import threading
from util.threadinglocal import local
import sys
import re
import warnings
import atexit
import os
import new
import types
import urllib
import weakref
import inspect
import sqlbuilder
from cache import CacheSet
import col
import main
from joins import sorter
from converters import sqlrepr
import classregistry
warnings.filterwarnings("ignore", "DB-API extension cursor.lastrowid used")
_connections = {}
def _closeConnection(ref):
conn = ref()
if conn is not None:
conn.close()
class ConsoleWriter:
def __init__(self, connection, loglevel):
# loglevel: None or empty string for stdout; or 'stderr'
self.loglevel = loglevel or "stdout"
self.dbEncoding = getattr(connection, "dbEncoding", None) or "ascii"
def write(self, text):
logfile = getattr(sys, self.loglevel)
if isinstance(text, unicode):
try:
text = text.encode(self.dbEncoding)
except UnicodeEncodeError:
text = repr(text)[1:-1]
logfile.write(text + '\n')
class LogWriter:
def __init__(self, connection, logger, loglevel):
self.logger = logger
self.loglevel = loglevel
self.logmethod = getattr(logger, loglevel)
def write(self, text):
self.logmethod(text)
def makeDebugWriter(connection, loggerName, loglevel):
if not loggerName:
return ConsoleWriter(connection, loglevel)
import logging
logger = logging.getLogger(loggerName)
return LogWriter(connection, logger, loglevel)
class Boolean(object):
"""A bool class that also understands some special string keywords (yes/no, true/false, on/off, 1/0)"""
_keywords = {'1': True, 'yes': True, 'true': True, 'on': True,
'0': False, 'no': False, 'false': False, 'off': False}
def __new__(cls, value):
try:
return Boolean._keywords[value.lower()]
except (AttributeError, KeyError):
return bool(value)
class DBConnection:
def __init__(self, name=None, debug=False, debugOutput=False,
cache=True, style=None, autoCommit=True,
debugThreading=False, registry=None,
logger=None, loglevel=None):
self.name = name
self.debug = Boolean(debug)
self.debugOutput = Boolean(debugOutput)
self.debugThreading = Boolean(debugThreading)
self.debugWriter = makeDebugWriter(self, logger, loglevel)
self.doCache = Boolean(cache)
self.cache = CacheSet(cache=self.doCache)
self.style = style
self._connectionNumbers = {}
self._connectionCount = 1
self.autoCommit = Boolean(autoCommit)
self.registry = registry or None
classregistry.registry(self.registry).addCallback(
self.soClassAdded)
registerConnectionInstance(self)
atexit.register(_closeConnection, weakref.ref(self))
def uri(self):
auth = getattr(self, 'user', '')
if auth:
if self.password:
auth = auth + ':' + self.password
auth = auth + '@'
else:
assert not getattr(self, 'password', None), (
'URIs cannot express passwords without usernames')
uri = '%s://%s' % (self.dbName, auth)
if self.host:
uri += self.host
uri += '/'
db = self.db
if db.startswith('/'):
db = path[1:]
return uri + db
def connectionFromURI(cls, uri):
raise NotImplemented
connectionFromURI = classmethod(connectionFromURI)
def _parseURI(uri):
schema, rest = uri.split(':', 1)
assert rest.startswith('/'), "URIs must start with scheme:/ -- you did not include a / (in %r)" % rest
if rest.startswith('/') and not rest.startswith('//'):
host = None
rest = rest[1:]
elif rest.startswith('///'):
host = None
rest = rest[3:]
else:
rest = rest[2:]
if rest.find('/') == -1:
host = rest
rest = ''
else:
host, rest = rest.split('/', 1)
if host and host.find('@') != -1:
user, host = host.rsplit('@', 1)
if user.find(':') != -1:
user, password = user.split(':', 1)
else:
password = None
else:
user = password = None
if host and host.find(':') != -1:
_host, port = host.split(':')
try:
port = int(port)
except ValueError:
raise ValueError, "port must be integer, got '%s' instead" % port
if not (1 <= port <= 65535):
raise ValueError, "port must be integer in the range 1-65535, got '%d' instead" % port
host = _host
else:
port = None
path = '/' + rest
if os.name == 'nt':
if (len(rest) > 1) and (rest[1] == '|'):
path = "%s:%s" % (rest[0], rest[2:])
args = {}
if path.find('?') != -1:
path, arglist = path.split('?', 1)
arglist = arglist.split('&')
for single in arglist:
argname, argvalue = single.split('=', 1)
argvalue = urllib.unquote(argvalue)
args[argname] = argvalue
return user, password, host, port, path, args
_parseURI = staticmethod(_parseURI)
def soClassAdded(self, soClass):
"""
This is called for each new class; we use this opportunity
to create an instance method that is bound to the class
and this connection.
