bzr commit into mysql-5.1-telco-6.2 branch (frazer:3004) Bug#47573

[Frazer Clement]

#At file:///home/frazer/bzr/mysql-5.1-telco-6.2/

 3004 Frazer Clement	2009-09-24
      Bug#47573 MySQL Cluster : Internal blob read buffer not always freed correctly.  Fix buffer release code and rename some vars to aid understanding
      modified:
        sql/ha_ndbcluster.cc
        sql/ha_ndbcluster.h

=== modified file 'sql/ha_ndbcluster.cc'
--- a/sql/ha_ndbcluster.cc	2009-09-24 14:10:29 +0000
+++ b/sql/ha_ndbcluster.cc	2009-09-24 14:22:10 +0000
@@ -703,8 +703,8 @@ int g_get_ndb_blobs_value(NdbBlob *ndb_b
     if (ndb_blob->getLength(len64) != 0)
       ERR_RETURN(ndb_blob->getNdbError());
     /* Align to Uint64. */
-    ha->m_blob_total_size+= (len64 + 7) & ~((Uint64)7);
-    if (ha->m_blob_total_size > 0xffffffff)
+    ha->m_blobs_row_total_size+= (len64 + 7) & ~((Uint64)7);
+    if (ha->m_blobs_row_total_size > 0xffffffff)
     {
       DBUG_ASSERT(FALSE);
       DBUG_RETURN(-1);
@@ -716,24 +716,26 @@ int g_get_ndb_blobs_value(NdbBlob *ndb_b
     Wait until all blobs are active with reading, so we can allocate
     and use a common buffer containing all.
   */
-  if (ha->m_blob_counter < ha->m_blob_expected_count)
+  if (ha->m_blob_counter < ha->m_blob_expected_count_per_row)
     DBUG_RETURN(0);
+
+  /* Reset blob counter for next row (scan scenario) */
   ha->m_blob_counter= 0;
 
-  /* Re-allocate bigger blob buffer if necessary. */
-  if (ha->m_blob_total_size > ha->m_blobs_buffer_size)
+  /* Re-allocate bigger blob buffer for this row if necessary. */
+  if (ha->m_blobs_row_total_size > ha->m_blobs_buffer_size)
   {
     my_free(ha->m_blobs_buffer, MYF(MY_ALLOW_ZERO_PTR));
     DBUG_PRINT("info", ("allocate blobs buffer size %u",
-                        (uint32)(ha->m_blob_total_size)));
+                        (uint32)(ha->m_blobs_row_total_size)));
     ha->m_blobs_buffer=
-      (uchar*) my_malloc(ha->m_blob_total_size, MYF(MY_WME));
+      (uchar*) my_malloc(ha->m_blobs_row_total_size, MYF(MY_WME));
     if (ha->m_blobs_buffer == NULL)
     {
       ha->m_blobs_buffer_size= 0;
       DBUG_RETURN(-1);
     }
-    ha->m_blobs_buffer_size= ha->m_blob_total_size;
+    ha->m_blobs_buffer_size= ha->m_blobs_row_total_size;
   }
 
   /*
@@ -825,9 +827,9 @@ ha_ndbcluster::get_blob_values(const Ndb
   DBUG_ENTER("ha_ndbcluster::get_blob_values");
 
   m_blob_counter= 0;
-  m_blob_expected_count= 0;
+  m_blob_expected_count_per_row= 0;
   m_blob_destination_record= dst_record;
-  m_blob_total_size= 0;
+  m_blobs_row_total_size= 0;
 
   for (i= 0; i < table_share->fields; i++) 
   {
@@ -842,7 +844,7 @@ ha_ndbcluster::get_blob_values(const Ndb
       if ((ndb_blob= ndb_op->getBlobHandle(i)) == NULL ||
           ndb_blob->setActiveHook(g_get_ndb_blobs_value, this) != 0)
         DBUG_RETURN(1);
-      m_blob_expected_count++;
+      m_blob_expected_count_per_row++;
     }
     else
       ndb_blob= NULL;
@@ -1034,12 +1036,12 @@ bool ha_ndbcluster::uses_blob_value(cons
 void ha_ndbcluster::release_blobs_buffer()
 {
   DBUG_ENTER("releaseBlobsBuffer");
-  if (m_blob_total_size > 0)
+  if (m_blobs_buffer_size > 0)
   {
-    DBUG_PRINT("info", ("Deleting blobs buffer, size %llu", m_blob_total_size));
+    DBUG_PRINT("info", ("Deleting blobs buffer, size %u", m_blobs_buffer_size));
     my_free(m_blobs_buffer, MYF(MY_ALLOW_ZERO_PTR));
     m_blobs_buffer= 0;
-    m_blob_total_size= 0;
+    m_blobs_row_total_size= 0;
     m_blobs_buffer_size= 0;
   }
   DBUG_VOID_RETURN;
@@ -6645,7 +6647,7 @@ ha_ndbcluster::ha_ndbcluster(handlerton 
   m_update_cannot_batch(FALSE),
   m_skip_auto_increment(TRUE),
   m_blobs_pending(0),
-  m_blob_total_size(0),
+  m_blobs_row_total_size(0),
   m_blobs_buffer(0),
   m_blobs_buffer_size(0),
   m_dupkey((uint) -1),

=== modified file 'sql/ha_ndbcluster.h'
--- a/sql/ha_ndbcluster.h	2009-09-08 11:02:48 +0000
+++ b/sql/ha_ndbcluster.h	2009-09-24 14:22:10 +0000
@@ -709,9 +709,9 @@ private:
 
   /* State for setActiveHook() callback for reading blob data. */
   uint m_blob_counter;
-  uint m_blob_expected_count;
+  uint m_blob_expected_count_per_row;
   uchar *m_blob_destination_record;
-  Uint64 m_blob_total_size;
+  Uint64 m_blobs_row_total_size; /* Bytes needed for all blobs in current row */
   
   // memory for blobs in one tuple
   uchar *m_blobs_buffer;