--- /dev/null
+/*
+ * Copyright (c) 2016-2020, 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.
+ */
+
+ /*-*************************************
+ * Dependencies
+ ***************************************/
+#include "zstd_compress_superblock.h"
+
+#include "../common/zstd_internal.h" /* ZSTD_getSequenceLength */
+#include "hist.h" /* HIST_countFast_wksp */
+#include "zstd_compress_internal.h"
+#include "zstd_compress_sequences.h"
+#include "zstd_compress_literals.h"
+
+/*-*************************************
+* Superblock entropy buffer structs
+***************************************/
+/** ZSTD_hufCTablesMetadata_t :
+ * Stores Literals Block Type for a super-block in hType, and
+ * huffman tree description in hufDesBuffer.
+ * hufDesSize refers to the size of huffman tree description in bytes.
+ * This metadata is populated in ZSTD_buildSuperBlockEntropy_literal() */
+typedef struct {
+ symbolEncodingType_e hType;
+ BYTE hufDesBuffer[500]; /* TODO give name to this value */
+ size_t hufDesSize;
+} ZSTD_hufCTablesMetadata_t;
+
+/** ZSTD_fseCTablesMetadata_t :
+ * Stores symbol compression modes for a super-block in {ll, ol, ml}Type, and
+ * fse tables in fseTablesBuffer.
+ * fseTablesSize refers to the size of fse tables in bytes.
+ * This metadata is populated in ZSTD_buildSuperBlockEntropy_sequences() */
+typedef struct {
+ symbolEncodingType_e llType;
+ symbolEncodingType_e ofType;
+ symbolEncodingType_e mlType;
+ BYTE fseTablesBuffer[500]; /* TODO give name to this value */
+ size_t fseTablesSize;
+ size_t lastCountSize; /* This is to account for bug in 1.3.4. More detail in ZSTD_compressSubBlock_sequences() */
+} ZSTD_fseCTablesMetadata_t;
+
+typedef struct {
+ ZSTD_hufCTablesMetadata_t hufMetadata;
+ ZSTD_fseCTablesMetadata_t fseMetadata;
+} ZSTD_entropyCTablesMetadata_t;
+
+
+/** ZSTD_buildSuperBlockEntropy_literal() :
+ * Builds entropy for the super-block literals.
+ * Stores literals block type (raw, rle, compressed, repeat) and
+ * huffman description table to hufMetadata.
+ * @return : size of huffman description table or error code */
+static size_t ZSTD_buildSuperBlockEntropy_literal(void* const src, size_t srcSize,
+ const ZSTD_hufCTables_t* prevHuf,
+ ZSTD_hufCTables_t* nextHuf,
+ ZSTD_hufCTablesMetadata_t* hufMetadata,
+ const int disableLiteralsCompression,
+ void* workspace, size_t wkspSize)
+{
+ BYTE* const wkspStart = (BYTE*)workspace;
+ BYTE* const wkspEnd = wkspStart + wkspSize;
+ BYTE* const countWkspStart = wkspStart;
+ unsigned* const countWksp = (unsigned*)workspace;
+ const size_t countWkspSize = (HUF_SYMBOLVALUE_MAX + 1) * sizeof(unsigned);
+ BYTE* const nodeWksp = countWkspStart + countWkspSize;
+ const size_t nodeWkspSize = wkspEnd-nodeWksp;
+ unsigned maxSymbolValue = 255;
+ unsigned huffLog = HUF_TABLELOG_DEFAULT;
+ HUF_repeat repeat = prevHuf->repeatMode;
+
+ DEBUGLOG(5, "ZSTD_buildSuperBlockEntropy_literal (srcSize=%zu)", srcSize);
+
+ /* Prepare nextEntropy assuming reusing the existing table */
+ memcpy(nextHuf, prevHuf, sizeof(*prevHuf));
+
+ if (disableLiteralsCompression) {
+ DEBUGLOG(5, "set_basic - disabled");
+ hufMetadata->hType = set_basic;
+ return 0;
+ }
+
+ /* small ? don't even attempt compression (speed opt) */
+# define COMPRESS_LITERALS_SIZE_MIN 63
+ { size_t const minLitSize = (prevHuf->repeatMode == HUF_repeat_valid) ? 6 : COMPRESS_LITERALS_SIZE_MIN;
+ if (srcSize <= minLitSize) {
+ DEBUGLOG(5, "set_basic - too small");
+ hufMetadata->hType = set_basic;
+ return 0;
+ }
+ }
+
+ /* Scan input and build symbol stats */
+ { size_t const largest = HIST_count_wksp (countWksp, &maxSymbolValue, (const BYTE*)src, srcSize, workspace, wkspSize);
+ FORWARD_IF_ERROR(largest, "HIST_count_wksp failed");
+ if (largest == srcSize) {
+ DEBUGLOG(5, "set_rle");
+ hufMetadata->hType = set_rle;
+ return 0;
+ }
+ if (largest <= (srcSize >> 7)+4) {
+ DEBUGLOG(5, "set_basic - no gain");
+ hufMetadata->hType = set_basic;
+ return 0;
+ }
+ }
+
+ /* Validate the previous Huffman table */
+ if (repeat == HUF_repeat_check && !HUF_validateCTable((HUF_CElt const*)prevHuf->CTable, countWksp, maxSymbolValue)) {
+ repeat = HUF_repeat_none;
+ }
+
+ /* Build Huffman Tree */
+ memset(nextHuf->CTable, 0, sizeof(nextHuf->CTable));
+ huffLog = HUF_optimalTableLog(huffLog, srcSize, maxSymbolValue);
