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-rw-r--r--src/zstd/lib/dictBuilder/fastcover.c757
1 files changed, 757 insertions, 0 deletions
diff --git a/src/zstd/lib/dictBuilder/fastcover.c b/src/zstd/lib/dictBuilder/fastcover.c
new file mode 100644
index 000000000..485c333b5
--- /dev/null
+++ b/src/zstd/lib/dictBuilder/fastcover.c
@@ -0,0 +1,757 @@
+/*
+ * Copyright (c) 2018-2020, 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 <stdio.h> /* fprintf */
+#include <stdlib.h> /* malloc, free, qsort */
+#include <string.h> /* memset */
+#include <time.h> /* clock */
+
+#include "../common/mem.h" /* read */
+#include "../common/pool.h"
+#include "../common/threading.h"
+#include "cover.h"
+#include "../common/zstd_internal.h" /* includes zstd.h */
+#ifndef ZDICT_STATIC_LINKING_ONLY
+#define ZDICT_STATIC_LINKING_ONLY
+#endif
+#include "zdict.h"
+
+
+/*-*************************************
+* Constants
+***************************************/
+#define FASTCOVER_MAX_SAMPLES_SIZE (sizeof(size_t) == 8 ? ((unsigned)-1) : ((unsigned)1 GB))
+#define FASTCOVER_MAX_F 31
+#define FASTCOVER_MAX_ACCEL 10
+#define DEFAULT_SPLITPOINT 0.75
+#define DEFAULT_F 20
+#define DEFAULT_ACCEL 1
+
+
+/*-*************************************
+* Console display
+***************************************/
+static int g_displayLevel = 2;
+#define DISPLAY(...) \
+ { \
+ fprintf(stderr, __VA_ARGS__); \
+ fflush(stderr); \
+ }
+#define LOCALDISPLAYLEVEL(displayLevel, l, ...) \
+ if (displayLevel >= l) { \
+ DISPLAY(__VA_ARGS__); \
+ } /* 0 : no display; 1: errors; 2: default; 3: details; 4: debug */
+#define DISPLAYLEVEL(l, ...) LOCALDISPLAYLEVEL(g_displayLevel, l, __VA_ARGS__)
+
+#define LOCALDISPLAYUPDATE(displayLevel, l, ...) \
+ if (displayLevel >= l) { \
+ if ((clock() - g_time > refreshRate) || (displayLevel >= 4)) { \
+ g_time = clock(); \
+ DISPLAY(__VA_ARGS__); \
+ } \
+ }
+#define DISPLAYUPDATE(l, ...) LOCALDISPLAYUPDATE(g_displayLevel, l, __VA_ARGS__)
+static const clock_t refreshRate = CLOCKS_PER_SEC * 15 / 100;
+static clock_t g_time = 0;
+
+
+/*-*************************************
+* Hash Functions
+***************************************/
+static const U64 prime6bytes = 227718039650203ULL;
+static size_t ZSTD_hash6(U64 u, U32 h) { return (size_t)(((u << (64-48)) * prime6bytes) >> (64-h)) ; }
+static size_t ZSTD_hash6Ptr(const void* p, U32 h) { return ZSTD_hash6(MEM_readLE64(p), h); }
+
+static const U64 prime8bytes = 0xCF1BBCDCB7A56463ULL;
+static size_t ZSTD_hash8(U64 u, U32 h) { return (size_t)(((u) * prime8bytes) >> (64-h)) ; }
+static size_t ZSTD_hash8Ptr(const void* p, U32 h) { return ZSTD_hash8(MEM_readLE64(p), h); }
+
+
+/**
+ * Hash the d-byte value pointed to by p and mod 2^f
+ */
+static size_t FASTCOVER_hashPtrToIndex(const void* p, U32 h, unsigned d) {
+ if (d == 6) {
+ return ZSTD_hash6Ptr(p, h) & ((1 << h) - 1);
+ }
+ return ZSTD_hash8Ptr(p, h) & ((1 << h) - 1);
+}
+
+
+/*-*************************************
+* Acceleration
+***************************************/
