
|
|
"format" paramstyle, which can be passed to
|
|
:paramref:`.create_engine.paramstyle`::
|
|
|
|
engine = create_engine(
|
|
'postgresql://scott:tiger@localhost:5432/test', paramstyle='format')
|
|
|
|
With the above engine, instead of a statement like::
|
|
|
|
INSERT INTO measurement ("Size (meters)") VALUES (%(Size (meters))s)
|
|
{'Size (meters)': 1}
|
|
|
|
we instead see::
|
|
|
|
INSERT INTO measurement ("Size (meters)") VALUES (%s)
|
|
(1, )
|
|
|
|
Where above, the dictionary style is converted into a tuple with positional
|
|
style.
|
|
|
|
|
|
Transactions
|
|
------------
|
|
|
|
The psycopg2 dialect fully supports SAVEPOINT and two-phase commit operations.
|
|
|
|
.. _psycopg2_isolation_level:
|
|
|
|
Psycopg2 Transaction Isolation Level
|
|
-------------------------------------
|
|
|
|
As discussed in :ref:`postgresql_isolation_level`,
|
|
all Postgresql dialects support setting of transaction isolation level
|
|
both via the ``isolation_level`` parameter passed to :func:`.create_engine`,
|
|
as well as the ``isolation_level`` argument used by
|
|
:meth:`.Connection.execution_options`. When using the psycopg2 dialect, these
|
|
options make use of psycopg2's ``set_isolation_level()`` connection method,
|
|
rather than emitting a Postgresql directive; this is because psycopg2's
|
|
API-level setting is always emitted at the start of each transaction in any
|
|
case.
|
|
|
|
The psycopg2 dialect supports these constants for isolation level:
|
|
|
|
* ``READ COMMITTED``
|
|
* ``READ UNCOMMITTED``
|
|
* ``REPEATABLE READ``
|
|
* ``SERIALIZABLE``
|
|
* ``AUTOCOMMIT``
|
|
|
|
.. versionadded:: 0.8.2 support for AUTOCOMMIT isolation level when using
|
|
psycopg2.
|
|
|
|
.. seealso::
|
|
|
|
:ref:`postgresql_isolation_level`
|
|
|
|
:ref:`pg8000_isolation_level`
|
|
|
|
|
|
NOTICE logging
|
|
---------------
|
|
|
|
The psycopg2 dialect will log Postgresql NOTICE messages via the
|
|
``sqlalchemy.dialects.postgresql`` logger::
|
|
|
|
import logging
|
|
logging.getLogger('sqlalchemy.dialects.postgresql').setLevel(logging.INFO)
|
|
|
|
.. _psycopg2_hstore::
|
|
|
|
HSTORE type
|
|
------------
|
|
|
|
The ``psycopg2`` DBAPI includes an extension to natively handle marshalling of
|
|
the HSTORE type. The SQLAlchemy psycopg2 dialect will enable this extension
|
|
by default when psycopg2 version 2.4 or greater is used, and
|
|
it is detected that the target database has the HSTORE type set up for use.
|
|
In other words, when the dialect makes the first
|
|
connection, a sequence like the following is performed:
|
|
|
|
1. Request the available HSTORE oids using
|
|
``psycopg2.extras.HstoreAdapter.get_oids()``.
|
|
If this function returns a list of HSTORE identifiers, we then determine
|
|
that the ``HSTORE`` extension is present.
|
|
This function is **skipped** if the version of psycopg2 installed is
|
|
less than version 2.4.
|
|
|
|
2. If the ``use_native_hstore`` flag is at its default of ``True``, and
|
|
we've detected that ``HSTORE`` oids are available, the
|
|
``psycopg2.extensions.register_hstore()`` extension is invoked for all
|
|
connections.
|
|
|
|
The ``register_hstore()`` extension has the effect of **all Python
|
|
dictionaries being accepted as parameters regardless of the type of target
|
|
column in SQL**. The dictionaries are converted by this extension into a
|
|
textual HSTORE expression. If this behavior is not desired, disable the
|
|
use of the hstore extension by setting ``use_native_hstore`` to ``False`` as
|
|
follows::
|
|
|
|
engine = create_engine("postgresql+psycopg2://scott:tiger@localhost/test",
|
|
use_native_hstore=False)
|
|
|
|
The ``HSTORE`` type is **still supported** when the
|
|
``psycopg2.extensions.register_hstore()`` extension is not used. It merely
|
|
means that the coercion between Python dictionaries and the HSTORE
|
|
string format, on both the parameter side and the result side, will take
|
|
place within SQLAlchemy's own marshalling logic, and not that of ``psycopg2``
|
|
which may be more performant.
