F.Y.I.
I've found my memory leak and discovered an error in the CW6 tutorials...
I coppied excactly what the memo tutorials said about reading a record and
found a serious memory leak when reading REPEATEDLY from a database.
//==========================================================================
===
//Old function
static void ReadRecord(DmOpenRef dbP, char *aRecord, int aRecordIndex)
{
CharPtr newText, recText;
Handle newHandle;
VoidHand recHandle;
// Check to make sure there is a record to retrieve.
if (aRecordIndex != noRecordSelected && DmNumRecords(dbP) > 0)
{
// Get a handle for the first record.
recHandle = DmGetRecord(dbP, aRecordIndex);
if (recHandle == NULL) {
StrCopy(aRecord,"");
return;
}
// Lock down the handle and get a pointer to the record
data.
recText = (CharPtr)MemHandleLock(recHandle);
// Allocate a new memory chunk that will contain a copy of
the data.
newHandle = (Handle)MemHandleNew(StrLen(recText) + 1);
// Lock down the handle and get a pointer to the memory
chunk.
newText = (CharPtr)MemHandleLock(newHandle);
// Copy the data from the record to the new memory chunk.
StrCopy(newText, recText);
StrCopy(aRecord,newText);
// Unlock the new memory chunk.
MemHandleUnlock(newHandle);
// Unlock the database record.
MemHandleUnlock(recHandle);
// Release the record to the database system.
// (The zero means that the record data hasn't been
changed.)
DmReleaseRecord(dbP, aRecordIndex, 0);
}
}
this is how i fixed it and it is working fine now:
//==========================================================================
===
//New function
static void ReadRecord(DmOpenRef dbP, char *aRecord, int aRecordIndex)
{
CharPtr recText;
VoidHand recHandle;
// Check to make sure there is a record to retrieve.
if ((aRecordIndex >= 0) && (aRecordIndex < DmNumRecords(dbP))) {
// Get a handle for the first record.
recHandle = DmGetRecord(dbP, aRecordIndex);
if (recHandle == NULL) {
StrCopy(aRecord,"");
return;
}
// Lock down the handle and get a pointer to the record
data.
recText = (CharPtr)MemHandleLock(recHandle);
// Copy the data from the record to the new memory chunk.
StrCopy(aRecord, recText);
// Unlock the database record.
MemHandleUnlock(recHandle);
// Release the record to the database system.
// (The zero means that the record data hasn't been
changed.)
DmReleaseRecord(dbP, aRecordIndex, 0);
}
}
Regards,
Herman
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