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-rw-r--r--lib/zstd/compress/huf_compress.c905
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diff --git a/lib/zstd/compress/huf_compress.c b/lib/zstd/compress/huf_compress.c
new file mode 100644
index 000000000..f76a526bf
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+++ b/lib/zstd/compress/huf_compress.c
@@ -0,0 +1,905 @@
+/* ******************************************************************
+ * Huffman encoder, part of New Generation Entropy library
+ * Copyright (c) Yann Collet, Facebook, Inc.
+ *
+ * You can contact the author at :
+ * - FSE+HUF source repository : https://github.com/Cyan4973/FiniteStateEntropy
+ * - Public forum : https://groups.google.com/forum/#!forum/lz4c
+ *
+ * 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.
+****************************************************************** */
+
+/* **************************************************************
+* Compiler specifics
+****************************************************************/
+
+
+/* **************************************************************
+* Includes
+****************************************************************/
+#include "../common/zstd_deps.h" /* ZSTD_memcpy, ZSTD_memset */
+#include "../common/compiler.h"
+#include "../common/bitstream.h"
+#include "hist.h"
+#define FSE_STATIC_LINKING_ONLY /* FSE_optimalTableLog_internal */
+#include "../common/fse.h" /* header compression */
+#define HUF_STATIC_LINKING_ONLY
+#include "../common/huf.h"
+#include "../common/error_private.h"
+
+
+/* **************************************************************
+* Error Management
+****************************************************************/
+#define HUF_isError ERR_isError
+#define HUF_STATIC_ASSERT(c) DEBUG_STATIC_ASSERT(c) /* use only *after* variable declarations */
+
+
+/* **************************************************************
+* Utils
+****************************************************************/
+unsigned HUF_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue)
+{
+ return FSE_optimalTableLog_internal(maxTableLog, srcSize, maxSymbolValue, 1);
+}
+
+
+/* *******************************************************
+* HUF : Huffman block compression
+*********************************************************/
+/* HUF_compressWeights() :
+ * Same as FSE_compress(), but dedicated to huff0's weights compression.
+ * The use case needs much less stack memory.
+ * Note : all elements within weightTable are supposed to be <= HUF_TABLELOG_MAX.
+ */
+#define MAX_FSE_TABLELOG_FOR_HUFF_HEADER 6
+
+typedef struct {
+ FSE_CTable CTable[FSE_CTABLE_SIZE_U32(MAX_FSE_TABLELOG_FOR_HUFF_HEADER, HUF_TABLELOG_MAX)];
+ U32 scratchBuffer[FSE_BUILD_CTABLE_WORKSPACE_SIZE_U32(HUF_TABLELOG_MAX, MAX_FSE_TABLELOG_FOR_HUFF_HEADER)];
+ unsigned count[HUF_TABLELOG_MAX+1];
+ S16 norm[HUF_TABLELOG_MAX+1];
+} HUF_CompressWeightsWksp;
+
+static size_t HUF_compressWeights(void* dst, size_t dstSize, const void* weightTable, size_t wtSize, void* workspace, size_t workspaceSize)
+{
+ BYTE* const ostart = (BYTE*) dst;
+ BYTE* op = ostart;
+ BYTE* const oend = ostart + dstSize;
+
+ unsigned maxSymbolValue = HUF_TABLELOG_MAX;
+ U32 tableLog = MAX_FSE_TABLELOG_FOR_HUFF_HEADER;
+ HUF_CompressWeightsWksp* wksp = (HUF_CompressWeightsWksp*)workspace;
+
+ if (workspaceSize < sizeof(HUF_CompressWeightsWksp)) return ERROR(GENERIC);
+
+ /* init conditions */
+ if (wtSize <= 1) return 0; /* Not compressible */
+
+ /* Scan input and build symbol stats */
+ { unsigned const maxCount = HIST_count_simple(wksp->count, &maxSymbolValue, weightTable, wtSize); /* never fails */
+ if (maxCount == wtSize) return 1; /* only a single symbol in src : rle */
+ if (maxCount == 1) return 0; /* each symbol present maximum once => not compressible */
+ }
+
+ tableLog = FSE_optimalTableLog(tableLog, wtSize, maxSymbolValue);
+ CHECK_F( FSE_normalizeCount(wksp->norm, tableLog, wksp->count, wtSize, maxSymbolValue, /* useLowProbCount */ 0) );
+
+ /* Write table description header */
+ { CHECK_V_F(hSize, FSE_writeNCount(op, (size_t)(oend-op), wksp->norm, maxSymbolValue, tableLog) );
+ op += hSize;
+ }
+
+ /* Compress */
+ CHECK_F( FSE_buildCTable_wksp(wksp->CTable, wksp->norm, maxSymbolValue, tableLog, wksp->scratchBuffer, sizeof(wksp->scratchBuffer)) );
+ { CHECK_V_F(cSize, FSE_compress_usingCTable(op, (size_t)(oend - op), weightTable, wtSize, wksp->CTable) );