+typedef struct {
+ unsigned finalize; /* Percentage of training samples used for ZDICT_finalizeDictionary */
+ unsigned skip; /* Number of dmer skipped between each dmer counted in computeFrequency */
+} FASTCOVER_accel_t;
+
+
+static const FASTCOVER_accel_t FASTCOVER_defaultAccelParameters[FASTCOVER_MAX_ACCEL+1] = {
+ { 100, 0 }, /* accel = 0, should not happen because accel = 0 defaults to accel = 1 */
+ { 100, 0 }, /* accel = 1 */
+ { 50, 1 }, /* accel = 2 */
+ { 34, 2 }, /* accel = 3 */
+ { 25, 3 }, /* accel = 4 */
+ { 20, 4 }, /* accel = 5 */
+ { 17, 5 }, /* accel = 6 */
+ { 14, 6 }, /* accel = 7 */
+ { 13, 7 }, /* accel = 8 */
+ { 11, 8 }, /* accel = 9 */
+ { 10, 9 }, /* accel = 10 */
+};
+
+
+/*-*************************************
+* Context
+***************************************/
+typedef struct {
+ const BYTE *samples;
+ size_t *offsets;
+ const size_t *samplesSizes;
+ size_t nbSamples;
+ size_t nbTrainSamples;
+ size_t nbTestSamples;
+ size_t nbDmers;
+ U32 *freqs;
+ unsigned d;
+ unsigned f;
+ FASTCOVER_accel_t accelParams;
+} FASTCOVER_ctx_t;
+
+
+/*-*************************************
+* Helper functions
+***************************************/
+/**
+ * Selects the best segment in an epoch.
+ * Segments of are scored according to the function:
+ *
+ * Let F(d) be the frequency of all dmers with hash value d.
+ * Let S_i be hash value of the dmer at position i of segment S which has length k.
+ *
+ * Score(S) = F(S_1) + F(S_2) + ... + F(S_{k-d+1})
+ *
+ * Once the dmer with hash value d is in the dictionary we set F(d) = 0.
+ */
+static COVER_segment_t FASTCOVER_selectSegment(const FASTCOVER_ctx_t *ctx,
+ U32 *freqs, U32 begin, U32 end,
+ ZDICT_cover_params_t parameters,
+ U16* segmentFreqs) {
+ /* Constants */
+ const U32 k = parameters.k;
+ const U32 d = parameters.d;
+ const U32 f = ctx->f;
+ const U32 dmersInK = k - d + 1;
+
+ /* Try each segment (activeSegment) and save the best (bestSegment) */
+ COVER_segment_t bestSegment = {0, 0, 0};
+ COVER_segment_t activeSegment;
+
+ /* Reset the activeDmers in the segment */
+ /* The activeSegment starts at the beginning of the epoch. */
+ activeSegment.begin = begin;
+ activeSegment.end = begin;
+ activeSegment.score = 0;
+
+ /* Slide the activeSegment through the whole epoch.
+ * Save the best segment in bestSegment.
+ */
+ while (activeSegment.end < end) {
+ /* Get hash value of current dmer */
+ const size_t idx = FASTCOVER_hashPtrToIndex(ctx->samples + activeSegment.end, f, d);
+
+ /* Add frequency of this index to score if this is the first occurrence of index in active segment */
+ if (segmentFreqs[idx] == 0) {
+ activeSegment.score += freqs[idx];
+ }
+ /* Increment end of segment and segmentFreqs*/
+ activeSegment.end += 1;
+ segmentFreqs[idx] += 1;
+ /* If the window is now too large, drop the first position */
+ if (activeSegment.end - activeSegment.begin == dmersInK + 1) {
+ /* Get hash value of the dmer to be eliminated from active segment */
+ const size_t delIndex = FASTCOVER_hashPtrToIndex(ctx->samples + activeSegment.begin, f, d);
