bzr commit into mysql-6.0-falcon-team branch (klewis:2897) Bug#40112

[Kevin Lewis]

#At file:///C:/Work/bzr/Merge/mysql-6.0-falcon-team/

 2897 Kevin Lewis	2008-11-02
      Bug#40112 - DeferredIndexWalker::next() was not prepared for the first 
      leaf bucket to be empty.  But it can become empty after several verbs 
      in the same transaction change the same records.  
      
      When the same record is changed more than once in the same transaction, 
      the older unneeded versions are deleted along with the index entries.  
      Even though DeferredIndex key nodes can be deleted, the buckets are not.  
      
      If the first leaf bucket is empty, DeferredIndexWalker::next() would 
      return NULL on the first call.  In SRLUpdateIndex::append(), this would
      result that nothing would be put into the Serial log at commit time for 
      this DeferredIndex.  Then this DefferedIndex would not get put into 
      index pages.
      
      The solution is to only return NULL on the first call to 
      DeferredIndexWalker::next() if the first leaf bucket is empty AND there 
      is no parent bucket.  Otherwise, use the normal mechanism to advance to 
      the next slot.
modified:
  storage/falcon/DeferredIndexWalker.cpp
  storage/falcon/Transaction.cpp

per-file messages:
  storage/falcon/DeferredIndexWalker.cpp
    Bug#40112 - Only return NULL on the first call to DeferredIndexWalker::
    next() if the first leaf bucket is empty AND there is no parent bucket.  
    Otherwise, use the normal mechanism to advance to the next slot.
  storage/falcon/Transaction.cpp
    Distinguish a System Transaction in LogXARecovery messages.
    Add LogXARecovery messages for rollbacks and commitNoUpdates.
=== modified file 'storage/falcon/DeferredIndexWalker.cpp'
--- a/storage/falcon/DeferredIndexWalker.cpp	2008-10-16 02:53:35 +0000
+++ b/storage/falcon/DeferredIndexWalker.cpp	2008-11-03 00:33:04 +0000
@@ -110,10 +110,16 @@ DINode* DeferredIndexWalker::next(void)
 		{
 		nodePending = false;
 
-		return currentNode = (slot >= leaf->count) ? NULL : leaf->nodes[slot];
+		if (slot < leaf->count)
+			return (currentNode = leaf->nodes[slot]);
+
+		if (!deferredIndex->levels)
+			return NULL;  // Only one bucket and it is empty
+		// else the first leaf is empty.  Back up a level.
 		}
+	else
+		++slot;
 
-	++slot;
 	DIBucket *bucket;
 		
 	for (;;)

=== modified file 'storage/falcon/Transaction.cpp'
--- a/storage/falcon/Transaction.cpp	2008-10-24 05:06:52 +0000
+++ b/storage/falcon/Transaction.cpp	2008-11-03 00:33:04 +0000
@@ -250,7 +250,8 @@ void Transaction::commit()
 
 	TransactionManager *transactionManager = database->transactionManager;
 	addRef();
-	Log::log(LogXARecovery, "%d: Commit transaction %d\n", database->deltaTime, transactionId);
+	Log::log(LogXARecovery, "%d: Commit %sTransaction %d\n", 
+		database->deltaTime, (systemTransaction ? "System " : ""),  transactionId);
 
 	if (state == Active)
 		{
@@ -340,6 +341,7 @@ void Transaction::commitNoUpdates(void)
 	TransactionManager *transactionManager = database->transactionManager;
 	addRef();
 	ASSERT(!deferredIndexes);
+	Log::log(LogXARecovery, "%d: CommitNoUpdates transaction %d\n", database->deltaTime, transactionId);
 	++transactionManager->committed;
 	
 	if (deferredIndexes)
@@ -384,6 +386,8 @@ void Transaction::rollback()
 	if (!isActive())
 		throw SQLEXCEPTION (RUNTIME_ERROR, "transaction is not active");
 
+	Log::log(LogXARecovery, "%d: Rollback transaction %d\n", database->deltaTime, transactionId);
+
 	if (deferredIndexes)
 		releaseDeferredIndexes();
 		
@@ -951,6 +955,9 @@ void Transaction::writeComplete(void)
 	if (dependencies == 0)
 		commitRecords();
 
+//	Log::log(LogXARecovery, "%d: WriteComplete %sTransaction %d\n", 
+// 	database->deltaTime, (systemTransaction ? "System " : ""),  transactionId);
+
 	writePending = false;
 }