+ if (cSize == 0) return 0; /* not enough space for compressed data */
+ op += cSize;
+ }
+
+ return (size_t)(op-ostart);
+}
+
+
+typedef struct {
+ HUF_CompressWeightsWksp wksp;
+ BYTE bitsToWeight[HUF_TABLELOG_MAX + 1]; /* precomputed conversion table */
+ BYTE huffWeight[HUF_SYMBOLVALUE_MAX];
+} HUF_WriteCTableWksp;
+
+size_t HUF_writeCTable_wksp(void* dst, size_t maxDstSize,
+ const HUF_CElt* CTable, unsigned maxSymbolValue, unsigned huffLog,
+ void* workspace, size_t workspaceSize)
+{
+ BYTE* op = (BYTE*)dst;
+ U32 n;
+ HUF_WriteCTableWksp* wksp = (HUF_WriteCTableWksp*)workspace;
+
+ /* check conditions */
+ if (workspaceSize < sizeof(HUF_WriteCTableWksp)) return ERROR(GENERIC);
+ if (maxSymbolValue > HUF_SYMBOLVALUE_MAX) return ERROR(maxSymbolValue_tooLarge);
+
+ /* convert to weight */
+ wksp->bitsToWeight[0] = 0;
+ for (n=1; n<huffLog+1; n++)
+ wksp->bitsToWeight[n] = (BYTE)(huffLog + 1 - n);
+ for (n=0; n<maxSymbolValue; n++)
+ wksp->huffWeight[n] = wksp->bitsToWeight[CTable[n].nbBits];
+
+ /* attempt weights compression by FSE */
+ { CHECK_V_F(hSize, HUF_compressWeights(op+1, maxDstSize-1, wksp->huffWeight, maxSymbolValue, &wksp->wksp, sizeof(wksp->wksp)) );
+ if ((hSize>1) & (hSize < maxSymbolValue/2)) { /* FSE compressed */
+ op[0] = (BYTE)hSize;
+ return hSize+1;
+ } }
+
+ /* write raw values as 4-bits (max : 15) */
+ if (maxSymbolValue > (256-128)) return ERROR(GENERIC); /* should not happen : likely means source cannot be compressed */
+ if (((maxSymbolValue+1)/2) + 1 > maxDstSize) return ERROR(dstSize_tooSmall); /* not enough space within dst buffer */
+ op[0] = (BYTE)(128 /*special case*/ + (maxSymbolValue-1));
+ wksp->huffWeight[maxSymbolValue] = 0; /* to be sure it doesn't cause msan issue in final combination */
+ for (n=0; n<maxSymbolValue; n+=2)
+ op[(n/2)+1] = (BYTE)((wksp->huffWeight[n] << 4) + wksp->huffWeight[n+1]);
+ return ((maxSymbolValue+1)/2) + 1;
+}
+
+/*! HUF_writeCTable() :
+ `CTable` : Huffman tree to save, using huf representation.
+ @return : size of saved CTable */
+size_t HUF_writeCTable (void* dst, size_t maxDstSize,
+ const HUF_CElt* CTable, unsigned maxSymbolValue, unsigned huffLog)
+{
+ HUF_WriteCTableWksp wksp;
+ return HUF_writeCTable_wksp(dst, maxDstSize, CTable, maxSymbolValue, huffLog, &wksp, sizeof(wksp));
+}
+
+
+size_t HUF_readCTable (HUF_CElt* CTable, unsigned* maxSymbolValuePtr, const void* src, size_t srcSize, unsigned* hasZeroWeights)
+{
+ BYTE huffWeight[HUF_SYMBOLVALUE_MAX + 1]; /* init not required, even though some static analyzer may complain */
+ U32 rankVal[HUF_TABLELOG_ABSOLUTEMAX + 1]; /* large enough for values from 0 to 16 */
+ U32 tableLog = 0;
+ U32 nbSymbols = 0;
+
+ /* get symbol weights */
+ CHECK_V_F(readSize, HUF_readStats(huffWeight, HUF_SYMBOLVALUE_MAX+1, rankVal, &nbSymbols, &tableLog, src, srcSize));
+ *hasZeroWeights = (rankVal[0] > 0);
+
+ /* check result */
+ if (tableLog > HUF_TABLELOG_MAX) return ERROR(tableLog_tooLarge);
+ if (nbSymbols > *maxSymbolValuePtr+1) return ERROR(maxSymbolValue_tooSmall);
+
+ /* Prepare base value per rank */
+ { U32 n, nextRankStart = 0;
+ for (n=1; n<=tableLog; n++) {
+ U32 curr = nextRankStart;
+ nextRankStart += (rankVal[n] << (n-1));
+ rankVal[n] = curr;
+ } }
+
+ /* fill nbBits */
+ { U32 n; for (n=0; n<nbSymbols; n++) {
+ const U32 w = huffWeight[n];
+ CTable[n].nbBits = (BYTE)(tableLog + 1 - w) & -(w != 0);
+ } }
+
+ /* fill val */
+ { U16 nbPerRank[HUF_TABLELOG_MAX+2] = {0}; /* support w=0=>n=tableLog+1 */
+ U16 valPerRank[HUF_TABLELOG_MAX+2] = {0};
+ { U32 n; for (n=0; n<nbSymbols; n++) nbPerRank[CTable[n].nbBits]++; }
+ /* determine stating value per rank */
+ valPerRank[tableLog+1] = 0; /* for w==0 */
+ { U16 min = 0;
+ U32 n; for (n=tableLog; n>0; n--) { /* start at n=tablelog <-> w=1 */
+ valPerRank[n] = min; /* get starting value within each rank */
+ min += nbPerRank[n];
+ min >>= 1;
+ } }
+ /* assign value within rank, symbol order */
+ { U32 n; for (n=0; n<nbSymbols; n++) CTable[n].val = valPerRank[CTable[n].nbBits]++; }
+ }
+
+ *maxSymbolValuePtr = nbSymbols - 1;
+ return readSize;
+}
+
+U32 HUF_getNbBits(const void* symbolTable, U32 symbolValue)
+{
+ const HUF_CElt* table = (const HUF_CElt*)symbolTable;
+ assert(symbolValue <= HUF_SYMBOLVALUE_MAX);
+ return table[symbolValue].nbBits;
+}
+
+
+typedef struct nodeElt_s {
+ U32 count;
+ U16 parent;
+ BYTE byte;
+ BYTE nbBits;
+} nodeElt;
+
+/*
+ * HUF_setMaxHeight():
+ * Enforces maxNbBits on the Huffman tree described in huffNode.