|
|
|
|
"""
|
|
from __future__ import absolute_import
|
|
|
|
import re
|
|
import logging
|
|
|
|
from ... import util, exc
|
|
import decimal
|
|
from ... import processors
|
|
from ...engine import result as _result
|
|
from ...sql import expression
|
|
from ... import types as sqltypes
|
|
from .base import PGDialect, PGCompiler, \
|
|
PGIdentifierPreparer, PGExecutionContext, \
|
|
ENUM, ARRAY, _DECIMAL_TYPES, _FLOAT_TYPES,\
|
|
_INT_TYPES, UUID
|
|
from .hstore import HSTORE
|
|
from .json import JSON, JSONB
|
|
|
|
try:
|
|
from uuid import UUID as _python_UUID
|
|
except ImportError:
|
|
_python_UUID = None
|
|
|
|
|
|
logger = logging.getLogger('sqlalchemy.dialects.postgresql')
|
|
|
|
|
|
class _PGNumeric(sqltypes.Numeric):
|
|
def bind_processor(self, dialect):
|
|
return None
|
|
|
|
def result_processor(self, dialect, coltype):
|
|
if self.asdecimal:
|
|
if coltype in _FLOAT_TYPES:
|
|
return processors.to_decimal_processor_factory(
|
|
decimal.Decimal,
|
|
self._effective_decimal_return_scale)
|
|
elif coltype in _DECIMAL_TYPES or coltype in _INT_TYPES:
|
|
# pg8000 returns Decimal natively for 1700
|
|
return None
|
|
else:
|
|
raise exc.InvalidRequestError(
|
|
"Unknown PG numeric type: %d" % coltype)
|
|
else:
|
|
if coltype in _FLOAT_TYPES:
|
|
# pg8000 returns float natively for 701
|
|
return None
|
|
elif coltype in _DECIMAL_TYPES or coltype in _INT_TYPES:
|
|
return processors.to_float
|
|
else:
|
|
raise exc.InvalidRequestError(
|
|
"Unknown PG numeric type: %d" % coltype)
|
|
|
|
|
|
class _PGEnum(ENUM):
|
|
def result_processor(self, dialect, coltype):
|
|
if self.native_enum and util.py2k and self.convert_unicode is True:
|
|
# we can't easily use PG's extensions here because
|
|
# the OID is on the fly, and we need to give it a python
|
|
# function anyway - not really worth it.
|
|
self.convert_unicode = "force_nocheck"
|
|
return super(_PGEnum, self).result_processor(dialect, coltype)
|
|
|
|
|
|
class _PGHStore(HSTORE):
|
|
def bind_processor(self, dialect):
|
|
if dialect._has_native_hstore:
|
|
return None
|
|
else:
|
|
return super(_PGHStore, self).bind_processor(dialect)
|
|
|
|
def result_processor(self, dialect, coltype):
|
|
if dialect._has_native_hstore:
|
|
return None
|
|
else:
|
|
return super(_PGHStore, self).result_processor(dialect, coltype)
|
|
|
|
|
|
class _PGJSON(JSON):
|
|
|
|
def result_processor(self, dialect, coltype):
|
|
if dialect._has_native_json:
|
|
return None
|
|
else:
|
|
return super(_PGJSON, self).result_processor(dialect, coltype)
|
|
|
|
|
|
class _PGJSONB(JSONB):
|
|
|
|
def result_processor(self, dialect, coltype):
|
|
if dialect._has_native_jsonb:
|
|
return None
|
|
else:
|
|
return super(_PGJSONB, self).result_processor(dialect, coltype)
|
|
|
|
|
|
class _PGUUID(UUID):
|
|
def bind_processor(self, dialect):
|
|
if not self.as_uuid and dialect.use_native_uuid:
|
|
nonetype = type(None)
|
|
|
|
def process(value):
|
|
if value is not None:
|
|
value = _python_UUID(value)
|
|
return value
|
|
return process
|
|
|
|
def result_processor(self, dialect, coltype):
|
|
if not self.as_uuid and dialect.use_native_uuid:
|
|
def process(value):
|
|
if value is not None:
|
|
value = str(value)
