1/*
2 * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
3 * All rights reserved.
4 *
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.
9 */
10
11
12/*-**************************************
13*  Tuning parameters
14****************************************/
15#define MINRATIO 4   /* minimum nb of apparition to be selected in dictionary */
16#define ZDICT_MAX_SAMPLES_SIZE (2000U << 20)
17#define ZDICT_MIN_SAMPLES_SIZE (ZDICT_CONTENTSIZE_MIN * MINRATIO)
18
19
20/*-**************************************
21*  Compiler Options
22****************************************/
23/* Unix Large Files support (>4GB) */
24#define _FILE_OFFSET_BITS 64
25#if (defined(__sun__) && (!defined(__LP64__)))   /* Sun Solaris 32-bits requires specific definitions */
26#  define _LARGEFILE_SOURCE
27#elif ! defined(__LP64__)                        /* No point defining Large file for 64 bit */
28#  define _LARGEFILE64_SOURCE
29#endif
30
31
32/*-*************************************
33*  Dependencies
34***************************************/
35#include <stdlib.h>        /* malloc, free */
36#include <string.h>        /* memset */
37#include <stdio.h>         /* fprintf, fopen, ftello64 */
38#include <time.h>          /* clock */
39
40#include "mem.h"           /* read */
41#include "fse.h"           /* FSE_normalizeCount, FSE_writeNCount */
42#define HUF_STATIC_LINKING_ONLY
43#include "huf.h"           /* HUF_buildCTable, HUF_writeCTable */
44#include "zstd_internal.h" /* includes zstd.h */
45#include "xxhash.h"        /* XXH64 */
46#include "divsufsort.h"
47#ifndef ZDICT_STATIC_LINKING_ONLY
48#  define ZDICT_STATIC_LINKING_ONLY
49#endif
50#include "zdict.h"
51
52
53/*-*************************************
54*  Constants
55***************************************/
56#define KB *(1 <<10)
57#define MB *(1 <<20)
58#define GB *(1U<<30)
59
60#define DICTLISTSIZE_DEFAULT 10000
61
62#define NOISELENGTH 32
63
64static const int g_compressionLevel_default = 3;
65static const U32 g_selectivity_default = 9;
66
67
68/*-*************************************
69*  Console display
70***************************************/
71#define DISPLAY(...)         { fprintf(stderr, __VA_ARGS__); fflush( stderr ); }
72#define DISPLAYLEVEL(l, ...) if (notificationLevel>=l) { DISPLAY(__VA_ARGS__); }    /* 0 : no display;   1: errors;   2: default;  3: details;  4: debug */
73
74static clock_t ZDICT_clockSpan(clock_t nPrevious) { return clock() - nPrevious; }
75
76static void ZDICT_printHex(const void* ptr, size_t length)
77{
78    const BYTE* const b = (const BYTE*)ptr;
79    size_t u;
80    for (u=0; u<length; u++) {
81        BYTE c = b[u];
82        if (c<32 || c>126) c = '.';   /* non-printable char */
83        DISPLAY("%c", c);
84    }
85}
86
87
88/*-********************************************************
89*  Helper functions
90**********************************************************/
91unsigned ZDICT_isError(size_t errorCode) { return ERR_isError(errorCode); }
92
93const char* ZDICT_getErrorName(size_t errorCode) { return ERR_getErrorName(errorCode); }
94
95unsigned ZDICT_getDictID(const void* dictBuffer, size_t dictSize)
96{
97    if (dictSize < 8) return 0;
98    if (MEM_readLE32(dictBuffer) != ZSTD_MAGIC_DICTIONARY) return 0;
99    return MEM_readLE32((const char*)dictBuffer + 4);
100}
101
102
103/*-********************************************************
104*  Dictionary training functions
105**********************************************************/
106static unsigned ZDICT_NbCommonBytes (size_t val)
107{
108    if (MEM_isLittleEndian()) {
109        if (MEM_64bits()) {
110#       if defined(_MSC_VER) && defined(_WIN64)
111            unsigned long r = 0;
112            _BitScanForward64( &r, (U64)val );
113            return (unsigned)(r>>3);
114#       elif defined(__GNUC__) && (__GNUC__ >= 3)
115            return (__builtin_ctzll((U64)val) >> 3);
116#       else