+ { size_t const maxBits = HUF_buildCTable_wksp((HUF_CElt*)nextHuf->CTable, countWksp,
+ maxSymbolValue, huffLog,
+ nodeWksp, nodeWkspSize);
+ FORWARD_IF_ERROR(maxBits, "HUF_buildCTable_wksp");
+ huffLog = (U32)maxBits;
+ { /* Build and write the CTable */
+ size_t const newCSize = HUF_estimateCompressedSize(
+ (HUF_CElt*)nextHuf->CTable, countWksp, maxSymbolValue);
+ size_t const hSize = HUF_writeCTable(
+ hufMetadata->hufDesBuffer, sizeof(hufMetadata->hufDesBuffer),
+ (HUF_CElt*)nextHuf->CTable, maxSymbolValue, huffLog);
+ /* Check against repeating the previous CTable */
+ if (repeat != HUF_repeat_none) {
+ size_t const oldCSize = HUF_estimateCompressedSize(
+ (HUF_CElt const*)prevHuf->CTable, countWksp, maxSymbolValue);
+ if (oldCSize < srcSize && (oldCSize <= hSize + newCSize || hSize + 12 >= srcSize)) {
+ DEBUGLOG(5, "set_repeat - smaller");
+ memcpy(nextHuf, prevHuf, sizeof(*prevHuf));
+ hufMetadata->hType = set_repeat;
+ return 0;
+ }
+ }
+ if (newCSize + hSize >= srcSize) {
+ DEBUGLOG(5, "set_basic - no gains");
+ memcpy(nextHuf, prevHuf, sizeof(*prevHuf));
+ hufMetadata->hType = set_basic;
+ return 0;
+ }
+ DEBUGLOG(5, "set_compressed (hSize=%u)", (U32)hSize);
+ hufMetadata->hType = set_compressed;
+ nextHuf->repeatMode = HUF_repeat_check;
+ return hSize;
+ }
+ }
+}
+
+/** ZSTD_buildSuperBlockEntropy_sequences() :
+ * Builds entropy for the super-block sequences.
+ * Stores symbol compression modes and fse table to fseMetadata.
+ * @return : size of fse tables or error code */
+static size_t ZSTD_buildSuperBlockEntropy_sequences(seqStore_t* seqStorePtr,
+ const ZSTD_fseCTables_t* prevEntropy,
+ ZSTD_fseCTables_t* nextEntropy,
+ const ZSTD_CCtx_params* cctxParams,
+ ZSTD_fseCTablesMetadata_t* fseMetadata,
+ void* workspace, size_t wkspSize)
+{
+ BYTE* const wkspStart = (BYTE*)workspace;
+ BYTE* const wkspEnd = wkspStart + wkspSize;
+ BYTE* const countWkspStart = wkspStart;
+ unsigned* const countWksp = (unsigned*)workspace;
+ const size_t countWkspSize = (MaxSeq + 1) * sizeof(unsigned);
+ BYTE* const cTableWksp = countWkspStart + countWkspSize;
+ const size_t cTableWkspSize = wkspEnd-cTableWksp;
+ ZSTD_strategy const strategy = cctxParams->cParams.strategy;
+ FSE_CTable* CTable_LitLength = nextEntropy->litlengthCTable;
+ FSE_CTable* CTable_OffsetBits = nextEntropy->offcodeCTable;
+ FSE_CTable* CTable_MatchLength = nextEntropy->matchlengthCTable;
+ const BYTE* const ofCodeTable = seqStorePtr->ofCode;
+ const BYTE* const llCodeTable = seqStorePtr->llCode;
+ const BYTE* const mlCodeTable = seqStorePtr->mlCode;
+ size_t const nbSeq = seqStorePtr->sequences - seqStorePtr->sequencesStart;
+ BYTE* const ostart = fseMetadata->fseTablesBuffer;
+ BYTE* const oend = ostart + sizeof(fseMetadata->fseTablesBuffer);
+ BYTE* op = ostart;
+
+ assert(cTableWkspSize >= (1 << MaxFSELog) * sizeof(FSE_FUNCTION_TYPE));
+ DEBUGLOG(5, "ZSTD_buildSuperBlockEntropy_sequences (nbSeq=%zu)", nbSeq);
+ memset(workspace, 0, wkspSize);
+
+ fseMetadata->lastCountSize = 0;
+ /* convert length/distances into codes */
+ ZSTD_seqToCodes(seqStorePtr);
+ /* build CTable for Literal Lengths */
+ { U32 LLtype;
+ unsigned max = MaxLL;
+ size_t const mostFrequent = HIST_countFast_wksp(countWksp, &max, llCodeTable, nbSeq, workspace, wkspSize); /* can't fail */
+ DEBUGLOG(5, "Building LL table");
+ nextEntropy->litlength_repeatMode = prevEntropy->litlength_repeatMode;
+ LLtype = ZSTD_selectEncodingType(&nextEntropy->litlength_repeatMode,
+ countWksp, max, mostFrequent, nbSeq,
+ LLFSELog, prevEntropy->litlengthCTable,
+ LL_defaultNorm, LL_defaultNormLog,
+ ZSTD_defaultAllowed, strategy);
+ assert(set_basic < set_compressed && set_rle < set_compressed);
+ assert(!(LLtype < set_compressed && nextEntropy->litlength_repeatMode != FSE_repeat_none)); /* We don't copy tables */
+ { size_t const countSize = ZSTD_buildCTable(op, oend - op, CTable_LitLength, LLFSELog, (symbolEncodingType_e)LLtype,
+ countWksp, max, llCodeTable, nbSeq, LL_defaultNorm, LL_defaultNormLog, MaxLL,
+ prevEntropy->litlengthCTable, sizeof(prevEntropy->litlengthCTable),
+ cTableWksp, cTableWkspSize);
+ FORWARD_IF_ERROR(countSize, "ZSTD_buildCTable for LitLens failed");
+ if (LLtype == set_compressed)
+ fseMetadata->lastCountSize = countSize;
+ op += countSize;
+ fseMetadata->llType = (symbolEncodingType_e) LLtype;
+ } }
+ /* build CTable for Offsets */
