From: Adam Harvey <aharvey@php.net>
Date: Mon, 8 Nov 2010 09:35:33 +0000 (+0000)
Subject: Implemented FR #53213 (Adler32 algorithm is very slow). Patch by zavasek at
X-Git-Tag: php-5.4.0alpha1~191^2~713
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=18096f4b6811432133e1e6f13b4914d3c1cfd6f9;p=php

Implemented FR #53213 (Adler32 algorithm is very slow). Patch by zavasek at
yandex dot ru.
---

diff --git a/NEWS b/NEWS
index 45aace19c8..a2f5622b71 100644
--- a/NEWS
+++ b/NEWS
@@ -124,6 +124,8 @@
 
 - Implemented FR #53238 (Make third parameter of preg_match_all optional).
   (Adam)
+- Implemented FR #53213 (Adler32 algorithm is very slow).
+  (zavasek at yandex dot ru)
 - Implemented FR #52555 (Ability to get HTTP response code). (Paul Dragoonis)
 - Implemented FR #51295 (SQLite3::busyTimeout not existing). (Mark)
 - Implemented FR #49366 (Make slash escaping optional in json_encode()). (Adam)
diff --git a/ext/hash/hash_adler32.c b/ext/hash/hash_adler32.c
index 24c63f5852..b19cc53021 100644
--- a/ext/hash/hash_adler32.c
+++ b/ext/hash/hash_adler32.c
@@ -34,9 +34,16 @@ PHP_HASH_API void PHP_ADLER32Update(PHP_ADLER32_CTX *context, const unsigned cha
 	s[0] = context->state & 0xffff;
 	s[1] = (context->state >> 16) & 0xffff;
 	for (i = 0; i < len; ++i) {
-		s[0] = (s[0] + input[i]) % 65521;
-		s[1] = (s[1] + s[0]) % 65521;
+		s[0] += input[i];
+		s[1] += s[0];
+		if (s[1]>=0x7fffffff)
+		{
+			s[0] = s[0] % 65521;
+			s[1] = s[1] % 65521;
+		}
 	}
+	s[0] = s[0] % 65521;
+	s[1] = s[1] % 65521;
 	context->state = s[0] + (s[1] << 16);
 }