2 * Copyright (c) Meta Platforms, Inc. and affiliates.
5 * This source code is licensed under both the BSD-style license (found in the
6 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
7 * in the COPYING file in the root directory of this source tree).
8 * You may select, at your option, one of the above-listed licenses.
11 /*-*************************************
13 ***************************************/
14 #include <stdio.h> /* fprintf */
15 #include <stdlib.h> /* malloc, free, qsort */
16 #include <string.h> /* memset */
17 #include <time.h> /* clock */
19 #ifndef ZDICT_STATIC_LINKING_ONLY
20 # define ZDICT_STATIC_LINKING_ONLY
23 #include "../common/mem.h" /* read */
24 #include "../common/pool.h"
25 #include "../common/threading.h"
26 #include "../common/zstd_internal.h" /* includes zstd.h */
27 #include "../compress/zstd_compress_internal.h" /* ZSTD_hash*() */
32 /*-*************************************
34 ***************************************/
36 * There are 32bit indexes used to ref samples, so limit samples size to 4GB
38 * For 32bit builds we choose 1 GB.
39 * Most 32bit platforms have 2GB user-mode addressable space and we allocate a large
40 * contiguous buffer, so 1GB is already a high limit.
42 #define FASTCOVER_MAX_SAMPLES_SIZE (sizeof(size_t) == 8 ? ((unsigned)-1) : ((unsigned)1 GB))
43 #define FASTCOVER_MAX_F 31
44 #define FASTCOVER_MAX_ACCEL 10
45 #define FASTCOVER_DEFAULT_SPLITPOINT 0.75
47 #define DEFAULT_ACCEL 1
50 /*-*************************************
52 ***************************************/
53 #ifndef LOCALDISPLAYLEVEL
54 static int g_displayLevel = 0;
57 #define DISPLAY(...) \
59 fprintf(stderr, __VA_ARGS__); \
62 #undef LOCALDISPLAYLEVEL
63 #define LOCALDISPLAYLEVEL(displayLevel, l, ...) \
64 if (displayLevel >= l) { \
65 DISPLAY(__VA_ARGS__); \
66 } /* 0 : no display; 1: errors; 2: default; 3: details; 4: debug */
68 #define DISPLAYLEVEL(l, ...) LOCALDISPLAYLEVEL(g_displayLevel, l, __VA_ARGS__)
70 #ifndef LOCALDISPLAYUPDATE
71 static const clock_t g_refreshRate = CLOCKS_PER_SEC * 15 / 100;
72 static clock_t g_time = 0;
74 #undef LOCALDISPLAYUPDATE
75 #define LOCALDISPLAYUPDATE(displayLevel, l, ...) \
76 if (displayLevel >= l) { \
77 if ((clock() - g_time > g_refreshRate) || (displayLevel >= 4)) { \
79 DISPLAY(__VA_ARGS__); \
83 #define DISPLAYUPDATE(l, ...) LOCALDISPLAYUPDATE(g_displayLevel, l, __VA_ARGS__)
86 /*-*************************************
88 ***************************************/
90 * Hash the d-byte value pointed to by p and mod 2^f into the frequency vector
92 static size_t FASTCOVER_hashPtrToIndex(const void* p, U32 f, unsigned d) {
94 return ZSTD_hash6Ptr(p, f);
96 return ZSTD_hash8Ptr(p, f);
100 /*-*************************************
102 ***************************************/
104 unsigned finalize; /* Percentage of training samples used for ZDICT_finalizeDictionary */
105 unsigned skip; /* Number of dmer skipped between each dmer counted in computeFrequency */
109 static const FASTCOVER_accel_t FASTCOVER_defaultAccelParameters[FASTCOVER_MAX_ACCEL+1] = {
110 { 100, 0 }, /* accel = 0, should not happen because accel = 0 defaults to accel = 1 */
111 { 100, 0 }, /* accel = 1 */
112 { 50, 1 }, /* accel = 2 */
113 { 34, 2 }, /* accel = 3 */
114 { 25, 3 }, /* accel = 4 */
115 { 20, 4 }, /* accel = 5 */
116 { 17, 5 }, /* accel = 6 */
117 { 14, 6 }, /* accel = 7 */
118 { 13, 7 }, /* accel = 8 */
119 { 11, 8 }, /* accel = 9 */
120 { 10, 9 }, /* accel = 10 */
124 /*-*************************************
126 ***************************************/
130 const size_t *samplesSizes;
132 size_t nbTrainSamples;
133 size_t nbTestSamples;
138 FASTCOVER_accel_t accelParams;
142 /*-*************************************
144 ***************************************/
146 * Selects the best segment in an epoch.
