From 980341b3c20b6b13cb1c06a501b0b49303f768e6 Mon Sep 17 00:00:00 2001
From: Robert Haas <rhaas@postgresql.org>
Date: Thu, 29 Jul 2010 20:11:48 +0000
Subject: [PATCH] Avoid using text_to_cstring() in levenshtein functions.
Operating directly on the underlying varlena saves palloc and memcpy
overhead, which testing shows to be significant.
Extracted from a larger patch by Alexander Korotkov.
---
contrib/fuzzystrmatch/fuzzystrmatch.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)
diff --git a/contrib/fuzzystrmatch/fuzzystrmatch.c b/contrib/fuzzystrmatch/fuzzystrmatch.c
index 0bf7c681a18..16908159188 100644
--- a/contrib/fuzzystrmatch/fuzzystrmatch.c
+++ b/contrib/fuzzystrmatch/fuzzystrmatch.c
@@ -5,7 +5,7 @@
*
* Joe Conway <mail@joeconway.com>
*
- * $PostgreSQL: pgsql/contrib/fuzzystrmatch/fuzzystrmatch.c,v 1.32 2010/01/02 16:57:32 momjian Exp $
+ * $PostgreSQL: pgsql/contrib/fuzzystrmatch/fuzzystrmatch.c,v 1.33 2010/07/29 20:11:48 rhaas Exp $
* Copyright (c) 2001-2010, PostgreSQL Global Development Group
* ALL RIGHTS RESERVED;
*
@@ -90,7 +90,7 @@ soundex_code(char letter)
*/
#define MAX_LEVENSHTEIN_STRLEN 255
-static int levenshtein_internal(const char *s, const char *t,
+static int levenshtein_internal(text *s, text *t,
int ins_c, int del_c, int sub_c);
@@ -191,7 +191,7 @@ getcode(char c)
* cases, but your mileage may vary.
*/
static int
-levenshtein_internal(const char *s, const char *t,
+levenshtein_internal(text *s, text *t,
int ins_c, int del_c, int sub_c)
{
int m,
@@ -203,8 +203,8 @@ levenshtein_internal(const char *s, const char *t,
const char *x;
const char *y;
- m = strlen(s);
- n = strlen(t);
+ m = VARSIZE_ANY_EXHDR(s);
+ n = VARSIZE_ANY_EXHDR(t);
/*
* We can transform an empty s into t with n insertions, or a non-empty t
@@ -244,7 +244,7 @@ levenshtein_internal(const char *s, const char *t,
prev[i] = i * del_c;
/* Loop through rows of the notional array */
- for (y = t, j = 1; j < n; y++, j++)
+ for (y = VARDATA_ANY(t), j = 1; j < n; y++, j++)
{
int *temp;
@@ -254,7 +254,7 @@ levenshtein_internal(const char *s, const char *t,
*/
curr[0] = j * ins_c;
- for (x = s, i = 1; i < m; x++, i++)
+ for (x = VARDATA_ANY(s), i = 1; i < m; x++, i++)
{
int ins;
int del;
@@ -288,8 +288,8 @@ PG_FUNCTION_INFO_V1(levenshtein_with_costs);
Datum
levenshtein_with_costs(PG_FUNCTION_ARGS)
{
- char *src = TextDatumGetCString(PG_GETARG_DATUM(0));
- char *dst = TextDatumGetCString(PG_GETARG_DATUM(1));
+ text *src = PG_GETARG_TEXT_PP(0);
+ text *dst = PG_GETARG_TEXT_PP(1);
int ins_c = PG_GETARG_INT32(2);
int del_c = PG_GETARG_INT32(3);
int sub_c = PG_GETARG_INT32(4);
@@ -302,8 +302,8 @@ PG_FUNCTION_INFO_V1(levenshtein);
Datum
levenshtein(PG_FUNCTION_ARGS)
{
- char *src = TextDatumGetCString(PG_GETARG_DATUM(0));
- char *dst = TextDatumGetCString(PG_GETARG_DATUM(1));
+ text *src = PG_GETARG_TEXT_PP(0);
+ text *dst = PG_GETARG_TEXT_PP(1);
PG_RETURN_INT32(levenshtein_internal(src, dst, 1, 1, 1));
}
--
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