blob: 941bb5a26ae66fcb8d1620a7e5723341a492e23e [file] [log] [blame]
Prince Pereirac1c21d62021-04-22 08:38:15 +00001/*-*************************************
2* Dependencies
3***************************************/
4#include <stdio.h> /* fprintf */
5#include <stdlib.h> /* malloc, free, qsort */
6#include <string.h> /* memset */
7#include <time.h> /* clock */
8
9#include "mem.h" /* read */
10#include "pool.h"
11#include "threading.h"
12#include "cover.h"
13#include "zstd_internal.h" /* includes zstd.h */
14#ifndef ZDICT_STATIC_LINKING_ONLY
15#define ZDICT_STATIC_LINKING_ONLY
16#endif
17#include "zdict.h"
18
19
20/*-*************************************
21* Constants
22***************************************/
23#define FASTCOVER_MAX_SAMPLES_SIZE (sizeof(size_t) == 8 ? ((unsigned)-1) : ((unsigned)1 GB))
24#define FASTCOVER_MAX_F 31
25#define FASTCOVER_MAX_ACCEL 10
26#define DEFAULT_SPLITPOINT 0.75
27#define DEFAULT_F 20
28#define DEFAULT_ACCEL 1
29
30
31/*-*************************************
32* Console display
33***************************************/
34static int g_displayLevel = 2;
35#define DISPLAY(...) \
36 { \
37 fprintf(stderr, __VA_ARGS__); \
38 fflush(stderr); \
39 }
40#define LOCALDISPLAYLEVEL(displayLevel, l, ...) \
41 if (displayLevel >= l) { \
42 DISPLAY(__VA_ARGS__); \
43 } /* 0 : no display; 1: errors; 2: default; 3: details; 4: debug */
44#define DISPLAYLEVEL(l, ...) LOCALDISPLAYLEVEL(g_displayLevel, l, __VA_ARGS__)
45
46#define LOCALDISPLAYUPDATE(displayLevel, l, ...) \
47 if (displayLevel >= l) { \
48 if ((clock() - g_time > refreshRate) || (displayLevel >= 4)) { \
49 g_time = clock(); \
50 DISPLAY(__VA_ARGS__); \
51 } \
52 }
53#define DISPLAYUPDATE(l, ...) LOCALDISPLAYUPDATE(g_displayLevel, l, __VA_ARGS__)
54static const clock_t refreshRate = CLOCKS_PER_SEC * 15 / 100;
55static clock_t g_time = 0;
56
57
58/*-*************************************
59* Hash Functions
60***************************************/
61static const U64 prime6bytes = 227718039650203ULL;
62static size_t ZSTD_hash6(U64 u, U32 h) { return (size_t)(((u << (64-48)) * prime6bytes) >> (64-h)) ; }
63static size_t ZSTD_hash6Ptr(const void* p, U32 h) { return ZSTD_hash6(MEM_readLE64(p), h); }
64
65static const U64 prime8bytes = 0xCF1BBCDCB7A56463ULL;
66static size_t ZSTD_hash8(U64 u, U32 h) { return (size_t)(((u) * prime8bytes) >> (64-h)) ; }
67static size_t ZSTD_hash8Ptr(const void* p, U32 h) { return ZSTD_hash8(MEM_readLE64(p), h); }
68
69
70/**
71 * Hash the d-byte value pointed to by p and mod 2^f
72 */
73static size_t FASTCOVER_hashPtrToIndex(const void* p, U32 h, unsigned d) {
74 if (d == 6) {
75 return ZSTD_hash6Ptr(p, h) & ((1 << h) - 1);
76 }
77 return ZSTD_hash8Ptr(p, h) & ((1 << h) - 1);
78}
79
80
81/*-*************************************
82* Acceleration
83***************************************/
84typedef struct {
85 unsigned finalize; /* Percentage of training samples used for ZDICT_finalizeDictionary */
86 unsigned skip; /* Number of dmer skipped between each dmer counted in computeFrequency */
87} FASTCOVER_accel_t;
88
89
90static const FASTCOVER_accel_t FASTCOVER_defaultAccelParameters[FASTCOVER_MAX_ACCEL+1] = {
91 { 100, 0 }, /* accel = 0, should not happen because accel = 0 defaults to accel = 1 */
92 { 100, 0 }, /* accel = 1 */
93 { 50, 1 }, /* accel = 2 */
94 { 34, 2 }, /* accel = 3 */
95 { 25, 3 }, /* accel = 4 */
96 { 20, 4 }, /* accel = 5 */
97 { 17, 5 }, /* accel = 6 */
98 { 14, 6 }, /* accel = 7 */
99 { 13, 7 }, /* accel = 8 */
100 { 11, 8 }, /* accel = 9 */
101 { 10, 9 }, /* accel = 10 */
102};
103
104
105/*-*************************************
106* Context
107***************************************/
108typedef struct {
109 const BYTE *samples;
110 size_t *offsets;
111 const size_t *samplesSizes;
112 size_t nbSamples;
113 size_t nbTrainSamples;
114 size_t nbTestSamples;
115 size_t nbDmers;
116 U32 *freqs;
117 unsigned d;
118 unsigned f;
119 FASTCOVER_accel_t accelParams;
120} FASTCOVER_ctx_t;
121
122
123/*-*************************************
124* Helper functions
125***************************************/
126/**
127 * Selects the best segment in an epoch.