147 * Segments of are scored according to the function:
149 * Let F(d) be the frequency of all dmers with hash value d.
150 * Let S_i be hash value of the dmer at position i of segment S which has length k.
152 * Score(S) = F(S_1) + F(S_2) + ... + F(S_{k-d+1})
154 * Once the dmer with hash value d is in the dictionary we set F(d) = 0.
156 static COVER_segment_t FASTCOVER_selectSegment(const FASTCOVER_ctx_t *ctx,
157 U32 *freqs, U32 begin, U32 end,
158 ZDICT_cover_params_t parameters,
161 const U32 k = parameters.k;
162 const U32 d = parameters.d;
163 const U32 f = ctx->f;
164 const U32 dmersInK = k - d + 1;
166 /* Try each segment (activeSegment) and save the best (bestSegment) */
167 COVER_segment_t bestSegment = {0, 0, 0};
168 COVER_segment_t activeSegment;
170 /* Reset the activeDmers in the segment */
171 /* The activeSegment starts at the beginning of the epoch. */
172 activeSegment.begin = begin;
173 activeSegment.end = begin;
174 activeSegment.score = 0;
176 /* Slide the activeSegment through the whole epoch.
177 * Save the best segment in bestSegment.
179 while (activeSegment.end < end) {
180 /* Get hash value of current dmer */
181 const size_t idx = FASTCOVER_hashPtrToIndex(ctx->samples + activeSegment.end, f, d);
183 /* Add frequency of this index to score if this is the first occurrence of index in active segment */
184 if (segmentFreqs[idx] == 0) {
185 activeSegment.score += freqs[idx];
187 /* Increment end of segment and segmentFreqs*/
188 activeSegment.end += 1;
189 segmentFreqs[idx] += 1;
190 /* If the window is now too large, drop the first position */
191 if (activeSegment.end - activeSegment.begin == dmersInK + 1) {
192 /* Get hash value of the dmer to be eliminated from active segment */
193 const size_t delIndex = FASTCOVER_hashPtrToIndex(ctx->samples + activeSegment.begin, f, d);
194 segmentFreqs[delIndex] -= 1;
195 /* Subtract frequency of this index from score if this is the last occurrence of this index in active segment */
196 if (segmentFreqs[delIndex] == 0) {
197 activeSegment.score -= freqs[delIndex];
199 /* Increment start of segment */
200 activeSegment.begin += 1;
203 /* If this segment is the best so far save it */
204 if (activeSegment.score > bestSegment.score) {
205 bestSegment = activeSegment;
209 /* Zero out rest of segmentFreqs array */
210 while (activeSegment.begin < end) {
211 const size_t delIndex = FASTCOVER_hashPtrToIndex(ctx->samples + activeSegment.begin, f, d);
212 segmentFreqs[delIndex] -= 1;
213 activeSegment.begin += 1;
217 /* Zero the frequency of hash value of each dmer covered by the chosen segment. */
219 for (pos = bestSegment.begin; pos != bestSegment.end; ++pos) {
220 const size_t i = FASTCOVER_hashPtrToIndex(ctx->samples + pos, f, d);
229 static int FASTCOVER_checkParameters(ZDICT_cover_params_t parameters,
230 size_t maxDictSize, unsigned f,
232 /* k, d, and f are required parameters */
233 if (parameters.d == 0 || parameters.k == 0) {
236 /* d has to be 6 or 8 */
237 if (parameters.d != 6 && parameters.d != 8) {
240 /* k <= maxDictSize */
241 if (parameters.k > maxDictSize) {
245 if (parameters.d > parameters.k) {
248 /* 0 < f <= FASTCOVER_MAX_F*/
249 if (f > FASTCOVER_MAX_F || f == 0) {
252 /* 0 < splitPoint <= 1 */
253 if (parameters.splitPoint <= 0 || parameters.splitPoint > 1) {
256 /* 0 < accel <= 10 */
257 if (accel > 10 || accel == 0) {
265 * Clean up a context initialized with `FASTCOVER_ctx_init()`.
