float
gistpenalty(GISTSTATE *giststate, int attno,
GISTENTRY *orig, bool isNullOrig,
GISTENTRY *add, bool isNullAdd)
{
float penalty = 0.0;
if (giststate->penaltyFn[attno].fn_strict == FALSE ||
(isNullOrig == FALSE && isNullAdd == FALSE))
{
FunctionCall3Coll(&giststate->penaltyFn[attno],
giststate->supportCollation[attno],
PointerGetDatum(orig),
PointerGetDatum(add),
PointerGetDatum(&penalty));
/* disallow negative or NaN penalty */
if (isnan(penalty) || penalty < 0.0)
penalty = 0.0;
}
else if (isNullOrig && isNullAdd)
penalty = 0.0;
else
penalty = 1e10; /* try to prevent mixing null and non-null
* values */
return penalty;
}
/*
* Given two deformed tuples, adjust the first one so that it's consistent
* with the summary values in both.
*/
static void
union_tuples(BrinDesc *bdesc, BrinMemTuple *a, BrinTuple *b)
{
int keyno;
BrinMemTuple *db;
MemoryContext cxt;
MemoryContext oldcxt;
/* Use our own memory context to avoid retail pfree */
cxt = AllocSetContextCreate(CurrentMemoryContext,
"brin union",
ALLOCSET_DEFAULT_SIZES);
oldcxt = MemoryContextSwitchTo(cxt);
db = brin_deform_tuple(bdesc, b);
MemoryContextSwitchTo(oldcxt);
for (keyno = 0; keyno < bdesc->bd_tupdesc->natts; keyno++)
{
FmgrInfo *unionFn;
BrinValues *col_a = &a->bt_columns[keyno];
BrinValues *col_b = &db->bt_columns[keyno];
unionFn = index_getprocinfo(bdesc->bd_index, keyno + 1,
BRIN_PROCNUM_UNION);
FunctionCall3Coll(unionFn,
bdesc->bd_index->rd_indcollation[keyno],
PointerGetDatum(bdesc),
PointerGetDatum(col_a),
PointerGetDatum(col_b));
}
MemoryContextDelete(cxt);
}
bool
gistKeyIsEQ(GISTSTATE *giststate, int attno, Datum a, Datum b)
{
bool result;
FunctionCall3Coll(&giststate->equalFn[attno],
giststate->supportCollation[attno],
a, b,
PointerGetDatum(&result));
return result;
}
/*
* Execute the index scan.
*
* This works by reading index TIDs from the revmap, and obtaining the index
* tuples pointed to by them; the summary values in the index tuples are
* compared to the scan keys. We return into the TID bitmap all the pages in
* ranges corresponding to index tuples that match the scan keys.
*
* If a TID from the revmap is read as InvalidTID, we know that range is
* unsummarized. Pages in those ranges need to be returned regardless of scan
* keys.
*/
int64
bringetbitmap(IndexScanDesc scan, TIDBitmap *tbm)
{
Relation idxRel = scan->indexRelation;
Buffer buf = InvalidBuffer;
BrinDesc *bdesc;
Oid heapOid;
Relation heapRel;
BrinOpaque *opaque;
BlockNumber nblocks;
BlockNumber heapBlk;
int totalpages = 0;
FmgrInfo *consistentFn;
MemoryContext oldcxt;
MemoryContext perRangeCxt;
opaque = (BrinOpaque *) scan->opaque;
bdesc = opaque->bo_bdesc;
pgstat_count_index_scan(idxRel);
/*
* We need to know the size of the table so that we know how long to
* iterate on the revmap.
*/
heapOid = IndexGetRelation(RelationGetRelid(idxRel), false);
heapRel = heap_open(heapOid, AccessShareLock);
nblocks = RelationGetNumberOfBlocks(heapRel);
heap_close(heapRel, AccessShareLock);
/*
* Make room for the consistent support procedures of indexed columns. We
* don't look them up here; we do that lazily the first time we see a scan
* key reference each of them. We rely on zeroing fn_oid to InvalidOid.