117            static const int DeBruijnBytePos[64] = { 0, 0, 0, 0, 0, 1, 1, 2, 0, 3, 1, 3, 1, 4, 2, 7, 0, 2, 3, 6, 1, 5, 3, 5, 1, 3, 4, 4, 2, 5, 6, 7, 7, 0, 1, 2, 3, 3, 4, 6, 2, 6, 5, 5, 3, 4, 5, 6, 7, 1, 2, 4, 6, 4, 4, 5, 7, 2, 6, 5, 7, 6, 7, 7 };
118            return DeBruijnBytePos[((U64)((val & -(long long)val) * 0x0218A392CDABBD3FULL)) >> 58];
119#       endif
120        } else { /* 32 bits */
121#       if defined(_MSC_VER)
122            unsigned long r=0;
123            _BitScanForward( &r, (U32)val );
124            return (unsigned)(r>>3);
125#       elif defined(__GNUC__) && (__GNUC__ >= 3)
126            return (__builtin_ctz((U32)val) >> 3);
127#       else
128            static const int DeBruijnBytePos[32] = { 0, 0, 3, 0, 3, 1, 3, 0, 3, 2, 2, 1, 3, 2, 0, 1, 3, 3, 1, 2, 2, 2, 2, 0, 3, 1, 2, 0, 1, 0, 1, 1 };
129            return DeBruijnBytePos[((U32)((val & -(S32)val) * 0x077CB531U)) >> 27];
130#       endif
131        }
132    } else {  /* Big Endian CPU */
133        if (MEM_64bits()) {
134#       if defined(_MSC_VER) && defined(_WIN64)
135            unsigned long r = 0;
136            _BitScanReverse64( &r, val );
137            return (unsigned)(r>>3);
138#       elif defined(__GNUC__) && (__GNUC__ >= 3)
139            return (__builtin_clzll(val) >> 3);
140#       else
141            unsigned r;
142            const unsigned n32 = sizeof(size_t)*4;   /* calculate this way due to compiler complaining in 32-bits mode */
143            if (!(val>>n32)) { r=4; } else { r=0; val>>=n32; }
144            if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; }
145            r += (!val);
146            return r;
147#       endif
148        } else { /* 32 bits */
149#       if defined(_MSC_VER)
150            unsigned long r = 0;
151            _BitScanReverse( &r, (unsigned long)val );
152            return (unsigned)(r>>3);
153#       elif defined(__GNUC__) && (__GNUC__ >= 3)
154            return (__builtin_clz((U32)val) >> 3);
155#       else
156            unsigned r;
157            if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; }
158            r += (!val);
159            return r;
160#       endif
161    }   }
162}
163
164
165/*! ZDICT_count() :
166    Count the nb of common bytes between 2 pointers.
167    Note : this function presumes end of buffer followed by noisy guard band.
168*/
169static size_t ZDICT_count(const void* pIn, const void* pMatch)
170{
171    const char* const pStart = (const char*)pIn;
172    for (;;) {
173        size_t const diff = MEM_readST(pMatch) ^ MEM_readST(pIn);
174        if (!diff) {
175            pIn = (const char*)pIn+sizeof(size_t);
176            pMatch = (const char*)pMatch+sizeof(size_t);
177            continue;
178        }
179        pIn = (const char*)pIn+ZDICT_NbCommonBytes(diff);
180        return (size_t)((const char*)pIn - pStart);
181    }
182}
183
184
185typedef struct {
186    U32 pos;
187    U32 length;
188    U32 savings;
189} dictItem;
190
191static void ZDICT_initDictItem(dictItem* d)
192{
193    d->pos = 1;
194    d->length = 0;
195    d->savings = (U32)(-1);
196}
197
198
199#define LLIMIT 64          /* heuristic determined experimentally */
200#define MINMATCHLENGTH 7   /* heuristic determined experimentally */
201static dictItem ZDICT_analyzePos(
202                       BYTE* doneMarks,
203                       const int* suffix, U32 start,
204                       const void* buffer, U32 minRatio, U32 notificationLevel)
205{
206    U32 lengthList[LLIMIT] = {0};
207    U32 cumulLength[LLIMIT] = {0};
208    U32 savings[LLIMIT] = {0};
209    const BYTE* b = (const BYTE*)buffer;
210    size_t maxLength = LLIMIT;
211    size_t pos = suffix[start];
212    U32 end = start;
213    dictItem solution;
214
215    /* init */
216    memset(&solution, 0, sizeof(solution));
217    doneMarks[pos] = 1;
218
219    /* trivial repetition cases */
220    if ( (MEM_read16(b+pos+0) == MEM_read16(b+pos+2))
221       ||(MEM_read16(b+pos+1) == MEM_read16(b+pos+3))