268 FASTCOVER_ctx_destroy(FASTCOVER_ctx_t* ctx)
281 * Calculate for frequency of hash value of each dmer in ctx->samples
284 FASTCOVER_computeFrequency(U32* freqs, const FASTCOVER_ctx_t* ctx)
286 const unsigned f = ctx->f;
287 const unsigned d = ctx->d;
288 const unsigned skip = ctx->accelParams.skip;
289 const unsigned readLength = MAX(d, 8);
291 assert(ctx->nbTrainSamples >= 5);
292 assert(ctx->nbTrainSamples <= ctx->nbSamples);
293 for (i = 0; i < ctx->nbTrainSamples; i++) {
294 size_t start = ctx->offsets[i]; /* start of current dmer */
295 size_t const currSampleEnd = ctx->offsets[i+1];
296 while (start + readLength <= currSampleEnd) {
297 const size_t dmerIndex = FASTCOVER_hashPtrToIndex(ctx->samples + start, f, d);
299 start = start + skip + 1;
306 * Prepare a context for dictionary building.
307 * The context is only dependent on the parameter `d` and can be used multiple
309 * Returns 0 on success or error code on error.
310 * The context must be destroyed with `FASTCOVER_ctx_destroy()`.
313 FASTCOVER_ctx_init(FASTCOVER_ctx_t* ctx,
314 const void* samplesBuffer,
315 const size_t* samplesSizes, unsigned nbSamples,
316 unsigned d, double splitPoint, unsigned f,
317 FASTCOVER_accel_t accelParams)
319 const BYTE* const samples = (const BYTE*)samplesBuffer;
320 const size_t totalSamplesSize = COVER_sum(samplesSizes, nbSamples);
321 /* Split samples into testing and training sets */
322 const unsigned nbTrainSamples = splitPoint < 1.0 ? (unsigned)((double)nbSamples * splitPoint) : nbSamples;
323 const unsigned nbTestSamples = splitPoint < 1.0 ? nbSamples - nbTrainSamples : nbSamples;
324 const size_t trainingSamplesSize = splitPoint < 1.0 ? COVER_sum(samplesSizes, nbTrainSamples) : totalSamplesSize;
325 const size_t testSamplesSize = splitPoint < 1.0 ? COVER_sum(samplesSizes + nbTrainSamples, nbTestSamples) : totalSamplesSize;
328 if (totalSamplesSize < MAX(d, sizeof(U64)) ||
329 totalSamplesSize >= (size_t)FASTCOVER_MAX_SAMPLES_SIZE) {
330 DISPLAYLEVEL(1, "Total samples size is too large (%u MB), maximum size is %u MB\n",
331 (unsigned)(totalSamplesSize >> 20), (FASTCOVER_MAX_SAMPLES_SIZE >> 20));
332 return ERROR(srcSize_wrong);
335 /* Check if there are at least 5 training samples */
336 if (nbTrainSamples < 5) {
337 DISPLAYLEVEL(1, "Total number of training samples is %u and is invalid\n", nbTrainSamples);
338 return ERROR(srcSize_wrong);
341 /* Check if there's testing sample */
342 if (nbTestSamples < 1) {
343 DISPLAYLEVEL(1, "Total number of testing samples is %u and is invalid.\n", nbTestSamples);
344 return ERROR(srcSize_wrong);
347 /* Zero the context */
348 memset(ctx, 0, sizeof(*ctx));
349 DISPLAYLEVEL(2, "Training on %u samples of total size %u\n", nbTrainSamples,
350 (unsigned)trainingSamplesSize);
351 DISPLAYLEVEL(2, "Testing on %u samples of total size %u\n", nbTestSamples,
352 (unsigned)testSamplesSize);
354 ctx->samples = samples;
355 ctx->samplesSizes = samplesSizes;
356 ctx->nbSamples = nbSamples;
357 ctx->nbTrainSamples = nbTrainSamples;
358 ctx->nbTestSamples = nbTestSamples;
359 ctx->nbDmers = trainingSamplesSize - MAX(d, sizeof(U64)) + 1;
362 ctx->accelParams = accelParams;
364 /* The offsets of each file */
365 ctx->offsets = (size_t*)calloc((nbSamples + 1), sizeof(size_t));
366 if (ctx->offsets == NULL) {
367 DISPLAYLEVEL(1, "Failed to allocate scratch buffers \n");
368 FASTCOVER_ctx_destroy(ctx);
369 return ERROR(memory_allocation);
372 /* Fill offsets from the samplesSizes */
375 assert(nbSamples >= 5);
376 for (i = 1; i <= nbSamples; ++i) {
377 ctx->offsets[i] = ctx->offsets[i - 1] + samplesSizes[i - 1];
381 /* Initialize frequency array of size 2^f */
382 ctx->freqs = (U32*)calloc(((U64)1 << f), sizeof(U32));
383 if (ctx->freqs == NULL) {
384 DISPLAYLEVEL(1, "Failed to allocate frequency table \n");
385 FASTCOVER_ctx_destroy(ctx);
386 return ERROR(memory_allocation);
389 DISPLAYLEVEL(2, "Computing frequencies\n");
390 FASTCOVER_computeFrequency(ctx->freqs, ctx);
397 * Given the prepared context build the dictionary.
