--- /dev/null
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * 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.
+ */
+
+/* *****************************************************************************
+ * Constructs a dictionary using a heuristic based on the following paper:
+ *
+ * Liao, Petri, Moffat, Wirth
+ * Effective Construction of Relative Lempel-Ziv Dictionaries
+ * Published in WWW 2016.
+ *
+ * Adapted from code originally written by @ot (Giuseppe Ottaviano).
+ ******************************************************************************/
+
+/*-*************************************
+* Dependencies
+***************************************/
+#include <stdio.h> /* fprintf */
+#include <stdlib.h> /* malloc, free, qsort */
+#include <string.h> /* memset */
+#include <time.h> /* clock */
+
+#ifndef ZDICT_STATIC_LINKING_ONLY
+# define ZDICT_STATIC_LINKING_ONLY
+#endif
+
+#include "../common/mem.h" /* read */
+#include "../common/pool.h"
+#include "../common/threading.h"
+#include "../common/zstd_internal.h" /* includes zstd.h */
+#include "../common/bits.h" /* ZSTD_highbit32 */
+#include "../zdict.h"
+#include "cover.h"
+
+/*-*************************************
+* Constants
+***************************************/
+/**
+* There are 32bit indexes used to ref samples, so limit samples size to 4GB
+* on 64bit builds.
+* For 32bit builds we choose 1 GB.
+* Most 32bit platforms have 2GB user-mode addressable space and we allocate a large
+* contiguous buffer, so 1GB is already a high limit.
+*/
+#define COVER_MAX_SAMPLES_SIZE (sizeof(size_t) == 8 ? ((unsigned)-1) : ((unsigned)1 GB))
+#define COVER_DEFAULT_SPLITPOINT 1.0
+
+/*-*************************************
+* Console display
+***************************************/
+#ifndef LOCALDISPLAYLEVEL
+static int g_displayLevel = 0;
+#endif
+#undef DISPLAY
+#define DISPLAY(...) \
+ { \
+ fprintf(stderr, __VA_ARGS__); \
+ fflush(stderr); \
+ }
+#undef LOCALDISPLAYLEVEL
+#define LOCALDISPLAYLEVEL(displayLevel, l, ...) \
+ if (displayLevel >= l) { \
+ DISPLAY(__VA_ARGS__); \
+ } /* 0 : no display; 1: errors; 2: default; 3: details; 4: debug */
+#undef DISPLAYLEVEL
+#define DISPLAYLEVEL(l, ...) LOCALDISPLAYLEVEL(g_displayLevel, l, __VA_ARGS__)
+
+#ifndef LOCALDISPLAYUPDATE
+static const clock_t g_refreshRate = CLOCKS_PER_SEC * 15 / 100;
+static clock_t g_time = 0;
+#endif
+#undef LOCALDISPLAYUPDATE
+#define LOCALDISPLAYUPDATE(displayLevel, l, ...) \
+ if (displayLevel >= l) { \
+ if ((clock() - g_time > g_refreshRate) || (displayLevel >= 4)) { \
+ g_time = clock(); \
+ DISPLAY(__VA_ARGS__); \
+ } \
+ }
+#undef DISPLAYUPDATE
+#define DISPLAYUPDATE(l, ...) LOCALDISPLAYUPDATE(g_displayLevel, l, __VA_ARGS__)
+
+/*-*************************************
+* Hash table
+***************************************
+* A small specialized hash map for storing activeDmers.
+* The map does not resize, so if it becomes full it will loop forever.
+* Thus, the map must be large enough to store every value.
+* The map implements linear probing and keeps its load less than 0.5.
+*/
+
+#define MAP_EMPTY_VALUE ((U32)-1)
+typedef struct COVER_map_pair_t_s {
+ U32 key;
+ U32 value;
+} COVER_map_pair_t;
+
+typedef struct COVER_map_s {
+ COVER_map_pair_t *data;
+ U32 sizeLog;
+ U32 size;
+ U32 sizeMask;
+} COVER_map_t;
+
+/**
+ * Clear the map.
+ */
+static void COVER_map_clear(COVER_map_t *map) {
+ memset(map->data, MAP_EMPTY_VALUE, map->size * sizeof(COVER_map_pair_t));
+}
+
+/**
+ * Initializes a map of the given size.
+ * Returns 1 on success and 0 on failure.
+ * The map must be destroyed with COVER_map_destroy().
+ * The map is only guaranteed to be large enough to hold size elements.
+ */
+static int COVER_map_init(COVER_map_t *map, U32 size) {
+ map->sizeLog = ZSTD_highbit32(size) + 2;
+ map->size = (U32)1 << map->sizeLog;
+ map->sizeMask = map->size - 1;
+ map->data = (COVER_map_pair_t *)malloc(map->size * sizeof(COVER_map_pair_t));
+ if (!map->data) {
+ map->sizeLog = 0;
+ map->size = 0;
+ return 0;
+ }
+ COVER_map_clear(map);
+ return 1;
+}
+
+/**
+ * Internal hash function
+ */
+static const U32 COVER_prime4bytes = 2654435761U;
+static U32 COVER_map_hash(COVER_map_t *map, U32 key) {
+ return (key * COVER_prime4bytes) >> (32 - map->sizeLog);
+}
+
+/**
+ * Helper function that returns the index that a key should be placed into.