"""
name = soClass.__name__
assert not hasattr(self, name), (
"Connection %r already has an attribute with the name "
"%r (and you just created the conflicting class %r)"
% (self, name, soClass))
setattr(self, name, ConnWrapper(soClass, self))
def expireAll(self):
"""
Expire all instances of objects for this connection.
"""
cache_set = self.cache
cache_set.weakrefAll()
for item in cache_set.getAll():
item.expire()
class ConnWrapper(object):
"""
This represents a SQLObject class that is bound to a specific
connection (instances have a connection instance variable, but
classes are global, so this is binds the connection variable
lazily when a class method is accessed)
"""
# @@: methods that take connection arguments should be explicitly
# marked up instead of the implicit use of a connection argument
# and inspect.getargspec()
def __init__(self, soClass, connection):
self._soClass = soClass
self._connection = connection
def __call__(self, *args, **kw):
kw['connection'] = self._connection
return self._soClass(*args, **kw)
def __getattr__(self, attr):
meth = getattr(self._soClass, attr)
if not isinstance(meth, types.MethodType):
# We don't need to wrap non-methods
return meth
try:
takes_conn = meth.takes_connection
except AttributeError:
args, varargs, varkw, defaults = inspect.getargspec(meth)
assert not varkw and not varargs, (
"I cannot tell whether I must wrap this method, "
"because it takes **kw: %r"
% meth)
takes_conn = 'connection' in args
meth.im_func.takes_connection = takes_conn
if not takes_conn:
return meth
return ConnMethodWrapper(meth, self._connection)
class ConnMethodWrapper(object):
def __init__(self, method, connection):
self._method = method
self._connection = connection
def __getattr__(self, attr):
return getattr(self._method, attr)
def __call__(self, *args, **kw):
kw['connection'] = self._connection
return self._method(*args, **kw)
def __repr__(self):
return '<Wrapped %r with connection %r>' % (
self._method, self._connection)
class DBAPI(DBConnection):
"""
Subclass must define a `makeConnection()` method, which
returns a newly-created connection object.
``queryInsertID`` must also be defined.
"""
dbName = None
def __init__(self, **kw):
self._pool = []
self._poolLock = threading.Lock()
DBConnection.__init__(self, **kw)
self._binaryType = type(self.module.Binary(''))
def _runWithConnection(self, meth, *args):
conn = self.getConnection()
try:
val = meth(conn, *args)
finally:
self.releaseConnection(conn)
return val
def getConnection(self):
self._poolLock.acquire()
try:
if not self._pool:
conn = self.makeConnection()
self._connectionNumbers[id(conn)] = self._connectionCount
self._connectionCount += 1
else:
conn = self._pool.pop()
if self.debug:
s = 'ACQUIRE'
if self._pool is not None:
s += ' pool=[%s]' % ', '.join([str(self._connectionNumbers[id(v)]) for v in self._pool])
self.printDebug(conn, s, 'Pool')
return conn
finally:
self._poolLock.release()
def releaseConnection(self, conn, explicit=False):
if self.debug:
if explicit:
s = 'RELEASE (explicit)'
else:
s = 'RELEASE (implicit, autocommit=%s)' % self.autoCommit
if self._pool is None:
s += ' no pooling'
else:
s += ' pool=[%s]' % ', '.join([str(self._connectionNumbers[id(v)]) for v in self._pool])
