python/mysqlclient
1
0
Fork 0
mirror of https://github.com/PyMySQL/mysqlclient.git synced 2026-03-13 08:00:02 +08:00
Code Issues Packages Projects Releases Wiki Activity

Lock the connection object during queries, or during transactions

Browse Source 
if transactional.
This commit is contained in:
adustman
2002-01-31 17:39:14 +00:00
parent 3bc6fb42af
commit 696d8cb282
1 changed files with 58 additions and 31 deletions
Download Patch File Download Diff File Expand all files Collapse all files

89
ZMySQLDA/lib/python/Products/ZMySQLDA/db.py
View File

@@ -153,6 +153,12 @@ def int_or_long(s):
try: return int(s)
except: return long(s)
"""Locking strategy:
The minimum that must be done is a mutex around a query, store_result
sequence. When using transactions, the mutex must go around the
entire transaction."""
class DB(TM):
Database_Connection=_mysql.connect
@@ -177,6 +183,7 @@ class DB(TM):
_p_oid=_p_changed=_registered=None
def __init__(self,connection):
from thread import allocate_lock
self.connection=connection
self.kwargs = kwargs = self._parse_connection_string(connection)
self.db=apply(self.Database_Connection, (), kwargs)
@@ -185,7 +192,8 @@ class DB(TM):
self.transactions = 0
elif not self.transactions and self._try_transactions == '+':
raise NotSupportedError, "transactions not supported by this server"
self._lock = allocate_lock()
def _parse_connection_string(self, connection):
kwargs = {'conv': self.conv}
items = split(connection)
@@ -219,20 +227,28 @@ class DB(TM):
_care=('TABLE', 'VIEW')):
r=[]
a=r.append
self.db.query("SHOW TABLES")
result = self.db.store_result()
while 1:
row = result.fetch_row(1)
if not row: break
if not self.transactions: self._lock.acquire()
try:
self.db.query("SHOW TABLES")
result = self.db.store_result()
finally:
if not self.transactions: self._lock.release()
row = result.fetch_row(1)
while row:
a({'TABLE_NAME': row[0][0], 'TABLE_TYPE': 'TABLE'})
row = result.fetch_row(1)
return r
def columns(self, table_name):
from string import join
try:
# Field, Type, Null, Key, Default, Extra
self.db.query('SHOW COLUMNS FROM %s' % table_name)
c=self.db.store_result()
try:
if not self.transactions: self._lock.acquire()
# Field, Type, Null, Key, Default, Extra
self.db.query('SHOW COLUMNS FROM %s' % table_name)
c=self.db.store_result()
finally:
if not self.transactions: self._lock.release()
except:
return ()
r=[]
@@ -278,23 +294,27 @@ class DB(TM):
result=()
db=self.db
try:
for qs in filter(None, map(strip,split(query_string, '\0'))):
qtype = upper(split(qs, None, 1)[0])
if qtype == "SELECT" and max_rows:
qs = "%s LIMIT %d" % (qs,max_rows)
r=0
db.query(qs)
c=db.store_result()
if desc is not None:
if c and (c.describe() != desc):
raise 'Query Error', (
'Multiple select schema are not allowed'
)
if c:
desc=c.describe()
result=c.fetch_row(max_rows)
else:
desc=None
try:
if not self.transactions: self._lock.acquire()
for qs in filter(None, map(strip,split(query_string, '\0'))):
qtype = upper(split(qs, None, 1)[0])
if qtype == "SELECT" and max_rows:
qs = "%s LIMIT %d" % (qs,max_rows)
r=0
db.query(qs)
c=db.store_result()
if desc is not None:
if c and (c.describe() != desc):
raise 'Query Error', (
'Multiple select schema are not allowed'
)
if c:
desc=c.describe()
result=c.fetch_row(max_rows)
else:
desc=None
finally:
if not self.transactions: self._lock.release()
except OperationalError, m:
if m[0] not in hosed_connection: raise
@@ -319,13 +339,20 @@ class DB(TM):
def string_literal(self, s): return self.db.string_literal(s)
def _begin(self, *ignored):
self.lock.acquire()
self.db.query("BEGIN")
self.db.store_result()
self.db.store_result()
def _finish(self, *ignored):
self.db.query("COMMIT")
self.db.store_result()
try:
self.db.query("COMMIT")
self.db.store_result()
finally:
self.lock.release()
def _abort(self, *ignored):
self.db.query("ROLLBACK")
self.db.store_result()
try:
self.db.query("ROLLBACK")
self.db.store_result()
finally:
self.lock.release()