400 FASTCOVER_buildDictionary(const FASTCOVER_ctx_t* ctx,
402 void* dictBuffer, size_t dictBufferCapacity,
403 ZDICT_cover_params_t parameters,
406 BYTE *const dict = (BYTE *)dictBuffer;
407 size_t tail = dictBufferCapacity;
408 /* Divide the data into epochs. We will select one segment from each epoch. */
409 const COVER_epoch_info_t epochs = COVER_computeEpochs(
410 (U32)dictBufferCapacity, (U32)ctx->nbDmers, parameters.k, 1);
411 const size_t maxZeroScoreRun = 10;
412 size_t zeroScoreRun = 0;
414 DISPLAYLEVEL(2, "Breaking content into %u epochs of size %u\n",
415 (U32)epochs.num, (U32)epochs.size);
416 /* Loop through the epochs until there are no more segments or the dictionary
419 for (epoch = 0; tail > 0; epoch = (epoch + 1) % epochs.num) {
420 const U32 epochBegin = (U32)(epoch * epochs.size);
421 const U32 epochEnd = epochBegin + epochs.size;
423 /* Select a segment */
424 COVER_segment_t segment = FASTCOVER_selectSegment(
425 ctx, freqs, epochBegin, epochEnd, parameters, segmentFreqs);
427 /* If the segment covers no dmers, then we are out of content.
428 * There may be new content in other epochs, for continue for some time.
430 if (segment.score == 0) {
431 if (++zeroScoreRun >= maxZeroScoreRun) {
438 /* Trim the segment if necessary and if it is too small then we are done */
439 segmentSize = MIN(segment.end - segment.begin + parameters.d - 1, tail);
440 if (segmentSize < parameters.d) {
444 /* We fill the dictionary from the back to allow the best segments to be
445 * referenced with the smallest offsets.
448 memcpy(dict + tail, ctx->samples + segment.begin, segmentSize);
451 (unsigned)(((dictBufferCapacity - tail) * 100) / dictBufferCapacity));
453 DISPLAYLEVEL(2, "\r%79s\r", "");
458 * Parameters for FASTCOVER_tryParameters().
460 typedef struct FASTCOVER_tryParameters_data_s {
461 const FASTCOVER_ctx_t* ctx;
463 size_t dictBufferCapacity;
464 ZDICT_cover_params_t parameters;
465 } FASTCOVER_tryParameters_data_t;
469 * Tries a set of parameters and updates the COVER_best_t with the results.
470 * This function is thread safe if zstd is compiled with multithreaded support.
471 * It takes its parameters as an *OWNING* opaque pointer to support threading.