+ *
+ * It sets all nodes with nbBits > maxNbBits to be maxNbBits. Then it adjusts
+ * the tree to so that it is a valid canonical Huffman tree.
+ *
+ * @pre The sum of the ranks of each symbol == 2^largestBits,
+ * where largestBits == huffNode[lastNonNull].nbBits.
+ * @post The sum of the ranks of each symbol == 2^largestBits,
+ * where largestBits is the return value <= maxNbBits.
+ *
+ * @param huffNode The Huffman tree modified in place to enforce maxNbBits.
+ * @param lastNonNull The symbol with the lowest count in the Huffman tree.
+ * @param maxNbBits The maximum allowed number of bits, which the Huffman tree
+ * may not respect. After this function the Huffman tree will
+ * respect maxNbBits.
+ * @return The maximum number of bits of the Huffman tree after adjustment,
+ * necessarily no more than maxNbBits.
+ */
+static U32 HUF_setMaxHeight(nodeElt* huffNode, U32 lastNonNull, U32 maxNbBits)
+{
+ const U32 largestBits = huffNode[lastNonNull].nbBits;
+ /* early exit : no elt > maxNbBits, so the tree is already valid. */
+ if (largestBits <= maxNbBits) return largestBits;
+
+ /* there are several too large elements (at least >= 2) */
+ { int totalCost = 0;
+ const U32 baseCost = 1 << (largestBits - maxNbBits);
+ int n = (int)lastNonNull;
+
+ /* Adjust any ranks > maxNbBits to maxNbBits.
+ * Compute totalCost, which is how far the sum of the ranks is
+ * we are over 2^largestBits after adjust the offending ranks.
+ */
+ while (huffNode[n].nbBits > maxNbBits) {
+ totalCost += baseCost - (1 << (largestBits - huffNode[n].nbBits));
+ huffNode[n].nbBits = (BYTE)maxNbBits;
+ n--;
+ }
+ /* n stops at huffNode[n].nbBits <= maxNbBits */
+ assert(huffNode[n].nbBits <= maxNbBits);
+ /* n end at index of smallest symbol using < maxNbBits */
+ while (huffNode[n].nbBits == maxNbBits) --n;
+
+ /* renorm totalCost from 2^largestBits to 2^maxNbBits
+ * note : totalCost is necessarily a multiple of baseCost */
+ assert((totalCost & (baseCost - 1)) == 0);
+ totalCost >>= (largestBits - maxNbBits);
+ assert(totalCost > 0);
+
+ /* repay normalized cost */
+ { U32 const noSymbol = 0xF0F0F0F0;
+ U32 rankLast[HUF_TABLELOG_MAX+2];
+
+ /* Get pos of last (smallest = lowest cum. count) symbol per rank */
+ ZSTD_memset(rankLast, 0xF0, sizeof(rankLast));
+ { U32 currentNbBits = maxNbBits;
+ int pos;
+ for (pos=n ; pos >= 0; pos--) {
+ if (huffNode[pos].nbBits >= currentNbBits) continue;
+ currentNbBits = huffNode[pos].nbBits; /* < maxNbBits */
+ rankLast[maxNbBits-currentNbBits] = (U32)pos;
+ } }
+
+ while (totalCost > 0) {
+ /* Try to reduce the next power of 2 above totalCost because we
+ * gain back half the rank.
+ */
+ U32 nBitsToDecrease = BIT_highbit32((U32)totalCost) + 1;
+ for ( ; nBitsToDecrease > 1; nBitsToDecrease--) {
+ U32 const highPos = rankLast[nBitsToDecrease];
+ U32 const lowPos = rankLast[nBitsToDecrease-1];
+ if (highPos == noSymbol) continue;
+ /* Decrease highPos if no symbols of lowPos or if it is
+ * not cheaper to remove 2 lowPos than highPos.
+ */
+ if (lowPos == noSymbol) break;
+ { U32 const highTotal = huffNode[highPos].count;
+ U32 const lowTotal = 2 * huffNode[lowPos].count;
+ if (highTotal <= lowTotal) break;
+ } }
+ /* only triggered when no more rank 1 symbol left => find closest one (note : there is necessarily at least one !) */
+ assert(rankLast[nBitsToDecrease] != noSymbol || nBitsToDecrease == 1);
+ /* HUF_MAX_TABLELOG test just to please gcc 5+; but it should not be necessary */
+ while ((nBitsToDecrease<=HUF_TABLELOG_MAX) && (rankLast[nBitsToDecrease] == noSymbol))
+ nBitsToDecrease++;
+ assert(rankLast[nBitsToDecrease] != noSymbol);
+ /* Increase the number of bits to gain back half the rank cost. */
+ totalCost -= 1 << (nBitsToDecrease-1);
+ huffNode[rankLast[nBitsToDecrease]].nbBits++;
+
+ /* Fix up the new rank.
+ * If the new rank was empty, this symbol is now its smallest.
+ * Otherwise, this symbol will be the largest in the new rank so no adjustment.
+ */
+ if (rankLast[nBitsToDecrease-1] == noSymbol)
+ rankLast[nBitsToDecrease-1] = rankLast[nBitsToDecrease];
+ /* Fix up the old rank.
+ * If the symbol was at position 0, meaning it was the highest weight symbol in the tree,
+ * it must be the only symbol in its rank, so the old rank now has no symbols.