128 * Segments of are scored according to the function:
129 *
130 * Let F(d) be the frequency of all dmers with hash value d.
131 * Let S_i be hash value of the dmer at position i of segment S which has length k.
132 *
133 * Score(S) = F(S_1) + F(S_2) + ... + F(S_{k-d+1})
134 *
135 * Once the dmer with hash value d is in the dictionary we set F(d) = 0.
136 */
137static COVER_segment_t FASTCOVER_selectSegment(const FASTCOVER_ctx_t *ctx,
138 U32 *freqs, U32 begin, U32 end,
139 ZDICT_cover_params_t parameters,
140 U16* segmentFreqs) {
141 /* Constants */
142 const U32 k = parameters.k;
143 const U32 d = parameters.d;
144 const U32 f = ctx->f;
145 const U32 dmersInK = k - d + 1;
146
147 /* Try each segment (activeSegment) and save the best (bestSegment) */
148 COVER_segment_t bestSegment = {0, 0, 0};
149 COVER_segment_t activeSegment;
150
151 /* Reset the activeDmers in the segment */
152 /* The activeSegment starts at the beginning of the epoch. */
153 activeSegment.begin = begin;
154 activeSegment.end = begin;
155 activeSegment.score = 0;
156
157 /* Slide the activeSegment through the whole epoch.
158 * Save the best segment in bestSegment.
159 */
160 while (activeSegment.end < end) {
161 /* Get hash value of current dmer */
162 const size_t idx = FASTCOVER_hashPtrToIndex(ctx->samples + activeSegment.end, f, d);
163
164 /* Add frequency of this index to score if this is the first occurrence of index in active segment */
165 if (segmentFreqs[idx] == 0) {
166 activeSegment.score += freqs[idx];
167 }
168 /* Increment end of segment and segmentFreqs*/
169 activeSegment.end += 1;
170 segmentFreqs[idx] += 1;
171 /* If the window is now too large, drop the first position */
172 if (activeSegment.end - activeSegment.begin == dmersInK + 1) {
173 /* Get hash value of the dmer to be eliminated from active segment */
174 const size_t delIndex = FASTCOVER_hashPtrToIndex(ctx->samples + activeSegment.begin, f, d);
175 segmentFreqs[delIndex] -= 1;
176 /* Subtract frequency of this index from score if this is the last occurrence of this index in active segment */
177 if (segmentFreqs[delIndex] == 0) {
178 activeSegment.score -= freqs[delIndex];
179 }
180 /* Increment start of segment */
181 activeSegment.begin += 1;
182 }
183
184 /* If this segment is the best so far save it */
185 if (activeSegment.score > bestSegment.score) {
186 bestSegment = activeSegment;
187 }
188 }
189
190 /* Zero out rest of segmentFreqs array */
191 while (activeSegment.begin < end) {
192 const size_t delIndex = FASTCOVER_hashPtrToIndex(ctx->samples + activeSegment.begin, f, d);