222       ||(MEM_read16(b+pos+2) == MEM_read16(b+pos+4)) ) {
223        /* skip and mark segment */
224        U16 const pattern16 = MEM_read16(b+pos+4);
225        U32 u, patternEnd = 6;
226        while (MEM_read16(b+pos+patternEnd) == pattern16) patternEnd+=2 ;
227        if (b[pos+patternEnd] == b[pos+patternEnd-1]) patternEnd++;
228        for (u=1; u<patternEnd; u++)
229            doneMarks[pos+u] = 1;
230        return solution;
231    }
232
233    /* look forward */
234    {   size_t length;
235        do {
236            end++;
237            length = ZDICT_count(b + pos, b + suffix[end]);
238        } while (length >= MINMATCHLENGTH);
239    }
240
241    /* look backward */
242    {   size_t length;
243        do {
244            length = ZDICT_count(b + pos, b + *(suffix+start-1));
245            if (length >=MINMATCHLENGTH) start--;
246        } while(length >= MINMATCHLENGTH);
247    }
248
249    /* exit if not found a minimum nb of repetitions */
250    if (end-start < minRatio) {
251        U32 idx;
252        for(idx=start; idx<end; idx++)
253            doneMarks[suffix[idx]] = 1;
254        return solution;
255    }
256
257    {   int i;
258        U32 searchLength;
259        U32 refinedStart = start;
260        U32 refinedEnd = end;
261
262        DISPLAYLEVEL(4, "\n");
263        DISPLAYLEVEL(4, "found %3u matches of length >= %i at pos %7u  ", (U32)(end-start), MINMATCHLENGTH, (U32)pos);
264        DISPLAYLEVEL(4, "\n");
265
266        for (searchLength = MINMATCHLENGTH ; ; searchLength++) {
267            BYTE currentChar = 0;
268            U32 currentCount = 0;
269            U32 currentID = refinedStart;
270            U32 id;
271            U32 selectedCount = 0;
272            U32 selectedID = currentID;
273            for (id =refinedStart; id < refinedEnd; id++) {
274                if (b[suffix[id] + searchLength] != currentChar) {
275                    if (currentCount > selectedCount) {
276                        selectedCount = currentCount;
277                        selectedID = currentID;
278                    }
279                    currentID = id;
280                    currentChar = b[ suffix[id] + searchLength];
281                    currentCount = 0;
282                }
283                currentCount ++;
284            }
285            if (currentCount > selectedCount) {  /* for last */
286                selectedCount = currentCount;
287                selectedID = currentID;
288            }
289
290            if (selectedCount < minRatio)
291                break;
292            refinedStart = selectedID;
293            refinedEnd = refinedStart + selectedCount;
294        }
295
296        /* evaluate gain based on new ref */
297        start = refinedStart;
298        pos = suffix[refinedStart];
299        end = start;
300        memset(lengthList, 0, sizeof(lengthList));
301
302        /* look forward */
303        {   size_t length;
304            do {
305                end++;
306                length = ZDICT_count(b + pos, b + suffix[end]);
307                if (length >= LLIMIT) length = LLIMIT-1;
308                lengthList[length]++;
309            } while (length >=MINMATCHLENGTH);
310        }
311
312        /* look backward */
313        {   size_t length = MINMATCHLENGTH;
314            while ((length >= MINMATCHLENGTH) & (start > 0)) {
315                length = ZDICT_count(b + pos, b + suffix[start - 1]);
316                if (length >= LLIMIT) length = LLIMIT - 1;
317                lengthList[length]++;
318                if (length >= MINMATCHLENGTH) start--;
319            }
320        }
321
322        /* largest useful length */
323        memset(cumulLength, 0, sizeof(cumulLength));
324        cumulLength[maxLength-1] = lengthList[maxLength-1];
325        for (i=(int)(maxLength-2); i>=0; i--)
326            cumulLength[i] = cumulLength[i+1] + lengthList[i];
327
328        for (i=LLIMIT-1; i>=MINMATCHLENGTH; i--) if (cumulLength[i]>=minRatio) break;
