entry->list = NULL;
entry->nlist = 0;
entry->matchBitmap = NULL;
- entry->matchResult = NULL;
entry->matchNtuples = -1;
+ entry->matchResult.blockno = InvalidBlockNumber;
entry->reduceResult = false;
entry->predictNumberResult = 0;
{
/*
* If we've exhausted all items on this block, move to next block
- * in the bitmap.
+ * in the bitmap. tbm_private_iterate() sets matchResult.blockno
+ * to InvalidBlockNumber when the bitmap is exhausted.
*/
- while (entry->matchResult == NULL ||
- (!entry->matchResult->lossy &&
+ while ((!BlockNumberIsValid(entry->matchResult.blockno)) ||
+ (!entry->matchResult.lossy &&
entry->offset >= entry->matchNtuples) ||
- entry->matchResult->blockno < advancePastBlk ||
+ entry->matchResult.blockno < advancePastBlk ||
(ItemPointerIsLossyPage(&advancePast) &&
- entry->matchResult->blockno == advancePastBlk))
+ entry->matchResult.blockno == advancePastBlk))
{
- entry->matchResult =
- tbm_private_iterate(entry->matchIterator);
-
- if (entry->matchResult == NULL)
+ if (!tbm_private_iterate(entry->matchIterator, &entry->matchResult))
{
+ Assert(!BlockNumberIsValid(entry->matchResult.blockno));
ItemPointerSetInvalid(&entry->curItem);
tbm_end_private_iterate(entry->matchIterator);
entry->matchIterator = NULL;
}
/* Exact pages need their tuple offsets extracted. */
- if (!entry->matchResult->lossy)
- entry->matchNtuples = tbm_extract_page_tuple(entry->matchResult,
+ if (!entry->matchResult.lossy)
+ entry->matchNtuples = tbm_extract_page_tuple(&entry->matchResult,
entry->matchOffsets,
TBM_MAX_TUPLES_PER_PAGE);
/*
* Reset counter to the beginning of entry->matchResult. Note:
- * entry->offset is still greater than entry->matchNtuples if
+ * entry->offset is still greater than matchResult.ntuples if
* matchResult is lossy. So, on next call we will get next
* result from TIDBitmap.
*/
* We're now on the first page after advancePast which has any
* items on it. If it's a lossy result, return that.
*/
- if (entry->matchResult->lossy)
+ if (entry->matchResult.lossy)
{
ItemPointerSetLossyPage(&entry->curItem,
- entry->matchResult->blockno);
+ entry->matchResult.blockno);
/*
* We might as well fall out of the loop; we could not
Assert(entry->matchNtuples > -1);
/* Skip over any offsets <= advancePast, and return that. */
- if (entry->matchResult->blockno == advancePastBlk)
+ if (entry->matchResult.blockno == advancePastBlk)
{
Assert(entry->matchNtuples > 0);
}
ItemPointerSet(&entry->curItem,
- entry->matchResult->blockno,
+ entry->matchResult.blockno,
entry->matchOffsets[entry->offset]);
entry->offset++;
ItemPointerSetMin(&scanEntry->curItem);
scanEntry->matchBitmap = NULL;
scanEntry->matchIterator = NULL;
- scanEntry->matchResult = NULL;
+ scanEntry->matchResult.blockno = InvalidBlockNumber;
scanEntry->matchNtuples = -1;
scanEntry->list = NULL;
scanEntry->nlist = 0;
Buffer buffer;
Snapshot snapshot;
int ntup;
- TBMIterateResult *tbmres;
+ TBMIterateResult tbmres;
OffsetNumber offsets[TBM_MAX_TUPLES_PER_PAGE];
int noffsets = -1;
{
CHECK_FOR_INTERRUPTS();
- tbmres = tbm_iterate(&scan->st.rs_tbmiterator);
-
- if (tbmres == NULL)
+ if (!tbm_iterate(&scan->st.rs_tbmiterator, &tbmres))
return false;
/* Exact pages need their tuple offsets extracted. */
- if (!tbmres->lossy)
- noffsets = tbm_extract_page_tuple(tbmres, offsets,
+ if (!tbmres.lossy)
+ noffsets = tbm_extract_page_tuple(&tbmres, offsets,
TBM_MAX_TUPLES_PER_PAGE);
/*
* reachable by the index.