self.printDebug(conn, s, 'Pool')
if self.supportTransactions and not explicit:
if self.autoCommit == 'exception':
if self.debug:
self.printDebug(conn, 'auto/exception', 'ROLLBACK')
conn.rollback()
raise Exception, 'Object used outside of a transaction; implicit COMMIT or ROLLBACK not allowed'
elif self.autoCommit:
if self.debug:
self.printDebug(conn, 'auto', 'COMMIT')
if not getattr(conn, 'autocommit', False):
conn.commit()
else:
if self.debug:
self.printDebug(conn, 'auto', 'ROLLBACK')
conn.rollback()
if self._pool is not None:
if conn not in self._pool:
# @@: We can get duplicate releasing of connections with
# the __del__ in Iteration (unfortunately, not sure why
# it happens)
self._pool.insert(0, conn)
else:
conn.close()
def printDebug(self, conn, s, name, type='query'):
if name == 'Pool' and self.debug != 'Pool':
return
if type == 'query':
sep = ': '
else:
sep = '->'
s = repr(s)
n = self._connectionNumbers[id(conn)]
spaces = ' '*(8-len(name))
if self.debugThreading:
threadName = threading.currentThread().getName()
threadName = (':' + threadName + ' '*(8-len(threadName)))
else:
threadName = ''
msg = '%(n)2i%(threadName)s/%(name)s%(spaces)s%(sep)s %(s)s' % locals()
self.debugWriter.write(msg)
def _executeRetry(self, conn, cursor, query):
if self.debug:
self.printDebug(conn, query, 'QueryR')
return cursor.execute(query)
def _query(self, conn, s):
if self.debug:
self.printDebug(conn, s, 'Query')
self._executeRetry(conn, conn.cursor(), s)
def query(self, s):
return self._runWithConnection(self._query, s)
def _queryAll(self, conn, s):
if self.debug:
self.printDebug(conn, s, 'QueryAll')
c = conn.cursor()
self._executeRetry(conn, c, s)
value = c.fetchall()
if self.debugOutput:
self.printDebug(conn, value, 'QueryAll', 'result')
return value
def queryAll(self, s):
return self._runWithConnection(self._queryAll, s)
def _queryAllDescription(self, conn, s):
"""
Like queryAll, but returns (description, rows), where the
description is cursor.description (which gives row types)
"""
if self.debug:
self.printDebug(conn, s, 'QueryAllDesc')
c = conn.cursor()
self._executeRetry(conn, c, s)
value = c.fetchall()
if self.debugOutput:
self.printDebug(conn, value, 'QueryAll', 'result')
return c.description, value
def queryAllDescription(self, s):
return self._runWithConnection(self._queryAllDescription, s)
def _queryOne(self, conn, s):
if self.debug:
self.printDebug(conn, s, 'QueryOne')
c = conn.cursor()
self._executeRetry(conn, c, s)
value = c.fetchone()
if self.debugOutput:
self.printDebug(conn, value, 'QueryOne', 'result')
return value
def queryOne(self, s):
return self._runWithConnection(self._queryOne, s)
def _insertSQL(self, table, names, values):
return ("INSERT INTO %s (%s) VALUES (%s)" %
(table, ', '.join(names),
', '.join([self.sqlrepr(v) for v in values])))
def transaction(self):
return Transaction(self)
def queryInsertID(self, soInstance, id, names, values):
return self._runWithConnection(self._queryInsertID, soInstance, id, names, values)
def iterSelect(self, select):
return select.IterationClass(self, self.getConnection(),
select, keepConnection=False)
def accumulateSelect(self, select, *expressions):
""" Apply an accumulate function(s) (SUM, COUNT, MIN, AVG, MAX, etc...)
to the select object.