+ */
+static U32 COVER_map_index(COVER_map_t *map, U32 key) {
+ const U32 hash = COVER_map_hash(map, key);
+ U32 i;
+ for (i = hash;; i = (i + 1) & map->sizeMask) {
+ COVER_map_pair_t *pos = &map->data[i];
+ if (pos->value == MAP_EMPTY_VALUE) {
+ return i;
+ }
+ if (pos->key == key) {
+ return i;
+ }
+ }
+}
+
+/**
+ * Returns the pointer to the value for key.
+ * If key is not in the map, it is inserted and the value is set to 0.
+ * The map must not be full.
+ */
+static U32 *COVER_map_at(COVER_map_t *map, U32 key) {
+ COVER_map_pair_t *pos = &map->data[COVER_map_index(map, key)];
+ if (pos->value == MAP_EMPTY_VALUE) {
+ pos->key = key;
+ pos->value = 0;
+ }
+ return &pos->value;
+}
+
+/**
+ * Deletes key from the map if present.
+ */
+static void COVER_map_remove(COVER_map_t *map, U32 key) {
+ U32 i = COVER_map_index(map, key);
+ COVER_map_pair_t *del = &map->data[i];
+ U32 shift = 1;
+ if (del->value == MAP_EMPTY_VALUE) {
+ return;
+ }
+ for (i = (i + 1) & map->sizeMask;; i = (i + 1) & map->sizeMask) {
+ COVER_map_pair_t *const pos = &map->data[i];
+ /* If the position is empty we are done */
+ if (pos->value == MAP_EMPTY_VALUE) {
+ del->value = MAP_EMPTY_VALUE;
+ return;
+ }
+ /* If pos can be moved to del do so */
+ if (((i - COVER_map_hash(map, pos->key)) & map->sizeMask) >= shift) {
+ del->key = pos->key;
+ del->value = pos->value;
+ del = pos;
+ shift = 1;
+ } else {
+ ++shift;
+ }
+ }
+}
+
+/**
+ * Destroys a map that is inited with COVER_map_init().
+ */
+static void COVER_map_destroy(COVER_map_t *map) {
+ if (map->data) {
+ free(map->data);
+ }
+ map->data = NULL;
+ map->size = 0;
+}
+
+/*-*************************************
+* Context
+***************************************/
+
+typedef struct {
+ const BYTE *samples;
+ size_t *offsets;
+ const size_t *samplesSizes;
+ size_t nbSamples;
+ size_t nbTrainSamples;
+ size_t nbTestSamples;
+ U32 *suffix;
+ size_t suffixSize;
+ U32 *freqs;
+ U32 *dmerAt;
+ unsigned d;
+} COVER_ctx_t;
+
+/* We need a global context for qsort... */
+static COVER_ctx_t *g_coverCtx = NULL;
+
+/*-*************************************
+* Helper functions
+***************************************/
+
+/**
+ * Returns the sum of the sample sizes.
+ */
+size_t COVER_sum(const size_t *samplesSizes, unsigned nbSamples) {
+ size_t sum = 0;
+ unsigned i;
+ for (i = 0; i < nbSamples; ++i) {
+ sum += samplesSizes[i];
+ }
+ return sum;
+}
+
+/**
+ * Returns -1 if the dmer at lp is less than the dmer at rp.
+ * Return 0 if the dmers at lp and rp are equal.
+ * Returns 1 if the dmer at lp is greater than the dmer at rp.
+ */
+static int COVER_cmp(COVER_ctx_t *ctx, const void *lp, const void *rp) {
+ U32 const lhs = *(U32 const *)lp;
+ U32 const rhs = *(U32 const *)rp;
+ return memcmp(ctx->samples + lhs, ctx->samples + rhs, ctx->d);
+}
+/**
+ * Faster version for d <= 8.
+ */
+static int COVER_cmp8(COVER_ctx_t *ctx, const void *lp, const void *rp) {
+ U64 const mask = (ctx->d == 8) ? (U64)-1 : (((U64)1 << (8 * ctx->d)) - 1);
+ U64 const lhs = MEM_readLE64(ctx->samples + *(U32 const *)lp) & mask;
+ U64 const rhs = MEM_readLE64(ctx->samples + *(U32 const *)rp) & mask;
+ if (lhs < rhs) {
+ return -1;
+ }
+ return (lhs > rhs);
+}
+
+/**
+ * Same as COVER_cmp() except ties are broken by pointer value
+ * NOTE: g_coverCtx must be set to call this function. A global is required because
+ * qsort doesn't take an opaque pointer.
+ */
+static int WIN_CDECL COVER_strict_cmp(const void *lp, const void *rp) {
+ int result = COVER_cmp(g_coverCtx, lp, rp);
+ if (result == 0) {
+ result = lp < rp ? -1 : 1;
+ }
+ return result;
+}
+/**
+ * Faster version for d <= 8.
+ */
+static int WIN_CDECL COVER_strict_cmp8(const void *lp, const void *rp) {
+ int result = COVER_cmp8(g_coverCtx, lp, rp);
+ if (result == 0) {
+ result = lp < rp ? -1 : 1;
+ }
+ return result;
+}
+
+/**
+ * Returns the first pointer in [first, last) whose element does not compare
+ * less than value. If no such element exists it returns last.