|
|
return value
|
|
return process
|
|
|
|
# When we're handed literal SQL, ensure it's a SELECT query. Since
|
|
# 8.3, combining cursors and "FOR UPDATE" has been fine.
|
|
SERVER_SIDE_CURSOR_RE = re.compile(
|
|
r'\s*SELECT',
|
|
re.I | re.UNICODE)
|
|
|
|
_server_side_id = util.counter()
|
|
|
|
|
|
class PGExecutionContext_psycopg2(PGExecutionContext):
|
|
def create_cursor(self):
|
|
# TODO: coverage for server side cursors + select.for_update()
|
|
|
|
if self.dialect.server_side_cursors:
|
|
is_server_side = \
|
|
self.execution_options.get('stream_results', True) and (
|
|
(self.compiled and isinstance(self.compiled.statement,
|
|
expression.Selectable)
|
|
or
|
|
(
|
|
(not self.compiled or
|
|
isinstance(self.compiled.statement,
|
|
expression.TextClause))
|
|
and self.statement and SERVER_SIDE_CURSOR_RE.match(
|
|
self.statement))
|
|
)
|
|
)
|
|
else:
|
|
is_server_side = \
|
|
self.execution_options.get('stream_results', False)
|
|
|
|
self.__is_server_side = is_server_side
|
|
if is_server_side:
|
|
# use server-side cursors:
|
|
# http://lists.initd.org/pipermail/psycopg/2007-January/005251.html
|
|
ident = "c_%s_%s" % (hex(id(self))[2:],
|
|
hex(_server_side_id())[2:])
|
|
return self._dbapi_connection.cursor(ident)
|
|
else:
|
|
return self._dbapi_connection.cursor()
|
|
|
|
def get_result_proxy(self):
|
|
# TODO: ouch
|
|
if logger.isEnabledFor(logging.INFO):
|
|
self._log_notices(self.cursor)
|
|
|
|
if self.__is_server_side:
|
|
return _result.BufferedRowResultProxy(self)
|
|
else:
|
|
return _result.ResultProxy(self)
|
|
|
|
def _log_notices(self, cursor):
|
|
for notice in cursor.connection.notices:
|
|
# NOTICE messages have a
|
|
# newline character at the end
|
|
logger.info(notice.rstrip())
|
|
|
|
cursor.connection.notices[:] = []
|
|
|
|
|
|
class PGCompiler_psycopg2(PGCompiler):
|
|
def visit_mod_binary(self, binary, operator, **kw):
|
|
return self.process(binary.left, **kw) + " %% " + \
|
|
self.process(binary.right, **kw)
|
|
|
|
def post_process_text(self, text):
|
|
return text.replace('%', '%%')
|
|
|
|
|
|
class PGIdentifierPreparer_psycopg2(PGIdentifierPreparer):
|
|
def _escape_identifier(self, value):
|
|
value = value.replace(self.escape_quote, self.escape_to_quote)
|
|
return value.replace('%', '%%')
|
|
|
|
|
|
class PGDialect_psycopg2(PGDialect):
|
|
driver = 'psycopg2'
|
|
if util.py2k:
|
|
supports_unicode_statements = False
|
|
|
|
default_paramstyle = 'pyformat'
|
|
# set to true based on psycopg2 version
|
|
supports_sane_multi_rowcount = False
|
|
execution_ctx_cls = PGExecutionContext_psycopg2
|
|
statement_compiler = PGCompiler_psycopg2
|
|
preparer = PGIdentifierPreparer_psycopg2
|
|
psycopg2_version = (0, 0)
|
|
|
|
FEATURE_VERSION_MAP = dict(
|
|
native_json=(2, 5),
|
|
native_jsonb=(2, 5, 4),
|
|
sane_multi_rowcount=(2, 0, 9),
|
|
array_oid=(2, 4, 3),
|
|
hstore_adapter=(2, 4)
|
|
)
|
|
|
|
_has_native_hstore = False
|
|
_has_native_json = False
|
|
_has_native_jsonb = False
|
|
|
|
engine_config_types = PGDialect.engine_config_types.union([
|
|
('use_native_unicode', util.asbool),
|
|
])
|
|
|
|
colspecs = util.update_copy(
|
