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-rw-r--r--src/backend/access/common/indextuple.c134
1 files changed, 47 insertions, 87 deletions
diff --git a/src/backend/access/common/indextuple.c b/src/backend/access/common/indextuple.c
index 15ed1824560..9f2bfb02c53 100644
--- a/src/backend/access/common/indextuple.c
+++ b/src/backend/access/common/indextuple.c
@@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/access/common/indextuple.c,v 1.46 2000/11/16 05:50:57 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/access/common/indextuple.c,v 1.47 2000/11/30 18:38:45 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -160,13 +160,13 @@ index_formtuple(TupleDesc tupleDescriptor,
*
* This caches attribute offsets in the attribute descriptor.
*
- * an alternate way to speed things up would be to cache offsets
+ * 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
+ * perform 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
* ----------------
@@ -177,13 +177,13 @@ nocache_index_getattr(IndexTuple tup,
TupleDesc tupleDesc,
bool *isnull)
{
+ Form_pg_attribute *att = tupleDesc->attrs;
char *tp; /* ptr to att in tuple */
- char *bp = NULL; /* ptr to att in tuple */
- int slow; /* do we have to walk nulls? */
+ bits8 *bp = NULL; /* ptr to null bitmask in tuple */
+ bool slow = false; /* do we have to walk nulls? */
int data_off; /* tuple data offset */
- Form_pg_attribute *att = tupleDesc->attrs;
- (void) isnull;
+ (void) isnull; /* not used */
/* ----------------
* sanity checks
* ----------------
@@ -209,17 +209,12 @@ nocache_index_getattr(IndexTuple tup,
data_off = IndexTupleHasMinHeader(tup) ? sizeof *tup :
IndexInfoFindDataOffset(tup->t_info);
+ attnum--;
+
if (IndexTupleNoNulls(tup))
{
- attnum--;
-
#ifdef IN_MACRO
/* This is handled in the macro */
-
- /* first attribute is always at position zero */
-
- if (attnum == 1)
- return (Datum) fetchatt(&(att[0]), (char *) tup + data_off);
if (att[attnum]->attcacheoff != -1)
{
return (Datum) fetchatt(&(att[attnum]),
@@ -227,20 +222,13 @@ nocache_index_getattr(IndexTuple tup,
att[attnum]->attcacheoff);
}
#endif
-
- slow = 0;
}
else
{ /* there's a null somewhere in the tuple */
-
- slow = 0;
/* ----------------
* check to see if desired att is null
* ----------------
*/
-
- attnum--;
-
bp = (char *) tup + sizeof(*tup); /* "knows" t_bits are
* here! */
#ifdef IN_MACRO
@@ -254,34 +242,28 @@ nocache_index_getattr(IndexTuple tup,
#endif
/* ----------------
- * Now check to see if any preceeding bits are null...
+ * Now check to see if any preceding bits are null...
* ----------------
*/
{
- int i = 0; /* current offset in bp */
- int mask; /* bit in byte we're looking at */
- char n; /* current byte in bp */
- int byte,
- finalbit;
+ int byte = attnum >> 3;
+ int finalbit = attnum & 0x07;
- byte = attnum >> 3;
- finalbit = attnum & 0x07;
-
- for (; i <= byte && !slow; i++)
+ /* check for nulls "before" final bit of last byte */
+ if ((~bp[byte]) & ((1 << finalbit) - 1))
+ slow = true;
+ else
{
- n = bp[i];
- if (i < byte)
- {
- /* check for nulls in any "earlier" bytes */
- if ((~n) != 0)
- slow = 1;
- }
- else
+ /* check for nulls in any "earlier" bytes */
+ int i;
+
+ for (i = 0; i < byte; i++)
{
- /* check for nulls "before" final bit of last byte */
- mask = (1 << finalbit) - 1;
- if ((~n) & mask)
- slow = 1;
+ if (bp[i] != 0xFF)
+ {
+ slow = true;
+ break;
+ }
}
}
}
@@ -298,24 +280,25 @@ nocache_index_getattr(IndexTuple tup,
return (Datum) fetchatt(&(att[attnum]),
tp + att[attnum]->attcacheoff);
}
- else if (attnum == 0)
- return (Datum) fetchatt(&(att[0]), (char *) tp);
else if (!IndexTupleAllFixed(tup))
{
- int j = 0;
+ int j;
- for (j = 0; j < attnum && !slow; j++)
- if (att[j]->attlen < 1 && !VARLENA_FIXED_SIZE(att[j]))
- slow = 1;
+ for (j = 0; j < attnum; j++)
+ if (att[j]->attlen <= 0)
+ {
+ slow = true;
+ break;
+ }
}
}
/*
- * 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 is false, and we got here, we know that we have a tuple with
+ * no nulls or varlenas before the target attribute. If possible, we
+ * also want to initialize the remainder of the attribute cached
+ * offset values.
*/
-
if (!slow)
{
int j = 1;
@@ -327,15 +310,12 @@ nocache_index_getattr(IndexTuple tup,
att[0]->attcacheoff = 0;
- while (att[j]->attcacheoff != -1)
+ while (j < attnum && att[j]->attcacheoff > 0)
j++;
- if (!VARLENA_FIXED_SIZE(att[j - 1]))
- off = att[j - 1]->attcacheoff + att[j - 1]->attlen;
- else
- off = att[j - 1]->attcacheoff + att[j - 1]->atttypmod;
+ off = att[j - 1]->attcacheoff + att[j - 1]->attlen;
- for (; j < attnum + 1; j++)
+ for (; j <= attnum; j++)
{
/*
@@ -347,14 +327,7 @@ nocache_index_getattr(IndexTuple tup,
att[j]->attcacheoff = off;
- /* The only varlena/-1 length value to get here is this */
- if (!VARLENA_FIXED_SIZE(att[j]))
- off += att[j]->attlen;
- else
- {
- Assert(att[j]->atttypmod == VARSIZE(tp + off));
- off += att[j]->atttypmod;
- }
+ off += att[j]->attlen;
}
return (Datum) fetchatt(&(att[attnum]), tp + att[attnum]->attcacheoff);
@@ -391,27 +364,14 @@ nocache_index_getattr(IndexTuple tup,
att[i]->attcacheoff = off;
}
- switch (att[i]->attlen)
+ if (att[i]->attlen == -1)
{
- case sizeof(char):
- off++;
- break;
- case sizeof(short):
- off += sizeof(short);
- break;
- case sizeof(int32):
- off += sizeof(int32);
- break;
- case -1:
- Assert(!VARLENA_FIXED_SIZE(att[i]) ||
- att[i]->atttypmod == VARSIZE(tp + off));
- off += VARSIZE(tp + off);
- if (!VARLENA_FIXED_SIZE(att[i]))
- usecache = false;
- break;
- default:
- off += att[i]->attlen;
- break;
+ off += VARSIZE(tp + off);
+ usecache = false;
+ }
+ else
+ {
+ off += att[i]->attlen;
}
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-29 00:11:25 +0000