+ */
+static const size_t *COVER_lower_bound(const size_t *first, const size_t *last,
+ size_t value) {
+ size_t count = last - first;
+ while (count != 0) {
+ size_t step = count / 2;
+ const size_t *ptr = first;
+ ptr += step;
+ if (*ptr < value) {
+ first = ++ptr;
+ count -= step + 1;
+ } else {
+ count = step;
+ }
+ }
+ return first;
+}
+
+/**
+ * Generic groupBy function.
+ * Groups an array sorted by cmp into groups with equivalent values.
+ * Calls grp for each group.
+ */
+static void
+COVER_groupBy(const void *data, size_t count, size_t size, COVER_ctx_t *ctx,
+ int (*cmp)(COVER_ctx_t *, const void *, const void *),
+ void (*grp)(COVER_ctx_t *, const void *, const void *)) {
+ const BYTE *ptr = (const BYTE *)data;
+ size_t num = 0;
+ while (num < count) {
+ const BYTE *grpEnd = ptr + size;
+ ++num;
+ while (num < count && cmp(ctx, ptr, grpEnd) == 0) {
+ grpEnd += size;
+ ++num;
+ }
+ grp(ctx, ptr, grpEnd);
+ ptr = grpEnd;
+ }
+}
+
+/*-*************************************
+* Cover functions
+***************************************/
+
+/**
+ * Called on each group of positions with the same dmer.
+ * Counts the frequency of each dmer and saves it in the suffix array.
+ * Fills `ctx->dmerAt`.
+ */
+static void COVER_group(COVER_ctx_t *ctx, const void *group,
+ const void *groupEnd) {
+ /* The group consists of all the positions with the same first d bytes. */
+ const U32 *grpPtr = (const U32 *)group;
+ const U32 *grpEnd = (const U32 *)groupEnd;
+ /* The dmerId is how we will reference this dmer.
+ * This allows us to map the whole dmer space to a much smaller space, the
+ * size of the suffix array.
+ */
+ const U32 dmerId = (U32)(grpPtr - ctx->suffix);
+ /* Count the number of samples this dmer shows up in */
+ U32 freq = 0;
+ /* Details */
+ const size_t *curOffsetPtr = ctx->offsets;
+ const size_t *offsetsEnd = ctx->offsets + ctx->nbSamples;
+ /* Once *grpPtr >= curSampleEnd this occurrence of the dmer is in a
+ * different sample than the last.
+ */
+ size_t curSampleEnd = ctx->offsets[0];
+ for (; grpPtr != grpEnd; ++grpPtr) {
+ /* Save the dmerId for this position so we can get back to it. */
+ ctx->dmerAt[*grpPtr] = dmerId;
+ /* Dictionaries only help for the first reference to the dmer.
+ * After that zstd can reference the match from the previous reference.
+ * So only count each dmer once for each sample it is in.
+ */
+ if (*grpPtr < curSampleEnd) {
+ continue;
+ }
+ freq += 1;
+ /* Binary search to find the end of the sample *grpPtr is in.
+ * In the common case that grpPtr + 1 == grpEnd we can skip the binary
+ * search because the loop is over.
+ */
+ if (grpPtr + 1 != grpEnd) {
+ const size_t *sampleEndPtr =
+ COVER_lower_bound(curOffsetPtr, offsetsEnd, *grpPtr);
+ curSampleEnd = *sampleEndPtr;
+ curOffsetPtr = sampleEndPtr + 1;
+ }
+ }
+ /* At this point we are never going to look at this segment of the suffix
+ * array again. We take advantage of this fact to save memory.
+ * We store the frequency of the dmer in the first position of the group,
+ * which is dmerId.
+ */
+ ctx->suffix[dmerId] = freq;
+}
+
+
+/**
+ * Selects the best segment in an epoch.
+ * Segments of are scored according to the function:
+ *
+ * Let F(d) be the frequency of dmer d.
+ * Let S_i be 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 d is in the dictionary we set F(d) = 0.
+ */
+static COVER_segment_t COVER_selectSegment(const COVER_ctx_t *ctx, U32 *freqs,
+ COVER_map_t *activeDmers, U32 begin,
+ U32 end,
+ ZDICT_cover_params_t parameters) {
+ /* Constants */
+ const U32 k = parameters.k;
+ const U32 d = parameters.d;
+ 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 */
+ COVER_map_clear(activeDmers);
+ /* 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) {
+ /* The dmerId for the dmer at the next position */
+ U32 newDmer = ctx->dmerAt[activeSegment.end];
+ /* The entry in activeDmers for this dmerId */
+ U32 *newDmerOcc = COVER_map_at(activeDmers, newDmer);
+ /* If the dmer isn't already present in the segment add its score. */
+ if (*newDmerOcc == 0) {
+ /* The paper suggest using the L-0.5 norm, but experiments show that it
+ * doesn't help.