+ segmentFreqs[delIndex] -= 1;
+ /* Subtract frequency of this index from score if this is the last occurrence of this index in active segment */
+ if (segmentFreqs[delIndex] == 0) {
+ activeSegment.score -= freqs[delIndex];
+ }
+ /* Increment start of segment */
+ activeSegment.begin += 1;
+ }
+
+ /* If this segment is the best so far save it */
+ if (activeSegment.score > bestSegment.score) {
+ bestSegment = activeSegment;
+ }
+ }
+
+ /* Zero out rest of segmentFreqs array */
+ while (activeSegment.begin < end) {
+ const size_t delIndex = FASTCOVER_hashPtrToIndex(ctx->samples + activeSegment.begin, f, d);
+ segmentFreqs[delIndex] -= 1;
+ activeSegment.begin += 1;
+ }
+
+ {
+ /* Zero the frequency of hash value of each dmer covered by the chosen segment. */
+ U32 pos;
+ for (pos = bestSegment.begin; pos != bestSegment.end; ++pos) {
+ const size_t i = FASTCOVER_hashPtrToIndex(ctx->samples + pos, f, d);
+ freqs[i] = 0;
+ }
+ }
+
+ return bestSegment;
+}
+
+
+static int FASTCOVER_checkParameters(ZDICT_cover_params_t parameters,
+ size_t maxDictSize, unsigned f,
+ unsigned accel) {
+ /* k, d, and f are required parameters */
+ if (parameters.d == 0 || parameters.k == 0) {
+ return 0;
+ }
+ /* d has to be 6 or 8 */
+ if (parameters.d != 6 && parameters.d != 8) {
+ return 0;
+ }
+ /* k <= maxDictSize */
+ if (parameters.k > maxDictSize) {
+ return 0;
+ }
+ /* d <= k */
+ if (parameters.d > parameters.k) {
+ return 0;
+ }
+ /* 0 < f <= FASTCOVER_MAX_F*/
+ if (f > FASTCOVER_MAX_F || f == 0) {
+ return 0;
+ }
+ /* 0 < splitPoint <= 1 */
+ if (parameters.splitPoint <= 0 || parameters.splitPoint > 1) {
+ return 0;
+ }
+ /* 0 < accel <= 10 */
+ if (accel > 10 || accel == 0) {
+ return 0;
+ }
+ return 1;
+}
+
+
+/**
+ * Clean up a context initialized with `FASTCOVER_ctx_init()`.
+ */
+static void
+FASTCOVER_ctx_destroy(FASTCOVER_ctx_t* ctx)
+{
+ if (!ctx) return;
+
+ free(ctx->freqs);
+ ctx->freqs = NULL;
+
+ free(ctx->offsets);
+ ctx->offsets = NULL;
+}
+
+
+/**
+ * Calculate for frequency of hash value of each dmer in ctx->samples
+ */
+static void
+FASTCOVER_computeFrequency(U32* freqs, const FASTCOVER_ctx_t* ctx)
+{
+ const unsigned f = ctx->f;
+ const unsigned d = ctx->d;
+ const unsigned skip = ctx->accelParams.skip;
+ const unsigned readLength = MAX(d, 8);
+ size_t i;
+ assert(ctx->nbTrainSamples >= 5);
+ assert(ctx->nbTrainSamples <= ctx->nbSamples);
+ for (i = 0; i < ctx->nbTrainSamples; i++) {
+ size_t start = ctx->offsets[i]; /* start of current dmer */
+ size_t const currSampleEnd = ctx->offsets[i+1];
+ while (start + readLength <= currSampleEnd) {
+ const size_t dmerIndex = FASTCOVER_hashPtrToIndex(ctx->samples + start, f, d);
+ freqs[dmerIndex]++;
+ start = start + skip + 1;
+ }
+ }
+}
+
+
+/**
+ * Prepare a context for dictionary building.
+ * The context is only dependent on the parameter `d` and can used multiple
+ * times.
+ * Returns 0 on success or error code on error.
+ * The context must be destroyed with `FASTCOVER_ctx_destroy()`.
