[CalendarServer-changes] [7254] CalendarServer/branches/users/glyph/subtransactions/twext/enterprise
source_changes at macosforge.org
source_changes at macosforge.org
Thu Mar 24 13:36:30 PDT 2011
Revision: 7254
http://trac.macosforge.org/projects/calendarserver/changeset/7254
Author: glyph at apple.com
Date: 2011-03-24 13:36:29 -0700 (Thu, 24 Mar 2011)
Log Message:
-----------
more edge cases; block commit, don't block abort, raise appropriate exceptions when invoked from the wrong place.
Modified Paths:
--------------
CalendarServer/branches/users/glyph/subtransactions/twext/enterprise/adbapi2.py
CalendarServer/branches/users/glyph/subtransactions/twext/enterprise/test/test_adbapi2.py
Modified: CalendarServer/branches/users/glyph/subtransactions/twext/enterprise/adbapi2.py
===================================================================
--- CalendarServer/branches/users/glyph/subtransactions/twext/enterprise/adbapi2.py 2011-03-24 20:36:18 UTC (rev 7253)
+++ CalendarServer/branches/users/glyph/subtransactions/twext/enterprise/adbapi2.py 2011-03-24 20:36:29 UTC (rev 7254)
@@ -356,16 +356,19 @@
This is the only L{IAsyncTransaction} implementation exposed to application
code.
+
+ It's also the only implementor of the C{commandBlock} method for grouping
+ commands together.
"""
def __init__(self, pool, baseTxn):
- self._pool = pool
- self._baseTxn = baseTxn
- self._complete = False
- self._currentBlock = None
- self._pendingBlocks = []
- self._stillExecuting = []
- self._blockedQueue = None
+ self._pool = pool
+ self._baseTxn = baseTxn
+ self._complete = False
+ self._currentBlock = None
+ self._blockedQueue = None
+ self._pendingBlocks = []
+ self._stillExecuting = []
def __repr__(self):
@@ -451,6 +454,11 @@
def commit(self):
+ if self._blockedQueue is not None:
+ # We're in the process of executing a block of commands. Wait until
+ # they're done. (Commit will be repeated in _checkNextBlock.)
+ return self._blockedQueue.commit()
+
self._markComplete()
return super(_SingleTxn, self).commit()
@@ -492,6 +500,7 @@
Create a L{CommandBlock} which will wait for all currently spooled
commands to complete before executing its own.
"""
+ self._checkComplete()
block = CommandBlock(self)
if self._currentBlock is None:
self._blockedQueue = _WaitingTxn(self._pool)
@@ -546,8 +555,20 @@
def execSQL(self, sql, args=None, raiseOnZeroRowCount=None, track=True):
"""
Execute some SQL within this command block.
+
+ @param sql: the SQL string to execute.
+
+ @param args: the SQL arguments.
+
+ @param raiseOnZeroRowCount: see L{IAsyncTransaction.execSQL}
+
+ @param track: an internal parameter; was this called by application code
+ or as part of unspooling some previously-queued requests? True if
+ application code, False if unspooling.
"""
- # FIXME: check 'ended'
+ if track and self._ended:
+ raise AlreadyFinishedError()
+ self._singleTxn._checkComplete()
if self._singleTxn._currentBlock is self and self._started:
d = self._singleTxn._execSQLForBlock(
sql, args, raiseOnZeroRowCount, self)
@@ -561,7 +582,8 @@
def _trackForEnd(self, d):
"""
Watch the following L{Deferred}, since we need to watch it to determine
- when C{end} should be considered done.
+ when C{end} should be considered done, and the next CommandBlock or
+ regular SQL statement should be unqueued.
"""
self._waitingForEnd.append(d)
@@ -576,6 +598,9 @@
if self._ended:
raise AlreadyFinishedError()
self._ended = True
+ # TODO: maybe this should return a Deferred that's a clone of
+ # _endDeferred, so that callers can determine when the block is really
+ # complete? Struggling for an actual use-case on that one.