"""
q = select.queryForSelect().newItems(expressions).unlimited().orderBy(None)
q = self.sqlrepr(q)
val = self.queryOne(q)
if len(expressions) == 1:
val = val[0]
return val
def queryForSelect(self, select):
return self.sqlrepr(select.queryForSelect())
def _SO_createJoinTable(self, join):
self.query(self._SO_createJoinTableSQL(join))
def _SO_createJoinTableSQL(self, join):
return ('CREATE TABLE %s (\n%s %s,\n%s %s\n)' %
(join.intermediateTable,
join.joinColumn,
self.joinSQLType(join),
join.otherColumn,
self.joinSQLType(join)))
def _SO_dropJoinTable(self, join):
self.query("DROP TABLE %s" % join.intermediateTable)
def _SO_createIndex(self, soClass, index):
self.query(self.createIndexSQL(soClass, index))
def createIndexSQL(self, soClass, index):
assert 0, 'Implement in subclasses'
def createTable(self, soClass):
createSql, constraints = self.createTableSQL(soClass)
self.query(createSql)
return constraints
def createReferenceConstraints(self, soClass):
refConstraints = [self.createReferenceConstraint(soClass, column) \
for column in soClass.sqlmeta.columnList \
if isinstance(column, col.SOForeignKey)]
refConstraintDefs = [constraint \
for constraint in refConstraints \
if constraint]
return refConstraintDefs
def createSQL(self, soClass):
tableCreateSQLs = getattr(soClass.sqlmeta, 'createSQL', None)
if tableCreateSQLs:
assert isinstance(tableCreateSQLs,(str,list,dict,tuple)), (
'%s.sqlmeta.createSQL must be a str, list, dict or tuple.' %
(soClass.__name__))
if isinstance(tableCreateSQLs, dict):
tableCreateSQLs = tableCreateSQLs.get(soClass._connection.dbName, [])
if isinstance(tableCreateSQLs, str):
tableCreateSQLs = [tableCreateSQLs]
if isinstance(tableCreateSQLs, tuple):
tableCreateSQLs = list(tableCreateSQLs)
assert isinstance(tableCreateSQLs,list), (
'Unable to create a list from %s.sqlmeta.createSQL' %
(soClass.__name__))
return tableCreateSQLs or []
def createTableSQL(self, soClass):
constraints = self.createReferenceConstraints(soClass)
extraSQL = self.createSQL(soClass)
createSql = ('CREATE TABLE %s (\n%s\n)' %
(soClass.sqlmeta.table, self.createColumns(soClass)))
return createSql, constraints + extraSQL
def createColumns(self, soClass):
columnDefs = [self.createIDColumn(soClass)] \
+ [self.createColumn(soClass, col)
for col in soClass.sqlmeta.columnList]
return ",\n".join([" %s" % c for c in columnDefs])
def createReferenceConstraint(self, soClass, col):
assert 0, "Implement in subclasses"
def createColumn(self, soClass, col):
assert 0, "Implement in subclasses"
def dropTable(self, tableName, cascade=False):
self.query("DROP TABLE %s" % tableName)
def clearTable(self, tableName):
# 3-03 @@: Should this have a WHERE 1 = 1 or similar
# clause? In some configurations without the WHERE clause
# the query won't go through, but maybe we shouldn't override
# that.
self.query("DELETE FROM %s" % tableName)
def createBinary(self, value):
"""
Create a binary object wrapper for the given database.
"""
# Default is Binary() function from the connection driver.
return self.module.Binary(value)