193 segmentFreqs[delIndex] -= 1;
194 activeSegment.begin += 1;
195 }
196
197 {
198 /* Zero the frequency of hash value of each dmer covered by the chosen segment. */
199 U32 pos;
200 for (pos = bestSegment.begin; pos != bestSegment.end; ++pos) {
201 const size_t i = FASTCOVER_hashPtrToIndex(ctx->samples + pos, f, d);
202 freqs[i] = 0;
203 }
204 }
205
206 return bestSegment;
207}
208
209
210static int FASTCOVER_checkParameters(ZDICT_cover_params_t parameters,
211 size_t maxDictSize, unsigned f,
212 unsigned accel) {
213 /* k, d, and f are required parameters */
214 if (parameters.d == 0 || parameters.k == 0) {
215 return 0;
216 }
217 /* d has to be 6 or 8 */
218 if (parameters.d != 6 && parameters.d != 8) {
219 return 0;
220 }
221 /* k <= maxDictSize */
222 if (parameters.k > maxDictSize) {
223 return 0;
224 }
225 /* d <= k */
226 if (parameters.d > parameters.k) {
227 return 0;
228 }
229 /* 0 < f <= FASTCOVER_MAX_F*/
230 if (f > FASTCOVER_MAX_F || f == 0) {
231 return 0;
232 }
233 /* 0 < splitPoint <= 1 */
234 if (parameters.splitPoint <= 0 || parameters.splitPoint > 1) {
235 return 0;
236 }
237 /* 0 < accel <= 10 */
238 if (accel > 10 || accel == 0) {
239 return 0;
240 }
241 return 1;
242}
243
244
245/**
246 * Clean up a context initialized with `FASTCOVER_ctx_init()`.
247 */
248static void
249FASTCOVER_ctx_destroy(FASTCOVER_ctx_t* ctx)
250{
251 if (!ctx) return;
252
253 free(ctx->freqs);
254 ctx->freqs = NULL;
255
256 free(ctx->offsets);
257 ctx->offsets = NULL;
258}
259
260
261/**
262 * Calculate for frequency of hash value of each dmer in ctx->samples
263 */
264static void
265FASTCOVER_computeFrequency(U32* freqs, const FASTCOVER_ctx_t* ctx)
266{
267 const unsigned f = ctx->f;
268 const unsigned d = ctx->d;
269 const unsigned skip = ctx->accelParams.skip;
270 const unsigned readLength = MAX(d, 8);
271 size_t i;
272 assert(ctx->nbTrainSamples >= 5);
273 assert(ctx->nbTrainSamples <= ctx->nbSamples);
274 for (i = 0; i < ctx->nbTrainSamples; i++) {
275 size_t start = ctx->offsets[i]; /* start of current dmer */
276 size_t const currSampleEnd = ctx->offsets[i+1];
277 while (start + readLength <= currSampleEnd) {
278 const size_t dmerIndex = FASTCOVER_hashPtrToIndex(ctx->samples + start, f, d);
279 freqs[dmerIndex]++;
280 start = start + skip + 1;
281 }
282 }
283}
284
285
286/**
287 * Prepare a context for dictionary building.
288 * The context is only dependent on the parameter `d` and can used multiple
289 * times.
290 * Returns 0 on success or error code on error.
291 * The context must be destroyed with `FASTCOVER_ctx_destroy()`.