+ * Otherwise, since the Huffman nodes are sorted by count, the previous position is now
+ * the smallest node in the rank. If the previous position belongs to a different rank,
+ * then the rank is now empty.
+ */
+ if (rankLast[nBitsToDecrease] == 0) /* special case, reached largest symbol */
+ rankLast[nBitsToDecrease] = noSymbol;
+ else {
+ rankLast[nBitsToDecrease]--;
+ if (huffNode[rankLast[nBitsToDecrease]].nbBits != maxNbBits-nBitsToDecrease)
+ rankLast[nBitsToDecrease] = noSymbol; /* this rank is now empty */
+ }
+ } /* while (totalCost > 0) */
+
+ /* If we've removed too much weight, then we have to add it back.
+ * To avoid overshooting again, we only adjust the smallest rank.
+ * We take the largest nodes from the lowest rank 0 and move them
+ * to rank 1. There's guaranteed to be enough rank 0 symbols because
+ * TODO.
+ */
+ while (totalCost < 0) { /* Sometimes, cost correction overshoot */
+ /* special case : no rank 1 symbol (using maxNbBits-1);
+ * let's create one from largest rank 0 (using maxNbBits).
+ */
+ if (rankLast[1] == noSymbol) {
+ while (huffNode[n].nbBits == maxNbBits) n--;
+ huffNode[n+1].nbBits--;
+ assert(n >= 0);
+ rankLast[1] = (U32)(n+1);
+ totalCost++;
+ continue;
+ }
+ huffNode[ rankLast[1] + 1 ].nbBits--;
+ rankLast[1]++;
+ totalCost ++;
+ }
+ } /* repay normalized cost */
+ } /* there are several too large elements (at least >= 2) */
+
+ return maxNbBits;
+}
+
+typedef struct {
+ U32 base;
+ U32 curr;
+} rankPos;
+
+typedef nodeElt huffNodeTable[HUF_CTABLE_WORKSPACE_SIZE_U32];
+
+#define RANK_POSITION_TABLE_SIZE 32
+
+typedef struct {
+ huffNodeTable huffNodeTbl;
+ rankPos rankPosition[RANK_POSITION_TABLE_SIZE];
+} HUF_buildCTable_wksp_tables;
+
+/*
+ * HUF_sort():
+ * Sorts the symbols [0, maxSymbolValue] by count[symbol] in decreasing order.
+ *
+ * @param[out] huffNode Sorted symbols by decreasing count. Only members `.count` and `.byte` are filled.
+ * Must have (maxSymbolValue + 1) entries.
+ * @param[in] count Histogram of the symbols.
+ * @param[in] maxSymbolValue Maximum symbol value.
+ * @param rankPosition This is a scratch workspace. Must have RANK_POSITION_TABLE_SIZE entries.
+ */
+static void HUF_sort(nodeElt* huffNode, const unsigned* count, U32 maxSymbolValue, rankPos* rankPosition)
+{
+ int n;
+ int const maxSymbolValue1 = (int)maxSymbolValue + 1;
+
+ /* Compute base and set curr to base.
+ * For symbol s let lowerRank = BIT_highbit32(count[n]+1) and rank = lowerRank + 1.
+ * Then 2^lowerRank <= count[n]+1 <= 2^rank.
+ * We attribute each symbol to lowerRank's base value, because we want to know where
+ * each rank begins in the output, so for rank R we want to count ranks R+1 and above.
+ */
+ ZSTD_memset(rankPosition, 0, sizeof(*rankPosition) * RANK_POSITION_TABLE_SIZE);
+ for (n = 0; n < maxSymbolValue1; ++n) {
+ U32 lowerRank = BIT_highbit32(count[n] + 1);
+ rankPosition[lowerRank].base++;
+ }
+ assert(rankPosition[RANK_POSITION_TABLE_SIZE - 1].base == 0);
+ for (n = RANK_POSITION_TABLE_SIZE - 1; n > 0; --n) {
+ rankPosition[n-1].base += rankPosition[n].base;
+ rankPosition[n-1].curr = rankPosition[n-1].base;
+ }
+ /* Sort */
+ for (n = 0; n < maxSymbolValue1; ++n) {
+ U32 const c = count[n];
+ U32 const r = BIT_highbit32(c+1) + 1;
+ U32 pos = rankPosition[r].curr++;
+ /* Insert into the correct position in the rank.
+ * We have at most 256 symbols, so this insertion should be fine.
+ */
+ while ((pos > rankPosition[r].base) && (c > huffNode[pos-1].count)) {
+ huffNode[pos] = huffNode[pos-1];
+ pos--;
+ }
+ huffNode[pos].count = c;
+ huffNode[pos].byte = (BYTE)n;
+ }
+}
+
+
+/* HUF_buildCTable_wksp() :
+ * Same as HUF_buildCTable(), but using externally allocated scratch buffer.
+ * `workSpace` must be aligned on 4-bytes boundaries, and be at least as large as sizeof(HUF_buildCTable_wksp_tables).
+ */
+#define STARTNODE (HUF_SYMBOLVALUE_MAX+1)
+
+/* HUF_buildTree():
+ * Takes the huffNode array sorted by HUF_sort() and builds an unlimited-depth Huffman tree.
+ *
+ * @param huffNode The array sorted by HUF_sort(). Builds the Huffman tree in this array.
+ * @param maxSymbolValue The maximum symbol value.
+ * @return The smallest node in the Huffman tree (by count).