*/
consistentFn = palloc0(sizeof(FmgrInfo) * bdesc->bd_tupdesc->natts);
/*
* Setup and use a per-range memory context, which is reset every time we
* loop below. This avoids having to free the tuples within the loop.
*/
perRangeCxt = AllocSetContextCreate(CurrentMemoryContext,
"bringetbitmap cxt",
ALLOCSET_DEFAULT_SIZES);
oldcxt = MemoryContextSwitchTo(perRangeCxt);
/*
* Now scan the revmap. We start by querying for heap page 0,
* incrementing by the number of pages per range; this gives us a full
* view of the table.
*/
for (heapBlk = 0; heapBlk < nblocks; heapBlk += opaque->bo_pagesPerRange)
{
bool addrange;
BrinTuple *tup;
OffsetNumber off;
Size size;
CHECK_FOR_INTERRUPTS();
MemoryContextResetAndDeleteChildren(perRangeCxt);
tup = brinGetTupleForHeapBlock(opaque->bo_rmAccess, heapBlk, &buf,
&off, &size, BUFFER_LOCK_SHARE,
scan->xs_snapshot);
if (tup)
{
tup = brin_copy_tuple(tup, size);
LockBuffer(buf, BUFFER_LOCK_UNLOCK);
}
/*
* For page ranges with no indexed tuple, we must return the whole
* range; otherwise, compare it to the scan keys.
*/
if (tup == NULL)
{
addrange = true;
}
else
{
BrinMemTuple *dtup;
dtup = brin_deform_tuple(bdesc, tup);
if (dtup->bt_placeholder)
{
/*
* Placeholder tuples are always returned, regardless of the
* values stored in them.
*/
addrange = true;
}
else
{
int keyno;
/*
* Compare scan keys with summary values stored for the range.
* If scan keys are matched, the page range must be added to
* the bitmap. We initially assume the range needs to be
* added; in particular this serves the case where there are
* no keys.
*/
addrange = true;
for (keyno = 0; keyno < scan->numberOfKeys; keyno++)
{
ScanKey key = &scan->keyData[keyno];
AttrNumber keyattno = key->sk_attno;
BrinValues *bval = &dtup->bt_columns[keyattno - 1];
Datum add;
/*
* The collation of the scan key must match the collation
* used in the index column (but only if the search is not
* IS NULL/ IS NOT NULL). Otherwise we shouldn't be using
* this index ...
*/
Assert((key->sk_flags & SK_ISNULL) ||
(key->sk_collation ==
bdesc->bd_tupdesc->attrs[keyattno - 1]->attcollation));
/* First time this column? look up consistent function */
if (consistentFn[keyattno - 1].fn_oid == InvalidOid)
{
FmgrInfo *tmp;
tmp = index_getprocinfo(idxRel, keyattno,
BRIN_PROCNUM_CONSISTENT);
fmgr_info_copy(&consistentFn[keyattno - 1], tmp,
CurrentMemoryContext);
}
/*
* Check whether the scan key is consistent with the page
* range values; if so, have the pages in the range added
* to the output bitmap.
*
* When there are multiple scan keys, failure to meet the
* criteria for a single one of them is enough to discard
* the range as a whole, so break out of the loop as soon
* as a false return value is obtained.
*/
add = FunctionCall3Coll(&consistentFn[keyattno - 1],
key->sk_collation,
PointerGetDatum(bdesc),
PointerGetDatum(bval),
PointerGetDatum(key));
addrange = DatumGetBool(add);
if (!addrange)
break;
}
}
}
/* add the pages in the range to the output bitmap, if needed */
if (addrange)
{
BlockNumber pageno;
for (pageno = heapBlk;
pageno <= heapBlk + opaque->bo_pagesPerRange - 1;
pageno++)
{
MemoryContextSwitchTo(oldcxt);
tbm_add_page(tbm, pageno);
totalpages++;
MemoryContextSwitchTo(perRangeCxt);
}
}
}
MemoryContextSwitchTo(oldcxt);
MemoryContextDelete(perRangeCxt);
if (buf != InvalidBuffer)
ReleaseBuffer(buf);
/*
* XXX We have an approximation of the number of *pages* that our scan
* returns, but we don't have a precise idea of the number of heap tuples
* involved.