473 static void FASTCOVER_tryParameters(void* opaque)
475 /* Save parameters as local variables */
476 FASTCOVER_tryParameters_data_t *const data = (FASTCOVER_tryParameters_data_t*)opaque;
477 const FASTCOVER_ctx_t *const ctx = data->ctx;
478 const ZDICT_cover_params_t parameters = data->parameters;
479 size_t dictBufferCapacity = data->dictBufferCapacity;
480 size_t totalCompressedSize = ERROR(GENERIC);
481 /* Initialize array to keep track of frequency of dmer within activeSegment */
482 U16* segmentFreqs = (U16*)calloc(((U64)1 << ctx->f), sizeof(U16));
483 /* Allocate space for hash table, dict, and freqs */
484 BYTE *const dict = (BYTE*)malloc(dictBufferCapacity);
485 COVER_dictSelection_t selection = COVER_dictSelectionError(ERROR(GENERIC));
486 U32* freqs = (U32*) malloc(((U64)1 << ctx->f) * sizeof(U32));
487 if (!segmentFreqs || !dict || !freqs) {
488 DISPLAYLEVEL(1, "Failed to allocate buffers: out of memory\n");
491 /* Copy the frequencies because we need to modify them */
492 memcpy(freqs, ctx->freqs, ((U64)1 << ctx->f) * sizeof(U32));
493 /* Build the dictionary */
494 { const size_t tail = FASTCOVER_buildDictionary(ctx, freqs, dict, dictBufferCapacity,
495 parameters, segmentFreqs);
497 const unsigned nbFinalizeSamples = (unsigned)(ctx->nbTrainSamples * ctx->accelParams.finalize / 100);
498 selection = COVER_selectDict(dict + tail, dictBufferCapacity, dictBufferCapacity - tail,
499 ctx->samples, ctx->samplesSizes, nbFinalizeSamples, ctx->nbTrainSamples, ctx->nbSamples, parameters, ctx->offsets,
500 totalCompressedSize);
502 if (COVER_dictSelectionIsError(selection)) {
503 DISPLAYLEVEL(1, "Failed to select dictionary\n");
509 COVER_best_finish(data->best, parameters, selection);
512 COVER_dictSelectionFree(selection);
518 FASTCOVER_convertToCoverParams(ZDICT_fastCover_params_t fastCoverParams,
519 ZDICT_cover_params_t* coverParams)
521 coverParams->k = fastCoverParams.k;
522 coverParams->d = fastCoverParams.d;
523 coverParams->steps = fastCoverParams.steps;
524 coverParams->nbThreads = fastCoverParams.nbThreads;
525 coverParams->splitPoint = fastCoverParams.splitPoint;
526 coverParams->zParams = fastCoverParams.zParams;
527 coverParams->shrinkDict = fastCoverParams.shrinkDict;
532 FASTCOVER_convertToFastCoverParams(ZDICT_cover_params_t coverParams,
533 ZDICT_fastCover_params_t* fastCoverParams,
534 unsigned f, unsigned accel)
536 fastCoverParams->k = coverParams.k;
537 fastCoverParams->d = coverParams.d;
538 fastCoverParams->steps = coverParams.steps;
539 fastCoverParams->nbThreads = coverParams.nbThreads;
540 fastCoverParams->splitPoint = coverParams.splitPoint;
541 fastCoverParams->f = f;
542 fastCoverParams->accel = accel;
543 fastCoverParams->zParams = coverParams.zParams;
544 fastCoverParams->shrinkDict = coverParams.shrinkDict;
548 ZDICTLIB_STATIC_API size_t
549 ZDICT_trainFromBuffer_fastCover(void* dictBuffer, size_t dictBufferCapacity,
550 const void* samplesBuffer,
551 const size_t* samplesSizes, unsigned nbSamples,
552 ZDICT_fastCover_params_t parameters)
554 BYTE* const dict = (BYTE*)dictBuffer;
556 ZDICT_cover_params_t coverParams;
557 FASTCOVER_accel_t accelParams;
558 /* Initialize global data */
559 g_displayLevel = (int)parameters.zParams.notificationLevel;
560 /* Assign splitPoint and f if not provided */
561 parameters.splitPoint = 1.0;
562 parameters.f = parameters.f == 0 ? DEFAULT_F : parameters.f;
563 parameters.accel = parameters.accel == 0 ? DEFAULT_ACCEL : parameters.accel;