292 */
293static size_t
294FASTCOVER_ctx_init(FASTCOVER_ctx_t* ctx,
295 const void* samplesBuffer,
296 const size_t* samplesSizes, unsigned nbSamples,
297 unsigned d, double splitPoint, unsigned f,
298 FASTCOVER_accel_t accelParams)
299{
300 const BYTE* const samples = (const BYTE*)samplesBuffer;
301 const size_t totalSamplesSize = COVER_sum(samplesSizes, nbSamples);
302 /* Split samples into testing and training sets */
303 const unsigned nbTrainSamples = splitPoint < 1.0 ? (unsigned)((double)nbSamples * splitPoint) : nbSamples;
304 const unsigned nbTestSamples = splitPoint < 1.0 ? nbSamples - nbTrainSamples : nbSamples;
305 const size_t trainingSamplesSize = splitPoint < 1.0 ? COVER_sum(samplesSizes, nbTrainSamples) : totalSamplesSize;
306 const size_t testSamplesSize = splitPoint < 1.0 ? COVER_sum(samplesSizes + nbTrainSamples, nbTestSamples) : totalSamplesSize;
307
308 /* Checks */
309 if (totalSamplesSize < MAX(d, sizeof(U64)) ||
310 totalSamplesSize >= (size_t)FASTCOVER_MAX_SAMPLES_SIZE) {
311 DISPLAYLEVEL(1, "Total samples size is too large (%u MB), maximum size is %u MB\n",
312 (unsigned)(totalSamplesSize >> 20), (FASTCOVER_MAX_SAMPLES_SIZE >> 20));
313 return ERROR(srcSize_wrong);
314 }
315
316 /* Check if there are at least 5 training samples */
317 if (nbTrainSamples < 5) {
318 DISPLAYLEVEL(1, "Total number of training samples is %u and is invalid\n", nbTrainSamples);
319 return ERROR(srcSize_wrong);
320 }
321
322 /* Check if there's testing sample */
323 if (nbTestSamples < 1) {
324 DISPLAYLEVEL(1, "Total number of testing samples is %u and is invalid.\n", nbTestSamples);
325 return ERROR(srcSize_wrong);
326 }
327
328 /* Zero the context */
329 memset(ctx, 0, sizeof(*ctx));
330 DISPLAYLEVEL(2, "Training on %u samples of total size %u\n", nbTrainSamples,
331 (unsigned)trainingSamplesSize);
332 DISPLAYLEVEL(2, "Testing on %u samples of total size %u\n", nbTestSamples,
333 (unsigned)testSamplesSize);
334
335 ctx->samples = samples;
336 ctx->samplesSizes = samplesSizes;
337 ctx->nbSamples = nbSamples;
338 ctx->nbTrainSamples = nbTrainSamples;
339 ctx->nbTestSamples = nbTestSamples;
340 ctx->nbDmers = trainingSamplesSize - MAX(d, sizeof(U64)) + 1;
341 ctx->d = d;
342 ctx->f = f;
343 ctx->accelParams = accelParams;
344
345 /* The offsets of each file */
346 ctx->offsets = (size_t*)calloc((nbSamples + 1), sizeof(size_t));
347 if (ctx->offsets == NULL) {
348 DISPLAYLEVEL(1, "Failed to allocate scratch buffers \n");
349 FASTCOVER_ctx_destroy(ctx);
350 return ERROR(memory_allocation);
351 }
352
353 /* Fill offsets from the samplesSizes */
354 { U32 i;
355 ctx->offsets[0] = 0;
356 assert(nbSamples >= 5);
357 for (i = 1; i <= nbSamples; ++i) {
358 ctx->offsets[i] = ctx->offsets[i - 1] + samplesSizes[i - 1];
359 }
360 }
361
362 /* Initialize frequency array of size 2^f */
363 ctx->freqs = (U32*)calloc(((U64)1 << f), sizeof(U32));
364 if (ctx->freqs == NULL) {
365 DISPLAYLEVEL(1, "Failed to allocate frequency table \n");
366 FASTCOVER_ctx_destroy(ctx);
367 return ERROR(memory_allocation);
368 }
369
370 DISPLAYLEVEL(2, "Computing frequencies\n");
371 FASTCOVER_computeFrequency(ctx->freqs, ctx);
372
373 return 0;
374}
375
376
377/**
378 * Given the prepared context build the dictionary.
379 */
380static size_t
381FASTCOVER_buildDictionary(const FASTCOVER_ctx_t* ctx,
382 U32* freqs,
383 void* dictBuffer, size_t dictBufferCapacity,
384 ZDICT_cover_params_t parameters,
385 U16* segmentFreqs)
386{
387 BYTE *const dict = (BYTE *)dictBuffer;
388 size_t tail = dictBufferCapacity;
389 /* Divide the data into epochs. We will select one segment from each epoch. */
390 const COVER_epoch_info_t epochs = COVER_computeEpochs(
391 (U32)dictBufferCapacity, (U32)ctx->nbDmers, parameters.k, 1);
392 const size_t maxZeroScoreRun = 10;
393 size_t zeroScoreRun = 0;
394 size_t epoch;
395 DISPLAYLEVEL(2, "Breaking content into %u epochs of size %u\n",
396 (U32)epochs.num, (U32)epochs.size);
397 /* Loop through the epochs until there are no more segments or the dictionary
398 * is full.
