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-rw-r--r--src/backend/access/common/indextuple.c427
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diff --git a/src/backend/access/common/indextuple.c b/src/backend/access/common/indextuple.c
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+/*-------------------------------------------------------------------------
+ *
+ * indextuple.c--
+ * This file contains index tuple accessor and mutator routines,
+ * as well as a few various tuple utilities.
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ * $Header: /cvsroot/pgsql/src/backend/access/common/indextuple.c,v 1.1.1.1 1996/07/09 06:21:09 scrappy Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#include <string.h>
+
+#include "c.h"
+#include "access/ibit.h"
+#include "access/itup.h" /* where the declarations go */
+#include "access/heapam.h"
+#include "access/genam.h"
+#include "access/tupdesc.h"
+#include "access/tupmacs.h"
+
+#include "storage/itemptr.h"
+#include "utils/elog.h"
+#include "utils/palloc.h"
+
+static Size IndexInfoFindDataOffset(unsigned short t_info);
+
+/* ----------------------------------------------------------------
+ * index_ tuple interface routines
+ * ----------------------------------------------------------------
+ */
+
+/* ----------------
+ * index_formtuple
+ * ----------------
+ */
+IndexTuple
+index_formtuple(TupleDesc tupleDescriptor,
+ Datum value[],
+ char null[])
+{
+ register char *tp; /* tuple pointer */
+ IndexTuple tuple; /* return tuple */
+ Size size, hoff;
+ int i;
+ unsigned short infomask = 0;
+ bool hasnull = false;
+ char tupmask = 0;
+ int numberOfAttributes = tupleDescriptor->natts;
+
+ if (numberOfAttributes > MaxIndexAttributeNumber)
+ elog(WARN, "index_formtuple: numberOfAttributes of %d > %d",
+ numberOfAttributes, MaxIndexAttributeNumber);
+
+
+ for (i = 0; i < numberOfAttributes && !hasnull; i++) {
+ if (null[i] != ' ') hasnull = true;
+ }
+
+ if (hasnull) infomask |= INDEX_NULL_MASK;
+
+ hoff = IndexInfoFindDataOffset(infomask);
+ size = hoff
+ + ComputeDataSize(tupleDescriptor,
+ value, null);
+ size = DOUBLEALIGN(size); /* be conservative */
+
+ tp = (char *) palloc(size);
+ tuple = (IndexTuple) tp;
+ memset(tp,0,(int)size);
+
+ DataFill((char *)tp + hoff,
+ tupleDescriptor,
+ value,
+ null,
+ &tupmask,
+ (hasnull ? (bits8*)tp + sizeof(*tuple) : NULL));
+
+ /*
+ * We do this because DataFill wants to initialize a "tupmask" which
+ * is used for HeapTuples, but we want an indextuple infomask. The only
+ * "relevent" info is the "has variable attributes" field, which is in
+ * mask position 0x02. We have already set the null mask above.
+ */
+
+ if (tupmask & 0x02) infomask |= INDEX_VAR_MASK;
+
+ /*
+ * Here we make sure that we can actually hold the size. We also want
+ * to make sure that size is not aligned oddly. This actually is a
+ * rather odd way to make sure the size is not too large overall.
+ */
+
+ if (size & 0xE000)
+ elog(WARN, "index_formtuple: data takes %d bytes: too big", size);
+
+
+ infomask |= size;
+
+ /* ----------------
+ * initialize metadata
+ * ----------------
+ */
+ tuple->t_info = infomask;
+ return (tuple);
+}
+
+/* ----------------
+ * fastgetiattr
+ *
+ * This is a newer version of fastgetiattr which attempts to be
+ * faster by caching attribute offsets in the attribute descriptor.
+ *
+ * an alternate way to speed things up would be to cache offsets
+ * with the tuple, but that seems more difficult unless you take
+ * the storage hit of actually putting those offsets into the
+ * tuple you send to disk. Yuck.
+ *
+ * This scheme will be slightly slower than that, but should
+ * preform well for queries which hit large #'s of tuples. After
+ * you cache the offsets once, examining all the other tuples using
+ * the same attribute descriptor will go much quicker. -cim 5/4/91
+ * ----------------
+ */
+char *
+fastgetiattr(IndexTuple tup,
+ int attnum,
+ TupleDesc tupleDesc,
+ bool *isnull)
+{
+ register char *tp; /* ptr to att in tuple */
+ register char *bp; /* ptr to att in tuple */
+ int slow; /* do we have to walk nulls? */
+ register int data_off; /* tuple data offset */
+
+ /* ----------------
+ * sanity checks
+ * ----------------
+ */
+
+ Assert(PointerIsValid(isnull));
+ Assert(attnum > 0);
+
+ /* ----------------
+ * Three cases:
+ *
+ * 1: No nulls and no variable length attributes.