# The _SO_* series of methods are sorts of "friend" methods
# with SQLObject. They grab values from the SQLObject instances
# or classes freely, but keep the SQLObject class from accessing
# the database directly. This way no SQL is actually created
# in the SQLObject class.
def _SO_update(self, so, values):
self.query("UPDATE %s SET %s WHERE %s = (%s)" %
(so.sqlmeta.table,
", ".join(["%s = (%s)" % (dbName, self.sqlrepr(value))
for dbName, value in values]),
so.sqlmeta.idName,
self.sqlrepr(so.id)))
def _SO_selectOne(self, so, columnNames):
return self._SO_selectOneAlt(so, columnNames, so.q.id==so.id)
def _SO_selectOneAlt(self, so, columnNames, condition):
if columnNames:
columns = [isinstance(x, basestring) and sqlbuilder.SQLConstant(x) or x for x in columnNames]
else:
columns = None
return self.queryOne(self.sqlrepr(sqlbuilder.Select(columns,
staticTables=[so.sqlmeta.table],
clause=condition)))
def _SO_delete(self, so):
self.query("DELETE FROM %s WHERE %s = (%s)" %
(so.sqlmeta.table,
so.sqlmeta.idName,
self.sqlrepr(so.id)))
def _SO_selectJoin(self, soClass, column, value):
return self.queryAll("SELECT %s FROM %s WHERE %s = (%s)" %
(soClass.sqlmeta.idName,
soClass.sqlmeta.table,
column,
self.sqlrepr(value)))
def _SO_intermediateJoin(self, table, getColumn, joinColumn, value):
return self.queryAll("SELECT %s FROM %s WHERE %s = (%s)" %
(getColumn,
table,
joinColumn,
self.sqlrepr(value)))
def _SO_intermediateDelete(self, table, firstColumn, firstValue,
secondColumn, secondValue):
self.query("DELETE FROM %s WHERE %s = (%s) AND %s = (%s)" %
(table,
firstColumn,
self.sqlrepr(firstValue),
secondColumn,
self.sqlrepr(secondValue)))
def _SO_intermediateInsert(self, table, firstColumn, firstValue,
secondColumn, secondValue):
self.query("INSERT INTO %s (%s, %s) VALUES (%s, %s)" %
(table,
firstColumn,
secondColumn,
self.sqlrepr(firstValue),
self.sqlrepr(secondValue)))
def _SO_columnClause(self, soClass, kw):
ops = {None: "IS"}
data = {}
if 'id' in kw:
data[soClass.sqlmeta.idName] = kw.pop('id')
for key, col in soClass.sqlmeta.columns.items():
if key in kw:
value = kw.pop(key)
if col.from_python:
value = col.from_python(value, sqlbuilder.SQLObjectState(soClass))
data[col.dbName] = value
elif col.foreignName in kw:
obj = kw.pop(col.foreignName)
if isinstance(obj, main.SQLObject):
data[col.dbName] = obj.id
else:
data[col.dbName] = obj
if kw:
# pick the first key from kw to use to raise the error,
raise TypeError, "got an unexpected keyword argument(s): %r" % kw.keys()
if not data:
return None
return ' AND '.join(
['%s %s %s' %
(dbName, ops.get(value, "="), self.sqlrepr(value))
for dbName, value
in data.items()])
def sqlrepr(self, v):
return sqlrepr(v, self.dbName)
def __del__(self):
self.close()
def close(self):
if not hasattr(self, '_pool'):
# Probably there was an exception while creating this
# instance, so it is incomplete.
return
if not self._pool:
return
self._poolLock.acquire()
try:
conns = self._pool[:]
self._pool[:] = []
for conn in conns:
try:
conn.close()
except self.module.Error:
pass
del conn
del conns
finally:
self._poolLock.release()
def createEmptyDatabase(self):
"""
Create an empty database.
"""
raise NotImplementedError
class Iteration(object):
def __init__(self, dbconn, rawconn, select, keepConnection=False):
self.dbconn = dbconn
self.rawconn = rawconn
self.select = select
self.keepConnection = keepConnection
self.cursor = rawconn.cursor()
self.query = self.dbconn.queryForSelect(select)
if dbconn.debug:
dbconn.printDebug(rawconn, self.query, 'Select')
self.dbconn._executeRetry(self.rawconn, self.cursor, self.query)
def __iter__(self):
return self
def next(self):
result = self.cursor.fetchone()
if result is None:
self._cleanup()
raise StopIteration
if result[0] is None:
return None
if self.select.ops.get('lazyColumns', 0):
obj = self.select.sourceClass.get(result[0], connection=self.dbconn)
return obj
else:
obj = self.select.sourceClass.get(result[0], selectResults=result[1:], connection=self.dbconn)
return obj
def _cleanup(self):
if getattr(self, 'query', None) is None:
# already cleaned up
return
self.query = None
if not self.keepConnection:
self.dbconn.releaseConnection(self.rawconn)
self.dbconn = self.rawconn = self.select = self.cursor = None
def __del__(self):
self._cleanup()
class Transaction(object):
def __init__(self, dbConnection):
# this is to skip __del__ in case of an exception in this __init__
self._obsolete = True
self._dbConnection = dbConnection
self._connection = dbConnection.getConnection()
self._dbConnection._setAutoCommit(self._connection, 0)
self.cache = CacheSet(cache=dbConnection.doCache)
self._deletedCache = {}
self._obsolete = False
def assertActive(self):
assert not self._obsolete, "This transaction has already gone through ROLLBACK; begin another transaction"
def query(self, s):
self.assertActive()
return self._dbConnection._query(self._connection, s)
def queryAll(self, s):
self.assertActive()
return self._dbConnection._queryAll(self._connection, s)
def queryOne(self, s):
self.assertActive()
return self._dbConnection._queryOne(self._connection, s)
def queryInsertID(self, soInstance, id, names, values):
self.assertActive()
return self._dbConnection._queryInsertID(
self._connection, soInstance, id, names, values)
def iterSelect(self, select):
self.assertActive()
