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##############################################################################
#
# Zope Public License (ZPL) Version 1.0
# -------------------------------------
#
# Copyright (c) Digital Creations. All rights reserved.
#
# This license has been certified as Open Source(tm).
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# 1. Redistributions in source code must retain the above copyright
# notice, this list of conditions, and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions, and the following disclaimer in
# the documentation and/or other materials provided with the
# distribution.
#
# 3. Digital Creations requests that attribution be given to Zope
# in any manner possible. Zope includes a "Powered by Zope"
# button that is installed by default. While it is not a license
# violation to remove this button, it is requested that the
# attribution remain. A significant investment has been put
# into Zope, and this effort will continue if the Zope community
# continues to grow. This is one way to assure that growth.
#
# 4. All advertising materials and documentation mentioning
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#
# In the event that the product being advertised includes an
# intact Zope distribution (with copyright and license included)
# then this clause is waived.
#
# 5. Names associated with Zope or Digital Creations must not be used to
# endorse or promote products derived from this software without
# prior written permission from Digital Creations.
#
# 6. Modified redistributions of any form whatsoever must retain
# the following acknowledgment:
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# for use in the Z Object Publishing Environment
# (http://www.zope.org/)."
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# 7. Modifications are encouraged but must be packaged separately as
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##############################################################################
'''$Id: db.py 565 2009-01-07 01:45:51Z eikenberry $'''
__version__='$Revision: 565 $'[11:-2]
import time
import _mysql
import MySQLdb
from _mysql_exceptions import (OperationalError, NotSupportedError,
ProgrammingError)
MySQLdb_version_required = (1,2,1)
try:
MySQLdb_version = MySQLdb.version_info[:3]
except AttributeError:
MySQLdb_version = getattr(_mysql, 'version_info', (0,0,0))
if MySQLdb_version < MySQLdb_version_required:
raise NotSupportedError, \
"ZMySQLDA requires at least MySQLdb %s, %s found" % \
(MySQLdb_version_required, _v)
from MySQLdb.converters import conversions
from MySQLdb.constants import FIELD_TYPE, CR, ER, CLIENT, FLAG
from ZODB.POSException import ConflictError
from DateTime import DateTime
from thread import get_ident, allocate_lock
import logging
LOG = logging.getLogger('ZMySQLDA')
from joinTM import joinTM
hosed_connection = {
CR.SERVER_GONE_ERROR: "Server gone.",
CR.SERVER_LOST: "Server lost.",
CR.COMMANDS_OUT_OF_SYNC: ("Commands out of sync. Possibly a misplaced"
" semicolon (;) in a query."),
}
query_syntax_error = (
ER.BAD_FIELD_ERROR,
)
key_types = {
"PRI": "PRIMARY KEY",
"MUL": "INDEX",
"UNI": "UNIQUE",
}
field_icons = "bin", "date", "datetime", "float", "int", "text", "time"
icon_xlate = {
"varchar": "text", "char": "text",
"enum": "what", "set": "what",
"double": "float", "numeric": "float",
"blob": "bin", "mediumblob": "bin", "longblob": "bin",
"tinytext": "text", "mediumtext": "text",
"longtext": "text", "timestamp": "datetime",
"decimal": "float", "smallint": "int",
"mediumint": "int", "bigint": "int",
}
type_xlate = {
"double": "float", "numeric": "float",
"decimal": "float", "smallint": "int",
"mediumint": "int", "bigint": "int",
"int": "int", "float": "float",
"timestamp": "datetime", "datetime": "datetime",
"time": "datetime",
}
def _mysql_timestamp_converter(s):
if len(s) < 14:
s = s + "0"*(14-len(s))
parts = map(int, (s[:4],s[4:6],s[6:8],
s[8:10],s[10:12],s[12:14]))
return DateTime("%04d-%02d-%02d %02d:%02d:%02d" % tuple(parts))
def DateTime_or_None(s):
try: return DateTime(s)
except: return None
def int_or_long(s):
try: return int(s)
except: return long(s)
class DBPool(object):
"""
This class is an interface to DB.
Its caracteristic is that an instance of this class interfaces multiple
instanes of DB class, each one being bound to a specific thread.
"""
connected_timestamp = ''
_create_db = False
use_unicode = False
def __init__(self, db_cls, create_db=False, use_unicode=False):
""" Set transaction managed DB class for use in pool.
"""
self.DB = db_cls
# pool of one db object/thread
self._db_pool = {}
self._db_lock = allocate_lock()
# auto-create db if not present on server
self._create_db = create_db
# unicode settings
self.use_unicode = use_unicode
def __call__(self, connection):
""" Parse the connection string.