+ */
+ activeSegment.score += freqs[newDmer];
+ }
+ /* Add the dmer to the segment */
+ activeSegment.end += 1;
+ *newDmerOcc += 1;
+
+ /* If the window is now too large, drop the first position */
+ if (activeSegment.end - activeSegment.begin == dmersInK + 1) {
+ U32 delDmer = ctx->dmerAt[activeSegment.begin];
+ U32 *delDmerOcc = COVER_map_at(activeDmers, delDmer);
+ activeSegment.begin += 1;
+ *delDmerOcc -= 1;
+ /* If this is the last occurrence of the dmer, subtract its score */
+ if (*delDmerOcc == 0) {
+ COVER_map_remove(activeDmers, delDmer);
+ activeSegment.score -= freqs[delDmer];
+ }
+ }
+
+ /* If this segment is the best so far save it */
+ if (activeSegment.score > bestSegment.score) {
+ bestSegment = activeSegment;
+ }
+ }
+ {
+ /* Trim off the zero frequency head and tail from the segment. */
+ U32 newBegin = bestSegment.end;
+ U32 newEnd = bestSegment.begin;
+ U32 pos;
+ for (pos = bestSegment.begin; pos != bestSegment.end; ++pos) {
+ U32 freq = freqs[ctx->dmerAt[pos]];
+ if (freq != 0) {
+ newBegin = MIN(newBegin, pos);
+ newEnd = pos + 1;
+ }
+ }
+ bestSegment.begin = newBegin;
+ bestSegment.end = newEnd;
+ }
+ {
+ /* Zero out the frequency of each dmer covered by the chosen segment. */
+ U32 pos;
+ for (pos = bestSegment.begin; pos != bestSegment.end; ++pos) {
+ freqs[ctx->dmerAt[pos]] = 0;
+ }
+ }
+ return bestSegment;
+}
+
+/**
+ * Check the validity of the parameters.
+ * Returns non-zero if the parameters are valid and 0 otherwise.
+ */
+static int COVER_checkParameters(ZDICT_cover_params_t parameters,
+ size_t maxDictSize) {
+ /* k and d are required parameters */
+ if (parameters.d == 0 || parameters.k == 0) {
+ return 0;
+ }
+ /* k <= maxDictSize */
+ if (parameters.k > maxDictSize) {
+ return 0;
+ }
+ /* d <= k */
+ if (parameters.d > parameters.k) {
+ return 0;
+ }
+ /* 0 < splitPoint <= 1 */
+ if (parameters.splitPoint <= 0 || parameters.splitPoint > 1){
+ return 0;
+ }
+ return 1;
+}
+
+/**
+ * Clean up a context initialized with `COVER_ctx_init()`.
+ */
+static void COVER_ctx_destroy(COVER_ctx_t *ctx) {
+ if (!ctx) {
+ return;
+ }
+ if (ctx->suffix) {
+ free(ctx->suffix);
+ ctx->suffix = NULL;
+ }
+ if (ctx->freqs) {
+ free(ctx->freqs);
+ ctx->freqs = NULL;
+ }
+ if (ctx->dmerAt) {
+ free(ctx->dmerAt);
+ ctx->dmerAt = NULL;
+ }
+ if (ctx->offsets) {
+ free(ctx->offsets);
+ ctx->offsets = NULL;
+ }
+}
+
+/**
+ * Prepare a context for dictionary building.
+ * The context is only dependent on the parameter `d` and can be used multiple
+ * times.
+ * Returns 0 on success or error code on error.
+ * The context must be destroyed with `COVER_ctx_destroy()`.
+ */
+static size_t COVER_ctx_init(COVER_ctx_t *ctx, const void *samplesBuffer,
+ const size_t *samplesSizes, unsigned nbSamples,
+ unsigned d, double splitPoint) {
+ 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)COVER_MAX_SAMPLES_SIZE) {
+ DISPLAYLEVEL(1, "Total samples size is too large (%u MB), maximum size is %u MB\n",
+ (unsigned)(totalSamplesSize>>20), (COVER_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.", 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.", 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;
+ /* Partial suffix array */
+ ctx->suffixSize = trainingSamplesSize - MAX(d, sizeof(U64)) + 1;
+ ctx->suffix = (U32 *)malloc(ctx->suffixSize * sizeof(U32));
+ /* Maps index to the dmerID */
+ ctx->dmerAt = (U32 *)malloc(ctx->suffixSize * sizeof(U32));
+ /* The offsets of each file */
+ ctx->offsets = (size_t *)malloc((nbSamples + 1) * sizeof(size_t));
+ if (!ctx->suffix || !ctx->dmerAt || !ctx->offsets) {
+ DISPLAYLEVEL(1, "Failed to allocate scratch buffers\n");
+ COVER_ctx_destroy(ctx);
+ return ERROR(memory_allocation);
+ }
+ ctx->freqs = NULL;
+ ctx->d = d;
+
+ /* Fill offsets from the samplesSizes */
+ {
+ U32 i;
+ ctx->offsets[0] = 0;
+ for (i = 1; i <= nbSamples; ++i) {
+ ctx->offsets[i] = ctx->offsets[i - 1] + samplesSizes[i - 1];
+ }
+ }
+ DISPLAYLEVEL(2, "Constructing partial suffix array\n");
+ {
+ /* suffix is a partial suffix array.
+ * It only sorts suffixes by their first parameters.d bytes.
+ * The sort is stable, so each dmer group is sorted by position in input.
+ */
+ U32 i;
+ for (i = 0; i < ctx->suffixSize; ++i) {
+ ctx->suffix[i] = i;
+ }
+ /* qsort doesn't take an opaque pointer, so pass as a global.
+ * On OpenBSD qsort() is not guaranteed to be stable, their mergesort() is.
