From e67716a2725037220a1d1226e12ff6212f1e5031 Mon Sep 17 00:00:00 2001 From: Bram Stein Date: Thu, 6 Nov 2014 16:22:16 +0100 Subject: Add Zopfli files. --- cache.h | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) create mode 100644 cache.h (limited to 'cache.h') diff --git a/cache.h b/cache.h new file mode 100644 index 0000000..5ca0c50 --- /dev/null +++ b/cache.h @@ -0,0 +1,66 @@ +/* +Copyright 2011 Google Inc. All Rights Reserved. + +Licensed under the Apache License, Version 2.0 (the "License"); +you may not use this file except in compliance with the License. +You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, software +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. + +Author: lode.vandevenne@gmail.com (Lode Vandevenne) +Author: jyrki.alakuijala@gmail.com (Jyrki Alakuijala) +*/ + +/* +The cache that speeds up ZopfliFindLongestMatch of lz77.c. +*/ + +#ifndef ZOPFLI_CACHE_H_ +#define ZOPFLI_CACHE_H_ + +#include "util.h" + +#ifdef ZOPFLI_LONGEST_MATCH_CACHE + +/* +Cache used by ZopfliFindLongestMatch to remember previously found length/dist +values. +This is needed because the squeeze runs will ask these values multiple times for +the same position. +Uses large amounts of memory, since it has to remember the distance belonging +to every possible shorter-than-the-best length (the so called "sublen" array). +*/ +typedef struct ZopfliLongestMatchCache { + unsigned short* length; + unsigned short* dist; + unsigned char* sublen; +} ZopfliLongestMatchCache; + +/* Initializes the ZopfliLongestMatchCache. */ +void ZopfliInitCache(size_t blocksize, ZopfliLongestMatchCache* lmc); + +/* Frees up the memory of the ZopfliLongestMatchCache. */ +void ZopfliCleanCache(ZopfliLongestMatchCache* lmc); + +/* Stores sublen array in the cache. */ +void ZopfliSublenToCache(const unsigned short* sublen, + size_t pos, size_t length, + ZopfliLongestMatchCache* lmc); + +/* Extracts sublen array from the cache. */ +void ZopfliCacheToSublen(const ZopfliLongestMatchCache* lmc, + size_t pos, size_t length, + unsigned short* sublen); +/* Returns the length up to which could be stored in the cache. */ +unsigned ZopfliMaxCachedSublen(const ZopfliLongestMatchCache* lmc, + size_t pos, size_t length); + +#endif /* ZOPFLI_LONGEST_MATCH_CACHE */ + +#endif /* ZOPFLI_CACHE_H_ */ -- cgit v1.2.3