##// END OF EJS Templates
revlog: add a small cache of unfiltered chunk...
revlog: add a small cache of unfiltered chunk This can provides a massive boost to the reading of multiple revision and the computation of a valid delta chain. This greatly help operation like `hg log --patch`, delta computation (helping pull/unbundle), linkrev adjustment (helping copy tracing). A first round of benchmark for `hg log --patch --limit 1000` shows improvement in the 10-20% range on "small" repository like pypy or mercurial and large improvements (about 33%) for more complex ones like netbeans and mozilla's. These speeds up are consistent with the improvement to `hg pull` (from a server sending poor deltas) I saw benchmarking this last year. Further benchmark will be run during the freeze. I added some configuration in the experimental space to be able to further test the effect of various tuning for now. This feature should fit well in the "usage/resource profile" configuration that we should land next cycle. When it does not provides a benefit the overhead of the cache seem to be around 2%, a small price for the big improvement. In addition I believe we could shave most of this overhead with a more efficent lru implementation.

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zstd_decompress_block.h
59 lines | 2.0 KiB | text/x-c | CLexer
/*
* Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
* You may select, at your option, one of the above-listed licenses.
*/
#ifndef ZSTD_DEC_BLOCK_H
#define ZSTD_DEC_BLOCK_H
/*-*******************************************************
* Dependencies
*********************************************************/
#include <stddef.h> /* size_t */
#include "zstd.h" /* DCtx, and some public functions */
#include "zstd_internal.h" /* blockProperties_t, and some public functions */
#include "zstd_decompress_internal.h" /* ZSTD_seqSymbol */
/* === Prototypes === */
/* note: prototypes already published within `zstd.h` :
* ZSTD_decompressBlock()
*/
/* note: prototypes already published within `zstd_internal.h` :
* ZSTD_getcBlockSize()
* ZSTD_decodeSeqHeaders()
*/
/* ZSTD_decompressBlock_internal() :
* decompress block, starting at `src`,
* into destination buffer `dst`.
* @return : decompressed block size,
* or an error code (which can be tested using ZSTD_isError())
*/
size_t ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize, const int frame);
/* ZSTD_buildFSETable() :
* generate FSE decoding table for one symbol (ll, ml or off)
* this function must be called with valid parameters only
* (dt is large enough, normalizedCounter distribution total is a power of 2, max is within range, etc.)
* in which case it cannot fail.
* Internal use only.
*/
void ZSTD_buildFSETable(ZSTD_seqSymbol* dt,
const short* normalizedCounter, unsigned maxSymbolValue,
const U32* baseValue, const U32* nbAdditionalBits,
unsigned tableLog);
#endif /* ZSTD_DEC_BLOCK_H */