399 */
400 for (epoch = 0; tail > 0; epoch = (epoch + 1) % epochs.num) {
401 const U32 epochBegin = (U32)(epoch * epochs.size);
402 const U32 epochEnd = epochBegin + epochs.size;
403 size_t segmentSize;
404 /* Select a segment */
405 COVER_segment_t segment = FASTCOVER_selectSegment(
406 ctx, freqs, epochBegin, epochEnd, parameters, segmentFreqs);
407
408 /* If the segment covers no dmers, then we are out of content.
409 * There may be new content in other epochs, for continue for some time.
410 */
411 if (segment.score == 0) {
412 if (++zeroScoreRun >= maxZeroScoreRun) {
413 break;
414 }
415 continue;
416 }
417 zeroScoreRun = 0;
418
419 /* Trim the segment if necessary and if it is too small then we are done */
420 segmentSize = MIN(segment.end - segment.begin + parameters.d - 1, tail);
421 if (segmentSize < parameters.d) {
422 break;
423 }
424
425 /* We fill the dictionary from the back to allow the best segments to be
426 * referenced with the smallest offsets.
427 */
428 tail -= segmentSize;
429 memcpy(dict + tail, ctx->samples + segment.begin, segmentSize);
430 DISPLAYUPDATE(
431 2, "\r%u%% ",
432 (unsigned)(((dictBufferCapacity - tail) * 100) / dictBufferCapacity));
433 }
434 DISPLAYLEVEL(2, "\r%79s\r", "");
435 return tail;
436}
437
438/**
439 * Parameters for FASTCOVER_tryParameters().
440 */
441typedef struct FASTCOVER_tryParameters_data_s {
442 const FASTCOVER_ctx_t* ctx;
443 COVER_best_t* best;
444 size_t dictBufferCapacity;
445 ZDICT_cover_params_t parameters;
446} FASTCOVER_tryParameters_data_t;
447
448
449/**
450 * Tries a set of parameters and updates the COVER_best_t with the results.
451 * This function is thread safe if zstd is compiled with multithreaded support.
452 * It takes its parameters as an *OWNING* opaque pointer to support threading.
453 */
454static void FASTCOVER_tryParameters(void *opaque)
455{
456 /* Save parameters as local variables */
457 FASTCOVER_tryParameters_data_t *const data = (FASTCOVER_tryParameters_data_t *)opaque;
458 const FASTCOVER_ctx_t *const ctx = data->ctx;
459 const ZDICT_cover_params_t parameters = data->parameters;
460 size_t dictBufferCapacity = data->dictBufferCapacity;
461 size_t totalCompressedSize = ERROR(GENERIC);
462 /* Initialize array to keep track of frequency of dmer within activeSegment */
463 U16* segmentFreqs = (U16 *)calloc(((U64)1 << ctx->f), sizeof(U16));
464 /* Allocate space for hash table, dict, and freqs */
465 BYTE *const dict = (BYTE * const)malloc(dictBufferCapacity);
466 COVER_dictSelection_t selection = COVER_dictSelectionError(ERROR(GENERIC));
467 U32 *freqs = (U32*) malloc(((U64)1 << ctx->f) * sizeof(U32));
468 if (!segmentFreqs || !dict || !freqs) {
469 DISPLAYLEVEL(1, "Failed to allocate buffers: out of memory\n");
470 goto _cleanup;
471 }
472 /* Copy the frequencies because we need to modify them */
473 memcpy(freqs, ctx->freqs, ((U64)1 << ctx->f) * sizeof(U32));
474 /* Build the dictionary */
475 { const size_t tail = FASTCOVER_buildDictionary(ctx, freqs, dict, dictBufferCapacity,
476 parameters, segmentFreqs);
477
478 const unsigned nbFinalizeSamples = (unsigned)(ctx->nbTrainSamples * ctx->accelParams.finalize / 100);
479 selection = COVER_selectDict(dict + tail, dictBufferCapacity - tail,
480 ctx->samples, ctx->samplesSizes, nbFinalizeSamples, ctx->nbTrainSamples, ctx->nbSamples, parameters, ctx->offsets,