+ */
+static size_t
+FASTCOVER_ctx_init(FASTCOVER_ctx_t* ctx,
+ const void* samplesBuffer,
+ const size_t* samplesSizes, unsigned nbSamples,
+ unsigned d, double splitPoint, unsigned f,
+ FASTCOVER_accel_t accelParams)
+{
+ const BYTE* const samples = (const BYTE*)samplesBuffer;
+ const size_t totalSamplesSize = COVER_sum(samplesSizes, nbSamples);
+ /* Split samples into testing and training sets */
+ const unsigned nbTrainSamples = splitPoint < 1.0 ? (unsigned)((double)nbSamples * splitPoint) : nbSamples;
+ const unsigned nbTestSamples = splitPoint < 1.0 ? nbSamples - nbTrainSamples : nbSamples;
+ const size_t trainingSamplesSize = splitPoint < 1.0 ? COVER_sum(samplesSizes, nbTrainSamples) : totalSamplesSize;
+ const size_t testSamplesSize = splitPoint < 1.0 ? COVER_sum(samplesSizes + nbTrainSamples, nbTestSamples) : totalSamplesSize;
+
+ /* Checks */
+ if (totalSamplesSize < MAX(d, sizeof(U64)) ||
+ totalSamplesSize >= (size_t)FASTCOVER_MAX_SAMPLES_SIZE) {
+ DISPLAYLEVEL(1, "Total samples size is too large (%u MB), maximum size is %u MB\n",
+ (unsigned)(totalSamplesSize >> 20), (FASTCOVER_MAX_SAMPLES_SIZE >> 20));
+ return ERROR(srcSize_wrong);
+ }
+
+ /* Check if there are at least 5 training samples */
+ if (nbTrainSamples < 5) {
+ DISPLAYLEVEL(1, "Total number of training samples is %u and is invalid\n", nbTrainSamples);
+ return ERROR(srcSize_wrong);
+ }
+
+ /* Check if there's testing sample */
+ if (nbTestSamples < 1) {
+ DISPLAYLEVEL(1, "Total number of testing samples is %u and is invalid.\n", nbTestSamples);
+ return ERROR(srcSize_wrong);
+ }
+
+ /* Zero the context */
+ memset(ctx, 0, sizeof(*ctx));
+ DISPLAYLEVEL(2, "Training on %u samples of total size %u\n", nbTrainSamples,
+ (unsigned)trainingSamplesSize);
+ DISPLAYLEVEL(2, "Testing on %u samples of total size %u\n", nbTestSamples,
+ (unsigned)testSamplesSize);
+
+ ctx->samples = samples;
+ ctx->samplesSizes = samplesSizes;
+ ctx->nbSamples = nbSamples;
+ ctx->nbTrainSamples = nbTrainSamples;
+ ctx->nbTestSamples = nbTestSamples;
+ ctx->nbDmers = trainingSamplesSize - MAX(d, sizeof(U64)) + 1;
+ ctx->d = d;
+ ctx->f = f;
+ ctx->accelParams = accelParams;
+
+ /* The offsets of each file */
+ ctx->offsets = (size_t*)calloc((nbSamples + 1), sizeof(size_t));
+ if (ctx->offsets == NULL) {
+ DISPLAYLEVEL(1, "Failed to allocate scratch buffers \n");
+ FASTCOVER_ctx_destroy(ctx);
+ return ERROR(memory_allocation);
+ }
+
+ /* Fill offsets from the samplesSizes */
+ { U32 i;
+ ctx->offsets[0] = 0;
+ assert(nbSamples >= 5);
+ for (i = 1; i <= nbSamples; ++i) {
+ ctx->offsets[i] = ctx->offsets[i - 1] + samplesSizes[i - 1];
+ }
+ }
+
+ /* Initialize frequency array of size 2^f */
+ ctx->freqs = (U32*)calloc(((U64)1 << f), sizeof(U32));
+ if (ctx->freqs == NULL) {
+ DISPLAYLEVEL(1, "Failed to allocate frequency table \n");
+ FASTCOVER_ctx_destroy(ctx);
+ return ERROR(memory_allocation);
+ }
+
+ DISPLAYLEVEL(2, "Computing frequencies\n");
+ FASTCOVER_computeFrequency(ctx->freqs, ctx);
+
+ return 0;
+}
+
+
+/**
+ * Given the prepared context build the dictionary.
+ */
+static size_t
+FASTCOVER_buildDictionary(const FASTCOVER_ctx_t* ctx,
+ U32* freqs,
+ void* dictBuffer, size_t dictBufferCapacity,
+ ZDICT_cover_params_t parameters,
+ U16* segmentFreqs)
+{
+ BYTE *const dict = (BYTE *)dictBuffer;
+ size_t tail = dictBufferCapacity;
+ /* Divide the data into epochs. We will select one segment from each epoch. */
+ const COVER_epoch_info_t epochs = COVER_computeEpochs(
+ (U32)dictBufferCapacity, (U32)ctx->nbDmers, parameters.k, 1);
+ const size_t maxZeroScoreRun = 10;
+ size_t zeroScoreRun = 0;
+ size_t epoch;
+ DISPLAYLEVEL(2, "Breaking content into %u epochs of size %u\n",
+ (U32)epochs.num, (U32)epochs.size);
+ /* Loop through the epochs until there are no more segments or the dictionary
+ * is full.