564 /* Convert to cover parameter */
565 memset(&coverParams, 0 , sizeof(coverParams));
566 FASTCOVER_convertToCoverParams(parameters, &coverParams);
568 if (!FASTCOVER_checkParameters(coverParams, dictBufferCapacity, parameters.f,
570 DISPLAYLEVEL(1, "FASTCOVER parameters incorrect\n");
571 return ERROR(parameter_outOfBound);
573 if (nbSamples == 0) {
574 DISPLAYLEVEL(1, "FASTCOVER must have at least one input file\n");
575 return ERROR(srcSize_wrong);
577 if (dictBufferCapacity < ZDICT_DICTSIZE_MIN) {
578 DISPLAYLEVEL(1, "dictBufferCapacity must be at least %u\n",
580 return ERROR(dstSize_tooSmall);
582 /* Assign corresponding FASTCOVER_accel_t to accelParams*/
583 accelParams = FASTCOVER_defaultAccelParameters[parameters.accel];
584 /* Initialize context */
586 size_t const initVal = FASTCOVER_ctx_init(&ctx, samplesBuffer, samplesSizes, nbSamples,
587 coverParams.d, parameters.splitPoint, parameters.f,
589 if (ZSTD_isError(initVal)) {
590 DISPLAYLEVEL(1, "Failed to initialize context\n");
594 COVER_warnOnSmallCorpus(dictBufferCapacity, ctx.nbDmers, g_displayLevel);
595 /* Build the dictionary */
596 DISPLAYLEVEL(2, "Building dictionary\n");
598 /* Initialize array to keep track of frequency of dmer within activeSegment */
599 U16* segmentFreqs = (U16 *)calloc(((U64)1 << parameters.f), sizeof(U16));
600 const size_t tail = FASTCOVER_buildDictionary(&ctx, ctx.freqs, dictBuffer,
601 dictBufferCapacity, coverParams, segmentFreqs);
602 const unsigned nbFinalizeSamples = (unsigned)(ctx.nbTrainSamples * ctx.accelParams.finalize / 100);
603 const size_t dictionarySize = ZDICT_finalizeDictionary(
604 dict, dictBufferCapacity, dict + tail, dictBufferCapacity - tail,
605 samplesBuffer, samplesSizes, nbFinalizeSamples, coverParams.zParams);
606 if (!ZSTD_isError(dictionarySize)) {
607 DISPLAYLEVEL(2, "Constructed dictionary of size %u\n",
608 (unsigned)dictionarySize);
610 FASTCOVER_ctx_destroy(&ctx);
612 return dictionarySize;
617 ZDICTLIB_STATIC_API size_t
618 ZDICT_optimizeTrainFromBuffer_fastCover(
619 void* dictBuffer, size_t dictBufferCapacity,
620 const void* samplesBuffer,
621 const size_t* samplesSizes, unsigned nbSamples,
622 ZDICT_fastCover_params_t* parameters)
624 ZDICT_cover_params_t coverParams;
625 FASTCOVER_accel_t accelParams;
627 const unsigned nbThreads = parameters->nbThreads;
628 const double splitPoint =
629 parameters->splitPoint <= 0.0 ? FASTCOVER_DEFAULT_SPLITPOINT : parameters->splitPoint;
630 const unsigned kMinD = parameters->d == 0 ? 6 : parameters->d;
631 const unsigned kMaxD = parameters->d == 0 ? 8 : parameters->d;
632 const unsigned kMinK = parameters->k == 0 ? 50 : parameters->k;
633 const unsigned kMaxK = parameters->k == 0 ? 2000 : parameters->k;
634 const unsigned kSteps = parameters->steps == 0 ? 40 : parameters->steps;
635 const unsigned kStepSize = MAX((kMaxK - kMinK) / kSteps, 1);
636 const unsigned kIterations =
637 (1 + (kMaxD - kMinD) / 2) * (1 + (kMaxK - kMinK) / kStepSize);
638 const unsigned f = parameters->f == 0 ? DEFAULT_F : parameters->f;
639 const unsigned accel = parameters->accel == 0 ? DEFAULT_ACCEL : parameters->accel;
640 const unsigned shrinkDict = 0;
641 /* Local variables */
642 const int displayLevel = (int)parameters->zParams.notificationLevel;
643 unsigned iteration = 1;
647 POOL_ctx *pool = NULL;
650 if (splitPoint <= 0 || splitPoint > 1) {
651 LOCALDISPLAYLEVEL(displayLevel, 1, "Incorrect splitPoint\n");
652 return ERROR(parameter_outOfBound);
654 if (accel == 0 || accel > FASTCOVER_MAX_ACCEL) {