Initiate a trial connection with the database to check
transactionality once instead of once per DB instance.
Create database if option is enabled and database doesn't exist.
"""
self.connection = connection
DB = self.DB
#
db_flags = DB._parse_connection_string(connection, self.use_unicode)
self._db_flags = db_flags
# connect to server to determin tranasactional capabilities
# can't use DB instance as it requires this information to work
try:
connection = MySQLdb.connect(**db_flags['kw_args'])
except OperationalError:
if self._create_db:
kw_args = db_flags.get('kw_args',{}).copy()
db = kw_args.pop('db',None)
if not db: raise
connection = MySQLdb.connect(**kw_args)
create_query = "create database %s" % db
if self.use_unicode:
create_query += (" default character set %s"
% DB.unicode_charset)
connection.query(create_query)
connection.store_result()
else:
raise
transactional = connection.server_capabilities & CLIENT.TRANSACTIONS
connection.close()
# Some tweaks to transaction/locking db_flags based on server setup
if db_flags['try_transactions'] == '-':
transactional = False
elif not transactional and db_flags['try_transactions'] == '+':
raise NotSupportedError, "transactions not supported by this server"
db_flags['transactions'] = transactional
del db_flags['try_transactions']
if transactional or db_flags['mysql_lock']:
db_flags['use_TM'] = True
# will not be 100% accurate in regard to per thread connections
# but as close as we're going to get it.
self.connected_timestamp = DateTime()
# return self as the database connection object
# (assigned to _v_database_connection)
return self
def closeConnection(self):
""" Close this threads connection. Used when DA is being reused
but the connection string has changed. Need to close the DB
instances and recreate to the new database. Only have to worry
about this thread as when each thread hits the new connection
string in the DA this method will be called.
"""
ident = get_ident()
try:
self._pool_del(ident)
except KeyError:
pass
def close(self):
""" Used when manually closing the database. Resetting the pool
dereferences the DB instances where they are then collected
and closed.
"""
self._db_pool = {}
def _pool_set(self, key, value):
""" Add a db to pool.
"""
self._db_lock.acquire()
try:
self._db_pool[key] = value
finally:
self._db_lock.release()
def _pool_get(self, key):
""" Get db from pool. Read only, no lock necessary.
"""
return self._db_pool.get(key)
def _pool_del(self, key):
""" Remove db from pool.
"""
self._db_lock.acquire()
try:
del self._db_pool[key]
finally:
self._db_lock.release()
def name(self):
""" Return name of database connected to.
"""
return self._db_flags['kw_args']['db']
# Passthrough aliases for methods on DB class.
def variables(self, *args, **kw):
return self._access_db(method_id='variables', args=args, kw=kw)
def tables(self, *args, **kw):
return self._access_db(method_id='tables', args=args, kw=kw)
def columns(self, *args, **kw):
return self._access_db(method_id='columns', args=args, kw=kw)
def query(self, *args, **kw):
return self._access_db(method_id='query', args=args, kw=kw)
def string_literal(self, *args, **kw):
return self._access_db(method_id='string_literal', args=args, kw=kw)
def unicode_literal(self, *args, **kw):
return self._access_db(method_id='unicode_literal', args=args, kw=kw)
def _access_db(self, method_id, args, kw):
"""
Generic method to call pooled objects' methods.
When the current thread had never issued any call, create a DB
instance.
"""
ident = get_ident()
db = self._pool_get(ident)
if db is None:
db = self.DB(**self._db_flags)
self._pool_set(ident, db)
return getattr(db, method_id)(*args, **kw)
class DB(joinTM):
Database_Error=_mysql.Error
defs={
FIELD_TYPE.CHAR: "i", FIELD_TYPE.DATE: "d", FIELD_TYPE.DATETIME: "d",
FIELD_TYPE.DECIMAL: "n", FIELD_TYPE.NEWDECIMAL: "n",
FIELD_TYPE.DOUBLE: "n", FIELD_TYPE.FLOAT: "n", FIELD_TYPE.INT24: "i",
FIELD_TYPE.LONG: "i", FIELD_TYPE.LONGLONG: "l",
FIELD_TYPE.SHORT: "i", FIELD_TYPE.TIMESTAMP: "d",
FIELD_TYPE.TINY: "i", FIELD_TYPE.YEAR: "i",
}
conv=conversions.copy()
conv[FIELD_TYPE.LONG] = int_or_long
conv[FIELD_TYPE.DATETIME] = DateTime_or_None
conv[FIELD_TYPE.DATE] = DateTime_or_None
conv[FIELD_TYPE.DECIMAL] = float
conv[FIELD_TYPE.NEWDECIMAL] = float
del conv[FIELD_TYPE.TIME]
# compatibility/fix for older mysqldb versions
# without this you can get character arrays for some values
# eg. group_concat()
if MySQLdb_version < (1, 2, 2):
conv[FIELD_TYPE.BLOB][0] = (FLAG.BINARY, str)
_p_oid=_p_changed=_registered=None
unicode_charset = 'utf8' # hardcoded for now
def __init__(self, connection=None, kw_args=None, use_TM=None,
mysql_lock=None, transactions=None):
self.connection = connection # backwards compat
self._kw_args = kw_args
self._mysql_lock = mysql_lock
self._use_TM = use_TM
self._transactions = transactions
self._forceReconnection()
def close(self):
""" Close connection and dereference.