+ */
+ g_coverCtx = ctx;
+#if defined(__OpenBSD__)
+ mergesort(ctx->suffix, ctx->suffixSize, sizeof(U32),
+ (ctx->d <= 8 ? &COVER_strict_cmp8 : &COVER_strict_cmp));
+#else
+ qsort(ctx->suffix, ctx->suffixSize, sizeof(U32),
+ (ctx->d <= 8 ? &COVER_strict_cmp8 : &COVER_strict_cmp));
+#endif
+ }
+ DISPLAYLEVEL(2, "Computing frequencies\n");
+ /* For each dmer group (group of positions with the same first d bytes):
+ * 1. For each position we set dmerAt[position] = dmerID. The dmerID is
+ * (groupBeginPtr - suffix). This allows us to go from position to
+ * dmerID so we can look up values in freq.
+ * 2. We calculate how many samples the dmer occurs in and save it in
+ * freqs[dmerId].
+ */
+ COVER_groupBy(ctx->suffix, ctx->suffixSize, sizeof(U32), ctx,
+ (ctx->d <= 8 ? &COVER_cmp8 : &COVER_cmp), &COVER_group);
+ ctx->freqs = ctx->suffix;
+ ctx->suffix = NULL;
+ return 0;
+}
+
+void COVER_warnOnSmallCorpus(size_t maxDictSize, size_t nbDmers, int displayLevel)
+{
+ const double ratio = (double)nbDmers / (double)maxDictSize;
+ if (ratio >= 10) {
+ return;
+ }
+ LOCALDISPLAYLEVEL(displayLevel, 1,
+ "WARNING: The maximum dictionary size %u is too large "
+ "compared to the source size %u! "
+ "size(source)/size(dictionary) = %f, but it should be >= "
+ "10! This may lead to a subpar dictionary! We recommend "
+ "training on sources at least 10x, and preferably 100x "
+ "the size of the dictionary! \n", (U32)maxDictSize,
+ (U32)nbDmers, ratio);
+}
+
+COVER_epoch_info_t COVER_computeEpochs(U32 maxDictSize,
+ U32 nbDmers, U32 k, U32 passes)
+{
+ const U32 minEpochSize = k * 10;
+ COVER_epoch_info_t epochs;
+ epochs.num = MAX(1, maxDictSize / k / passes);
+ epochs.size = nbDmers / epochs.num;
+ if (epochs.size >= minEpochSize) {
+ assert(epochs.size * epochs.num <= nbDmers);
+ return epochs;
+ }
+ epochs.size = MIN(minEpochSize, nbDmers);
+ epochs.num = nbDmers / epochs.size;
+ assert(epochs.size * epochs.num <= nbDmers);
+ return epochs;
+}
+
+/**
+ * Given the prepared context build the dictionary.
+ */
+static size_t COVER_buildDictionary(const COVER_ctx_t *ctx, U32 *freqs,
+ COVER_map_t *activeDmers, void *dictBuffer,
+ size_t dictBufferCapacity,
+ ZDICT_cover_params_t parameters) {
+ 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->suffixSize, parameters.k, 4);
+ const size_t maxZeroScoreRun = MAX(10, MIN(100, epochs.num >> 3));
+ 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 = COVER_selectSegment(
+ ctx, freqs, activeDmers, epochBegin, epochEnd, parameters);
+ /* 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;
+}
+
+ZDICTLIB_API size_t ZDICT_trainFromBuffer_cover(
+ void *dictBuffer, size_t dictBufferCapacity,
+ const void *samplesBuffer, const size_t *samplesSizes, unsigned nbSamples,
+ ZDICT_cover_params_t parameters)
+{
+ BYTE* const dict = (BYTE*)dictBuffer;
+ COVER_ctx_t ctx;
+ COVER_map_t activeDmers;
+ parameters.splitPoint = 1.0;
+ /* Initialize global data */
+ g_displayLevel = (int)parameters.zParams.notificationLevel;
+ /* Checks */
+ if (!COVER_checkParameters(parameters, dictBufferCapacity)) {
+ DISPLAYLEVEL(1, "Cover parameters incorrect\n");
+ return ERROR(parameter_outOfBound);
+ }
+ if (nbSamples == 0) {
+ DISPLAYLEVEL(1, "Cover 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);
+ }
+ /* Initialize context and activeDmers */
+ {
+ size_t const initVal = COVER_ctx_init(&ctx, samplesBuffer, samplesSizes, nbSamples,
+ parameters.d, parameters.splitPoint);
+ if (ZSTD_isError(initVal)) {
+ return initVal;
+ }
+ }
+ COVER_warnOnSmallCorpus(dictBufferCapacity, ctx.suffixSize, g_displayLevel);
+ if (!COVER_map_init(&activeDmers, parameters.k - parameters.d + 1)) {
+ DISPLAYLEVEL(1, "Failed to allocate dmer map: out of memory\n");
