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https://github.com/facebook/zstd.git
synced 2025-03-07 09:26:03 +02:00
0abf2baef9
The split literals buffer patch increased streaming decompression memory by 64KB (shrunk lit buffer from 128KB to 64KB, and added 128KB). This patch removes the added 128KB buffer, because it isn't necessary. The buffer was there because the literals compression code didn't know the true `blockSizeMax` of the frame, and always put split literals so they ended 128KB - 32 from the beginning of the block. Instead, we can pass down the true `blockSizeMax` and ensure that the split literals end up at `blockSizeMax - 32` from the beginning of the block. We already reserve a full `blockSizeMax` bytes in streaming mode, so we won't be overwriting the extDict window.
74 lines
2.6 KiB
C
74 lines
2.6 KiB
C
/*
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* Copyright (c) Meta Platforms, Inc. and affiliates.
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* All rights reserved.
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*
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* This source code is licensed under both the BSD-style license (found in the
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* LICENSE file in the root directory of this source tree) and the GPLv2 (found
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* in the COPYING file in the root directory of this source tree).
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* You may select, at your option, one of the above-listed licenses.
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*/
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#ifndef ZSTD_DEC_BLOCK_H
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#define ZSTD_DEC_BLOCK_H
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/*-*******************************************************
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* Dependencies
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*********************************************************/
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#include "../common/zstd_deps.h" /* size_t */
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#include "../zstd.h" /* DCtx, and some public functions */
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#include "../common/zstd_internal.h" /* blockProperties_t, and some public functions */
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#include "zstd_decompress_internal.h" /* ZSTD_seqSymbol */
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/* === Prototypes === */
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/* note: prototypes already published within `zstd.h` :
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* ZSTD_decompressBlock()
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*/
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/* note: prototypes already published within `zstd_internal.h` :
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* ZSTD_getcBlockSize()
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* ZSTD_decodeSeqHeaders()
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*/
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/* Streaming state is used to inform allocation of the literal buffer */
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typedef enum {
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not_streaming = 0,
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is_streaming = 1
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} streaming_operation;
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/* ZSTD_decompressBlock_internal() :
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* decompress block, starting at `src`,
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* into destination buffer `dst`.
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* @return : decompressed block size,
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* or an error code (which can be tested using ZSTD_isError())
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*/
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size_t ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx,
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void* dst, size_t dstCapacity,
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const void* src, size_t srcSize, const streaming_operation streaming);
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/* ZSTD_buildFSETable() :
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* generate FSE decoding table for one symbol (ll, ml or off)
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* this function must be called with valid parameters only
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* (dt is large enough, normalizedCounter distribution total is a power of 2, max is within range, etc.)
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* in which case it cannot fail.
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* The workspace must be 4-byte aligned and at least ZSTD_BUILD_FSE_TABLE_WKSP_SIZE bytes, which is
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* defined in zstd_decompress_internal.h.
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* Internal use only.
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*/
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void ZSTD_buildFSETable(ZSTD_seqSymbol* dt,
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const short* normalizedCounter, unsigned maxSymbolValue,
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const U32* baseValue, const U8* nbAdditionalBits,
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unsigned tableLog, void* wksp, size_t wkspSize,
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int bmi2);
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/* Internal definition of ZSTD_decompressBlock() to avoid deprecation warnings. */
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size_t ZSTD_decompressBlock_deprecated(ZSTD_DCtx* dctx,
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void* dst, size_t dstCapacity,
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const void* src, size_t srcSize);
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#endif /* ZSTD_DEC_BLOCK_H */
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