*/
} while (!IsolationIsSerializable() &&
- tbmres->blockno >= hscan->rs_nblocks);
+ tbmres.blockno >= hscan->rs_nblocks);
/* Got a valid block */
- *blockno = tbmres->blockno;
- *recheck = tbmres->recheck;
+ *blockno = tbmres.blockno;
+ *recheck = tbmres.recheck;
/*
* We can skip fetching the heap page if we don't need any fields from the
* page are visible to our transaction.
*/
if (!(scan->rs_flags & SO_NEED_TUPLES) &&
- !tbmres->recheck &&
- VM_ALL_VISIBLE(scan->rs_rd, tbmres->blockno, &bscan->rs_vmbuffer))
+ !tbmres.recheck &&
+ VM_ALL_VISIBLE(scan->rs_rd, tbmres.blockno, &bscan->rs_vmbuffer))
{
/* can't be lossy in the skip_fetch case */
- Assert(!tbmres->lossy);
+ Assert(!tbmres.lossy);
Assert(bscan->rs_empty_tuples_pending >= 0);
Assert(noffsets > -1);
return true;
}
- block = tbmres->blockno;
+ block = tbmres.blockno;
/*
* Acquire pin on the target heap page, trading in any pin we held before.
/*
* We need two separate strategies for lossy and non-lossy cases.
*/
- if (!tbmres->lossy)
+ if (!tbmres.lossy)
{
/*
* Bitmap is non-lossy, so we just look through the offsets listed in
Assert(ntup <= MaxHeapTuplesPerPage);
hscan->rs_ntuples = ntup;
- if (tbmres->lossy)
+ if (tbmres.lossy)
(*lossy_pages)++;
else
(*exact_pages)++;
{
#ifdef USE_PREFETCH
ParallelBitmapHeapState *pstate = node->pstate;
- TBMIterateResult *tbmpre;
+ TBMIterateResult tbmpre;
if (pstate == NULL)
{
}
else if (!tbm_exhausted(prefetch_iterator))
{
- tbmpre = tbm_iterate(prefetch_iterator);
- node->prefetch_blockno = tbmpre ? tbmpre->blockno :
- InvalidBlockNumber;
+ tbm_iterate(prefetch_iterator, &tbmpre);
+ node->prefetch_blockno = tbmpre.blockno;
}
return;
}
*/
if (!tbm_exhausted(prefetch_iterator))
{
- tbmpre = tbm_iterate(prefetch_iterator);
- node->prefetch_blockno = tbmpre ? tbmpre->blockno :
- InvalidBlockNumber;
+ tbm_iterate(prefetch_iterator, &tbmpre);
+ node->prefetch_blockno = tbmpre.blockno;
}
}
}
{
while (node->prefetch_pages < node->prefetch_target)
{
- TBMIterateResult *tbmpre = tbm_iterate(prefetch_iterator);
+ TBMIterateResult tbmpre;
bool skip_fetch;
- if (tbmpre == NULL)
+ if (!tbm_iterate(prefetch_iterator, &tbmpre))
{
/* No more pages to prefetch */
+ Assert(!BlockNumberIsValid(tbmpre.blockno));
tbm_end_iterate(prefetch_iterator);
break;
}
node->prefetch_pages++;
- node->prefetch_blockno = tbmpre->blockno;
+ node->prefetch_blockno = tbmpre.blockno;
/*
* If we expect not to have to actually read this heap page,
* prefetch_pages?)
