static bool PersistentStore_GetFreeTuple(
PersistentStoreData *storeData,
PersistentStoreSharedData *storeSharedData,
ItemPointer freeTid)
{
Datum *values;
HeapTuple tupleCopy;
int64 persistentSerialNum;
ItemPointerData previousFreeTid;
MemSet(freeTid, 0, sizeof(ItemPointerData));
if (Debug_persistent_store_print)
elog(PersistentStore_DebugPrintLevel(),
"PersistentStore_GetFreeTuple: Enter: maximum free order number " INT64_FORMAT ", free TID %s ('%s')",
storeSharedData->maxFreeOrderNum,
ItemPointerToString(&storeSharedData->freeTid),
storeData->tableName);
if (storeSharedData->maxFreeOrderNum == 0)
{
return false; // No free tuples.
}
if (gp_persistent_skip_free_list)
{
if (Debug_persistent_store_print)
elog(PersistentStore_DebugPrintLevel(),
"PersistentStore_GetFreeTuple: Skipping because gp_persistent_skip_free_list GUC is ON ('%s')",
storeData->tableName);
return false; // Pretend no free tuples.
}
Assert(storeSharedData->freeTid.ip_posid != 0);
/*
* Read the current last free tuple.
*/
values = (Datum*)palloc(storeData->numAttributes * sizeof(Datum));
PersistentStore_ReadTuple(
storeData,
storeSharedData,
&storeSharedData->freeTid,
values,
&tupleCopy);
PersistentStore_ExtractOurTupleData(
storeData,
values,
&persistentSerialNum,
&previousFreeTid);
if (PersistentStore_IsZeroTid(&previousFreeTid))
elog(ERROR, "Expected persistent store tuple at %s to be free ('%s')",
ItemPointerToString(&storeSharedData->freeTid),
storeData->tableName);
if (storeSharedData->maxFreeOrderNum == 1)
Assert(ItemPointerCompare(&previousFreeTid, &storeSharedData->freeTid) == 0);
if (persistentSerialNum != storeSharedData->maxFreeOrderNum)
elog(ERROR, "Expected persistent store tuple at %s to have order number " INT64_FORMAT " (found " INT64_FORMAT ", '%s')",
ItemPointerToString(&storeSharedData->freeTid),
storeSharedData->maxFreeOrderNum,
persistentSerialNum,
storeData->tableName);
*freeTid = storeSharedData->freeTid;
storeSharedData->maxFreeOrderNum--;
storeSharedData->freeTid = previousFreeTid;
pfree(values);
heap_freetuple(tupleCopy);
if (Debug_persistent_store_print)
elog(PersistentStore_DebugPrintLevel(),
"PersistentStore_GetFreeTuple: Exit: maximum free order number " INT64_FORMAT ", free TID %s ('%s')",
storeSharedData->maxFreeOrderNum,
ItemPointerToString(&storeSharedData->freeTid),
storeData->tableName);
return true;
}
/*
* Check if the free TID is valid. If not, the free list is corrupted and we
* pretend there are no free tuples to reset the free list. The corrupted free
* list will be detached and cleaned during recovery or pt rebuild.
*/
static bool PersistentStore_ValidateFreeTID(
PersistentStoreData *storeData,
PersistentStoreSharedData *storeSharedData,
ItemPointer previousFreeTid)
{
Datum *values;
HeapTuple tupleCopy;
int64 persistentSerialNum;
bool tidIsValid = true;
if (storeSharedData->maxFreeOrderNum <= 0)
return true; /* No tuple to check */
values = (Datum*)palloc(storeData->numAttributes * sizeof(Datum));
PersistentStore_ReadTuple(
storeData,
storeSharedData,
&storeSharedData->freeTid,
values,
&tupleCopy);
PersistentStore_ExtractOurTupleData(
storeData,
values,
&persistentSerialNum,
previousFreeTid);
if (storeSharedData->maxFreeOrderNum == 1 && ItemPointerCompare(previousFreeTid, &storeSharedData->freeTid) != 0)
{
tidIsValid = false;
ereport(WARNING,
(errmsg("integrity check for PT freeTid failed"),
errdetail("expected to have previous FreeTID at %s equal to itself (found %s, %s)",
ItemPointerToString(&storeSharedData->freeTid),
ItemPointerToString2(previousFreeTid),
storeData->tableName)));
}
if (PersistentStore_IsZeroTid(previousFreeTid))
{
tidIsValid = false;
ereport(WARNING,
(errmsg("integrity check for PT freeTid failed"),
errdetail("expected to have previous FreeTID at %s to be free (found %s, %s)",
ItemPointerToString(&storeSharedData->freeTid),
ItemPointerToString2(previousFreeTid),
storeData->tableName)));
}
if (persistentSerialNum != storeSharedData->maxFreeOrderNum)
{
tidIsValid = false;
ereport(WARNING,
(errmsg("integrity check for PT freeTid failed"),
errdetail("expected persistent store tuple at %s to have order number " INT64_FORMAT " (found " INT64_FORMAT ", '%s')",
ItemPointerToString(&storeSharedData->freeTid),
storeSharedData->maxFreeOrderNum,
persistentSerialNum,
storeData->tableName)));
}
pfree(values);
heap_freetuple(tupleCopy);
/* If the free TID is not valid, switch to a new free list here */
if (!tidIsValid)
{
ItemPointerSet(previousFreeTid, 0, 0);
storeSharedData->maxFreeOrderNum = 0;
MemSet(&storeSharedData->freeTid, 0, sizeof(ItemPointerData));
ereport(WARNING,
(errmsg("switched to new free TID list")));
}
return tidIsValid;
}