# We can't keep the cursor open with results in a transaction,
# because we might want to use the connection while we're
# still iterating through the results.
# @@: But would it be okay for psycopg, with threadsafety
# level 2?
return iter(list(select.IterationClass(self, self._connection,
select, keepConnection=True)))
def _SO_delete(self, inst):
cls = inst.__class__.__name__
if not self._deletedCache.has_key(cls):
self._deletedCache[cls] = []
self._deletedCache[cls].append(inst.id)
meth = new.instancemethod(self._dbConnection._SO_delete.im_func, self, self.__class__)
return meth(inst)
def commit(self, close=False):
if self._obsolete:
# @@: is it okay to get extraneous commits?
return
if self._dbConnection.debug:
self._dbConnection.printDebug(self._connection, '', 'COMMIT')
self._connection.commit()
subCaches = [(sub[0], sub[1].allIDs()) for sub in self.cache.allSubCachesByClassNames().items()]
subCaches.extend([(x[0], x[1]) for x in self._deletedCache.items()])
for cls, ids in subCaches:
for id in ids:
inst = self._dbConnection.cache.tryGetByName(id, cls)
if inst is not None:
inst.expire()
if close:
self._makeObsolete()
def rollback(self):
if self._obsolete:
# @@: is it okay to get extraneous rollbacks?
return
if self._dbConnection.debug:
self._dbConnection.printDebug(self._connection, '', 'ROLLBACK')
subCaches = [(sub, sub.allIDs()) for sub in self.cache.allSubCaches()]
self._connection.rollback()
for subCache, ids in subCaches:
for id in ids:
inst = subCache.tryGet(id)
if inst is not None:
inst.expire()
self._makeObsolete()
def __getattr__(self, attr):
"""
If nothing else works, let the parent connection handle it.
Except with this transaction as 'self'. Poor man's
acquisition? Bad programming? Okay, maybe.
"""
self.assertActive()
attr = getattr(self._dbConnection, attr)
try:
func = attr.im_func
except AttributeError:
if isinstance(attr, ConnWrapper):
return ConnWrapper(attr._soClass, self)
else:
return attr
else:
meth = new.instancemethod(func, self, self.__class__)
return meth
def _makeObsolete(self):
self._obsolete = True
if self._dbConnection.autoCommit:
self._dbConnection._setAutoCommit(self._connection, 1)
self._dbConnection.releaseConnection(self._connection,
explicit=True)
self._connection = None
self._deletedCache = {}
def begin(self):
# @@: Should we do this, or should begin() be a no-op when we're
# not already obsolete?
assert self._obsolete, "You cannot begin a new transaction session without rolling back this one"
self._obsolete = False
self._connection = self._dbConnection.getConnection()
self._dbConnection._setAutoCommit(self._connection, 0)
def __del__(self):
if self._obsolete:
return
self.rollback()
def close(self):
raise TypeError('You cannot just close transaction - you should either call rollback(), commit() or commit(close=True) to close the underlying connection.')
class ConnectionHub(object):
"""
This object serves as a hub for connections, so that you can pass
in a ConnectionHub to a SQLObject subclass as though it was a
connection, but actually bind a real database connection later.
You can also bind connections on a per-thread basis.
You must hang onto the original ConnectionHub instance, as you
cannot retrieve it again from the class or instance.