+ */
+static int HUF_buildTree(nodeElt* huffNode, U32 maxSymbolValue)
+{
+ nodeElt* const huffNode0 = huffNode - 1;
+ int nonNullRank;
+ int lowS, lowN;
+ int nodeNb = STARTNODE;
+ int n, nodeRoot;
+ /* init for parents */
+ nonNullRank = (int)maxSymbolValue;
+ while(huffNode[nonNullRank].count == 0) nonNullRank--;
+ lowS = nonNullRank; nodeRoot = nodeNb + lowS - 1; lowN = nodeNb;
+ huffNode[nodeNb].count = huffNode[lowS].count + huffNode[lowS-1].count;
+ huffNode[lowS].parent = huffNode[lowS-1].parent = (U16)nodeNb;
+ nodeNb++; lowS-=2;
+ for (n=nodeNb; n<=nodeRoot; n++) huffNode[n].count = (U32)(1U<<30);
+ huffNode0[0].count = (U32)(1U<<31); /* fake entry, strong barrier */
+
+ /* create parents */
+ while (nodeNb <= nodeRoot) {
+ int const n1 = (huffNode[lowS].count < huffNode[lowN].count) ? lowS-- : lowN++;
+ int const n2 = (huffNode[lowS].count < huffNode[lowN].count) ? lowS-- : lowN++;
+ huffNode[nodeNb].count = huffNode[n1].count + huffNode[n2].count;
+ huffNode[n1].parent = huffNode[n2].parent = (U16)nodeNb;
+ nodeNb++;
+ }
+
+ /* distribute weights (unlimited tree height) */
+ huffNode[nodeRoot].nbBits = 0;
+ for (n=nodeRoot-1; n>=STARTNODE; n--)
+ huffNode[n].nbBits = huffNode[ huffNode[n].parent ].nbBits + 1;
+ for (n=0; n<=nonNullRank; n++)
+ huffNode[n].nbBits = huffNode[ huffNode[n].parent ].nbBits + 1;
+
+ return nonNullRank;
+}
+
+/*
+ * HUF_buildCTableFromTree():
+ * Build the CTable given the Huffman tree in huffNode.
+ *
+ * @param[out] CTable The output Huffman CTable.
+ * @param huffNode The Huffman tree.
+ * @param nonNullRank The last and smallest node in the Huffman tree.
+ * @param maxSymbolValue The maximum symbol value.
+ * @param maxNbBits The exact maximum number of bits used in the Huffman tree.
+ */
+static void HUF_buildCTableFromTree(HUF_CElt* CTable, nodeElt const* huffNode, int nonNullRank, U32 maxSymbolValue, U32 maxNbBits)
+{
+ /* fill result into ctable (val, nbBits) */
+ int n;
+ U16 nbPerRank[HUF_TABLELOG_MAX+1] = {0};
+ U16 valPerRank[HUF_TABLELOG_MAX+1] = {0};
+ int const alphabetSize = (int)(maxSymbolValue + 1);
+ for (n=0; n<=nonNullRank; n++)
+ nbPerRank[huffNode[n].nbBits]++;
+ /* determine starting value per rank */
+ { U16 min = 0;
+ for (n=(int)maxNbBits; n>0; n--) {
+ valPerRank[n] = min; /* get starting value within each rank */
+ min += nbPerRank[n];
+ min >>= 1;
+ } }
+ for (n=0; n<alphabetSize; n++)
+ CTable[huffNode[n].byte].nbBits = huffNode[n].nbBits; /* push nbBits per symbol, symbol order */
+ for (n=0; n<alphabetSize; n++)
+ CTable[n].val = valPerRank[CTable[n].nbBits]++; /* assign value within rank, symbol order */
+}
+
+size_t HUF_buildCTable_wksp (HUF_CElt* tree, const unsigned* count, U32 maxSymbolValue, U32 maxNbBits, void* workSpace, size_t wkspSize)
+{
+ HUF_buildCTable_wksp_tables* const wksp_tables = (HUF_buildCTable_wksp_tables*)workSpace;
+ nodeElt* const huffNode0 = wksp_tables->huffNodeTbl;
+ nodeElt* const huffNode = huffNode0+1;
+ int nonNullRank;
+
+ /* safety checks */
+ if (((size_t)workSpace & 3) != 0) return ERROR(GENERIC); /* must be aligned on 4-bytes boundaries */
+ if (wkspSize < sizeof(HUF_buildCTable_wksp_tables))
+ return ERROR(workSpace_tooSmall);
+ if (maxNbBits == 0) maxNbBits = HUF_TABLELOG_DEFAULT;
+ if (maxSymbolValue > HUF_SYMBOLVALUE_MAX)
+ return ERROR(maxSymbolValue_tooLarge);
+ ZSTD_memset(huffNode0, 0, sizeof(huffNodeTable));
+
+ /* sort, decreasing order */
+ HUF_sort(huffNode, count, maxSymbolValue, wksp_tables->rankPosition);
+
+ /* build tree */
+ nonNullRank = HUF_buildTree(huffNode, maxSymbolValue);
+
+ /* enforce maxTableLog */
+ maxNbBits = HUF_setMaxHeight(huffNode, (U32)nonNullRank, maxNbBits);
+ if (maxNbBits > HUF_TABLELOG_MAX) return ERROR(GENERIC); /* check fit into table */
+
+ HUF_buildCTableFromTree(tree, huffNode, nonNullRank, maxSymbolValue, maxNbBits);
+
+ return maxNbBits;
+}
+
+size_t HUF_estimateCompressedSize(const HUF_CElt* CTable, const unsigned* count, unsigned maxSymbolValue)
+{
+ size_t nbBits = 0;
+ int s;
+ for (s = 0; s <= (int)maxSymbolValue; ++s) {