+ */
+ for (epoch = 0; tail > 0; epoch = (epoch + 1) % epochs.num) {
+ const U32 epochBegin = (U32)(epoch * epochs.size);
+ const U32 epochEnd = epochBegin + epochs.size;
+ size_t segmentSize;
+ /* Select a segment */
+ COVER_segment_t segment = FASTCOVER_selectSegment(
+ ctx, freqs, epochBegin, epochEnd, parameters, segmentFreqs);
+
+ /* If the segment covers no dmers, then we are out of content.
+ * There may be new content in other epochs, for continue for some time.
+ */
+ if (segment.score == 0) {
+ if (++zeroScoreRun >= maxZeroScoreRun) {
+ break;
+ }
+ continue;
+ }
+ zeroScoreRun = 0;
+
+ /* Trim the segment if necessary and if it is too small then we are done */
+ segmentSize = MIN(segment.end - segment.begin + parameters.d - 1, tail);
+ if (segmentSize < parameters.d) {
+ break;
+ }
+
+ /* We fill the dictionary from the back to allow the best segments to be
+ * referenced with the smallest offsets.
+ */
+ tail -= segmentSize;
+ memcpy(dict + tail, ctx->samples + segment.begin, segmentSize);
+ DISPLAYUPDATE(
+ 2, "\r%u%% ",
+ (unsigned)(((dictBufferCapacity - tail) * 100) / dictBufferCapacity));
+ }
+ DISPLAYLEVEL(2, "\r%79s\r", "");
+ return tail;
+}
+
+/**
+ * Parameters for FASTCOVER_tryParameters().
+ */
+typedef struct FASTCOVER_tryParameters_data_s {
+ const FASTCOVER_ctx_t* ctx;
+ COVER_best_t* best;
+ size_t dictBufferCapacity;
+ ZDICT_cover_params_t parameters;
+} FASTCOVER_tryParameters_data_t;
+
+
+/**
+ * Tries a set of parameters and updates the COVER_best_t with the results.
+ * This function is thread safe if zstd is compiled with multithreaded support.
+ * It takes its parameters as an *OWNING* opaque pointer to support threading.
+ */
+static void FASTCOVER_tryParameters(void *opaque)
+{
+ /* Save parameters as local variables */
+ FASTCOVER_tryParameters_data_t *const data = (FASTCOVER_tryParameters_data_t *)opaque;
+ const FASTCOVER_ctx_t *const ctx = data->ctx;
+ const ZDICT_cover_params_t parameters = data->parameters;
+ size_t dictBufferCapacity = data->dictBufferCapacity;
+ size_t totalCompressedSize = ERROR(GENERIC);
+ /* Initialize array to keep track of frequency of dmer within activeSegment */
+ U16* segmentFreqs = (U16 *)calloc(((U64)1 << ctx->f), sizeof(U16));
+ /* Allocate space for hash table, dict, and freqs */
+ BYTE *const dict = (BYTE * const)malloc(dictBufferCapacity);
+ COVER_dictSelection_t selection = COVER_dictSelectionError(ERROR(GENERIC));
+ U32 *freqs = (U32*) malloc(((U64)1 << ctx->f) * sizeof(U32));
+ if (!segmentFreqs || !dict || !freqs) {
+ DISPLAYLEVEL(1, "Failed to allocate buffers: out of memory\n");
+ goto _cleanup;
+ }
+ /* Copy the frequencies because we need to modify them */
+ memcpy(freqs, ctx->freqs, ((U64)1 << ctx->f) * sizeof(U32));
+ /* Build the dictionary */
+ { const size_t tail = FASTCOVER_buildDictionary(ctx, freqs, dict, dictBufferCapacity,
+ parameters, segmentFreqs);
+
+ const unsigned nbFinalizeSamples = (unsigned)(ctx->nbTrainSamples * ctx->accelParams.finalize / 100);
+ selection = COVER_selectDict(dict + tail, dictBufferCapacity - tail,
+ ctx->samples, ctx->samplesSizes, nbFinalizeSamples, ctx->nbTrainSamples, ctx->nbSamples, parameters, ctx->offsets,