*/
skip_fetch = (!(scan->rs_flags & SO_NEED_TUPLES) &&
- !tbmpre->recheck &&
+ !tbmpre.recheck &&
VM_ALL_VISIBLE(node->ss.ss_currentRelation,
- tbmpre->blockno,
+ tbmpre.blockno,
&node->pvmbuffer));
if (!skip_fetch)
- PrefetchBuffer(scan->rs_rd, MAIN_FORKNUM, tbmpre->blockno);
+ PrefetchBuffer(scan->rs_rd, MAIN_FORKNUM, tbmpre.blockno);
}
}
{
while (1)
{
- TBMIterateResult *tbmpre;
+ TBMIterateResult tbmpre;
bool do_prefetch = false;
bool skip_fetch;
if (!do_prefetch)
return;
- tbmpre = tbm_iterate(prefetch_iterator);
- if (tbmpre == NULL)
+ if (!tbm_iterate(prefetch_iterator, &tbmpre))
{
+ Assert(!BlockNumberIsValid(tbmpre.blockno));
/* No more pages to prefetch */
tbm_end_iterate(prefetch_iterator);
break;
}
- node->prefetch_blockno = tbmpre->blockno;
+ node->prefetch_blockno = tbmpre.blockno;
/* As above, skip prefetch if we expect not to need page */
skip_fetch = (!(scan->rs_flags & SO_NEED_TUPLES) &&
- !tbmpre->recheck &&
+ !tbmpre.recheck &&
VM_ALL_VISIBLE(node->ss.ss_currentRelation,
- tbmpre->blockno,
+ tbmpre.blockno,
&node->pvmbuffer));
if (!skip_fetch)
- PrefetchBuffer(scan->rs_rd, MAIN_FORKNUM, tbmpre->blockno);
+ PrefetchBuffer(scan->rs_rd, MAIN_FORKNUM, tbmpre.blockno);
}
}
}
int spageptr; /* next spages index */
int schunkptr; /* next schunks index */
int schunkbit; /* next bit to check in current schunk */
- TBMIterateResult output;
};
/*
PTEntryArray *ptbase; /* pagetable element array */
PTIterationArray *ptpages; /* sorted exact page index list */
PTIterationArray *ptchunks; /* sorted lossy page index list */
- TBMIterateResult output;
};
/* Local function prototypes */
/*
* tbm_private_iterate - scan through next page of a TIDBitmap
*
- * Returns a TBMIterateResult representing one page, or NULL if there are
- * no more pages to scan. Pages are guaranteed to be delivered in numerical
- * order. If lossy is true, then the bitmap is "lossy" and failed to
- * remember the exact tuples to look at on this page --- the caller must
- * examine all tuples on the page and check if they meet the intended
- * condition. result->ntuples is set to -1 when the bitmap is lossy.
- * If result->recheck is true, only the indicated tuples need
- * be examined, but the condition must be rechecked anyway. (For ease of
- * testing, recheck is always set true when lossy is true.)
+ * Caller must pass in a TBMIterateResult to be filled.
+ *
+ * Pages are guaranteed to be delivered in numerical order.
+ *
+ * Returns false when there are no more pages to scan and true otherwise. When
+ * there are no more pages to scan, tbmres->blockno is set to
+ * InvalidBlockNumber.
+ *
+ * If lossy is true, then the bitmap is "lossy" and failed to remember
+ * the exact tuples to look at on this page --- the caller must examine all
+ * tuples on the page and check if they meet the intended condition. If lossy
+ * is false, the caller must later extract the tuple offsets from the page
+ * pointed to by internal_page with tbm_extract_page_tuple.
+ *
+ * If tbmres->recheck is true, only the indicated tuples need be examined, but
+ * the condition must be rechecked anyway. (For ease of testing, recheck is
+ * always set true when lossy is true.)
*/
-TBMIterateResult *
-tbm_private_iterate(TBMPrivateIterator *iterator)
+bool
+tbm_private_iterate(TBMPrivateIterator *iterator, TBMIterateResult *tbmres)
{
TIDBitmap *tbm = iterator->tbm;
- TBMIterateResult *output = &(iterator->output);
Assert(tbm->iterating == TBM_ITERATING_PRIVATE);
chunk_blockno < tbm->spages[iterator->spageptr]->blockno)
{
/* Return a lossy page indicator from the chunk */
- output->blockno = chunk_blockno;
- output->lossy = true;
- output->recheck = true;
- output->internal_page = NULL;
+ tbmres->blockno = chunk_blockno;
+ tbmres->lossy = true;
+ tbmres->recheck = true;
+ tbmres->internal_page = NULL;
iterator->schunkbit++;
- return output;
+ return true;
}
}
else
page = tbm->spages[iterator->spageptr];
- output->internal_page = page;
- output->blockno = page->blockno;
- output->lossy = false;
- output->recheck = page->recheck;
+ tbmres->internal_page = page;
+ tbmres->blockno = page->blockno;
+ tbmres->lossy = false;
+ tbmres->recheck = page->recheck;
iterator->spageptr++;
- return output;
+ return true;
}
/* Nothing more in the bitmap */
- return NULL;
+ tbmres->blockno = InvalidBlockNumber;
+ return false;
}
/*
* across multiple processes. We need to acquire the iterator LWLock,
* before accessing the shared members.