+ COVER_ctx_destroy(&ctx);
+ return ERROR(memory_allocation);
+ }
+
+ DISPLAYLEVEL(2, "Building dictionary\n");
+ {
+ const size_t tail =
+ COVER_buildDictionary(&ctx, ctx.freqs, &activeDmers, dictBuffer,
+ dictBufferCapacity, parameters);
+ const size_t dictionarySize = ZDICT_finalizeDictionary(
+ dict, dictBufferCapacity, dict + tail, dictBufferCapacity - tail,
+ samplesBuffer, samplesSizes, nbSamples, parameters.zParams);
+ if (!ZSTD_isError(dictionarySize)) {
+ DISPLAYLEVEL(2, "Constructed dictionary of size %u\n",
+ (unsigned)dictionarySize);
+ }
+ COVER_ctx_destroy(&ctx);
+ COVER_map_destroy(&activeDmers);
+ return dictionarySize;
+ }
+}
+
+
+
+size_t COVER_checkTotalCompressedSize(const ZDICT_cover_params_t parameters,
+ const size_t *samplesSizes, const BYTE *samples,
+ size_t *offsets,
+ size_t nbTrainSamples, size_t nbSamples,
+ BYTE *const dict, size_t dictBufferCapacity) {
+ size_t totalCompressedSize = ERROR(GENERIC);
+ /* Pointers */
+ ZSTD_CCtx *cctx;
+ ZSTD_CDict *cdict;
+ void *dst;
+ /* Local variables */
+ size_t dstCapacity;
+ size_t i;
+ /* Allocate dst with enough space to compress the maximum sized sample */
+ {
+ size_t maxSampleSize = 0;
+ i = parameters.splitPoint < 1.0 ? nbTrainSamples : 0;
+ for (; i < nbSamples; ++i) {
+ maxSampleSize = MAX(samplesSizes[i], maxSampleSize);
+ }
+ dstCapacity = ZSTD_compressBound(maxSampleSize);
+ dst = malloc(dstCapacity);
+ }
+ /* Create the cctx and cdict */
+ cctx = ZSTD_createCCtx();
+ cdict = ZSTD_createCDict(dict, dictBufferCapacity,
+ parameters.zParams.compressionLevel);
+ if (!dst || !cctx || !cdict) {
+ goto _compressCleanup;
+ }
+ /* Compress each sample and sum their sizes (or error) */
+ totalCompressedSize = dictBufferCapacity;
+ i = parameters.splitPoint < 1.0 ? nbTrainSamples : 0;
+ for (; i < nbSamples; ++i) {
+ const size_t size = ZSTD_compress_usingCDict(
+ cctx, dst, dstCapacity, samples + offsets[i],
+ samplesSizes[i], cdict);
+ if (ZSTD_isError(size)) {
+ totalCompressedSize = size;
+ goto _compressCleanup;
+ }
+ totalCompressedSize += size;
+ }
+_compressCleanup:
+ ZSTD_freeCCtx(cctx);
+ ZSTD_freeCDict(cdict);
+ if (dst) {
+ free(dst);
+ }
+ return totalCompressedSize;
+}
+
+
+/**
+ * Initialize the `COVER_best_t`.
+ */
+void COVER_best_init(COVER_best_t *best) {
+ if (best==NULL) return; /* compatible with init on NULL */
+ (void)ZSTD_pthread_mutex_init(&best->mutex, NULL);
+ (void)ZSTD_pthread_cond_init(&best->cond, NULL);
+ best->liveJobs = 0;
+ best->dict = NULL;
+ best->dictSize = 0;
+ best->compressedSize = (size_t)-1;
+ memset(&best->parameters, 0, sizeof(best->parameters));
+}
+
+/**
+ * Wait until liveJobs == 0.
+ */
+void COVER_best_wait(COVER_best_t *best) {
+ if (!best) {
+ return;
+ }
+ ZSTD_pthread_mutex_lock(&best->mutex);
+ while (best->liveJobs != 0) {
+ ZSTD_pthread_cond_wait(&best->cond, &best->mutex);
+ }
+ ZSTD_pthread_mutex_unlock(&best->mutex);
+}
+
+/**
+ * Call COVER_best_wait() and then destroy the COVER_best_t.
+ */
+void COVER_best_destroy(COVER_best_t *best) {
+ if (!best) {
+ return;
+ }
+ COVER_best_wait(best);
+ if (best->dict) {
+ free(best->dict);
+ }
+ ZSTD_pthread_mutex_destroy(&best->mutex);
+ ZSTD_pthread_cond_destroy(&best->cond);
+}
+
+/**
+ * Called when a thread is about to be launched.
+ * Increments liveJobs.
+ */
+void COVER_best_start(COVER_best_t *best) {
+ if (!best) {
+ return;
+ }
+ ZSTD_pthread_mutex_lock(&best->mutex);
+ ++best->liveJobs;
+ ZSTD_pthread_mutex_unlock(&best->mutex);
+}
+
+/**
+ * Called when a thread finishes executing, both on error or success.
+ * Decrements liveJobs and signals any waiting threads if liveJobs == 0.
+ * If this dictionary is the best so far save it and its parameters.