+ totalCompressedSize);
+
+ if (COVER_dictSelectionIsError(selection)) {
+ DISPLAYLEVEL(1, "Failed to select dictionary\n");
+ goto _cleanup;
+ }
+ }
+_cleanup:
+ free(dict);
+ COVER_best_finish(data->best, parameters, selection);
+ free(data);
+ free(segmentFreqs);
+ COVER_dictSelectionFree(selection);
+ free(freqs);
+}
+
+
+static void
+FASTCOVER_convertToCoverParams(ZDICT_fastCover_params_t fastCoverParams,
+ ZDICT_cover_params_t* coverParams)
+{
+ coverParams->k = fastCoverParams.k;
+ coverParams->d = fastCoverParams.d;
+ coverParams->steps = fastCoverParams.steps;
+ coverParams->nbThreads = fastCoverParams.nbThreads;
+ coverParams->splitPoint = fastCoverParams.splitPoint;
+ coverParams->zParams = fastCoverParams.zParams;
+ coverParams->shrinkDict = fastCoverParams.shrinkDict;
+}
+
+
+static void
+FASTCOVER_convertToFastCoverParams(ZDICT_cover_params_t coverParams,
+ ZDICT_fastCover_params_t* fastCoverParams,
+ unsigned f, unsigned accel)
+{
+ fastCoverParams->k = coverParams.k;
+ fastCoverParams->d = coverParams.d;
+ fastCoverParams->steps = coverParams.steps;
+ fastCoverParams->nbThreads = coverParams.nbThreads;
+ fastCoverParams->splitPoint = coverParams.splitPoint;
+ fastCoverParams->f = f;
+ fastCoverParams->accel = accel;
+ fastCoverParams->zParams = coverParams.zParams;
+ fastCoverParams->shrinkDict = coverParams.shrinkDict;
+}
+
+
+ZDICTLIB_API size_t
+ZDICT_trainFromBuffer_fastCover(void* dictBuffer, size_t dictBufferCapacity,
+ const void* samplesBuffer,
+ const size_t* samplesSizes, unsigned nbSamples,
+ ZDICT_fastCover_params_t parameters)
+{
+ BYTE* const dict = (BYTE*)dictBuffer;
+ FASTCOVER_ctx_t ctx;
+ ZDICT_cover_params_t coverParams;
+ FASTCOVER_accel_t accelParams;
+ /* Initialize global data */
+ g_displayLevel = parameters.zParams.notificationLevel;
+ /* Assign splitPoint and f if not provided */
+ parameters.splitPoint = 1.0;
+ parameters.f = parameters.f == 0 ? DEFAULT_F : parameters.f;
+ parameters.accel = parameters.accel == 0 ? DEFAULT_ACCEL : parameters.accel;
+ /* Convert to cover parameter */
+ memset(&coverParams, 0 , sizeof(coverParams));
+ FASTCOVER_convertToCoverParams(parameters, &coverParams);
+ /* Checks */
+ if (!FASTCOVER_checkParameters(coverParams, dictBufferCapacity, parameters.f,
+ parameters.accel)) {
+ DISPLAYLEVEL(1, "FASTCOVER parameters incorrect\n");
+ return ERROR(parameter_outOfBound);
+ }
+ if (nbSamples == 0) {
+ DISPLAYLEVEL(1, "FASTCOVER must have at least one input file\n");
+ return ERROR(srcSize_wrong);
+ }
+ if (dictBufferCapacity < ZDICT_DICTSIZE_MIN) {
+ DISPLAYLEVEL(1, "dictBufferCapacity must be at least %u\n",
+ ZDICT_DICTSIZE_MIN);
+ return ERROR(dstSize_tooSmall);
+ }
+ /* Assign corresponding FASTCOVER_accel_t to accelParams*/
+ accelParams = FASTCOVER_defaultAccelParameters[parameters.accel];
+ /* Initialize context */
+ {
+ size_t const initVal = FASTCOVER_ctx_init(&ctx, samplesBuffer, samplesSizes, nbSamples,
+ coverParams.d, parameters.splitPoint, parameters.f,
+ accelParams);
+ if (ZSTD_isError(initVal)) {
+ DISPLAYLEVEL(1, "Failed to initialize context\n");
+ return initVal;
+ }
+ }
+ COVER_warnOnSmallCorpus(dictBufferCapacity, ctx.nbDmers, g_displayLevel);
