From 32ba2b516066688ff56e6d62a7ff4a01c88f5700 Mon Sep 17 00:00:00 2001
From: Robert Haas <rhaas@postgresql.org>
Date: Tue, 21 Dec 2010 22:11:40 -0500
Subject: [PATCH] Use memcmp() rather than strncmp() when shorter string length
is known.
It appears that this will be faster for all but the shortest strings;
at least one some platforms, memcmp() can use word-at-a-time comparisons.
Noah Misch, somewhat pared down.
---
contrib/hstore/hstore_io.c | 8 ++++----
contrib/hstore/hstore_op.c | 26 +++++++++++++-------------
contrib/ltree/ltree_gist.c | 2 +-
contrib/ltree/ltree_op.c | 8 ++++----
src/backend/nodes/readfuncs.c | 2 +-
src/backend/utils/adt/varchar.c | 6 +++---
src/backend/utils/adt/varlena.c | 14 +++++++-------
7 files changed, 33 insertions(+), 33 deletions(-)
diff --git a/contrib/hstore/hstore_io.c b/contrib/hstore/hstore_io.c
index 0058f5c1b3f..0d6f0b6b138 100644
--- a/contrib/hstore/hstore_io.c
+++ b/contrib/hstore/hstore_io.c
@@ -280,9 +280,9 @@ comparePairs(const void *a, const void *b)
{
if (((Pairs *) a)->keylen == ((Pairs *) b)->keylen)
{
- int res = strncmp(((Pairs *) a)->key,
- ((Pairs *) b)->key,
- ((Pairs *) a)->keylen);
+ int res = memcmp(((Pairs *) a)->key,
+ ((Pairs *) b)->key,
+ ((Pairs *) a)->keylen);
if (res)
return res;
@@ -324,7 +324,7 @@ hstoreUniquePairs(Pairs *a, int4 l, int4 *buflen)
while (ptr - a < l)
{
if (ptr->keylen == res->keylen &&
- strncmp(ptr->key, res->key, res->keylen) == 0)
+ memcmp(ptr->key, res->key, res->keylen) == 0)
{
if (ptr->needfree)
{
diff --git a/contrib/hstore/hstore_op.c b/contrib/hstore/hstore_op.c
index 8d73a463aba..93d8cbcaebb 100644
--- a/contrib/hstore/hstore_op.c
+++ b/contrib/hstore/hstore_op.c
@@ -49,7 +49,7 @@ hstoreFindKey(HStore *hs, int *lowbound, char *key, int keylen)
stopMiddle = stopLow + (stopHigh - stopLow) / 2;
if (HS_KEYLEN(entries, stopMiddle) == keylen)
- difference = strncmp(HS_KEY(entries, base, stopMiddle), key, keylen);
+ difference = memcmp(HS_KEY(entries, base, stopMiddle), key, keylen);
else
difference = (HS_KEYLEN(entries, stopMiddle) > keylen) ? 1 : -1;
@@ -263,7 +263,7 @@ hstore_delete(PG_FUNCTION_ARGS)
int len = HS_KEYLEN(es, i);
char *ptrs = HS_KEY(es, bufs, i);
- if (!(len == keylen && strncmp(ptrs, keyptr, keylen) == 0))
+ if (!(len == keylen && memcmp(ptrs, keyptr, keylen) == 0))
{
int vallen = HS_VALLEN(es, i);
@@ -331,9 +331,9 @@ hstore_delete_array(PG_FUNCTION_ARGS)
int skeylen = HS_KEYLEN(es, i);
if (skeylen == key_pairs[j].keylen)
- difference = strncmp(HS_KEY(es, ps, i),
- key_pairs[j].key,
- key_pairs[j].keylen);
+ difference = memcmp(HS_KEY(es, ps, i),
+ key_pairs[j].key,
+ key_pairs[j].keylen);
else
difference = (skeylen > key_pairs[j].keylen) ? 1 : -1;
}
@@ -416,9 +416,9 @@ hstore_delete_hstore(PG_FUNCTION_ARGS)
int s2keylen = HS_KEYLEN(es2, j);
if (skeylen == s2keylen)
- difference = strncmp(HS_KEY(es, ps, i),
- HS_KEY(es2, ps2, j),
- skeylen);
+ difference = memcmp(HS_KEY(es, ps, i),
+ HS_KEY(es2, ps2, j),
+ skeylen);
else
difference = (skeylen > s2keylen) ? 1 : -1;
}
@@ -433,7 +433,7 @@ hstore_delete_hstore(PG_FUNCTION_ARGS)