+ nbBits += CTable[s].nbBits * count[s];
+ }
+ return nbBits >> 3;
+}
+
+int HUF_validateCTable(const HUF_CElt* CTable, const unsigned* count, unsigned maxSymbolValue) {
+ int bad = 0;
+ int s;
+ for (s = 0; s <= (int)maxSymbolValue; ++s) {
+ bad |= (count[s] != 0) & (CTable[s].nbBits == 0);
+ }
+ return !bad;
+}
+
+size_t HUF_compressBound(size_t size) { return HUF_COMPRESSBOUND(size); }
+
+FORCE_INLINE_TEMPLATE void
+HUF_encodeSymbol(BIT_CStream_t* bitCPtr, U32 symbol, const HUF_CElt* CTable)
+{
+ BIT_addBitsFast(bitCPtr, CTable[symbol].val, CTable[symbol].nbBits);
+}
+
+#define HUF_FLUSHBITS(s) BIT_flushBits(s)
+
+#define HUF_FLUSHBITS_1(stream) \
+ if (sizeof((stream)->bitContainer)*8 < HUF_TABLELOG_MAX*2+7) HUF_FLUSHBITS(stream)
+
+#define HUF_FLUSHBITS_2(stream) \
+ if (sizeof((stream)->bitContainer)*8 < HUF_TABLELOG_MAX*4+7) HUF_FLUSHBITS(stream)
+
+FORCE_INLINE_TEMPLATE size_t
+HUF_compress1X_usingCTable_internal_body(void* dst, size_t dstSize,
+ const void* src, size_t srcSize,
+ const HUF_CElt* CTable)
+{
+ const BYTE* ip = (const BYTE*) src;
+ BYTE* const ostart = (BYTE*)dst;
+ BYTE* const oend = ostart + dstSize;
+ BYTE* op = ostart;
+ size_t n;
+ BIT_CStream_t bitC;
+
+ /* init */
+ if (dstSize < 8) return 0; /* not enough space to compress */
+ { size_t const initErr = BIT_initCStream(&bitC, op, (size_t)(oend-op));
+ if (HUF_isError(initErr)) return 0; }
+
+ n = srcSize & ~3; /* join to mod 4 */
+ switch (srcSize & 3)
+ {
+ case 3:
+ HUF_encodeSymbol(&bitC, ip[n+ 2], CTable);
+ HUF_FLUSHBITS_2(&bitC);
+ ZSTD_FALLTHROUGH;
+ case 2:
+ HUF_encodeSymbol(&bitC, ip[n+ 1], CTable);
+ HUF_FLUSHBITS_1(&bitC);
+ ZSTD_FALLTHROUGH;
+ case 1:
+ HUF_encodeSymbol(&bitC, ip[n+ 0], CTable);
+ HUF_FLUSHBITS(&bitC);
+ ZSTD_FALLTHROUGH;
+ case 0: ZSTD_FALLTHROUGH;
+ default: break;
+ }
+
+ for (; n>0; n-=4) { /* note : n&3==0 at this stage */
+ HUF_encodeSymbol(&bitC, ip[n- 1], CTable);
+ HUF_FLUSHBITS_1(&bitC);
+ HUF_encodeSymbol(&bitC, ip[n- 2], CTable);
+ HUF_FLUSHBITS_2(&bitC);
+ HUF_encodeSymbol(&bitC, ip[n- 3], CTable);
+ HUF_FLUSHBITS_1(&bitC);
+ HUF_encodeSymbol(&bitC, ip[n- 4], CTable);
+ HUF_FLUSHBITS(&bitC);
+ }
+
+ return BIT_closeCStream(&bitC);
+}
+
+#if DYNAMIC_BMI2
+
+static TARGET_ATTRIBUTE("bmi2") size_t
+HUF_compress1X_usingCTable_internal_bmi2(void* dst, size_t dstSize,
+ const void* src, size_t srcSize,
+ const HUF_CElt* CTable)
+{
+ return HUF_compress1X_usingCTable_internal_body(dst, dstSize, src, srcSize, CTable);
+}
+
+static size_t
+HUF_compress1X_usingCTable_internal_default(void* dst, size_t dstSize,
+ const void* src, size_t srcSize,
+ const HUF_CElt* CTable)
+{
+ return HUF_compress1X_usingCTable_internal_body(dst, dstSize, src, srcSize, CTable);
+}
+
+static size_t
+HUF_compress1X_usingCTable_internal(void* dst, size_t dstSize,
+ const void* src, size_t srcSize,
+ const HUF_CElt* CTable, const int bmi2)
+{
+ if (bmi2) {
+ return HUF_compress1X_usingCTable_internal_bmi2(dst, dstSize, src, srcSize, CTable);
+ }
+ return HUF_compress1X_usingCTable_internal_default(dst, dstSize, src, srcSize, CTable);
+}
+
+#else
+
+static size_t
+HUF_compress1X_usingCTable_internal(void* dst, size_t dstSize,
+ const void* src, size_t srcSize,
+ const HUF_CElt* CTable, const int bmi2)
+{
+ (void)bmi2;
+ return HUF_compress1X_usingCTable_internal_body(dst, dstSize, src, srcSize, CTable);
+}
+
+#endif
+
+size_t HUF_compress1X_usingCTable(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable)
+{
+ return HUF_compress1X_usingCTable_internal(dst, dstSize, src, srcSize, CTable, /* bmi2 */ 0);
+}
+
+
+static size_t
+HUF_compress4X_usingCTable_internal(void* dst, size_t dstSize,
+ const void* src, size_t srcSize,
+ const HUF_CElt* CTable, int bmi2)
+{
+ size_t const segmentSize = (srcSize+3)/4; /* first 3 segments */
+ const BYTE* ip = (const BYTE*) src;
+ const BYTE* const iend = ip + srcSize;
+ BYTE* const ostart = (BYTE*) dst;
+ BYTE* const oend = ostart + dstSize;
+ BYTE* op = ostart;
+
+ if (dstSize < 6 + 1 + 1 + 1 + 8) return 0; /* minimum space to compress successfully */