+ */
+void COVER_best_finish(COVER_best_t *best, ZDICT_cover_params_t parameters,
+ COVER_dictSelection_t selection) {
+ void* dict = selection.dictContent;
+ size_t compressedSize = selection.totalCompressedSize;
+ size_t dictSize = selection.dictSize;
+ if (!best) {
+ return;
+ }
+ {
+ size_t liveJobs;
+ ZSTD_pthread_mutex_lock(&best->mutex);
+ --best->liveJobs;
+ liveJobs = best->liveJobs;
+ /* If the new dictionary is better */
+ if (compressedSize < best->compressedSize) {
+ /* Allocate space if necessary */
+ if (!best->dict || best->dictSize < dictSize) {
+ if (best->dict) {
+ free(best->dict);
+ }
+ best->dict = malloc(dictSize);
+ if (!best->dict) {
+ best->compressedSize = ERROR(GENERIC);
+ best->dictSize = 0;
+ ZSTD_pthread_cond_signal(&best->cond);
+ ZSTD_pthread_mutex_unlock(&best->mutex);
+ return;
+ }
+ }
+ /* Save the dictionary, parameters, and size */
+ if (dict) {
+ memcpy(best->dict, dict, dictSize);
+ best->dictSize = dictSize;
+ best->parameters = parameters;
+ best->compressedSize = compressedSize;
+ }
+ }
+ if (liveJobs == 0) {
+ ZSTD_pthread_cond_broadcast(&best->cond);
+ }
+ ZSTD_pthread_mutex_unlock(&best->mutex);
+ }
+}
+
+static COVER_dictSelection_t setDictSelection(BYTE* buf, size_t s, size_t csz)
+{
+ COVER_dictSelection_t ds;
+ ds.dictContent = buf;
+ ds.dictSize = s;
+ ds.totalCompressedSize = csz;
+ return ds;
+}
+
+COVER_dictSelection_t COVER_dictSelectionError(size_t error) {
+ return setDictSelection(NULL, 0, error);
+}
+
+unsigned COVER_dictSelectionIsError(COVER_dictSelection_t selection) {
+ return (ZSTD_isError(selection.totalCompressedSize) || !selection.dictContent);
+}
+
+void COVER_dictSelectionFree(COVER_dictSelection_t selection){
+ free(selection.dictContent);
+}
+
+COVER_dictSelection_t COVER_selectDict(BYTE* customDictContent, size_t dictBufferCapacity,
+ size_t dictContentSize, const BYTE* samplesBuffer, const size_t* samplesSizes, unsigned nbFinalizeSamples,
+ size_t nbCheckSamples, size_t nbSamples, ZDICT_cover_params_t params, size_t* offsets, size_t totalCompressedSize) {
+
+ size_t largestDict = 0;
+ size_t largestCompressed = 0;
+ BYTE* customDictContentEnd = customDictContent + dictContentSize;
+
+ BYTE * largestDictbuffer = (BYTE *)malloc(dictBufferCapacity);
+ BYTE * candidateDictBuffer = (BYTE *)malloc(dictBufferCapacity);
+ double regressionTolerance = ((double)params.shrinkDictMaxRegression / 100.0) + 1.00;
+
+ if (!largestDictbuffer || !candidateDictBuffer) {
+ free(largestDictbuffer);
+ free(candidateDictBuffer);
+ return COVER_dictSelectionError(dictContentSize);
+ }
+
+ /* Initial dictionary size and compressed size */
+ memcpy(largestDictbuffer, customDictContent, dictContentSize);
+ dictContentSize = ZDICT_finalizeDictionary(
+ largestDictbuffer, dictBufferCapacity, customDictContent, dictContentSize,
+ samplesBuffer, samplesSizes, nbFinalizeSamples, params.zParams);
+
+ if (ZDICT_isError(dictContentSize)) {
+ free(largestDictbuffer);
+ free(candidateDictBuffer);
+ return COVER_dictSelectionError(dictContentSize);
+ }
+
+ totalCompressedSize = COVER_checkTotalCompressedSize(params, samplesSizes,
+ samplesBuffer, offsets,
+ nbCheckSamples, nbSamples,
+ largestDictbuffer, dictContentSize);
+
+ if (ZSTD_isError(totalCompressedSize)) {
+ free(largestDictbuffer);
+ free(candidateDictBuffer);
+ return COVER_dictSelectionError(totalCompressedSize);
+ }
+
+ if (params.shrinkDict == 0) {
+ free(candidateDictBuffer);
+ return setDictSelection(largestDictbuffer, dictContentSize, totalCompressedSize);
+ }
+
+ largestDict = dictContentSize;
+ largestCompressed = totalCompressedSize;
+ dictContentSize = ZDICT_DICTSIZE_MIN;
+
+ /* Largest dict is initially at least ZDICT_DICTSIZE_MIN */
+ while (dictContentSize < largestDict) {
+ memcpy(candidateDictBuffer, largestDictbuffer, largestDict);
+ dictContentSize = ZDICT_finalizeDictionary(
+ candidateDictBuffer, dictBufferCapacity, customDictContentEnd - dictContentSize, dictContentSize,
+ samplesBuffer, samplesSizes, nbFinalizeSamples, params.zParams);
+
+ if (ZDICT_isError(dictContentSize)) {
+ free(largestDictbuffer);
+ free(candidateDictBuffer);
+ return COVER_dictSelectionError(dictContentSize);
+
+ }
+
+ totalCompressedSize = COVER_checkTotalCompressedSize(params, samplesSizes,
+ samplesBuffer, offsets,
+ nbCheckSamples, nbSamples,
+ candidateDictBuffer, dictContentSize);
+
+ if (ZSTD_isError(totalCompressedSize)) {
+ free(largestDictbuffer);
+ free(candidateDictBuffer);
+ return COVER_dictSelectionError(totalCompressedSize);
+ }
+
+ if ((double)totalCompressedSize <= (double)largestCompressed * regressionTolerance) {
+ free(largestDictbuffer);
+ return setDictSelection( candidateDictBuffer, dictContentSize, totalCompressedSize );
+ }
+ dictContentSize *= 2;
+ }
+ dictContentSize = largestDict;
+ totalCompressedSize = largestCompressed;
+ free(candidateDictBuffer);
+ return setDictSelection( largestDictbuffer, dictContentSize, totalCompressedSize );
+}
+
+/**
+ * Parameters for COVER_tryParameters().