if (snullval != HS_VALISNULL(es2, j)
|| (!snullval
&& (svallen != HS_VALLEN(es2, j)
- || strncmp(HS_VAL(es, ps, i), HS_VAL(es2, ps2, j), svallen) != 0)))
+ || memcmp(HS_VAL(es, ps, i), HS_VAL(es2, ps2, j), svallen) != 0)))
{
HS_COPYITEM(ed, bufd, pd,
HS_KEY(es, ps, i), HS_KEYLEN(es, i),
@@ -526,9 +526,9 @@ hstore_concat(PG_FUNCTION_ARGS)
int s2keylen = HS_KEYLEN(es2, s2idx);
if (s1keylen == s2keylen)
- difference = strncmp(HS_KEY(es1, ps1, s1idx),
- HS_KEY(es2, ps2, s2idx),
- s1keylen);
+ difference = memcmp(HS_KEY(es1, ps1, s1idx),
+ HS_KEY(es2, ps2, s2idx),
+ s1keylen);
else
difference = (s1keylen > s2keylen) ? 1 : -1;
}
@@ -996,7 +996,7 @@ hstore_contains(PG_FUNCTION_ARGS)
if (nullval != HS_VALISNULL(ve, idx)
|| (!nullval
&& (vallen != HS_VALLEN(ve, idx)
- || strncmp(HS_VAL(te, tstr, i), HS_VAL(ve, vstr, idx), vallen))))
+ || memcmp(HS_VAL(te, tstr, i), HS_VAL(ve, vstr, idx), vallen))))
res = false;
}
else
diff --git a/contrib/ltree/ltree_gist.c b/contrib/ltree/ltree_gist.c
index 5fa7b59d32d..47a85bbabc2 100644
--- a/contrib/ltree/ltree_gist.c
+++ b/contrib/ltree/ltree_gist.c
@@ -546,7 +546,7 @@ gist_tqcmp(ltree *t, lquery *q)
while (an > 0 && bn > 0)
{
bl = LQL_FIRST(ql);
- if ((res = strncmp(al->name, bl->name, Min(al->len, bl->len))) == 0)
+ if ((res = memcmp(al->name, bl->name, Min(al->len, bl->len))) == 0)
{
if (al->len != bl->len)
return al->len - bl->len;
diff --git a/contrib/ltree/ltree_op.c b/contrib/ltree/ltree_op.c
index 2ddfdec7eb1..2b048d4b7c5 100644
--- a/contrib/ltree/ltree_op.c
+++ b/contrib/ltree/ltree_op.c
@@ -68,7 +68,7 @@ ltree_compare(const ltree *a, const ltree *b)
while (an > 0 && bn > 0)
{
- if ((res = strncmp(al->name, bl->name, Min(al->len, bl->len))) == 0)
+ if ((res = memcmp(al->name, bl->name, Min(al->len, bl->len))) == 0)
{
if (al->len != bl->len)
return (al->len - bl->len) * 10 * (an + 1);
@@ -165,7 +165,7 @@ inner_isparent(const ltree *c, const ltree *p)
{
if (cl->len != pl->len)
return false;
- if (strncmp(cl->name, pl->name, cl->len))
+ if (memcmp(cl->name, pl->name, cl->len))
return false;
pn--;
@@ -373,7 +373,7 @@ ltree_index(PG_FUNCTION_ARGS)
bptr = LTREE_FIRST(b);
for (j = 0; j < b->numlevel; j++)
{
- if (!(aptr->len == bptr->len && strncmp(aptr->name, bptr->name, aptr->len) == 0))
+ if (!(aptr->len == bptr->len && memcmp(aptr->name, bptr->name, aptr->len) == 0))
break;
aptr = LEVEL_NEXT(aptr);
bptr = LEVEL_NEXT(bptr);
@@ -451,7 +451,7 @@ lca_inner(ltree **a, int len)
num = 0;
for (i = 0; i < Min(tmp, (*ptr)->numlevel - 1); i++)
{
- if (l1->len == l2->len && strncmp(l1->name, l2->name, l1->len) == 0)
+ if (l1->len == l2->len && memcmp(l1->name, l2->name, l1->len) == 0)
num = i + 1;
else
break;
diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index 933d58ada5f..d0d0b1cfe39 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -1196,7 +1196,7 @@ parseNodeString(void)
token = pg_strtok(&length);
#define MATCH(tokname, namelen) \
- (length == namelen && strncmp(token, tokname, namelen) == 0)
+ (length == namelen && memcmp(token, tokname, namelen) == 0)
if (MATCH("QUERY", 5))
return_value = _readQuery();