"""
if getattr(self,'db',None):
self.db.close()
self.db = None
__del__ = close
def _forceReconnection(self):
""" (Re)Connect to database.
"""
try: # try to clean up first
self.db.close()
except: pass
self.db = MySQLdb.connect(**self._kw_args)
# Newer mysqldb requires ping argument to attmept a reconnect.
# This setting is persistent, so only needed once per connection.
if MySQLdb_version >= (1, 2, 2):
self.db.ping(True)
@classmethod
def _parse_connection_string(cls, connection, use_unicode=False):
""" Done as a class method to both allow access to class attribute
conv (conversion) settings while allowing for wrapping pool class
use of this method. The former is important to allow for subclasses
to override the conv settings while the latter is important so
the connection string doesn't have to be parsed for each instance
in the pool.
"""
kw_args = {'conv':cls.conv}
flags = {'kw_args':kw_args, 'connection':connection}
if use_unicode:
kw_args['use_unicode'] = use_unicode
kw_args['charset'] = cls.unicode_charset
items = connection.split()
flags['use_TM'] = None
if _mysql.get_client_info()[0] >= '5':
kw_args['client_flag'] = CLIENT.MULTI_STATEMENTS
if items:
lockreq, items = items[0], items[1:]
if lockreq[0] == "*":
flags['mysql_lock'] = lockreq[1:]
db_host, items = items[0], items[1:]
flags['use_TM'] = True # redundant. eliminate?
else:
flags['mysql_lock'] = None
db_host = lockreq
if '@' in db_host:
db, host = db_host.split('@',1)
kw_args['db'] = db
if ':' in host:
host, port = host.split(':',1)
kw_args['port'] = int(port)
kw_args['host'] = host
else:
kw_args['db'] = db_host
if kw_args['db'] and kw_args['db'][0] in ('+', '-'):
flags['try_transactions'] = kw_args['db'][0]
kw_args['db'] = kw_args['db'][1:]
else:
flags['try_transactions'] = None
if not kw_args['db']:
del kw_args['db']
if items:
kw_args['user'], items = items[0], items[1:]
if items:
kw_args['passwd'], items = items[0], items[1:]
if items:
kw_args['unix_socket'], items = items[0], items[1:]
return flags
def tables(self, rdb=0,
_care=('TABLE', 'VIEW')):
""" Returns list of tables.
"""
r=[]
a=r.append
result = self._query("SHOW TABLES")
row = result.fetch_row(1)
while row:
table_name = row[0][0]
a({'table_name': table_name, 'table_type': 'table'})
row = result.fetch_row(1)
return r
def columns(self, table_name):
""" Returns list of columns for [table_name].
"""
try:
# Field, Type, Null, Key, Default, Extra
c = self._query('SHOW COLUMNS FROM %s' % table_name)
except:
return ()
r=[]
for Field, Type, Null, Key, Default, Extra in c.fetch_row(0):
info = {}
field_default = ''
if Default is not None:
info['default'] = Default
field_default = "DEFAULT '%s'" % Default
if '(' in Type:
end = Type.rfind(')')
short_type, size = Type[:end].split('(',1)
if short_type not in ('set','enum'):
if ',' in size:
info['scale'], info['precision'] = \
map(int, size.split(',',1))
else:
info['scale'] = int(size)
else:
short_type = Type
if short_type in field_icons:
info['icon'] = short_type
else:
info['icon'] = icon_xlate.get(short_type, "what")
info['name'] = Field
info['type'] = short_type
info['extra'] = Extra,
info['description'] = ' '.join([Type, field_default, Extra or '',
key_types.get(Key, Key or ''),
Null != 'NULL' and 'NOT NULL' or ''])
info['nullable'] = (Null == 'YES') and 1 or 0
if Key:
info['index'] = True
info['key'] = Key
if Key == 'PRI':
info['primary_key'] = True
info['unique'] = True
elif Key == 'UNI':
info['unique'] = True
r.append(info)
return r
def variables(self):
""" Return dictionary of current mysql variable/values.