*/
return totalpages * 10;
}
/*
* Extract the index key values from an indexable item
*
* The resulting key values are sorted, and any duplicates are removed.
* This avoids generating redundant index entries.
*/
Datum *
ginExtractEntries(GinState *ginstate, OffsetNumber attnum,
Datum value, bool isNull,
int32 *nentries, GinNullCategory **categories)
{
Datum *entries;
bool *nullFlags;
int32 i;
/*
* We don't call the extractValueFn on a null item. Instead generate a
* placeholder.
*/
if (isNull)
{
*nentries = 1;
entries = (Datum *) palloc(sizeof(Datum));
entries[0] = (Datum) 0;
*categories = (GinNullCategory *) palloc(sizeof(GinNullCategory));
(*categories)[0] = GIN_CAT_NULL_ITEM;
return entries;
}
/* OK, call the opclass's extractValueFn */
nullFlags = NULL; /* in case extractValue doesn't set it */
entries = (Datum *)
DatumGetPointer(FunctionCall3Coll(&ginstate->extractValueFn[attnum - 1],
ginstate->supportCollation[attnum - 1],
value,
PointerGetDatum(nentries),
PointerGetDatum(&nullFlags)));
/*
* Generate a placeholder if the item contained no keys.
*/
if (entries == NULL || *nentries <= 0)
{
*nentries = 1;
entries = (Datum *) palloc(sizeof(Datum));
entries[0] = (Datum) 0;
*categories = (GinNullCategory *) palloc(sizeof(GinNullCategory));
(*categories)[0] = GIN_CAT_EMPTY_ITEM;
return entries;
}
/*
* If the extractValueFn didn't create a nullFlags array, create one,
* assuming that everything's non-null. Otherwise, run through the array
* and make sure each value is exactly 0 or 1; this ensures binary
* compatibility with the GinNullCategory representation.
*/
if (nullFlags == NULL)
nullFlags = (bool *) palloc0(*nentries * sizeof(bool));
else
{
for (i = 0; i < *nentries; i++)
nullFlags[i] = (nullFlags[i] ? true : false);
}
/* now we can use the nullFlags as category codes */
*categories = (GinNullCategory *) nullFlags;
/*
* If there's more than one key, sort and unique-ify.
*
* XXX Using qsort here is notationally painful, and the overhead is
* pretty bad too. For small numbers of keys it'd likely be better to use
* a simple insertion sort.
*/
if (*nentries > 1)
{
keyEntryData *keydata;
cmpEntriesArg arg;
keydata = (keyEntryData *) palloc(*nentries * sizeof(keyEntryData));
for (i = 0; i < *nentries; i++)
{
keydata[i].datum = entries[i];
keydata[i].isnull = nullFlags[i];
}
arg.cmpDatumFunc = &ginstate->compareFn[attnum - 1];
arg.collation = ginstate->supportCollation[attnum - 1];
arg.haveDups = false;
qsort_arg(keydata, *nentries, sizeof(keyEntryData),
cmpEntries, (void *) &arg);
if (arg.haveDups)
{
/* there are duplicates, must get rid of 'em */
int32 j;
entries[0] = keydata[0].datum;
nullFlags[0] = keydata[0].isnull;
j = 1;
for (i = 1; i < *nentries; i++)
{
if (cmpEntries(&keydata[i - 1], &keydata[i], &arg) != 0)
{
entries[j] = keydata[i].datum;
nullFlags[j] = keydata[i].isnull;
j++;
}
}
*nentries = j;
}
else
{
/* easy, no duplicates */
for (i = 0; i < *nentries; i++)
{
entries[i] = keydata[i].datum;
nullFlags[i] = keydata[i].isnull;
}
}
pfree(keydata);
}
return entries;
}