481 totalCompressedSize);
482
483 if (COVER_dictSelectionIsError(selection)) {
484 DISPLAYLEVEL(1, "Failed to select dictionary\n");
485 goto _cleanup;
486 }
487 }
488_cleanup:
489 free(dict);
490 COVER_best_finish(data->best, parameters, selection);
491 free(data);
492 free(segmentFreqs);
493 COVER_dictSelectionFree(selection);
494 free(freqs);
495}
496
497
498static void
499FASTCOVER_convertToCoverParams(ZDICT_fastCover_params_t fastCoverParams,
500 ZDICT_cover_params_t* coverParams)
501{
502 coverParams->k = fastCoverParams.k;
503 coverParams->d = fastCoverParams.d;
504 coverParams->steps = fastCoverParams.steps;
505 coverParams->nbThreads = fastCoverParams.nbThreads;
506 coverParams->splitPoint = fastCoverParams.splitPoint;
507 coverParams->zParams = fastCoverParams.zParams;
508 coverParams->shrinkDict = fastCoverParams.shrinkDict;
509}
510
511
512static void
513FASTCOVER_convertToFastCoverParams(ZDICT_cover_params_t coverParams,
514 ZDICT_fastCover_params_t* fastCoverParams,
515 unsigned f, unsigned accel)
516{
517 fastCoverParams->k = coverParams.k;
518 fastCoverParams->d = coverParams.d;
519 fastCoverParams->steps = coverParams.steps;
520 fastCoverParams->nbThreads = coverParams.nbThreads;
521 fastCoverParams->splitPoint = coverParams.splitPoint;
522 fastCoverParams->f = f;
523 fastCoverParams->accel = accel;
524 fastCoverParams->zParams = coverParams.zParams;
525 fastCoverParams->shrinkDict = coverParams.shrinkDict;
526}
527
528
529ZDICTLIB_API size_t
530ZDICT_trainFromBuffer_fastCover(void* dictBuffer, size_t dictBufferCapacity,
531 const void* samplesBuffer,
532 const size_t* samplesSizes, unsigned nbSamples,
533 ZDICT_fastCover_params_t parameters)
534{
535 BYTE* const dict = (BYTE*)dictBuffer;
536 FASTCOVER_ctx_t ctx;
537 ZDICT_cover_params_t coverParams;
538 FASTCOVER_accel_t accelParams;
539 /* Initialize global data */
540 g_displayLevel = parameters.zParams.notificationLevel;
541 /* Assign splitPoint and f if not provided */
542 parameters.splitPoint = 1.0;
543 parameters.f = parameters.f == 0 ? DEFAULT_F : parameters.f;
544 parameters.accel = parameters.accel == 0 ? DEFAULT_ACCEL : parameters.accel;
545 /* Convert to cover parameter */
546 memset(&coverParams, 0 , sizeof(coverParams));
547 FASTCOVER_convertToCoverParams(parameters, &coverParams);
548 /* Checks */
549 if (!FASTCOVER_checkParameters(coverParams, dictBufferCapacity, parameters.f,
550 parameters.accel)) {
551 DISPLAYLEVEL(1, "FASTCOVER parameters incorrect\n");
552 return ERROR(parameter_outOfBound);
553 }
554 if (nbSamples == 0) {
555 DISPLAYLEVEL(1, "FASTCOVER must have at least one input file\n");
556 return ERROR(srcSize_wrong);
557 }
558 if (dictBufferCapacity < ZDICT_DICTSIZE_MIN) {
559 DISPLAYLEVEL(1, "dictBufferCapacity must be at least %u\n",
560 ZDICT_DICTSIZE_MIN);
561 return ERROR(dstSize_tooSmall);
562 }
563 /* Assign corresponding FASTCOVER_accel_t to accelParams*/
564 accelParams = FASTCOVER_defaultAccelParameters[parameters.accel];
565 /* Initialize context */
566 {
567 size_t const initVal = FASTCOVER_ctx_init(&ctx, samplesBuffer, samplesSizes, nbSamples,
568 coverParams.d, parameters.splitPoint, parameters.f,
569 accelParams);
570 if (ZSTD_isError(initVal)) {
571 DISPLAYLEVEL(1, "Failed to initialize context\n");
572 return initVal;
573 }
574 }