To use the hub, do something like::
hub = ConnectionHub()
class MyClass(SQLObject):
_connection = hub
hub.threadConnection = connectionFromURI('...')
"""
def __init__(self):
self.threadingLocal = threading_local()
def __get__(self, obj, type=None):
# I'm a little surprised we have to do this, but apparently
# the object's private dictionary of attributes doesn't
# override this descriptor.
if (obj is not None) and obj.__dict__.has_key('_connection'):
return obj.__dict__['_connection']
return self.getConnection()
def __set__(self, obj, value):
obj.__dict__['_connection'] = value
def getConnection(self):
try:
return self.threadingLocal.connection
except AttributeError:
try:
return self.processConnection
except AttributeError:
raise AttributeError(
"No connection has been defined for this thread "
"or process")
def doInTransaction(self, func, *args, **kw):
"""
This routine can be used to run a function in a transaction,
rolling the transaction back if any exception is raised from
that function, and committing otherwise.
Use like::
sqlhub.doInTransaction(process_request, os.environ)
This will run ``process_request(os.environ)``. The return
value will be preserved.
"""
# @@: In Python 2.5, something usable with with: should also
# be added.
try:
old_conn = self.threadingLocal.connection
old_conn_is_threading = True
except AttributeError:
old_conn = self.processConnection
old_conn_is_threading = False
conn = old_conn.transaction()
if old_conn_is_threading:
self.threadConnection = conn
else:
self.processConnection = conn
try:
try:
value = func(*args, **kw)
except:
conn.rollback()
raise
else:
conn.commit(close=True)
return value
finally:
if old_conn_is_threading:
self.threadConnection = old_conn
else:
self.processConnection = old_conn
def _set_threadConnection(self, value):
self.threadingLocal.connection = value
def _get_threadConnection(self):
return self.threadingLocal.connection
def _del_threadConnection(self):
del self.threadingLocal.connection
threadConnection = property(_get_threadConnection,
_set_threadConnection,
_del_threadConnection)
class ConnectionURIOpener(object):
def __init__(self):
self.schemeBuilders = {}
self.instanceNames = {}
self.cachedURIs = {}
def registerConnection(self, schemes, builder):
for uriScheme in schemes:
assert not self.schemeBuilders.has_key(uriScheme) \
or self.schemeBuilders[uriScheme] is builder, \
"A driver has already been registered for the URI scheme %s" % uriScheme
self.schemeBuilders[uriScheme] = builder
def registerConnectionInstance(self, inst):
if inst.name:
assert not self.instanceNames.has_key(inst.name) \
or self.instanceNames[inst.name] is cls, \
"A instance has already been registered with the name %s" % inst.name
assert inst.name.find(':') == -1, "You cannot include ':' in your class names (%r)" % cls.name
self.instanceNames[inst.name] = inst
def connectionForURI(self, uri, **args):
if args:
if '?' not in uri:
uri += '?' + urllib.urlencode(args)
else:
uri += '&' + urllib.urlencode(args)
if self.cachedURIs.has_key(uri):
return self.cachedURIs[uri]
if uri.find(':') != -1:
scheme, rest = uri.split(':', 1)
connCls = self.dbConnectionForScheme(scheme)
conn = connCls.connectionFromURI(uri)
else:
# We just have a name, not a URI
assert self.instanceNames.has_key(uri), \
"No SQLObject driver exists under the name %s" % uri
conn = self.instanceNames[uri]
# @@: Do we care if we clobber another connection?
self.cachedURIs[uri] = conn
return conn
def dbConnectionForScheme(self, scheme):
assert self.schemeBuilders.has_key(scheme), (
"No SQLObject driver exists for %s (only %s)"
% (scheme, ', '.join(self.schemeBuilders.keys())))
return self.schemeBuilders[scheme]()
TheURIOpener = ConnectionURIOpener()
registerConnection = TheURIOpener.registerConnection
registerConnectionInstance = TheURIOpener.registerConnectionInstance
connectionForURI = TheURIOpener.connectionForURI
dbConnectionForScheme = TheURIOpener.dbConnectionForScheme
# Register DB URI schemas
import firebird
import maxdb
import mssql
import mysql
import postgres
import sqlite
import sybase
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