diff --git a/src/backend/utils/adt/varchar.c b/src/backend/utils/adt/varchar.c
index 34acfb36180..b3d7ba3f403 100644
--- a/src/backend/utils/adt/varchar.c
+++ b/src/backend/utils/adt/varchar.c
@@ -690,7 +690,7 @@ bpchareq(PG_FUNCTION_ARGS)
if (len1 != len2)
result = false;
else
- result = (strncmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2), len1) == 0);
+ result = (memcmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2), len1) == 0);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
@@ -717,7 +717,7 @@ bpcharne(PG_FUNCTION_ARGS)
if (len1 != len2)
result = true;
else
- result = (strncmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2), len1) != 0);
+ result = (memcmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2), len1) != 0);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
@@ -905,7 +905,7 @@ internal_bpchar_pattern_compare(BpChar *arg1, BpChar *arg2)
len1 = bcTruelen(arg1);
len2 = bcTruelen(arg2);
- result = strncmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2), Min(len1, len2));
+ result = memcmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2), Min(len1, len2));
if (result != 0)
return result;
else if (len1 < len2)
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index ee83e2f3088..2fa740ac8c0 100644
--- a/src/backend/utils/adt/varlena.c
+++ b/src/backend/utils/adt/varlena.c
@@ -1286,7 +1286,7 @@ varstr_cmp(char *arg1, int len1, char *arg2, int len2)
*/
if (lc_collate_is_c())
{
- result = strncmp(arg1, arg2, Min(len1, len2));
+ result = memcmp(arg1, arg2, Min(len1, len2));
if ((result == 0) && (len1 != len2))
result = (len1 < len2) ? -1 : 1;
}
@@ -1370,7 +1370,7 @@ varstr_cmp(char *arg1, int len1, char *arg2, int len2)
*/
if (result == 0)
{
- result = strncmp(arg1, arg2, Min(len1, len2));
+ result = memcmp(arg1, arg2, Min(len1, len2));
if ((result == 0) && (len1 != len2))
result = (len1 < len2) ? -1 : 1;
}
@@ -1462,8 +1462,8 @@ texteq(PG_FUNCTION_ARGS)
if (VARSIZE_ANY_EXHDR(arg1) != VARSIZE_ANY_EXHDR(arg2))
result = false;
else
- result = (strncmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2),
- VARSIZE_ANY_EXHDR(arg1)) == 0);
+ result = (memcmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2),
+ VARSIZE_ANY_EXHDR(arg1)) == 0);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
@@ -1485,8 +1485,8 @@ textne(PG_FUNCTION_ARGS)
if (VARSIZE_ANY_EXHDR(arg1) != VARSIZE_ANY_EXHDR(arg2))
result = true;
else
- result = (strncmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2),
- VARSIZE_ANY_EXHDR(arg1)) != 0);
+ result = (memcmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2),
+ VARSIZE_ANY_EXHDR(arg1)) != 0);
PG_FREE_IF_COPY(arg1, 0);
PG_FREE_IF_COPY(arg2, 1);
@@ -1612,7 +1612,7 @@ internal_text_pattern_compare(text *arg1, text *arg2)
len1 = VARSIZE_ANY_EXHDR(arg1);
len2 = VARSIZE_ANY_EXHDR(arg2);
- result = strncmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2), Min(len1, len2));
+ result = memcmp(VARDATA_ANY(arg1), VARDATA_ANY(arg2), Min(len1, len2));
if (result != 0)
return result;
else if (len1 < len2)
--
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