+ { U32 Offtype;
+ unsigned max = MaxOff;
+ size_t const mostFrequent = HIST_countFast_wksp(countWksp, &max, ofCodeTable, nbSeq, workspace, wkspSize); /* can't fail */
+ /* We can only use the basic table if max <= DefaultMaxOff, otherwise the offsets are too large */
+ ZSTD_defaultPolicy_e const defaultPolicy = (max <= DefaultMaxOff) ? ZSTD_defaultAllowed : ZSTD_defaultDisallowed;
+ DEBUGLOG(5, "Building OF table");
+ nextEntropy->offcode_repeatMode = prevEntropy->offcode_repeatMode;
+ Offtype = ZSTD_selectEncodingType(&nextEntropy->offcode_repeatMode,
+ countWksp, max, mostFrequent, nbSeq,
+ OffFSELog, prevEntropy->offcodeCTable,
+ OF_defaultNorm, OF_defaultNormLog,
+ defaultPolicy, strategy);
+ assert(!(Offtype < set_compressed && nextEntropy->offcode_repeatMode != FSE_repeat_none)); /* We don't copy tables */
+ { size_t const countSize = ZSTD_buildCTable(op, oend - op, CTable_OffsetBits, OffFSELog, (symbolEncodingType_e)Offtype,
+ countWksp, max, ofCodeTable, nbSeq, OF_defaultNorm, OF_defaultNormLog, DefaultMaxOff,
+ prevEntropy->offcodeCTable, sizeof(prevEntropy->offcodeCTable),
+ cTableWksp, cTableWkspSize);
+ FORWARD_IF_ERROR(countSize, "ZSTD_buildCTable for Offsets failed");
+ if (Offtype == set_compressed)
+ fseMetadata->lastCountSize = countSize;
+ op += countSize;
+ fseMetadata->ofType = (symbolEncodingType_e) Offtype;
+ } }
+ /* build CTable for MatchLengths */
+ { U32 MLtype;
+ unsigned max = MaxML;
+ size_t const mostFrequent = HIST_countFast_wksp(countWksp, &max, mlCodeTable, nbSeq, workspace, wkspSize); /* can't fail */
+ DEBUGLOG(5, "Building ML table (remaining space : %i)", (int)(oend-op));
+ nextEntropy->matchlength_repeatMode = prevEntropy->matchlength_repeatMode;
+ MLtype = ZSTD_selectEncodingType(&nextEntropy->matchlength_repeatMode,
+ countWksp, max, mostFrequent, nbSeq,
+ MLFSELog, prevEntropy->matchlengthCTable,
+ ML_defaultNorm, ML_defaultNormLog,
+ ZSTD_defaultAllowed, strategy);
+ assert(!(MLtype < set_compressed && nextEntropy->matchlength_repeatMode != FSE_repeat_none)); /* We don't copy tables */
+ { size_t const countSize = ZSTD_buildCTable(op, oend - op, CTable_MatchLength, MLFSELog, (symbolEncodingType_e)MLtype,
+ countWksp, max, mlCodeTable, nbSeq, ML_defaultNorm, ML_defaultNormLog, MaxML,
+ prevEntropy->matchlengthCTable, sizeof(prevEntropy->matchlengthCTable),
+ cTableWksp, cTableWkspSize);
+ FORWARD_IF_ERROR(countSize, "ZSTD_buildCTable for MatchLengths failed");
+ if (MLtype == set_compressed)
+ fseMetadata->lastCountSize = countSize;
+ op += countSize;
+ fseMetadata->mlType = (symbolEncodingType_e) MLtype;
+ } }
+ assert((size_t) (op-ostart) <= sizeof(fseMetadata->fseTablesBuffer));
+ return op-ostart;
+}
+
+
+/** ZSTD_buildSuperBlockEntropy() :
+ * Builds entropy for the super-block.
+ * @return : 0 on success or error code */
+static size_t
+ZSTD_buildSuperBlockEntropy(seqStore_t* seqStorePtr,
+ const ZSTD_entropyCTables_t* prevEntropy,
+ ZSTD_entropyCTables_t* nextEntropy,
+ const ZSTD_CCtx_params* cctxParams,
+ ZSTD_entropyCTablesMetadata_t* entropyMetadata,
+ void* workspace, size_t wkspSize)
+{
+ size_t const litSize = seqStorePtr->lit - seqStorePtr->litStart;
+ DEBUGLOG(5, "ZSTD_buildSuperBlockEntropy");
+ entropyMetadata->hufMetadata.hufDesSize =
+ ZSTD_buildSuperBlockEntropy_literal(seqStorePtr->litStart, litSize,
+ &prevEntropy->huf, &nextEntropy->huf,
+ &entropyMetadata->hufMetadata,
+ ZSTD_disableLiteralsCompression(cctxParams),
+ workspace, wkspSize);
+ FORWARD_IF_ERROR(entropyMetadata->hufMetadata.hufDesSize, "ZSTD_buildSuperBlockEntropy_literal failed");
+ entropyMetadata->fseMetadata.fseTablesSize =
+ ZSTD_buildSuperBlockEntropy_sequences(seqStorePtr,
+ &prevEntropy->fse, &nextEntropy->fse,
+ cctxParams,
+ &entropyMetadata->fseMetadata,
+ workspace, wkspSize);
+ FORWARD_IF_ERROR(entropyMetadata->fseMetadata.fseTablesSize, "ZSTD_buildSuperBlockEntropy_sequences failed");
+ return 0;
+}
+
+/** ZSTD_compressSubBlock_literal() :
+ * Compresses literals section for a sub-block.
+ * When we have to write the Huffman table we will sometimes choose a header
+ * size larger than necessary. This is because we have to pick the header size
+ * before we know the table size + compressed size, so we have a bound on the
+ * table size. If we guessed incorrectly, we fall back to uncompressed literals.
