Update of /usr/cvs/Public/pygresql/module
In directory druid.net:/tmp/cvs-serv20177
Modified Files:
pgdb.py
Log Message:
Simplified type casting further. The DBAPI types cannot be cached anyway, so we
check only the Postgres types, keeping them as keys in a dictionary.
To see the diffs for this commit:
http://www.druid.net/pygresql/viewcvs.cgi/cvs/pygresql/module/pgdb.py.diff?r1=1.39&r2=1.40
Index: pgdb.py
===================================================================
RCS file: /usr/cvs/Public/pygresql/module/pgdb.py,v
retrieving revision 1.39
retrieving revision 1.40
diff -u -r1.39 -r1.40
--- pgdb.py 31 Oct 2008 17:13:50 -0000 1.39
+++ pgdb.py 1 Nov 2008 10:37:54 -0000 1.40
@@ -4,7 +4,7 @@
#
# Written by D'Arcy J.M. Cain
#
-# $Id: pgdb.py,v 1.39 2008/10/31 17:13:50 cito Exp $
+# $Id: pgdb.py,v 1.40 2008/11/01 10:37:54 cito Exp $
#
"""pgdb - DB-API 2.0 compliant module for PygreSQL.
@@ -78,7 +78,8 @@
except ImportError: # otherwise (Python < 2.4)
Decimal = float # use float instead of Decimal
-### module constants
+
+### Module Constants
# compliant with DB SIG 2.0
apilevel = '2.0'
@@ -89,75 +90,48 @@
# this module use extended python format codes
paramstyle = 'pyformat'
-### internal type handling class
+
+### Internal Types Handling
+
+def _cast_bool(value):
+ return value[:1] in ['t', 'T']
+
+
+def _cast_money(value):
+ return Decimal(''.join(filter(
+ lambda v: v in '0123456789.-', value)))
+
+
+_cast = {'bool': _cast_bool,
+ 'int2': int, 'int4': int, 'serial': int,
+ 'int8': long, 'oid': long, 'oid8': long,
+ 'float4': float, 'float8': float,
+ 'numeric': Decimal, 'money': _cast_money}
+
class pgdbTypeCache:
"""Cache for database types."""
def __init__(self, cnx):
+ """Initialize type cache for connection."""
self._src = cnx.source()
self._cache = {}
- self._casters = {}
def typecast(self, typ, value):
- return self._typecaster(typ)(value)
-
- def _typecaster(self, typ):
- # Type comparisons are very expensive because of the
- # shear amount of string comparisons it will generate.
- # Cache type casters for much better performance
- # when fetching many values.
- try:
- return self._casters[typ]
- except KeyError:
- caster = self._create_typecaster(typ)
- self._casters[typ] = caster
- return caster
-
- def _create_typecaster(self, typ):
-
- def no_cast(value):
+ """Cast value to database type."""
+ if value is None:
+ # for NULL values, no typecast is necessary
+ return None
+ cast = _cast.get(typ)
+ if cast is None:
+ # no typecast available or necessary
return value
-
- def cast_bool(value):
- return value[:1] in ['t','T']
-
- def cast_money(value):
- return Decimal(''.join(filter(
- lambda v: v in '0123456789.-', value)))
-
- def cast(caster):
- def cast_if_not_none(value):
- if value is None:
- # NULL/None are equivalent regardless
of type
- return None
- else:
- return caster(value)
- return cast_if_not_none
-
- if typ == BOOL:
- return cast(cast_bool)
- elif typ == STRING or typ == BINARY:
- return no_cast
- elif typ == INTEGER:
- return cast(int)
- elif typ == LONG:
- return cast(long)
- elif typ == FLOAT:
- return cast(float)
- elif typ == NUMERIC:
- return cast(Decimal)
- elif typ == MONEY:
- return cast(cast_money)
- elif typ == DATETIME:
- # format may differ ... we'll give string
- return no_cast
- elif typ == ROWID:
- return cast(long)
else:
- return no_cast
+ return cast(value)
+ typecast = staticmethod(typecast)
def getdescr(self, oid):
+ """Get name of database type with given oid."""
try:
return self._cache[oid]
except:
@@ -167,13 +141,49 @@
res = self._src.fetch(1)[0]
# The column name is omitted from the return value.
# It will have to be prepended by the caller.
- res = (res[0],
- None, int(res[1]),
+ res = (res[0], None, int(res[1]),
None, None, None)
self._cache[oid] = res
return res
+class _quoteitem(dict):
+ def __getitem__(self, key):
+ return _quote(super(_quoteitem, self).__getitem__(key))
+
+
+def _quote(x):
+ if isinstance(x, DateTimeType):
+ x = str(x)
+ elif isinstance(x, unicode):
+ x = x.encode( 'utf-8' )
+ if isinstance(x, types.StringType):
+ x = "'%s'" % str(x).replace("\\", "\\\\").replace("'", "''")
+ elif isinstance(x, (types.IntType, types.LongType, types.FloatType)):
+ pass
+ elif x is None:
+ x = 'NULL'
+ elif isinstance(x, (types.ListType, types.TupleType)):
+ x = '(%s)' % ','.join(map(lambda x: str(_quote(x)), x))
+ elif Decimal is not float and isinstance(x, Decimal):
+ pass
+ elif hasattr(x, '__pg_repr__'):
+ x = x.__pg_repr__()
+ else:
+ raise InterfaceError('do not know how to handle type %s' %
type(x))
+ return x
+
+
+def _quoteparams(s, params):
+ if hasattr(params, 'has_key'):
+ params = _quoteitem(params)
+ else:
+ params = tuple(map(_quote, params))
+ return s % params
+
+
+### Cursor Object
+
class pgdbCursor:
"""Cursor Object."""
@@ -311,41 +321,7 @@
pass
-class _quoteitem(dict):
- def __getitem__(self, key):
- return _quote(super(_quoteitem, self).__getitem__(key))
-
-
-def _quote(x):
- if isinstance(x, DateTimeType):
- x = str(x)
- elif isinstance(x, unicode):
- x = x.encode( 'utf-8' )
- if isinstance(x, types.StringType):
- x = "'%s'" % str(x).replace("\\", "\\\\").replace("'", "''")
- elif isinstance(x, (types.IntType, types.LongType, types.FloatType)):
- pass
- elif x is None:
- x = 'NULL'
- elif isinstance(x, (types.ListType, types.TupleType)):
- x = '(%s)' % ','.join(map(lambda x: str(_quote(x)), x))
- elif Decimal is not float and isinstance(x, Decimal):
- pass
- elif hasattr(x, '__pg_repr__'):
- x = x.__pg_repr__()
- else:
- raise InterfaceError('do not know how to handle type %s' %
type(x))
- return x
-
-
-def _quoteparams(s, params):
- if hasattr(params, 'has_key'):
- params = _quoteitem(params)
- else:
- params = tuple(map(_quote, params))
-
- return s % params
-
+### Connection Objects
class pgdbCnx:
"""Connection Object."""
@@ -527,7 +503,7 @@
return str
-# if run as script, print some information
+# If run as script, print some information:
if __name__ == '__main__':
print 'PyGreSQL version', version
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