+ if (srcSize < 12) return 0; /* no saving possible : too small input */
+ op += 6; /* jumpTable */
+
+ assert(op <= oend);
+ { CHECK_V_F(cSize, HUF_compress1X_usingCTable_internal(op, (size_t)(oend-op), ip, segmentSize, CTable, bmi2) );
+ if (cSize==0) return 0;
+ assert(cSize <= 65535);
+ MEM_writeLE16(ostart, (U16)cSize);
+ op += cSize;
+ }
+
+ ip += segmentSize;
+ assert(op <= oend);
+ { CHECK_V_F(cSize, HUF_compress1X_usingCTable_internal(op, (size_t)(oend-op), ip, segmentSize, CTable, bmi2) );
+ if (cSize==0) return 0;
+ assert(cSize <= 65535);
+ MEM_writeLE16(ostart+2, (U16)cSize);
+ op += cSize;
+ }
+
+ ip += segmentSize;
+ assert(op <= oend);
+ { CHECK_V_F(cSize, HUF_compress1X_usingCTable_internal(op, (size_t)(oend-op), ip, segmentSize, CTable, bmi2) );
+ if (cSize==0) return 0;
+ assert(cSize <= 65535);
+ MEM_writeLE16(ostart+4, (U16)cSize);
+ op += cSize;
+ }
+
+ ip += segmentSize;
+ assert(op <= oend);
+ assert(ip <= iend);
+ { CHECK_V_F(cSize, HUF_compress1X_usingCTable_internal(op, (size_t)(oend-op), ip, (size_t)(iend-ip), CTable, bmi2) );
+ if (cSize==0) return 0;
+ op += cSize;
+ }
+
+ return (size_t)(op-ostart);
+}
+
+size_t HUF_compress4X_usingCTable(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable)
+{
+ return HUF_compress4X_usingCTable_internal(dst, dstSize, src, srcSize, CTable, /* bmi2 */ 0);
+}
+
+typedef enum { HUF_singleStream, HUF_fourStreams } HUF_nbStreams_e;
+
+static size_t HUF_compressCTable_internal(
+ BYTE* const ostart, BYTE* op, BYTE* const oend,
+ const void* src, size_t srcSize,
+ HUF_nbStreams_e nbStreams, const HUF_CElt* CTable, const int bmi2)
+{
+ size_t const cSize = (nbStreams==HUF_singleStream) ?
+ HUF_compress1X_usingCTable_internal(op, (size_t)(oend - op), src, srcSize, CTable, bmi2) :
+ HUF_compress4X_usingCTable_internal(op, (size_t)(oend - op), src, srcSize, CTable, bmi2);
+ if (HUF_isError(cSize)) { return cSize; }
+ if (cSize==0) { return 0; } /* uncompressible */
+ op += cSize;
+ /* check compressibility */
+ assert(op >= ostart);
+ if ((size_t)(op-ostart) >= srcSize-1) { return 0; }
+ return (size_t)(op-ostart);
+}
+
+typedef struct {
+ unsigned count[HUF_SYMBOLVALUE_MAX + 1];
+ HUF_CElt CTable[HUF_SYMBOLVALUE_MAX + 1];
+ union {
+ HUF_buildCTable_wksp_tables buildCTable_wksp;
+ HUF_WriteCTableWksp writeCTable_wksp;
+ } wksps;
+} HUF_compress_tables_t;
+
+/* HUF_compress_internal() :
+ * `workSpace_align4` must be aligned on 4-bytes boundaries,
+ * and occupies the same space as a table of HUF_WORKSPACE_SIZE_U32 unsigned */
+static size_t
+HUF_compress_internal (void* dst, size_t dstSize,
+ const void* src, size_t srcSize,
+ unsigned maxSymbolValue, unsigned huffLog,
+ HUF_nbStreams_e nbStreams,
+ void* workSpace_align4, size_t wkspSize,
+ HUF_CElt* oldHufTable, HUF_repeat* repeat, int preferRepeat,
+ const int bmi2)
+{
+ HUF_compress_tables_t* const table = (HUF_compress_tables_t*)workSpace_align4;
+ BYTE* const ostart = (BYTE*)dst;
+ BYTE* const oend = ostart + dstSize;
+ BYTE* op = ostart;
+
+ HUF_STATIC_ASSERT(sizeof(*table) <= HUF_WORKSPACE_SIZE);
+ assert(((size_t)workSpace_align4 & 3) == 0); /* must be aligned on 4-bytes boundaries */
+
+ /* checks & inits */
+ if (wkspSize < HUF_WORKSPACE_SIZE) return ERROR(workSpace_tooSmall);
+ if (!srcSize) return 0; /* Uncompressed */
+ if (!dstSize) return 0; /* cannot fit anything within dst budget */
+ if (srcSize > HUF_BLOCKSIZE_MAX) return ERROR(srcSize_wrong); /* current block size limit */
+ if (huffLog > HUF_TABLELOG_MAX) return ERROR(tableLog_tooLarge);
+ if (maxSymbolValue > HUF_SYMBOLVALUE_MAX) return ERROR(maxSymbolValue_tooLarge);
+ if (!maxSymbolValue) maxSymbolValue = HUF_SYMBOLVALUE_MAX;
+ if (!huffLog) huffLog = HUF_TABLELOG_DEFAULT;
+
+ /* Heuristic : If old table is valid, use it for small inputs */
+ if (preferRepeat && repeat && *repeat == HUF_repeat_valid) {
+ return HUF_compressCTable_internal(ostart, op, oend,
+ src, srcSize,
+ nbStreams, oldHufTable, bmi2);
+ }
+
+ /* Scan input and build symbol stats */