+ *
+ * We write the header when writeEntropy=1 and set entropyWrriten=1 when we succeeded
+ * in writing the header, otherwise it is set to 0.
+ *
+ * hufMetadata->hType has literals block type info.
+ * If it is set_basic, all sub-blocks literals section will be Raw_Literals_Block.
+ * If it is set_rle, all sub-blocks literals section will be RLE_Literals_Block.
+ * If it is set_compressed, first sub-block's literals section will be Compressed_Literals_Block
+ * If it is set_compressed, first sub-block's literals section will be Treeless_Literals_Block
+ * and the following sub-blocks' literals sections will be Treeless_Literals_Block.
+ * @return : compressed size of literals section of a sub-block
+ * Or 0 if it unable to compress.
+ * Or error code */
+static size_t ZSTD_compressSubBlock_literal(const HUF_CElt* hufTable,
+ const ZSTD_hufCTablesMetadata_t* hufMetadata,
+ const BYTE* literals, size_t litSize,
+ void* dst, size_t dstSize,
+ const int bmi2, int writeEntropy, int* entropyWritten)
+{
+ size_t const header = writeEntropy ? 200 : 0;
+ size_t const lhSize = 3 + (litSize >= (1 KB - header)) + (litSize >= (16 KB - header));
+ BYTE* const ostart = (BYTE*)dst;
+ BYTE* const oend = ostart + dstSize;
+ BYTE* op = ostart + lhSize;
+ U32 const singleStream = lhSize == 3;
+ symbolEncodingType_e hType = writeEntropy ? hufMetadata->hType : set_repeat;
+ size_t cLitSize = 0;
+
+ (void)bmi2; /* TODO bmi2... */
+
+ DEBUGLOG(5, "ZSTD_compressSubBlock_literal (litSize=%zu, lhSize=%zu, writeEntropy=%d)", litSize, lhSize, writeEntropy);
+
+ *entropyWritten = 0;
+ if (litSize == 0 || hufMetadata->hType == set_basic) {
+ DEBUGLOG(5, "ZSTD_compressSubBlock_literal using raw literal");
+ return ZSTD_noCompressLiterals(dst, dstSize, literals, litSize);
+ } else if (hufMetadata->hType == set_rle) {
+ DEBUGLOG(5, "ZSTD_compressSubBlock_literal using rle literal");
+ return ZSTD_compressRleLiteralsBlock(dst, dstSize, literals, litSize);
+ }
+
+ assert(litSize > 0);
+ assert(hufMetadata->hType == set_compressed || hufMetadata->hType == set_repeat);
+
+ if (writeEntropy && hufMetadata->hType == set_compressed) {
+ memcpy(op, hufMetadata->hufDesBuffer, hufMetadata->hufDesSize);
+ op += hufMetadata->hufDesSize;
+ cLitSize += hufMetadata->hufDesSize;
+ DEBUGLOG(5, "ZSTD_compressSubBlock_literal (hSize=%zu)", hufMetadata->hufDesSize);
+ }
+
+ /* TODO bmi2 */
+ { const size_t cSize = singleStream ? HUF_compress1X_usingCTable(op, oend-op, literals, litSize, hufTable)
+ : HUF_compress4X_usingCTable(op, oend-op, literals, litSize, hufTable);
+ op += cSize;
+ cLitSize += cSize;
+ if (cSize == 0 || ERR_isError(cSize)) {
+ DEBUGLOG(5, "Failed to write entropy tables %s", ZSTD_getErrorName(cSize));
+ return 0;
+ }
+ /* If we expand and we aren't writing a header then emit uncompressed */
+ if (!writeEntropy && cLitSize >= litSize) {
+ DEBUGLOG(5, "ZSTD_compressSubBlock_literal using raw literal because uncompressible");
+ return ZSTD_noCompressLiterals(dst, dstSize, literals, litSize);
+ }
+ /* If we are writing headers then allow expansion that doesn't change our header size. */
+ if (lhSize < (size_t)(3 + (cLitSize >= 1 KB) + (cLitSize >= 16 KB))) {
+ assert(cLitSize > litSize);
+ DEBUGLOG(5, "Literals expanded beyond allowed header size");
+ return ZSTD_noCompressLiterals(dst, dstSize, literals, litSize);
+ }
+ DEBUGLOG(5, "ZSTD_compressSubBlock_literal (cSize=%zu)", cSize);
+ }
+
+ /* Build header */
+ switch(lhSize)
+ {
+ case 3: /* 2 - 2 - 10 - 10 */
+ { U32 const lhc = hType + ((!singleStream) << 2) + ((U32)litSize<<4) + ((U32)cLitSize<<14);
+ MEM_writeLE24(ostart, lhc);
+ break;
+ }
+ case 4: /* 2 - 2 - 14 - 14 */
+ { U32 const lhc = hType + (2 << 2) + ((U32)litSize<<4) + ((U32)cLitSize<<18);
+ MEM_writeLE32(ostart, lhc);
+ break;
+ }
+ case 5: /* 2 - 2 - 18 - 18 */
+ { U32 const lhc = hType + (3 << 2) + ((U32)litSize<<4) + ((U32)cLitSize<<22);
+ MEM_writeLE32(ostart, lhc);
+ ostart[4] = (BYTE)(cLitSize >> 10);
+ break;
+ }
+ default: /* not possible : lhSize is {3,4,5} */
+ assert(0);
+ }
+ *entropyWritten = 1;
+ DEBUGLOG(5, "Compressed literals: %u -> %u", (U32)litSize, (U32)(op-ostart));
+ return op-ostart;
+}
+
+static size_t ZSTD_seqDecompressedSize(seqStore_t const* seqStore, const seqDef* sequences, size_t nbSeq, size_t litSize, int lastSequence) {
+ const seqDef* const sstart = sequences;
+ const seqDef* const send = sequences + nbSeq;
+ const seqDef* sp = sstart;
+ size_t matchLengthSum = 0;
+ size_t litLengthSum = 0;
+ while (send-sp > 0) {
+ ZSTD_sequenceLength const seqLen = ZSTD_getSequenceLength(seqStore, sp);
+ litLengthSum += seqLen.litLength;
+ matchLengthSum += seqLen.matchLength;
+ sp++;
+ }
+ assert(litLengthSum <= litSize);
+ if (!lastSequence) {
+ assert(litLengthSum == litSize);
+ }
+ return matchLengthSum + litSize;
+}
+
+/** ZSTD_compressSubBlock_sequences() :
+ * Compresses sequences section for a sub-block.