+ /* Build the dictionary */
+ DISPLAYLEVEL(2, "Building dictionary\n");
+ {
+ /* Initialize array to keep track of frequency of dmer within activeSegment */
+ U16* segmentFreqs = (U16 *)calloc(((U64)1 << parameters.f), sizeof(U16));
+ const size_t tail = FASTCOVER_buildDictionary(&ctx, ctx.freqs, dictBuffer,
+ dictBufferCapacity, coverParams, segmentFreqs);
+ const unsigned nbFinalizeSamples = (unsigned)(ctx.nbTrainSamples * ctx.accelParams.finalize / 100);
+ const size_t dictionarySize = ZDICT_finalizeDictionary(
+ dict, dictBufferCapacity, dict + tail, dictBufferCapacity - tail,
+ samplesBuffer, samplesSizes, nbFinalizeSamples, coverParams.zParams);
+ if (!ZSTD_isError(dictionarySize)) {
+ DISPLAYLEVEL(2, "Constructed dictionary of size %u\n",
+ (unsigned)dictionarySize);
+ }
+ FASTCOVER_ctx_destroy(&ctx);
+ free(segmentFreqs);
+ return dictionarySize;
+ }
+}
+
+
+ZDICTLIB_API size_t
+ZDICT_optimizeTrainFromBuffer_fastCover(
+ void* dictBuffer, size_t dictBufferCapacity,
+ const void* samplesBuffer,
+ const size_t* samplesSizes, unsigned nbSamples,
+ ZDICT_fastCover_params_t* parameters)
+{
+ ZDICT_cover_params_t coverParams;
+ FASTCOVER_accel_t accelParams;
+ /* constants */
+ const unsigned nbThreads = parameters->nbThreads;
+ const double splitPoint =
+ parameters->splitPoint <= 0.0 ? DEFAULT_SPLITPOINT : parameters->splitPoint;
+ const unsigned kMinD = parameters->d == 0 ? 6 : parameters->d;
+ const unsigned kMaxD = parameters->d == 0 ? 8 : parameters->d;
+ const unsigned kMinK = parameters->k == 0 ? 50 : parameters->k;
+ const unsigned kMaxK = parameters->k == 0 ? 2000 : parameters->k;
+ const unsigned kSteps = parameters->steps == 0 ? 40 : parameters->steps;
+ const unsigned kStepSize = MAX((kMaxK - kMinK) / kSteps, 1);
+ const unsigned kIterations =
+ (1 + (kMaxD - kMinD) / 2) * (1 + (kMaxK - kMinK) / kStepSize);
+ const unsigned f = parameters->f == 0 ? DEFAULT_F : parameters->f;
+ const unsigned accel = parameters->accel == 0 ? DEFAULT_ACCEL : parameters->accel;
+ const unsigned shrinkDict = 0;
+ /* Local variables */
+ const int displayLevel = parameters->zParams.notificationLevel;
+ unsigned iteration = 1;
+ unsigned d;
+ unsigned k;
+ COVER_best_t best;
+ POOL_ctx *pool = NULL;
+ int warned = 0;
+ /* Checks */
+ if (splitPoint <= 0 || splitPoint > 1) {
+ LOCALDISPLAYLEVEL(displayLevel, 1, "Incorrect splitPoint\n");
+ return ERROR(parameter_outOfBound);
+ }
+ if (accel == 0 || accel > FASTCOVER_MAX_ACCEL) {
+ LOCALDISPLAYLEVEL(displayLevel, 1, "Incorrect accel\n");
+ return ERROR(parameter_outOfBound);
+ }
+ if (kMinK < kMaxD || kMaxK < kMinK) {
+ LOCALDISPLAYLEVEL(displayLevel, 1, "Incorrect k\n");
+ return ERROR(parameter_outOfBound);
+ }
+ if (nbSamples == 0) {
+ LOCALDISPLAYLEVEL(displayLevel, 1, "FASTCOVER must have at least one input file\n");
+ return ERROR(srcSize_wrong);
+ }
+ if (dictBufferCapacity < ZDICT_DICTSIZE_MIN) {
+ LOCALDISPLAYLEVEL(displayLevel, 1, "dictBufferCapacity must be at least %u\n",
+ ZDICT_DICTSIZE_MIN);
+ return ERROR(dstSize_tooSmall);
+ }
+ if (nbThreads > 1) {
+ pool = POOL_create(nbThreads, 1);
+ if (!pool) {
+ return ERROR(memory_allocation);
+ }
+ }
+ /* Initialization */