|
PGDialect.colspecs,
|
|
{
|
|
sqltypes.Numeric: _PGNumeric,
|
|
ENUM: _PGEnum, # needs force_unicode
|
|
sqltypes.Enum: _PGEnum, # needs force_unicode
|
|
HSTORE: _PGHStore,
|
|
JSON: _PGJSON,
|
|
JSONB: _PGJSONB,
|
|
UUID: _PGUUID
|
|
}
|
|
)
|
|
|
|
def __init__(self, server_side_cursors=False, use_native_unicode=True,
|
|
client_encoding=None,
|
|
use_native_hstore=True, use_native_uuid=True,
|
|
**kwargs):
|
|
PGDialect.__init__(self, **kwargs)
|
|
self.server_side_cursors = server_side_cursors
|
|
self.use_native_unicode = use_native_unicode
|
|
self.use_native_hstore = use_native_hstore
|
|
self.use_native_uuid = use_native_uuid
|
|
self.supports_unicode_binds = use_native_unicode
|
|
self.client_encoding = client_encoding
|
|
if self.dbapi and hasattr(self.dbapi, '__version__'):
|
|
m = re.match(r'(\d+)\.(\d+)(?:\.(\d+))?',
|
|
self.dbapi.__version__)
|
|
if m:
|
|
self.psycopg2_version = tuple(
|
|
int(x)
|
|
for x in m.group(1, 2, 3)
|
|
if x is not None)
|
|
|
|
def initialize(self, connection):
|
|
super(PGDialect_psycopg2, self).initialize(connection)
|
|
self._has_native_hstore = self.use_native_hstore and \
|
|
self._hstore_oids(connection.connection) \
|
|
is not None
|
|
self._has_native_json = \
|
|
self.psycopg2_version >= self.FEATURE_VERSION_MAP['native_json']
|
|
self._has_native_jsonb = \
|
|
self.psycopg2_version >= self.FEATURE_VERSION_MAP['native_jsonb']
|
|
|
|
# http://initd.org/psycopg/docs/news.html#what-s-new-in-psycopg-2-0-9
|
|
self.supports_sane_multi_rowcount = \
|
|
self.psycopg2_version >= \
|
|
self.FEATURE_VERSION_MAP['sane_multi_rowcount']
|
|
|
|
@classmethod
|
|
def dbapi(cls):
|
|
import psycopg2
|
|
return psycopg2
|
|
|
|
@classmethod
|
|
def _psycopg2_extensions(cls):
|
|
from psycopg2 import extensions
|
|
return extensions
|
|
|
|
@classmethod
|
|
def _psycopg2_extras(cls):
|
|
from psycopg2 import extras
|
|
return extras
|
|
|
|
@util.memoized_property
|
|
def _isolation_lookup(self):
|
|
extensions = self._psycopg2_extensions()
|
|
return {
|
|
'AUTOCOMMIT': extensions.ISOLATION_LEVEL_AUTOCOMMIT,
|
|
'READ COMMITTED': extensions.ISOLATION_LEVEL_READ_COMMITTED,
|
|
'READ UNCOMMITTED': extensions.ISOLATION_LEVEL_READ_UNCOMMITTED,
|
|
'REPEATABLE READ': extensions.ISOLATION_LEVEL_REPEATABLE_READ,
|
|
'SERIALIZABLE': extensions.ISOLATION_LEVEL_SERIALIZABLE
|
|
}
|
|
|
|
def set_isolation_level(self, connection, level):
|
|
try:
|
|
level = self._isolation_lookup[level.replace('_', ' ')]
|
|
except KeyError:
|
|
raise exc.ArgumentError(
|
|
"Invalid value '%s' for isolation_level. "
|
|
"Valid isolation levels for %s are %s" %
|
|
(level, self.name, ", ".join(self._isolation_lookup))
|
|
)
|
|
|
|
connection.set_isolation_level(level)
|
|
|
|
def on_connect(self):
|
|
extras = self._psycopg2_extras()
|
|
extensions = self._psycopg2_extensions()
|
|
|
|
fns = []
|
|
if self.client_encoding is not None:
|
|
def on_connect(conn):
|
|
conn.set_client_encoding(self.client_encoding)
|
|
fns.append(on_connect)
|
|
|
|
if self.isolation_level is not None:
|
|
def on_connect(conn):
|
|
self.set_isolation_level(conn, self.isolation_level)
|
|