+ * fseMetadata->llType, fseMetadata->ofType, and fseMetadata->mlType have
+ * symbol compression modes for the super-block.
+ * The first successfully compressed block will have these in its header.
+ * We set entropyWritten=1 when we succeed in compressing the sequences.
+ * The following sub-blocks will always have repeat mode.
+ * @return : compressed size of sequences section of a sub-block
+ * Or 0 if it is unable to compress
+ * Or error code. */
+static size_t ZSTD_compressSubBlock_sequences(const ZSTD_fseCTables_t* fseTables,
+ const ZSTD_fseCTablesMetadata_t* fseMetadata,
+ const seqDef* sequences, size_t nbSeq,
+ const BYTE* llCode, const BYTE* mlCode, const BYTE* ofCode,
+ const ZSTD_CCtx_params* cctxParams,
+ void* dst, size_t dstCapacity,
+ const int bmi2, int writeEntropy, int* entropyWritten)
+{
+ const int longOffsets = cctxParams->cParams.windowLog > STREAM_ACCUMULATOR_MIN;
+ BYTE* const ostart = (BYTE*)dst;
+ BYTE* const oend = ostart + dstCapacity;
+ BYTE* op = ostart;
+ BYTE* seqHead;
+
+ DEBUGLOG(5, "ZSTD_compressSubBlock_sequences (nbSeq=%zu, writeEntropy=%d, longOffsets=%d)", nbSeq, writeEntropy, longOffsets);
+
+ *entropyWritten = 0;
+ /* Sequences Header */
+ RETURN_ERROR_IF((oend-op) < 3 /*max nbSeq Size*/ + 1 /*seqHead*/,
+ dstSize_tooSmall, "");
+ if (nbSeq < 0x7F)
+ *op++ = (BYTE)nbSeq;
+ else if (nbSeq < LONGNBSEQ)
+ op[0] = (BYTE)((nbSeq>>8) + 0x80), op[1] = (BYTE)nbSeq, op+=2;
+ else
+ op[0]=0xFF, MEM_writeLE16(op+1, (U16)(nbSeq - LONGNBSEQ)), op+=3;
+ if (nbSeq==0) {
+ return op - ostart;
+ }
+
+ /* seqHead : flags for FSE encoding type */
+ seqHead = op++;
+
+ DEBUGLOG(5, "ZSTD_compressSubBlock_sequences (seqHeadSize=%u)", (unsigned)(op-ostart));
+
+ if (writeEntropy) {
+ const U32 LLtype = fseMetadata->llType;
+ const U32 Offtype = fseMetadata->ofType;
+ const U32 MLtype = fseMetadata->mlType;
+ DEBUGLOG(5, "ZSTD_compressSubBlock_sequences (fseTablesSize=%zu)", fseMetadata->fseTablesSize);
+ *seqHead = (BYTE)((LLtype<<6) + (Offtype<<4) + (MLtype<<2));
+ memcpy(op, fseMetadata->fseTablesBuffer, fseMetadata->fseTablesSize);
+ op += fseMetadata->fseTablesSize;
+ } else {
+ const U32 repeat = set_repeat;
+ *seqHead = (BYTE)((repeat<<6) + (repeat<<4) + (repeat<<2));
+ }
+
+ { size_t const bitstreamSize = ZSTD_encodeSequences(
+ op, oend - op,
+ fseTables->matchlengthCTable, mlCode,
+ fseTables->offcodeCTable, ofCode,
+ fseTables->litlengthCTable, llCode,
+ sequences, nbSeq,
+ longOffsets, bmi2);
+ FORWARD_IF_ERROR(bitstreamSize, "ZSTD_encodeSequences failed");
+ op += bitstreamSize;
+ /* zstd versions <= 1.3.4 mistakenly report corruption when
+ * FSE_readNCount() receives a buffer < 4 bytes.
+ * Fixed by https://github.com/facebook/zstd/pull/1146.
+ * This can happen when the last set_compressed table present is 2
+ * bytes and the bitstream is only one byte.
+ * In this exceedingly rare case, we will simply emit an uncompressed
+ * block, since it isn't worth optimizing.
+ */
+#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+ if (writeEntropy && fseMetadata->lastCountSize && fseMetadata->lastCountSize + bitstreamSize < 4) {
+ /* NCountSize >= 2 && bitstreamSize > 0 ==> lastCountSize == 3 */
+ assert(fseMetadata->lastCountSize + bitstreamSize == 3);
+ DEBUGLOG(5, "Avoiding bug in zstd decoder in versions <= 1.3.4 by "
+ "emitting an uncompressed block.");
+ return 0;
+ }
+#endif
+ DEBUGLOG(5, "ZSTD_compressSubBlock_sequences (bitstreamSize=%zu)", bitstreamSize);
+ }
+
+ /* zstd versions <= 1.4.0 mistakenly report error when
+ * sequences section body size is less than 3 bytes.
+ * Fixed by https://github.com/facebook/zstd/pull/1664.