655 LOCALDISPLAYLEVEL(displayLevel, 1, "Incorrect accel\n");
656 return ERROR(parameter_outOfBound);
658 if (kMinK < kMaxD || kMaxK < kMinK) {
659 LOCALDISPLAYLEVEL(displayLevel, 1, "Incorrect k\n");
660 return ERROR(parameter_outOfBound);
662 if (nbSamples == 0) {
663 LOCALDISPLAYLEVEL(displayLevel, 1, "FASTCOVER must have at least one input file\n");
664 return ERROR(srcSize_wrong);
666 if (dictBufferCapacity < ZDICT_DICTSIZE_MIN) {
667 LOCALDISPLAYLEVEL(displayLevel, 1, "dictBufferCapacity must be at least %u\n",
669 return ERROR(dstSize_tooSmall);
672 pool = POOL_create(nbThreads, 1);
674 return ERROR(memory_allocation);
678 COVER_best_init(&best);
679 memset(&coverParams, 0 , sizeof(coverParams));
680 FASTCOVER_convertToCoverParams(*parameters, &coverParams);
681 accelParams = FASTCOVER_defaultAccelParameters[accel];
682 /* Turn down global display level to clean up display at level 2 and below */
683 g_displayLevel = displayLevel == 0 ? 0 : displayLevel - 1;
684 /* Loop through d first because each new value needs a new context */
685 LOCALDISPLAYLEVEL(displayLevel, 2, "Trying %u different sets of parameters\n",
687 for (d = kMinD; d <= kMaxD; d += 2) {
688 /* Initialize the context for this value of d */
690 LOCALDISPLAYLEVEL(displayLevel, 3, "d=%u\n", d);
692 size_t const initVal = FASTCOVER_ctx_init(&ctx, samplesBuffer, samplesSizes, nbSamples, d, splitPoint, f, accelParams);
693 if (ZSTD_isError(initVal)) {
694 LOCALDISPLAYLEVEL(displayLevel, 1, "Failed to initialize context\n");
695 COVER_best_destroy(&best);
701 COVER_warnOnSmallCorpus(dictBufferCapacity, ctx.nbDmers, displayLevel);
704 /* Loop through k reusing the same context */
705 for (k = kMinK; k <= kMaxK; k += kStepSize) {
706 /* Prepare the arguments */
707 FASTCOVER_tryParameters_data_t *data = (FASTCOVER_tryParameters_data_t *)malloc(
708 sizeof(FASTCOVER_tryParameters_data_t));
709 LOCALDISPLAYLEVEL(displayLevel, 3, "k=%u\n", k);
711 LOCALDISPLAYLEVEL(displayLevel, 1, "Failed to allocate parameters\n");
712 COVER_best_destroy(&best);
713 FASTCOVER_ctx_destroy(&ctx);
715 return ERROR(memory_allocation);
719 data->dictBufferCapacity = dictBufferCapacity;
720 data->parameters = coverParams;
721 data->parameters.k = k;
722 data->parameters.d = d;
723 data->parameters.splitPoint = splitPoint;
724 data->parameters.steps = kSteps;
725 data->parameters.shrinkDict = shrinkDict;
726 data->parameters.zParams.notificationLevel = (unsigned)g_displayLevel;
727 /* Check the parameters */
728 if (!FASTCOVER_checkParameters(data->parameters, dictBufferCapacity,
729 data->ctx->f, accel)) {
730 DISPLAYLEVEL(1, "FASTCOVER parameters incorrect\n");
734 /* Call the function and pass ownership of data to it */
735 COVER_best_start(&best);
737 POOL_add(pool, &FASTCOVER_tryParameters, data);
739 FASTCOVER_tryParameters(data);
742 LOCALDISPLAYUPDATE(displayLevel, 2, "\r%u%% ",
743 (unsigned)((iteration * 100) / kIterations));
746 COVER_best_wait(&best);
747 FASTCOVER_ctx_destroy(&ctx);
749 LOCALDISPLAYLEVEL(displayLevel, 2, "\r%79s\r", "");
750 /* Fill the output buffer and parameters with output of the best parameters */
752 const size_t dictSize = best.dictSize;
753 if (ZSTD_isError(best.compressedSize)) {
754 const size_t compressedSize = best.compressedSize;
755 COVER_best_destroy(&best);
757 return compressedSize;
759 FASTCOVER_convertToFastCoverParams(best.parameters, parameters, f, accel);
760 memcpy(dictBuffer, best.dict, dictSize);
761 COVER_best_destroy(&best);