+ * 2: Has a null or a varlena AFTER att.
+ * 3: Has nulls or varlenas BEFORE att.
+ * ----------------
+ */
+
+ *isnull = false;
+ data_off = IndexTupleHasMinHeader(tup) ? sizeof *tup :
+ IndexInfoFindDataOffset(tup->t_info);
+
+ if (IndexTupleNoNulls(tup)) {
+
+ /* first attribute is always at position zero */
+
+ if (attnum == 1) {
+ return(fetchatt(&(tupleDesc->attrs[0]), (char *) tup + data_off));
+ }
+ attnum--;
+
+ if (tupleDesc->attrs[attnum]->attcacheoff > 0) {
+ return(fetchatt(&(tupleDesc->attrs[attnum]),
+ (char *) tup + data_off +
+ tupleDesc->attrs[attnum]->attcacheoff));
+ }
+
+ tp = (char *) tup + data_off;
+
+ slow = 0;
+ }else { /* there's a null somewhere in the tuple */
+
+ bp = (char *) tup + sizeof(*tup); /* "knows" t_bits are here! */
+ slow = 0;
+ /* ----------------
+ * check to see if desired att is null
+ * ----------------
+ */
+
+ attnum--;
+ {
+ if (att_isnull(attnum, bp)) {
+ *isnull = true;
+ return NULL;
+ }
+ }
+ /* ----------------
+ * Now check to see if any preceeding bits are null...
+ * ----------------
+ */
+ {
+ register int i = 0; /* current offset in bp */
+ register int mask; /* bit in byte we're looking at */
+ register char n; /* current byte in bp */
+ register int byte, finalbit;
+
+ byte = attnum >> 3;
+ finalbit = attnum & 0x07;
+
+ for (; i <= byte; i++) {
+ n = bp[i];
+ if (i < byte) {
+ /* check for nulls in any "earlier" bytes */
+ if ((~n) != 0) {
+ slow++;
+ break;
+ }
+ } else {
+ /* check for nulls "before" final bit of last byte*/
+ mask = (finalbit << 1) - 1;
+ if ((~n) & mask)
+ slow++;
+ }
+ }
+ }
+ tp = (char *) tup + data_off;
+ }
+
+ /* now check for any non-fixed length attrs before our attribute */
+
+ if (!slow) {
+ if (tupleDesc->attrs[attnum]->attcacheoff > 0) {
+ return(fetchatt(&(tupleDesc->attrs[attnum]),
+ tp + tupleDesc->attrs[attnum]->attcacheoff));
+ }else if (!IndexTupleAllFixed(tup)) {
+ register int j = 0;
+
+ for (j = 0; j < attnum && !slow; j++)
+ if (tupleDesc->attrs[j]->attlen < 1) slow = 1;
+ }
+ }
+
+ /*
+ * if slow is zero, and we got here, we know that we have a tuple with
+ * no nulls. We also know that we have to initialize the remainder of
+ * the attribute cached offset values.
+ */
+
+ if (!slow) {
+ register int j = 1;
+ register long off;
+
+ /*
+ * need to set cache for some atts
+ */
+
+ tupleDesc->attrs[0]->attcacheoff = 0;
+
+ while (tupleDesc->attrs[j]->attcacheoff > 0) j++;
+
+ off = tupleDesc->attrs[j-1]->attcacheoff +
+ tupleDesc->attrs[j-1]->attlen;
+
+ for (; j < attnum + 1; j++) {
+ /*
+ * Fix me when going to a machine with more than a four-byte
+ * word!
+ */
+
+ switch(tupleDesc->attrs[j]->attlen)
+ {
+ case -1:
+ off = (tupleDesc->attrs[j]->attalign=='d')?
+ DOUBLEALIGN(off):INTALIGN(off);
+ break;
+ case sizeof(char):
+ break;
+ case sizeof(short):
+ off = SHORTALIGN(off);
+ break;
+ case sizeof(int32):
+ off = INTALIGN(off);
+ break;
+ default:
+ if (tupleDesc->attrs[j]->attlen > sizeof(int32))
+ off = (tupleDesc->attrs[j]->attalign=='d')?