+ COVER_best_init(&best);
+ memset(&coverParams, 0 , sizeof(coverParams));
+ FASTCOVER_convertToCoverParams(*parameters, &coverParams);
+ accelParams = FASTCOVER_defaultAccelParameters[accel];
+ /* Turn down global display level to clean up display at level 2 and below */
+ g_displayLevel = displayLevel == 0 ? 0 : displayLevel - 1;
+ /* Loop through d first because each new value needs a new context */
+ LOCALDISPLAYLEVEL(displayLevel, 2, "Trying %u different sets of parameters\n",
+ kIterations);
+ for (d = kMinD; d <= kMaxD; d += 2) {
+ /* Initialize the context for this value of d */
+ FASTCOVER_ctx_t ctx;
+ LOCALDISPLAYLEVEL(displayLevel, 3, "d=%u\n", d);
+ {
+ size_t const initVal = FASTCOVER_ctx_init(&ctx, samplesBuffer, samplesSizes, nbSamples, d, splitPoint, f, accelParams);
+ if (ZSTD_isError(initVal)) {
+ LOCALDISPLAYLEVEL(displayLevel, 1, "Failed to initialize context\n");
+ COVER_best_destroy(&best);
+ POOL_free(pool);
+ return initVal;
+ }
+ }
+ if (!warned) {
+ COVER_warnOnSmallCorpus(dictBufferCapacity, ctx.nbDmers, displayLevel);
+ warned = 1;
+ }
+ /* Loop through k reusing the same context */
+ for (k = kMinK; k <= kMaxK; k += kStepSize) {
+ /* Prepare the arguments */
+ FASTCOVER_tryParameters_data_t *data = (FASTCOVER_tryParameters_data_t *)malloc(
+ sizeof(FASTCOVER_tryParameters_data_t));
+ LOCALDISPLAYLEVEL(displayLevel, 3, "k=%u\n", k);
+ if (!data) {
+ LOCALDISPLAYLEVEL(displayLevel, 1, "Failed to allocate parameters\n");
+ COVER_best_destroy(&best);
+ FASTCOVER_ctx_destroy(&ctx);
+ POOL_free(pool);
+ return ERROR(memory_allocation);
+ }
+ data->ctx = &ctx;
+ data->best = &best;
+ data->dictBufferCapacity = dictBufferCapacity;
+ data->parameters = coverParams;
+ data->parameters.k = k;
+ data->parameters.d = d;
+ data->parameters.splitPoint = splitPoint;
+ data->parameters.steps = kSteps;
+ data->parameters.shrinkDict = shrinkDict;
+ data->parameters.zParams.notificationLevel = g_displayLevel;
+ /* Check the parameters */
+ if (!FASTCOVER_checkParameters(data->parameters, dictBufferCapacity,
+ data->ctx->f, accel)) {
+ DISPLAYLEVEL(1, "FASTCOVER parameters incorrect\n");
+ free(data);
+ continue;
+ }
+ /* Call the function and pass ownership of data to it */
+ COVER_best_start(&best);
+ if (pool) {
+ POOL_add(pool, &FASTCOVER_tryParameters, data);
+ } else {
+ FASTCOVER_tryParameters(data);
+ }
+ /* Print status */
+ LOCALDISPLAYUPDATE(displayLevel, 2, "\r%u%% ",
+ (unsigned)((iteration * 100) / kIterations));
+ ++iteration;
+ }
+ COVER_best_wait(&best);
+ FASTCOVER_ctx_destroy(&ctx);
+ }
+ LOCALDISPLAYLEVEL(displayLevel, 2, "\r%79s\r", "");
+ /* Fill the output buffer and parameters with output of the best parameters */
+ {
+ const size_t dictSize = best.dictSize;
+ if (ZSTD_isError(best.compressedSize)) {
+ const size_t compressedSize = best.compressedSize;
+ COVER_best_destroy(&best);
+ POOL_free(pool);
+ return compressedSize;
+ }
+ FASTCOVER_convertToFastCoverParams(best.parameters, parameters, f, accel);
+ memcpy(dictBuffer, best.dict, dictSize);
+ COVER_best_destroy(&best);
+ POOL_free(pool);
+ return dictSize;
+ }
+
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-10-30 10:27:28 +0000