+ * This can happen when the previous sequences section block is compressed
+ * with rle mode and the current block's sequences section is compressed
+ * with repeat mode where sequences section body size can be 1 byte.
+ */
+#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+ if (op-seqHead < 4) {
+ DEBUGLOG(5, "Avoiding bug in zstd decoder in versions <= 1.4.0 by emitting "
+ "an uncompressed block when sequences are < 4 bytes");
+ return 0;
+ }
+#endif
+
+ *entropyWritten = 1;
+ return op - ostart;
+}
+
+/** ZSTD_compressSubBlock() :
+ * Compresses a single sub-block.
+ * @return : compressed size of the sub-block
+ * Or 0 if it failed to compress. */
+static size_t ZSTD_compressSubBlock(const ZSTD_entropyCTables_t* entropy,
+ const ZSTD_entropyCTablesMetadata_t* entropyMetadata,
+ const seqDef* sequences, size_t nbSeq,
+ const BYTE* literals, size_t litSize,
+ const BYTE* llCode, const BYTE* mlCode, const BYTE* ofCode,
+ const ZSTD_CCtx_params* cctxParams,
+ void* dst, size_t dstCapacity,
+ const int bmi2,
+ int writeLitEntropy, int writeSeqEntropy,
+ int* litEntropyWritten, int* seqEntropyWritten,
+ U32 lastBlock)
+{
+ BYTE* const ostart = (BYTE*)dst;
+ BYTE* const oend = ostart + dstCapacity;
+ BYTE* op = ostart + ZSTD_blockHeaderSize;
+ DEBUGLOG(5, "ZSTD_compressSubBlock (litSize=%zu, nbSeq=%zu, writeLitEntropy=%d, writeSeqEntropy=%d, lastBlock=%d)",
+ litSize, nbSeq, writeLitEntropy, writeSeqEntropy, lastBlock);
+ { size_t cLitSize = ZSTD_compressSubBlock_literal((const HUF_CElt*)entropy->huf.CTable,
+ &entropyMetadata->hufMetadata, literals, litSize,
+ op, oend-op, bmi2, writeLitEntropy, litEntropyWritten);
+ FORWARD_IF_ERROR(cLitSize, "ZSTD_compressSubBlock_literal failed");
+ if (cLitSize == 0) return 0;
+ op += cLitSize;
+ }
+ { size_t cSeqSize = ZSTD_compressSubBlock_sequences(&entropy->fse,
+ &entropyMetadata->fseMetadata,
+ sequences, nbSeq,
+ llCode, mlCode, ofCode,
+ cctxParams,
+ op, oend-op,
+ bmi2, writeSeqEntropy, seqEntropyWritten);
+ FORWARD_IF_ERROR(cSeqSize, "ZSTD_compressSubBlock_sequences failed");
+ if (cSeqSize == 0) return 0;
+ op += cSeqSize;
+ }
+ /* Write block header */
+ { size_t cSize = (op-ostart)-ZSTD_blockHeaderSize;
+ U32 const cBlockHeader24 = lastBlock + (((U32)bt_compressed)<<1) + (U32)(cSize << 3);
+ MEM_writeLE24(ostart, cBlockHeader24);
+ }
+ return op-ostart;
+}
+
+static size_t ZSTD_estimateSubBlockSize_literal(const BYTE* literals, size_t litSize,
+ const ZSTD_hufCTables_t* huf,
+ const ZSTD_hufCTablesMetadata_t* hufMetadata,
+ void* workspace, size_t wkspSize,
+ int writeEntropy)
+{
+ unsigned* const countWksp = (unsigned*)workspace;
+ unsigned maxSymbolValue = 255;
+ size_t literalSectionHeaderSize = 3; /* Use hard coded size of 3 bytes */
+
+ if (hufMetadata->hType == set_basic) return litSize;
+ else if (hufMetadata->hType == set_rle) return 1;
+ else if (hufMetadata->hType == set_compressed || hufMetadata->hType == set_repeat) {
+ size_t const largest = HIST_count_wksp (countWksp, &maxSymbolValue, (const BYTE*)literals, litSize, workspace, wkspSize);
+ if (ZSTD_isError(largest)) return litSize;
+ { size_t cLitSizeEstimate = HUF_estimateCompressedSize((const HUF_CElt*)huf->CTable, countWksp, maxSymbolValue);
+ if (writeEntropy) cLitSizeEstimate += hufMetadata->hufDesSize;
+ return cLitSizeEstimate + literalSectionHeaderSize;
+ } }
+ assert(0); /* impossible */
+ return 0;
+}
+
+static size_t ZSTD_estimateSubBlockSize_symbolType(symbolEncodingType_e type,
+ const BYTE* codeTable, unsigned maxCode,
+ size_t nbSeq, const FSE_CTable* fseCTable,
+ const U32* additionalBits,
+ short const* defaultNorm, U32 defaultNormLog,
+ void* workspace, size_t wkspSize)
+{
+ unsigned* const countWksp = (unsigned*)workspace;
+ const BYTE* ctp = codeTable;
+ const BYTE* const ctStart = ctp;
+ const BYTE* const ctEnd = ctStart + nbSeq;
+ size_t cSymbolTypeSizeEstimateInBits = 0;
+ unsigned max = maxCode;
+
+ HIST_countFast_wksp(countWksp, &max, codeTable, nbSeq, workspace, wkspSize); /* can't fail */
+ if (type == set_basic) {
+ cSymbolTypeSizeEstimateInBits = ZSTD_crossEntropyCost(defaultNorm, defaultNormLog, countWksp, max);
+ } else if (type == set_rle) {
+ cSymbolTypeSizeEstimateInBits = 0;
+ } else if (type == set_compressed || type == set_repeat) {
+ cSymbolTypeSizeEstimateInBits = ZSTD_fseBitCost(fseCTable, countWksp, max);
+ }
+ if (ZSTD_isError(cSymbolTypeSizeEstimateInBits)) return nbSeq * 10;
+ while (ctp < ctEnd) {
+ if (additionalBits) cSymbolTypeSizeEstimateInBits += additionalBits[*ctp];
+ else cSymbolTypeSizeEstimateInBits += *ctp; /* for offset, offset code is also the number of additional bits */