575 COVER_warnOnSmallCorpus(dictBufferCapacity, ctx.nbDmers, g_displayLevel);
576 /* Build the dictionary */
577 DISPLAYLEVEL(2, "Building dictionary\n");
578 {
579 /* Initialize array to keep track of frequency of dmer within activeSegment */
580 U16* segmentFreqs = (U16 *)calloc(((U64)1 << parameters.f), sizeof(U16));
581 const size_t tail = FASTCOVER_buildDictionary(&ctx, ctx.freqs, dictBuffer,
582 dictBufferCapacity, coverParams, segmentFreqs);
583 const unsigned nbFinalizeSamples = (unsigned)(ctx.nbTrainSamples * ctx.accelParams.finalize / 100);
584 const size_t dictionarySize = ZDICT_finalizeDictionary(
585 dict, dictBufferCapacity, dict + tail, dictBufferCapacity - tail,
586 samplesBuffer, samplesSizes, nbFinalizeSamples, coverParams.zParams);
587 if (!ZSTD_isError(dictionarySize)) {
588 DISPLAYLEVEL(2, "Constructed dictionary of size %u\n",
589 (unsigned)dictionarySize);
590 }
591 FASTCOVER_ctx_destroy(&ctx);
592 free(segmentFreqs);
593 return dictionarySize;
594 }
595}
596
597
598ZDICTLIB_API size_t
599ZDICT_optimizeTrainFromBuffer_fastCover(
600 void* dictBuffer, size_t dictBufferCapacity,
601 const void* samplesBuffer,
602 const size_t* samplesSizes, unsigned nbSamples,
603 ZDICT_fastCover_params_t* parameters)
604{
605 ZDICT_cover_params_t coverParams;
606 FASTCOVER_accel_t accelParams;
607 /* constants */
608 const unsigned nbThreads = parameters->nbThreads;
609 const double splitPoint =
610 parameters->splitPoint <= 0.0 ? DEFAULT_SPLITPOINT : parameters->splitPoint;
611 const unsigned kMinD = parameters->d == 0 ? 6 : parameters->d;
612 const unsigned kMaxD = parameters->d == 0 ? 8 : parameters->d;
613 const unsigned kMinK = parameters->k == 0 ? 50 : parameters->k;
614 const unsigned kMaxK = parameters->k == 0 ? 2000 : parameters->k;
615 const unsigned kSteps = parameters->steps == 0 ? 40 : parameters->steps;
616 const unsigned kStepSize = MAX((kMaxK - kMinK) / kSteps, 1);
617 const unsigned kIterations =
618 (1 + (kMaxD - kMinD) / 2) * (1 + (kMaxK - kMinK) / kStepSize);
619 const unsigned f = parameters->f == 0 ? DEFAULT_F : parameters->f;
620 const unsigned accel = parameters->accel == 0 ? DEFAULT_ACCEL : parameters->accel;
621 const unsigned shrinkDict = 0;
622 /* Local variables */
623 const int displayLevel = parameters->zParams.notificationLevel;
624 unsigned iteration = 1;
625 unsigned d;
626 unsigned k;
627 COVER_best_t best;
628 POOL_ctx *pool = NULL;
629 int warned = 0;
630 /* Checks */
631 if (splitPoint <= 0 || splitPoint > 1) {
632 LOCALDISPLAYLEVEL(displayLevel, 1, "Incorrect splitPoint\n");
633 return ERROR(parameter_outOfBound);
634 }
635 if (accel == 0 || accel > FASTCOVER_MAX_ACCEL) {
636 LOCALDISPLAYLEVEL(displayLevel, 1, "Incorrect accel\n");
637 return ERROR(parameter_outOfBound);
638 }
639 if (kMinK < kMaxD || kMaxK < kMinK) {
640 LOCALDISPLAYLEVEL(displayLevel, 1, "Incorrect k\n");
641 return ERROR(parameter_outOfBound);
642 }
643 if (nbSamples == 0) {
644 LOCALDISPLAYLEVEL(displayLevel, 1, "FASTCOVER must have at least one input file\n");
645 return ERROR(srcSize_wrong);
646 }
647 if (dictBufferCapacity < ZDICT_DICTSIZE_MIN) {
648 LOCALDISPLAYLEVEL(displayLevel, 1, "dictBufferCapacity must be at least %u\n",
649 ZDICT_DICTSIZE_MIN);
650 return ERROR(dstSize_tooSmall);
651 }
652 if (nbThreads > 1) {
653 pool = POOL_create(nbThreads, 1);
654 if (!pool) {