+ DOUBLEALIGN(off) : LONGALIGN(off);
+ else
+ elog(WARN, "fastgetiattr: attribute %d has len %d",
+ j, tupleDesc->attrs[j]->attlen);
+ break;
+
+ }
+
+ tupleDesc->attrs[j]->attcacheoff = off;
+ off += tupleDesc->attrs[j]->attlen;
+ }
+
+ return(fetchatt( &(tupleDesc->attrs[attnum]),
+ tp + tupleDesc->attrs[attnum]->attcacheoff));
+ }else {
+ register bool usecache = true;
+ register int off = 0;
+ register int i;
+
+ /*
+ * Now we know that we have to walk the tuple CAREFULLY.
+ */
+
+ for (i = 0; i < attnum; i++) {
+ if (!IndexTupleNoNulls(tup)) {
+ if (att_isnull(i, bp)) {
+ usecache = false;
+ continue;
+ }
+ }
+
+ if (usecache && tupleDesc->attrs[i]->attcacheoff > 0) {
+ off = tupleDesc->attrs[i]->attcacheoff;
+ if (tupleDesc->attrs[i]->attlen == -1)
+ usecache = false;
+ else
+ continue;
+ }
+
+ if (usecache) tupleDesc->attrs[i]->attcacheoff = off;
+ switch(tupleDesc->attrs[i]->attlen)
+ {
+ case sizeof(char):
+ off++;
+ break;
+ case sizeof(short):
+ off = SHORTALIGN(off) + sizeof(short);
+ break;
+ case -1:
+ usecache = false;
+ off = (tupleDesc->attrs[i]->attalign=='d')?
+ DOUBLEALIGN(off):INTALIGN(off);
+ off += VARSIZE(tp + off);
+ break;
+ default:
+ if (tupleDesc->attrs[i]->attlen > sizeof(int32))
+ off = (tupleDesc->attrs[i]->attalign=='d') ?
+ DOUBLEALIGN(off) + tupleDesc->attrs[i]->attlen :
+ LONGALIGN(off) + tupleDesc->attrs[i]->attlen;
+ else
+ elog(WARN, "fastgetiattr2: attribute %d has len %d",
+ i, tupleDesc->attrs[i]->attlen);
+
+ break;
+ }
+ }
+
+ return(fetchatt(&tupleDesc->attrs[attnum], tp + off));
+ }
+}
+
+/* ----------------
+ * index_getattr
+ * ----------------
+ */
+Datum
+index_getattr(IndexTuple tuple,
+ AttrNumber attNum,
+ TupleDesc tupDesc,
+ bool *isNullOutP)
+{
+ Assert (attNum > 0);
+
+ return (Datum)
+ fastgetiattr(tuple, attNum, tupDesc, isNullOutP);
+}
+
+RetrieveIndexResult
+FormRetrieveIndexResult(ItemPointer indexItemPointer,
+ ItemPointer heapItemPointer)
+{
+ RetrieveIndexResult result;
+
+ Assert(ItemPointerIsValid(indexItemPointer));
+ Assert(ItemPointerIsValid(heapItemPointer));
+
+ result = (RetrieveIndexResult) palloc(sizeof *result);
+
+ result->index_iptr = *indexItemPointer;
+ result->heap_iptr = *heapItemPointer;
+
+ return (result);
+}
+
+/*
+ * Takes an infomask as argument (primarily because this needs to be usable
+ * at index_formtuple time so enough space is allocated).
+ *
+ * Change me if adding an attribute to IndexTuples!!!!!!!!!!!
+ */
+static Size
+IndexInfoFindDataOffset(unsigned short t_info)
+{
+ if (!(t_info & INDEX_NULL_MASK))
+ return((Size) sizeof(IndexTupleData));
+ else {
+ Size size = sizeof(IndexTupleData);
+
+ if (t_info & INDEX_NULL_MASK) {
+ size += sizeof(IndexAttributeBitMapData);
+ }
+ return DOUBLEALIGN(size); /* be conservative */
+ }
+}
+
+/*
+ * Copies source into target. If *target == NULL, we palloc space; otherwise
+ * we assume we have space that is already palloc'ed.
+ */
+void
+CopyIndexTuple(IndexTuple source, IndexTuple *target)
+{
+ Size size;
+ IndexTuple ret;
+
+ size = IndexTupleSize(source);
+ if (*target == NULL) {
+ *target = (IndexTuple) palloc(size);
+ }
+
+ ret = *target;
+ memmove((char*)ret, (char*)source, size);
+}
+
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