DeferredList(self._waitingForEnd).chainDeferred(self._endDeferred)
@@ -734,6 +759,8 @@
@return: an L{IAsyncTransaction}
"""
if self._stopping:
+ # FIXME: should be wrapping a _SingleTxn around this to get
+ # .commandBlock()
return _NoTxn(self)
if self._free:
basetxn = self._free.pop(0)
Modified: CalendarServer/branches/users/glyph/subtransactions/twext/enterprise/test/test_adbapi2.py
===================================================================
--- CalendarServer/branches/users/glyph/subtransactions/twext/enterprise/test/test_adbapi2.py 2011-03-24 20:36:18 UTC (rev 7253)
+++ CalendarServer/branches/users/glyph/subtransactions/twext/enterprise/test/test_adbapi2.py 2011-03-24 20:36:29 UTC (rev 7254)
@@ -959,3 +959,81 @@
block.end()
self.assertRaises(AlreadyFinishedError, block.end)
+
+ def test_commandBlockDelaysCommit(self):
+ """
+ Some command blocks need to run asynchronously, without the overall
+ transaction-managing code knowing how far they've progressed. Therefore
+ when you call {IAsyncTransaction.commit}(), it should not actually take
+ effect if there are any pending command blocks.
+ """
+ txn = self.pool.connection()
+ block = txn.commandBlock()
+ commitResult = resultOf(txn.commit())
+ block.execSQL("in block")
+ self.assertEquals(commitResult, [])
+ self.assertEquals(self.factory.connections[0].cursors[0].allExecutions,
+ [("in block", [])])
+ block.end()
+ self.assertEquals(commitResult, [None])
+
+
+ def test_commandBlockDoesntDelayAbort(self):
+ """
+ A L{CommandBlock} can't possibly have anything interesting to say about
+ a transaction that gets rolled back, so C{abort} applies immediately;
+ all outstanding C{execSQL}s will fail immediately, on both command
+ blocks and on the transaction itself.
+ """
+ txn = self.pool.connection()
+ block = txn.commandBlock()
+ block2 = txn.commandBlock()
+ abortResult = resultOf(txn.abort())
+ self.assertEquals(abortResult, [None])
+ self.assertRaises(AlreadyFinishedError, block2.execSQL, "bar")
+ self.assertRaises(AlreadyFinishedError, block.execSQL, "foo")
+ self.assertRaises(AlreadyFinishedError, txn.execSQL, "baz")
+ self.assertEquals(self.factory.connections[0].cursors[0].allExecutions,
+ [])
+ # end() should _not_ raise an exception, because this is the sort of
+ # thing that might be around a try/finally or try/except; it's just
+ # putting the commandBlock itself into a state consistent with the
+ # transaction.
+ block.end()
+ block2.end()
+
+
+ def test_endedBlockDoesntExecuteMoreSQL(self):
+ """
+ Attempting to execute SQL on a L{CommandBlock} which has had C{end}
+ called on it will result in an L{AlreadyFinishedError}.
+ """
+ txn = self.pool.connection()
+ block = txn.commandBlock()
+ block.end()
+ self.assertRaises(AlreadyFinishedError, block.execSQL, "hello")
+ self.assertEquals(self.factory.connections[0].cursors[0].allExecutions,
+ [])
+
+
+ def test_commandBlockAfterCommitRaises(self):
+ """
+ Once an L{IAsyncTransaction} has been committed, L{commandBlock} raises
+ an exception.
+ """
+ txn = self.pool.connection()
+ txn.commit()
+ self.assertRaises(AlreadyFinishedError, txn.commandBlock)
+
+
+ def test_commandBlockAfterAbortRaises(self):
+ """
+ Once an L{IAsyncTransaction} has been committed, L{commandBlock} raises
+ an exception.
+ """
+ txn = self.pool.connection()
+ txn.abort()
+ self.assertRaises(AlreadyFinishedError, txn.commandBlock)
+
+
+
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