"""
# variable_name, value
variables = self._query('SHOW VARIABLES')
return dict((name, value) for name, value in variables.fetch_row(0))
def _query(self, query, force_reconnect=False):
"""
Send a query to MySQL server.
It reconnects automaticaly if needed and the following conditions are
met:
- It has not just tried to reconnect (ie, this function will not
attempt to connect twice per call).
- This conection is not transactionnal and has set no MySQL locks,
because they are bound to the connection. This check can be
overridden by passing force_reconnect with True value.
"""
try:
self.db.query(query)
except OperationalError, m:
if m[0] in query_syntax_error:
raise OperationalError(m[0], '%s: %s' % (m[1], query))
if ((not force_reconnect) and \
(self._mysql_lock or self._transactions)) or \
m[0] not in hosed_connection:
LOG.warning('query failed: %s' % (query,))
raise
# Hm. maybe the db is hosed. Let's restart it.
if m[0] in hosed_connection:
LOG.error('%s Forcing a reconnect.' % hosed_connection[m[0]])
self._forceReconnection()
self.db.query(query)
except ProgrammingError, m:
if m[0] in hosed_connection:
self._forceReconnection()
LOG.error('%s Forcing a reconnect.' % hosed_connection[m[0]])
else:
LOG.warning('query failed: %s' % (query,))
raise
return self.db.store_result()
def query(self, query_string, max_rows=1000):
""" API method for making the query to mysql.
"""
self._use_TM and self._register()
desc=None
result=()
for qs in filter(None, [q.strip() for q in query_string.split('\0')]):
qtype = qs.split(None, 1)[0].upper()
if qtype == "SELECT" and max_rows:
qs = "%s LIMIT %d" % (qs,max_rows)
r=0
c = self._query(qs)
if desc is not None:
if c and (c.describe() != desc):
raise ProgrammingError(
'Multiple select schema are not allowed'
)
if c:
desc=c.describe()
result=c.fetch_row(max_rows)
else:
desc=None
if qtype == "CALL":
# For stored procedures, skip the status result
self.db.next_result()
if desc is None: return (),()
items=[]
func=items.append
defs=self.defs
for d in desc:
item={'name': d[0],
'type': defs.get(d[1],"t"),
'width': d[2],
'null': d[6]
}
func(item)
return items, result
def string_literal(self, s):
""" Called from zope to quote/escape strings for inclusion
in a query.
"""
return self.db.string_literal(s)
def unicode_literal(self, s):
""" Similar to string_literal but encodes it first.
"""
return self.db.unicode_literal(s)
# Zope 2-phase transaction handling methods
def _begin(self, *ignored):
""" Called from _register() upon first query.
"""
try:
self._transaction_begun = True
self.db.ping()
if self._transactions:
self._query("BEGIN")
if self._mysql_lock:
self._query("SELECT GET_LOCK('%s',0)" % self._mysql_lock)
except:
LOG.error("exception during _begin", exc_info=True)
raise ConflictError
def _finish(self, *ignored):
""" Called as final event in transaction system.
"""
if not self._transaction_begun:
return
self._transaction_begun = False
try:
if self._mysql_lock:
self._query("SELECT RELEASE_LOCK('%s')" % self._mysql_lock)
if self._transactions:
self._query("COMMIT")
except:
LOG.error("exception during _finish", exc_info=True)
raise ConflictError
def _abort(self, *ignored):
""" Called in case of transactional error.
"""
if not self._transaction_begun:
return
self._transaction_begun = False
if self._mysql_lock:
self._query("SELECT RELEASE_LOCK('%s')" % self._mysql_lock)
if self._transactions:
self._query("ROLLBACK")
else:
LOG.error("aborting when non-transactional")
def _mysql_version(self):
""" Return mysql server version.
Note instances of this class are not persistent.
"""
_version = getattr(self, '_version', None)
if not _version:
self._version = _version = self.variables().get('version')
return _version
def savepoint(self):
""" Basic savepoint support.
Raise AttributeErrors to trigger optimistic savepoint handling
in zope's transaction code.
"""
if self._mysql_version() < '5.0.2':
# mysql supports savepoints in versions 5.0.3+
LOG.warning("Savepoints unsupported with Mysql < 5.0.3")
raise AttributeError
if not self._transaction_begun:
LOG.error("Savepoint used outside of transaction.")
raise AttributeError
return _SavePoint(self)
class _SavePoint(object):
""" Simple savepoint object
"""
def __init__(self, dm):
self.dm = dm
self.ident = ident = str(time.time()).replace('.','sp')
dm._query("SAVEPOINT %s" % ident)
def rollback(self):
self.dm._query("ROLLBACK TO %s" % self.ident)

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