*/
-TBMIterateResult *
-tbm_shared_iterate(TBMSharedIterator *iterator)
+bool
+tbm_shared_iterate(TBMSharedIterator *iterator, TBMIterateResult *tbmres)
{
- TBMIterateResult *output = &iterator->output;
TBMSharedIteratorState *istate = iterator->state;
PagetableEntry *ptbase = NULL;
int *idxpages = NULL;
chunk_blockno < ptbase[idxpages[istate->spageptr]].blockno)
{
/* Return a lossy page indicator from the chunk */
- output->blockno = chunk_blockno;
- output->lossy = true;
- output->recheck = true;
- output->internal_page = NULL;
+ tbmres->blockno = chunk_blockno;
+ tbmres->lossy = true;
+ tbmres->recheck = true;
+ tbmres->internal_page = NULL;
istate->schunkbit++;
LWLockRelease(&istate->lock);
- return output;
+ return true;
}
}
{
PagetableEntry *page = &ptbase[idxpages[istate->spageptr]];
- output->internal_page = page;
- output->blockno = page->blockno;
- output->lossy = false;
- output->recheck = page->recheck;
+ tbmres->internal_page = page;
+ tbmres->blockno = page->blockno;
+ tbmres->lossy = false;
+ tbmres->recheck = page->recheck;
istate->spageptr++;
LWLockRelease(&istate->lock);
- return output;
+ return true;
}
LWLockRelease(&istate->lock);
/* Nothing more in the bitmap */
- return NULL;
+ tbmres->blockno = InvalidBlockNumber;
+ return false;
}
/*
}
/*
- * Get the next TBMIterateResult from the shared or private bitmap iterator.
+ * Populate the next TBMIterateResult using the shared or private bitmap
+ * iterator. Returns false when there is nothing more to scan.
*/
-TBMIterateResult *
-tbm_iterate(TBMIterator *iterator)
+bool
+tbm_iterate(TBMIterator *iterator, TBMIterateResult *tbmres)
{
Assert(iterator);
+ Assert(tbmres);
if (iterator->shared)
- return tbm_shared_iterate(iterator->i.shared_iterator);
+ return tbm_shared_iterate(iterator->i.shared_iterator, tbmres);
else
- return tbm_private_iterate(iterator->i.private_iterator);
+ return tbm_private_iterate(iterator->i.private_iterator, tbmres);
}
/* for a partial-match or full-scan query, we accumulate all TIDs here */
TIDBitmap *matchBitmap;
TBMPrivateIterator *matchIterator;
- TBMIterateResult *matchResult;
+
+ /*
+ * If blockno is InvalidBlockNumber, all of the other fields in the
+ * matchResult are meaningless.
+ */
+ TBMIterateResult matchResult;
OffsetNumber matchOffsets[TBM_MAX_TUPLES_PER_PAGE];
int matchNtuples;
extern TBMPrivateIterator *tbm_begin_private_iterate(TIDBitmap *tbm);
extern dsa_pointer tbm_prepare_shared_iterate(TIDBitmap *tbm);
-extern TBMIterateResult *tbm_private_iterate(TBMPrivateIterator *iterator);
-extern TBMIterateResult *tbm_shared_iterate(TBMSharedIterator *iterator);
+extern bool tbm_private_iterate(TBMPrivateIterator *iterator, TBMIterateResult *tbmres);
+extern bool tbm_shared_iterate(TBMSharedIterator *iterator, TBMIterateResult *tbmres);
extern void tbm_end_private_iterate(TBMPrivateIterator *iterator);
extern void tbm_end_shared_iterate(TBMSharedIterator *iterator);
extern TBMSharedIterator *tbm_attach_shared_iterate(dsa_area *dsa,
dsa_area *dsa, dsa_pointer dsp);
extern void tbm_end_iterate(TBMIterator *iterator);
-extern TBMIterateResult *tbm_iterate(TBMIterator *iterator);
+extern bool tbm_iterate(TBMIterator *iterator, TBMIterateResult *tbmres);
static inline bool
tbm_exhausted(TBMIterator *iterator)