+ ctp++;
+ }
+ return cSymbolTypeSizeEstimateInBits / 8;
+}
+
+static size_t ZSTD_estimateSubBlockSize_sequences(const BYTE* ofCodeTable,
+ const BYTE* llCodeTable,
+ const BYTE* mlCodeTable,
+ size_t nbSeq,
+ const ZSTD_fseCTables_t* fseTables,
+ const ZSTD_fseCTablesMetadata_t* fseMetadata,
+ void* workspace, size_t wkspSize,
+ int writeEntropy)
+{
+ size_t sequencesSectionHeaderSize = 3; /* Use hard coded size of 3 bytes */
+ size_t cSeqSizeEstimate = 0;
+ cSeqSizeEstimate += ZSTD_estimateSubBlockSize_symbolType(fseMetadata->ofType, ofCodeTable, MaxOff,
+ nbSeq, fseTables->offcodeCTable, NULL,
+ OF_defaultNorm, OF_defaultNormLog,
+ workspace, wkspSize);
+ cSeqSizeEstimate += ZSTD_estimateSubBlockSize_symbolType(fseMetadata->llType, llCodeTable, MaxLL,
+ nbSeq, fseTables->litlengthCTable, LL_bits,
+ LL_defaultNorm, LL_defaultNormLog,
+ workspace, wkspSize);
+ cSeqSizeEstimate += ZSTD_estimateSubBlockSize_symbolType(fseMetadata->mlType, mlCodeTable, MaxML,
+ nbSeq, fseTables->matchlengthCTable, ML_bits,
+ ML_defaultNorm, ML_defaultNormLog,
+ workspace, wkspSize);
+ if (writeEntropy) cSeqSizeEstimate += fseMetadata->fseTablesSize;
+ return cSeqSizeEstimate + sequencesSectionHeaderSize;
+}
+
+static size_t ZSTD_estimateSubBlockSize(const BYTE* literals, size_t litSize,
+ const BYTE* ofCodeTable,
+ const BYTE* llCodeTable,
+ const BYTE* mlCodeTable,
+ size_t nbSeq,
+ const ZSTD_entropyCTables_t* entropy,
+ const ZSTD_entropyCTablesMetadata_t* entropyMetadata,
+ void* workspace, size_t wkspSize,
+ int writeLitEntropy, int writeSeqEntropy) {
+ size_t cSizeEstimate = 0;
+ cSizeEstimate += ZSTD_estimateSubBlockSize_literal(literals, litSize,
+ &entropy->huf, &entropyMetadata->hufMetadata,
+ workspace, wkspSize, writeLitEntropy);
+ cSizeEstimate += ZSTD_estimateSubBlockSize_sequences(ofCodeTable, llCodeTable, mlCodeTable,
+ nbSeq, &entropy->fse, &entropyMetadata->fseMetadata,
+ workspace, wkspSize, writeSeqEntropy);
+ return cSizeEstimate + ZSTD_blockHeaderSize;
+}
+
+static int ZSTD_needSequenceEntropyTables(ZSTD_fseCTablesMetadata_t const* fseMetadata)
+{
+ if (fseMetadata->llType == set_compressed || fseMetadata->llType == set_rle)
+ return 1;
+ if (fseMetadata->mlType == set_compressed || fseMetadata->mlType == set_rle)
+ return 1;
+ if (fseMetadata->ofType == set_compressed || fseMetadata->ofType == set_rle)
+ return 1;
+ return 0;
+}
+
+/** ZSTD_compressSubBlock_multi() :
+ * Breaks super-block into multiple sub-blocks and compresses them.
+ * Entropy will be written to the first block.
+ * The following blocks will use repeat mode to compress.
+ * All sub-blocks are compressed blocks (no raw or rle blocks).
+ * @return : compressed size of the super block (which is multiple ZSTD blocks)
+ * Or 0 if it failed to compress. */
+static size_t ZSTD_compressSubBlock_multi(const seqStore_t* seqStorePtr,
+ const ZSTD_compressedBlockState_t* prevCBlock,
+ ZSTD_compressedBlockState_t* nextCBlock,
+ const ZSTD_entropyCTablesMetadata_t* entropyMetadata,
+ const ZSTD_CCtx_params* cctxParams,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ const int bmi2, U32 lastBlock,
+ void* workspace, size_t wkspSize)
+{
+ const seqDef* const sstart = seqStorePtr->sequencesStart;
+ const seqDef* const send = seqStorePtr->sequences;
+ const seqDef* sp = sstart;
+ const BYTE* const lstart = seqStorePtr->litStart;
+ const BYTE* const lend = seqStorePtr->lit;
+ const BYTE* lp = lstart;
+ BYTE const* ip = (BYTE const*)src;
+ BYTE const* const iend = ip + srcSize;
+ BYTE* const ostart = (BYTE*)dst;
+ BYTE* const oend = ostart + dstCapacity;
+ BYTE* op = ostart;
+ const BYTE* llCodePtr = seqStorePtr->llCode;
+ const BYTE* mlCodePtr = seqStorePtr->mlCode;
+ const BYTE* ofCodePtr = seqStorePtr->ofCode;
+ size_t targetCBlockSize = cctxParams->targetCBlockSize;
+ size_t litSize, seqCount;
+ int writeLitEntropy = entropyMetadata->hufMetadata.hType == set_compressed;
+ int writeSeqEntropy = 1;
+ int lastSequence = 0;
+
+ DEBUGLOG(5, "ZSTD_compressSubBlock_multi (litSize=%u, nbSeq=%u)",
+ (unsigned)(lend-lp), (unsigned)(send-sstart));
+
+ litSize = 0;
+ seqCount = 0;
+ do {
+ size_t cBlockSizeEstimate = 0;
+ if (sstart == send) {
+ lastSequence = 1;
+ } else {
+ const seqDef* const sequence = sp + seqCount;
+ lastSequence = sequence == send - 1;
+ litSize += ZSTD_getSequenceLength(seqStorePtr, sequence).litLength;
+ seqCount++;
+ }
+ if (lastSequence) {
+ assert(lp <= lend);
+ assert(litSize <= (size_t)(lend - lp));
+ litSize = (size_t)(lend - lp);
+ }
+ /* I think there is an optimization opportunity here.