+ { CHECK_V_F(largest, HIST_count_wksp (table->count, &maxSymbolValue, (const BYTE*)src, srcSize, workSpace_align4, wkspSize) );
+ if (largest == srcSize) { *ostart = ((const BYTE*)src)[0]; return 1; } /* single symbol, rle */
+ if (largest <= (srcSize >> 7)+4) return 0; /* heuristic : probably not compressible enough */
+ }
+
+ /* Check validity of previous table */
+ if ( repeat
+ && *repeat == HUF_repeat_check
+ && !HUF_validateCTable(oldHufTable, table->count, maxSymbolValue)) {
+ *repeat = HUF_repeat_none;
+ }
+ /* Heuristic : use existing table for small inputs */
+ if (preferRepeat && repeat && *repeat != HUF_repeat_none) {
+ return HUF_compressCTable_internal(ostart, op, oend,
+ src, srcSize,
+ nbStreams, oldHufTable, bmi2);
+ }
+
+ /* Build Huffman Tree */
+ huffLog = HUF_optimalTableLog(huffLog, srcSize, maxSymbolValue);
+ { size_t const maxBits = HUF_buildCTable_wksp(table->CTable, table->count,
+ maxSymbolValue, huffLog,
+ &table->wksps.buildCTable_wksp, sizeof(table->wksps.buildCTable_wksp));
+ CHECK_F(maxBits);
+ huffLog = (U32)maxBits;
+ /* Zero unused symbols in CTable, so we can check it for validity */
+ ZSTD_memset(table->CTable + (maxSymbolValue + 1), 0,
+ sizeof(table->CTable) - ((maxSymbolValue + 1) * sizeof(HUF_CElt)));
+ }
+
+ /* Write table description header */
+ { CHECK_V_F(hSize, HUF_writeCTable_wksp(op, dstSize, table->CTable, maxSymbolValue, huffLog,
+ &table->wksps.writeCTable_wksp, sizeof(table->wksps.writeCTable_wksp)) );
+ /* Check if using previous huffman table is beneficial */
+ if (repeat && *repeat != HUF_repeat_none) {
+ size_t const oldSize = HUF_estimateCompressedSize(oldHufTable, table->count, maxSymbolValue);
+ size_t const newSize = HUF_estimateCompressedSize(table->CTable, table->count, maxSymbolValue);
+ if (oldSize <= hSize + newSize || hSize + 12 >= srcSize) {
+ return HUF_compressCTable_internal(ostart, op, oend,
+ src, srcSize,
+ nbStreams, oldHufTable, bmi2);
+ } }
+
+ /* Use the new huffman table */
+ if (hSize + 12ul >= srcSize) { return 0; }
+ op += hSize;
+ if (repeat) { *repeat = HUF_repeat_none; }
+ if (oldHufTable)
+ ZSTD_memcpy(oldHufTable, table->CTable, sizeof(table->CTable)); /* Save new table */
+ }
+ return HUF_compressCTable_internal(ostart, op, oend,
+ src, srcSize,
+ nbStreams, table->CTable, bmi2);
+}
+
+
+size_t HUF_compress1X_wksp (void* dst, size_t dstSize,
+ const void* src, size_t srcSize,
+ unsigned maxSymbolValue, unsigned huffLog,
+ void* workSpace, size_t wkspSize)
+{
+ return HUF_compress_internal(dst, dstSize, src, srcSize,
+ maxSymbolValue, huffLog, HUF_singleStream,
+ workSpace, wkspSize,
+ NULL, NULL, 0, 0 /*bmi2*/);
+}
+
+size_t HUF_compress1X_repeat (void* dst, size_t dstSize,
+ const void* src, size_t srcSize,
+ unsigned maxSymbolValue, unsigned huffLog,
+ void* workSpace, size_t wkspSize,
+ HUF_CElt* hufTable, HUF_repeat* repeat, int preferRepeat, int bmi2)
+{
+ return HUF_compress_internal(dst, dstSize, src, srcSize,
+ maxSymbolValue, huffLog, HUF_singleStream,
+ workSpace, wkspSize, hufTable,
+ repeat, preferRepeat, bmi2);
+}
+
+/* HUF_compress4X_repeat():
+ * compress input using 4 streams.
+ * provide workspace to generate compression tables */
+size_t HUF_compress4X_wksp (void* dst, size_t dstSize,
+ const void* src, size_t srcSize,
+ unsigned maxSymbolValue, unsigned huffLog,
+ void* workSpace, size_t wkspSize)
+{
+ return HUF_compress_internal(dst, dstSize, src, srcSize,
+ maxSymbolValue, huffLog, HUF_fourStreams,
+ workSpace, wkspSize,
+ NULL, NULL, 0, 0 /*bmi2*/);
+}
+
+/* HUF_compress4X_repeat():
+ * compress input using 4 streams.
+ * re-use an existing huffman compression table */
+size_t HUF_compress4X_repeat (void* dst, size_t dstSize,
+ const void* src, size_t srcSize,
+ unsigned maxSymbolValue, unsigned huffLog,
+ void* workSpace, size_t wkspSize,
+ HUF_CElt* hufTable, HUF_repeat* repeat, int preferRepeat, int bmi2)
+{
+ return HUF_compress_internal(dst, dstSize, src, srcSize,
+ maxSymbolValue, huffLog, HUF_fourStreams,
+ workSpace, wkspSize,
+ hufTable, repeat, preferRepeat, bmi2);
+}
+