fns.append(on_connect)
|
|
|
|
if self.dbapi and self.use_native_uuid:
|
|
def on_connect(conn):
|
|
extras.register_uuid(None, conn)
|
|
fns.append(on_connect)
|
|
|
|
if self.dbapi and self.use_native_unicode:
|
|
def on_connect(conn):
|
|
extensions.register_type(extensions.UNICODE, conn)
|
|
extensions.register_type(extensions.UNICODEARRAY, conn)
|
|
fns.append(on_connect)
|
|
|
|
if self.dbapi and self.use_native_hstore:
|
|
def on_connect(conn):
|
|
hstore_oids = self._hstore_oids(conn)
|
|
if hstore_oids is not None:
|
|
oid, array_oid = hstore_oids
|
|
kw = {'oid': oid}
|
|
if util.py2k:
|
|
kw['unicode'] = True
|
|
if self.psycopg2_version >= \
|
|
self.FEATURE_VERSION_MAP['array_oid']:
|
|
kw['array_oid'] = array_oid
|
|
extras.register_hstore(conn, **kw)
|
|
fns.append(on_connect)
|
|
|
|
if self.dbapi and self._json_deserializer:
|
|
def on_connect(conn):
|
|
if self._has_native_json:
|
|
extras.register_default_json(
|
|
conn, loads=self._json_deserializer)
|
|
if self._has_native_jsonb:
|
|
extras.register_default_jsonb(
|
|
conn, loads=self._json_deserializer)
|
|
fns.append(on_connect)
|
|
|
|
if fns:
|
|
def on_connect(conn):
|
|
for fn in fns:
|
|
fn(conn)
|
|
return on_connect
|
|
else:
|
|
return None
|
|
|
|
@util.memoized_instancemethod
|
|
def _hstore_oids(self, conn):
|
|
if self.psycopg2_version >= self.FEATURE_VERSION_MAP['hstore_adapter']:
|
|
extras = self._psycopg2_extras()
|
|
oids = extras.HstoreAdapter.get_oids(conn)
|
|
if oids is not None and oids[0]:
|
|
return oids[0:2]
|
|
return None
|
|
|
|
def create_connect_args(self, url):
|
|
opts = url.translate_connect_args(username='user')
|
|
if 'port' in opts:
|
|
opts['port'] = int(opts['port'])
|
|
opts.update(url.query)
|
|
return ([], opts)
|
|
|
|
def is_disconnect(self, e, connection, cursor):
|
|
if isinstance(e, self.dbapi.Error):
|
|
# check the "closed" flag. this might not be
|
|
# present on old psycopg2 versions. Also,
|
|
# this flag doesn't actually help in a lot of disconnect
|
|
# situations, so don't rely on it.
|
|
if getattr(connection, 'closed', False):
|
|
return True
|
|
|
|
# checks based on strings. in the case that .closed
|
|
# didn't cut it, fall back onto these.
|
|
str_e = str(e).partition("\n")[0]
|
|
for msg in [
|
|
# these error messages from libpq: interfaces/libpq/fe-misc.c
|
|
# and interfaces/libpq/fe-secure.c.
|
|
'terminating connection',
|
|
'closed the connection',
|
|
'connection not open',
|
|
'could not receive data from server',
|
|
'could not send data to server',
|
|
# psycopg2 client errors, psycopg2/conenction.h,
|
|
# psycopg2/cursor.h
|
|
'connection already closed',
|
|
'cursor already closed',
|
|
# not sure where this path is originally from, it may
|
|
# be obsolete. It really says "losed", not "closed".
|
|
'losed the connection unexpectedly',
|
|
# these can occur in newer SSL
|
|
'connection has been closed unexpectedly',
|
|
'SSL SYSCALL error: Bad file descriptor',
|
|
'SSL SYSCALL error: EOF detected',
|
|
]:
|
|
idx = str_e.find(msg)
|
|
if idx >= 0 and '"' not in str_e[:idx]:
|
|
return True
|
|
return False
|
|
|
|
dialect = PGDialect_psycopg2
|