+ * Calling ZSTD_estimateSubBlockSize for every sequence can be wasteful
+ * since it recalculates estimate from scratch.
+ * For example, it would recount literal distribution and symbol codes everytime.
+ */
+ cBlockSizeEstimate = ZSTD_estimateSubBlockSize(lp, litSize, ofCodePtr, llCodePtr, mlCodePtr, seqCount,
+ &nextCBlock->entropy, entropyMetadata,
+ workspace, wkspSize, writeLitEntropy, writeSeqEntropy);
+ if (cBlockSizeEstimate > targetCBlockSize || lastSequence) {
+ int litEntropyWritten = 0;
+ int seqEntropyWritten = 0;
+ const size_t decompressedSize = ZSTD_seqDecompressedSize(seqStorePtr, sp, seqCount, litSize, lastSequence);
+ const size_t cSize = ZSTD_compressSubBlock(&nextCBlock->entropy, entropyMetadata,
+ sp, seqCount,
+ lp, litSize,
+ llCodePtr, mlCodePtr, ofCodePtr,
+ cctxParams,
+ op, oend-op,
+ bmi2, writeLitEntropy, writeSeqEntropy,
+ &litEntropyWritten, &seqEntropyWritten,
+ lastBlock && lastSequence);
+ FORWARD_IF_ERROR(cSize, "ZSTD_compressSubBlock failed");
+ if (cSize > 0 && cSize < decompressedSize) {
+ DEBUGLOG(5, "Committed the sub-block");
+ assert(ip + decompressedSize <= iend);
+ ip += decompressedSize;
+ sp += seqCount;
+ lp += litSize;
+ op += cSize;
+ llCodePtr += seqCount;
+ mlCodePtr += seqCount;
+ ofCodePtr += seqCount;
+ litSize = 0;
+ seqCount = 0;
+ /* Entropy only needs to be written once */
+ if (litEntropyWritten) {
+ writeLitEntropy = 0;
+ }
+ if (seqEntropyWritten) {
+ writeSeqEntropy = 0;
+ }
+ }
+ }
+ } while (!lastSequence);
+ if (writeLitEntropy) {
+ DEBUGLOG(5, "ZSTD_compressSubBlock_multi has literal entropy tables unwritten");
+ memcpy(&nextCBlock->entropy.huf, &prevCBlock->entropy.huf, sizeof(prevCBlock->entropy.huf));
+ }
+ if (writeSeqEntropy && ZSTD_needSequenceEntropyTables(&entropyMetadata->fseMetadata)) {
+ /* If we haven't written our entropy tables, then we've violated our contract and
+ * must emit an uncompressed block.
+ */
+ DEBUGLOG(5, "ZSTD_compressSubBlock_multi has sequence entropy tables unwritten");
+ return 0;
+ }
+ if (ip < iend) {
+ size_t const cSize = ZSTD_noCompressBlock(op, oend - op, ip, iend - ip, lastBlock);
+ DEBUGLOG(5, "ZSTD_compressSubBlock_multi last sub-block uncompressed, %zu bytes", (size_t)(iend - ip));
+ FORWARD_IF_ERROR(cSize, "ZSTD_noCompressBlock failed");
+ assert(cSize != 0);
+ op += cSize;
+ /* We have to regenerate the repcodes because we've skipped some sequences */
+ if (sp < send) {
+ seqDef const* seq;
+ repcodes_t rep;
+ memcpy(&rep, prevCBlock->rep, sizeof(rep));
+ for (seq = sstart; seq < sp; ++seq) {
+ rep = ZSTD_updateRep(rep.rep, seq->offset - 1, ZSTD_getSequenceLength(seqStorePtr, seq).litLength == 0);
+ }
+ memcpy(nextCBlock->rep, &rep, sizeof(rep));
+ }
+ }
+ DEBUGLOG(5, "ZSTD_compressSubBlock_multi compressed");
+ return op-ostart;
+}
+
+size_t ZSTD_compressSuperBlock(ZSTD_CCtx* zc,
+ void* dst, size_t dstCapacity,
+ void const* src, size_t srcSize,
+ unsigned lastBlock) {
+ ZSTD_entropyCTablesMetadata_t entropyMetadata;
+
+ FORWARD_IF_ERROR(ZSTD_buildSuperBlockEntropy(&zc->seqStore,
+ &zc->blockState.prevCBlock->entropy,
+ &zc->blockState.nextCBlock->entropy,
+ &zc->appliedParams,
+ &entropyMetadata,
+ zc->entropyWorkspace, HUF_WORKSPACE_SIZE /* statically allocated in resetCCtx */), "");
+
+ return ZSTD_compressSubBlock_multi(&zc->seqStore,
+ zc->blockState.prevCBlock,
+ zc->blockState.nextCBlock,
+ &entropyMetadata,
+ &zc->appliedParams,
+ dst, dstCapacity,
+ src, srcSize,
+ zc->bmi2, lastBlock,
+ zc->entropyWorkspace, HUF_WORKSPACE_SIZE /* statically allocated in resetCCtx */);
+}
projects / ceph.git / blobdiff