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Diffstat (limited to 'lib/python2.7/site-packages/SQLAlchemy-0.7.0-py2.7-linux-x86_64.egg/sqlalchemy/dialects/postgresql/psycopg2.py')
| -rwxr-xr-x | lib/python2.7/site-packages/SQLAlchemy-0.7.0-py2.7-linux-x86_64.egg/sqlalchemy/dialects/postgresql/psycopg2.py | 334 |
1 files changed, 0 insertions, 334 deletions
diff --git a/lib/python2.7/site-packages/SQLAlchemy-0.7.0-py2.7-linux-x86_64.egg/sqlalchemy/dialects/postgresql/psycopg2.py b/lib/python2.7/site-packages/SQLAlchemy-0.7.0-py2.7-linux-x86_64.egg/sqlalchemy/dialects/postgresql/psycopg2.py deleted file mode 100755 index 2a3b4297..00000000 --- a/lib/python2.7/site-packages/SQLAlchemy-0.7.0-py2.7-linux-x86_64.egg/sqlalchemy/dialects/postgresql/psycopg2.py +++ /dev/null @@ -1,334 +0,0 @@ -# postgresql/psycopg2.py -# Copyright (C) 2005-2011 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 - -"""Support for the PostgreSQL database via the psycopg2 driver. - -Driver ------- - -The psycopg2 driver is available at http://pypi.python.org/pypi/psycopg2/ . -The dialect has several behaviors which are specifically tailored towards compatibility -with this module. - -Note that psycopg1 is **not** supported. - -Connecting ----------- - -URLs are of the form -``postgresql+psycopg2://user:password@host:port/dbname[?key=value&key=value...]``. - -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.base.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. - -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). - This includes the options ``SERIALIZABLE``, ``READ COMMITTED``, - ``READ UNCOMMITTED`` and ``REPEATABLE READ``. -* stream_results - Enable or disable usage of server side cursors. - If ``None`` or not set, the ``server_side_cursors`` option of the :class:`.Engine` is used. - -Unicode -------- - -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. Note that this setting requires that the PG client encoding be set to -one which can accomodate the kind of character data being passed - typically -``utf-8``. If the Postgresql database is configured for ``SQL_ASCII`` -encoding, which is often the default for PG installations, it may be necessary -for non-ascii strings to be encoded into a specific encoding before being -passed to the DBAPI. If changing the database's client encoding setting is not -an option, specify ``use_native_unicode=False`` as a keyword argument to -``create_engine()``, and take note of the ``encoding`` setting as well, which -also defaults to ``utf-8``. Note that disabling "native unicode" mode has a -slight performance penalty, as SQLAlchemy now must translate unicode strings -to/from an encoding such as utf-8, a task that is handled more efficiently -within the Psycopg2 driver natively. - -Transactions ------------- - -The psycopg2 dialect fully supports SAVEPOINT and two-phase commit operations. - -Transaction Isolation Level ---------------------------- - -The ``isolation_level`` parameter of :func:`.create_engine` here makes use -psycopg2's ``set_isolation_level()`` connection method, rather than -issuing a ``SET SESSION CHARACTERISTICS`` command. This because psycopg2 -resets the isolation level on each new transaction, and needs to know -at the API level what level should be used. - -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) - - -""" - -import random -import re -import logging - -from sqlalchemy import util, exc -from sqlalchemy.util.compat import decimal -from sqlalchemy import processors -from sqlalchemy.engine import base -from sqlalchemy.sql import expression -from sqlalchemy import types as sqltypes -from sqlalchemy.dialects.postgresql.base import PGDialect, PGCompiler, \ - PGIdentifierPreparer, PGExecutionContext, \ - ENUM, ARRAY, _DECIMAL_TYPES, _FLOAT_TYPES,\ - _INT_TYPES - - -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) - 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 __init__(self, *arg, **kw): - super(_PGEnum, self).__init__(*arg, **kw) - # Py2K - if self.convert_unicode: - self.convert_unicode = "force" - # end Py2K - -class _PGArray(ARRAY): - def __init__(self, *arg, **kw): - super(_PGArray, self).__init__(*arg, **kw) - # Py2K - # FIXME: this check won't work for setups that - # have convert_unicode only on their create_engine(). - if isinstance(self.item_type, sqltypes.String) and \ - self.item_type.convert_unicode: - self.item_type.convert_unicode = "force" - # end Py2K - -# 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) - -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(random.randint(0, 65535))[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 base.BufferedRowResultProxy(self) - else: - return base.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(self, binary, **kw): - return self.process(binary.left) + " %% " + self.process(binary.right) - - 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' - # Py2K - supports_unicode_statements = False - # end Py2K - default_paramstyle = 'pyformat' - supports_sane_multi_rowcount = False - execution_ctx_cls = PGExecutionContext_psycopg2 - statement_compiler = PGCompiler_psycopg2 - preparer = PGIdentifierPreparer_psycopg2 - psycopg2_version = (0, 0) - - colspecs = util.update_copy( - PGDialect.colspecs, - { - sqltypes.Numeric : _PGNumeric, - ENUM : _PGEnum, # needs force_unicode - sqltypes.Enum : _PGEnum, # needs force_unicode - ARRAY : _PGArray, # needs force_unicode - } - ) - - def __init__(self, server_side_cursors=False, use_native_unicode=True, **kwargs): - PGDialect.__init__(self, **kwargs) - self.server_side_cursors = server_side_cursors - self.use_native_unicode = use_native_unicode - self.supports_unicode_binds = use_native_unicode - 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) - - @classmethod - def dbapi(cls): - psycopg = __import__('psycopg2') - return psycopg - - @util.memoized_property - def _isolation_lookup(self): - extensions = __import__('psycopg2.extensions').extensions - return { - '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): - if self.isolation_level is not None: - def base_on_connect(conn): - self.set_isolation_level(conn, self.isolation_level) - else: - base_on_connect = None - - if self.dbapi and self.use_native_unicode: - extensions = __import__('psycopg2.extensions').extensions - def connect(conn): - extensions.register_type(extensions.UNICODE, conn) - if base_on_connect: - base_on_connect(conn) - return connect - else: - return base_on_connect - - 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.OperationalError): - # these error messages from libpq: interfaces/libpq/fe-misc.c. - # TODO: these are sent through gettext in libpq and we can't - # check within other locales - consider using connection.closed - return 'closed the connection' in str(e) or \ - 'connection not open' in str(e) or \ - 'could not receive data from server' in str(e) - elif isinstance(e, self.dbapi.InterfaceError): - # psycopg2 client errors, psycopg2/conenction.h, psycopg2/cursor.h - return 'connection already closed' in str(e) or \ - 'cursor already closed' in str(e) - elif isinstance(e, self.dbapi.ProgrammingError): - # not sure where this path is originally from, it may - # be obsolete. It really says "losed", not "closed". - return "losed the connection unexpectedly" in str(e) - else: - return False - -dialect = PGDialect_psycopg2 - |