+ */
+typedef struct COVER_tryParameters_data_s {
+ const COVER_ctx_t *ctx;
+ COVER_best_t *best;
+ size_t dictBufferCapacity;
+ ZDICT_cover_params_t parameters;
+} COVER_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 COVER_tryParameters(void *opaque)
+{
+ /* Save parameters as local variables */
+ COVER_tryParameters_data_t *const data = (COVER_tryParameters_data_t*)opaque;
+ const COVER_ctx_t *const ctx = data->ctx;
+ const ZDICT_cover_params_t parameters = data->parameters;
+ size_t dictBufferCapacity = data->dictBufferCapacity;
+ size_t totalCompressedSize = ERROR(GENERIC);
+ /* Allocate space for hash table, dict, and freqs */
+ COVER_map_t activeDmers;
+ BYTE* const dict = (BYTE*)malloc(dictBufferCapacity);
+ COVER_dictSelection_t selection = COVER_dictSelectionError(ERROR(GENERIC));
+ U32* const freqs = (U32*)malloc(ctx->suffixSize * sizeof(U32));
+ if (!COVER_map_init(&activeDmers, parameters.k - parameters.d + 1)) {
+ DISPLAYLEVEL(1, "Failed to allocate dmer map: out of memory\n");
+ goto _cleanup;
+ }
+ if (!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, ctx->suffixSize * sizeof(U32));
+ /* Build the dictionary */
+ {
+ const size_t tail = COVER_buildDictionary(ctx, freqs, &activeDmers, dict,
+ dictBufferCapacity, parameters);
+ selection = COVER_selectDict(dict + tail, dictBufferCapacity, dictBufferCapacity - tail,
+ ctx->samples, ctx->samplesSizes, (unsigned)ctx->nbTrainSamples, 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);
+ COVER_map_destroy(&activeDmers);
+ COVER_dictSelectionFree(selection);
+ free(freqs);
+}
+
+ZDICTLIB_API size_t ZDICT_optimizeTrainFromBuffer_cover(
+ void* dictBuffer, size_t dictBufferCapacity, const void* samplesBuffer,
+ const size_t* samplesSizes, unsigned nbSamples,
+ ZDICT_cover_params_t* parameters)
+{
+ /* constants */
+ const unsigned nbThreads = parameters->nbThreads;
+ const double splitPoint =
+ parameters->splitPoint <= 0.0 ? COVER_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 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 parameters\n");
+ return ERROR(parameter_outOfBound);
+ }
+ if (kMinK < kMaxD || kMaxK < kMinK) {
+ LOCALDISPLAYLEVEL(displayLevel, 1, "Incorrect parameters\n");
+ return ERROR(parameter_outOfBound);
+ }
+ if (nbSamples == 0) {
+ DISPLAYLEVEL(1, "Cover 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);
+ }
+ if (nbThreads > 1) {
+ pool = POOL_create(nbThreads, 1);
+ if (!pool) {
+ return ERROR(memory_allocation);
+ }
+ }
+ /* Initialization */
+ COVER_best_init(&best);
+ /* 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 */
+ COVER_ctx_t ctx;
+ LOCALDISPLAYLEVEL(displayLevel, 3, "d=%u\n", d);
+ {
+ const size_t initVal = COVER_ctx_init(&ctx, samplesBuffer, samplesSizes, nbSamples, d, splitPoint);
+ 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.suffixSize, displayLevel);
+ warned = 1;
+ }
+ /* Loop through k reusing the same context */
+ for (k = kMinK; k <= kMaxK; k += kStepSize) {
+ /* Prepare the arguments */
+ COVER_tryParameters_data_t *data = (COVER_tryParameters_data_t *)malloc(
+ sizeof(COVER_tryParameters_data_t));
+ LOCALDISPLAYLEVEL(displayLevel, 3, "k=%u\n", k);
+ if (!data) {
+ LOCALDISPLAYLEVEL(displayLevel, 1, "Failed to allocate parameters\n");
+ COVER_best_destroy(&best);
+ COVER_ctx_destroy(&ctx);
+ POOL_free(pool);
+ return ERROR(memory_allocation);
+ }
+ data->ctx = &ctx;
+ data->best = &best;
+ data->dictBufferCapacity = dictBufferCapacity;
+ data->parameters = *parameters;
+ 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 (!COVER_checkParameters(data->parameters, dictBufferCapacity)) {
+ DISPLAYLEVEL(1, "Cover 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, &COVER_tryParameters, data);
+ } else {
+ COVER_tryParameters(data);
+ }
+ /* Print status */
+ LOCALDISPLAYUPDATE(displayLevel, 2, "\r%u%% ",
+ (unsigned)((iteration * 100) / kIterations));
+ ++iteration;
+ }
+ COVER_best_wait(&best);
+ COVER_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;
+ }
+ *parameters = best.parameters;
+ memcpy(dictBuffer, best.dict, dictSize);
+ COVER_best_destroy(&best);
+ POOL_free(pool);
+ return dictSize;
+ }
+}
notaz.gp2x.de / pcsx_rearmed.git / blobdiff