From f5dff44736911b10c83d2717ca53ad90dd967758 Mon Sep 17 00:00:00 2001
From: Bruce Momjian <bruce@momjian.us>
Date: Mon, 25 Feb 2002 04:06:52 +0000
Subject: [PATCH] I've attached a simple patch which should improve the
performance of hashname() and reduce the penalty incured when NAMEDATALEN is
increased. I posted this to -hackers a couple days ago, and there haven't
been any major complaints. It passes the regression tests. See -hackers for
more discussion, as well as the suggestion from Tom Lane on which this patch
is based.
Unless anyone sees any problems, please apply for 7.3.
Cheers,
Neil Conway
---
src/backend/access/hash/hashfunc.c | 8 ++++----
src/backend/utils/cache/catcache.c | 22 ++--------------------
src/include/access/hash.h | 4 ++--
3 files changed, 8 insertions(+), 26 deletions(-)
diff --git a/src/backend/access/hash/hashfunc.c b/src/backend/access/hash/hashfunc.c
index 4cb157c702c..9cb2a02cf3a 100644
--- a/src/backend/access/hash/hashfunc.c
+++ b/src/backend/access/hash/hashfunc.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/access/hash/hashfunc.c,v 1.30 2001/03/22 03:59:13 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/access/hash/hashfunc.c,v 1.31 2002/02/25 04:06:47 momjian Exp $
*
* NOTES
* These functions are stored in pg_amproc. For each operator class
@@ -95,7 +95,7 @@ hashname(PG_FUNCTION_ARGS)
{
char *key = NameStr(*PG_GETARG_NAME(0));
- return hash_any((char *) key, NAMEDATALEN);
+ return hash_any(key, strlen(key));
}
/*
@@ -125,7 +125,7 @@ hashvarlena(PG_FUNCTION_ARGS)
*
* (Comment from the original db3 hashing code: )
*
- * "This is INCREDIBLY ugly, but fast. We break the string up into 8 byte
+ * This is INCREDIBLY ugly, but fast. We break the string up into 8 byte
* units. On the first time through the loop we get the 'leftover bytes'
* (strlen % 8). On every later iteration, we perform 8 HASHC's so we handle
* all 8 bytes. Essentially, this saves us 7 cmp & branch instructions. If
@@ -134,7 +134,7 @@ hashvarlena(PG_FUNCTION_ARGS)
* "OZ's original sdbm hash"
*/
Datum
-hash_any(char *keydata, int keylen)
+hash_any(const char *keydata, int keylen)
{
uint32 n;
int loop;
diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c
index 47ab410cfc2..4339f51f3d7 100644
--- a/src/backend/utils/cache/catcache.c
+++ b/src/backend/utils/cache/catcache.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/utils/cache/catcache.c,v 1.87 2002/02/19 20:11:17 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/cache/catcache.c,v 1.88 2002/02/25 04:06:50 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@@ -97,7 +97,6 @@ static Index CatalogCacheComputeHashIndex(CatCache *cache,
static Index CatalogCacheComputeTupleHashIndex(CatCache *cache,
HeapTuple tuple);
static void CatalogCacheInitializeCache(CatCache *cache);
-static Datum cc_hashname(PG_FUNCTION_ARGS);
#ifdef CATCACHE_STATS
static void CatCachePrintStats(void);
#endif
@@ -116,7 +115,7 @@ GetCCHashFunc(Oid keytype)
case CHAROID:
return hashchar;
case NAMEOID:
- return cc_hashname;
+ return hashname;
case INT2OID:
return hashint2;
case INT2VECTOROID:
@@ -137,23 +136,6 @@ GetCCHashFunc(Oid keytype)
}
}
-static Datum
-cc_hashname(PG_FUNCTION_ARGS)
-{
- /*
- * We need our own variant of hashname because we want to accept
- * null-terminated C strings as search values for name fields. So, we
- * have to make sure the data is correctly padded before we compute
- * the hash value.
- */
- NameData my_n;
-
- namestrcpy(&my_n, NameStr(*PG_GETARG_NAME(0)));
-
- return DirectFunctionCall1(hashname, NameGetDatum(&my_n));
-}
-
-
#ifdef CATCACHE_STATS
static void
diff --git a/src/include/access/hash.h b/src/include/access/hash.h
index 835d778d904..c88f34f54a9 100644
--- a/src/include/access/hash.h
+++ b/src/include/access/hash.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: hash.h,v 1.42 2001/11/05 17:46:31 momjian Exp $
+ * $Id: hash.h,v 1.43 2002/02/25 04:06:52 momjian Exp $
*
* NOTES
* modeled after Margo Seltzer's hash implementation for unix.
@@ -265,7 +265,7 @@ extern Datum hashoidvector(PG_FUNCTION_ARGS);
extern Datum hashint2vector(PG_FUNCTION_ARGS);
extern Datum hashname(PG_FUNCTION_ARGS);
extern Datum hashvarlena(PG_FUNCTION_ARGS);
-extern Datum hash_any(char *keydata, int keylen);
+extern Datum hash_any(const char *keydata, int keylen);
/* private routines */
--
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