655 return ERROR(memory_allocation);
656 }
657 }
658 /* Initialization */
659 COVER_best_init(&best);
660 memset(&coverParams, 0 , sizeof(coverParams));
661 FASTCOVER_convertToCoverParams(*parameters, &coverParams);
662 accelParams = FASTCOVER_defaultAccelParameters[accel];
663 /* Turn down global display level to clean up display at level 2 and below */
664 g_displayLevel = displayLevel == 0 ? 0 : displayLevel - 1;
665 /* Loop through d first because each new value needs a new context */
666 LOCALDISPLAYLEVEL(displayLevel, 2, "Trying %u different sets of parameters\n",
667 kIterations);
668 for (d = kMinD; d <= kMaxD; d += 2) {
669 /* Initialize the context for this value of d */
670 FASTCOVER_ctx_t ctx;
671 LOCALDISPLAYLEVEL(displayLevel, 3, "d=%u\n", d);
672 {
673 size_t const initVal = FASTCOVER_ctx_init(&ctx, samplesBuffer, samplesSizes, nbSamples, d, splitPoint, f, accelParams);
674 if (ZSTD_isError(initVal)) {
675 LOCALDISPLAYLEVEL(displayLevel, 1, "Failed to initialize context\n");
676 COVER_best_destroy(&best);
677 POOL_free(pool);
678 return initVal;
679 }
680 }
681 if (!warned) {
682 COVER_warnOnSmallCorpus(dictBufferCapacity, ctx.nbDmers, displayLevel);
683 warned = 1;
684 }
685 /* Loop through k reusing the same context */
686 for (k = kMinK; k <= kMaxK; k += kStepSize) {
687 /* Prepare the arguments */
688 FASTCOVER_tryParameters_data_t *data = (FASTCOVER_tryParameters_data_t *)malloc(
689 sizeof(FASTCOVER_tryParameters_data_t));
690 LOCALDISPLAYLEVEL(displayLevel, 3, "k=%u\n", k);
691 if (!data) {
692 LOCALDISPLAYLEVEL(displayLevel, 1, "Failed to allocate parameters\n");
693 COVER_best_destroy(&best);
694 FASTCOVER_ctx_destroy(&ctx);
695 POOL_free(pool);
696 return ERROR(memory_allocation);
697 }
698 data->ctx = &ctx;
699 data->best = &best;
700 data->dictBufferCapacity = dictBufferCapacity;
701 data->parameters = coverParams;
702 data->parameters.k = k;
703 data->parameters.d = d;
704 data->parameters.splitPoint = splitPoint;
705 data->parameters.steps = kSteps;
706 data->parameters.shrinkDict = shrinkDict;
707 data->parameters.zParams.notificationLevel = g_displayLevel;
708 /* Check the parameters */
709 if (!FASTCOVER_checkParameters(data->parameters, dictBufferCapacity,
710 data->ctx->f, accel)) {
711 DISPLAYLEVEL(1, "FASTCOVER parameters incorrect\n");
712 free(data);
713 continue;
714 }
715 /* Call the function and pass ownership of data to it */
716 COVER_best_start(&best);
717 if (pool) {
718 POOL_add(pool, &FASTCOVER_tryParameters, data);
719 } else {
720 FASTCOVER_tryParameters(data);
721 }
722 /* Print status */
723 LOCALDISPLAYUPDATE(displayLevel, 2, "\r%u%% ",
724 (unsigned)((iteration * 100) / kIterations));
725 ++iteration;
726 }
727 COVER_best_wait(&best);
728 FASTCOVER_ctx_destroy(&ctx);
729 }
730 LOCALDISPLAYLEVEL(displayLevel, 2, "\r%79s\r", "");
731 /* Fill the output buffer and parameters with output of the best parameters */
732 {
733 const size_t dictSize = best.dictSize;
734 if (ZSTD_isError(best.compressedSize)) {
735 const size_t compressedSize = best.compressedSize;
736 COVER_best_destroy(&best);
737 POOL_free(pool);
738 return compressedSize;
739 }
740 FASTCOVER_convertToFastCoverParams(best.parameters, parameters, f, accel);
741 memcpy(dictBuffer, best.dict, dictSize);
742 COVER_best_destroy(&best);
743 POOL_free(pool);
744 return dictSize;
745 }
746
747}