329        maxLength = i;
330
331        /* reduce maxLength in case of final into repetitive data */
332        {   U32 l = (U32)maxLength;
333            BYTE const c = b[pos + maxLength-1];
334            while (b[pos+l-2]==c) l--;
335            maxLength = l;
336        }
337        if (maxLength < MINMATCHLENGTH) return solution;   /* skip : no long-enough solution */
338
339        /* calculate savings */
340        savings[5] = 0;
341        for (i=MINMATCHLENGTH; i<=(int)maxLength; i++)
342            savings[i] = savings[i-1] + (lengthList[i] * (i-3));
343
344        DISPLAYLEVEL(4, "Selected ref at position %u, of length %u : saves %u (ratio: %.2f)  \n",
345                     (U32)pos, (U32)maxLength, savings[maxLength], (double)savings[maxLength] / maxLength);
346
347        solution.pos = (U32)pos;
348        solution.length = (U32)maxLength;
349        solution.savings = savings[maxLength];
350
351        /* mark positions done */
352        {   U32 id;
353            for (id=start; id<end; id++) {
354                U32 p, pEnd, length;
355                U32 const testedPos = suffix[id];
356                if (testedPos == pos)
357                    length = solution.length;
358                else {
359                    length = (U32)ZDICT_count(b+pos, b+testedPos);
360                    if (length > solution.length) length = solution.length;
361                }
362                pEnd = (U32)(testedPos + length);
363                for (p=testedPos; p<pEnd; p++)
364                    doneMarks[p] = 1;
365    }   }   }
366
367    return solution;
368}
369
370
371static int isIncluded(const void* in, const void* container, size_t length)
372{
373    const char* const ip = (const char*) in;
374    const char* const into = (const char*) container;
375    size_t u;
376
377    for (u=0; u<length; u++) {  /* works because end of buffer is a noisy guard band */
378        if (ip[u] != into[u]) break;
379    }
380
381    return u==length;
382}
383
384/*! ZDICT_tryMerge() :
385    check if dictItem can be merged, do it if possible
386    @return : id of destination elt, 0 if not merged
387*/
388static U32 ZDICT_tryMerge(dictItem* table, dictItem elt, U32 eltNbToSkip, const void* buffer)
389{
390    const U32 tableSize = table->pos;
391    const U32 eltEnd = elt.pos + elt.length;
392    const char* const buf = (const char*) buffer;
393
394    /* tail overlap */
395    U32 u; for (u=1; u<tableSize; u++) {
396        if (u==eltNbToSkip) continue;
397        if ((table[u].pos > elt.pos) && (table[u].pos <= eltEnd)) {  /* overlap, existing > new */
398            /* append */
399            U32 const addedLength = table[u].pos - elt.pos;
400            table[u].length += addedLength;
401            table[u].pos = elt.pos;
402            table[u].savings += elt.savings * addedLength / elt.length;   /* rough approx */
403            table[u].savings += elt.length / 8;    /* rough approx bonus */
404            elt = table[u];
405            /* sort : improve rank */
406            while ((u>1) && (table[u-1].savings < elt.savings))
407            table[u] = table[u-1], u--;
408            table[u] = elt;
409            return u;
410    }   }
411
412    /* front overlap */
413    for (u=1; u<tableSize; u++) {
414        if (u==eltNbToSkip) continue;
415
416        if ((table[u].pos + table[u].length >= elt.pos) && (table[u].pos < elt.pos)) {  /* overlap, existing < new */
417            /* append */
418            int const addedLength = (int)eltEnd - (table[u].pos + table[u].length);
419            table[u].savings += elt.length / 8;    /* rough approx bonus */
420            if (addedLength > 0) {   /* otherwise, elt fully included into existing */
421                table[u].length += addedLength;
422                table[u].savings += elt.savings * addedLength / elt.length;   /* rough approx */
423            }
424            /* sort : improve rank */
425            elt = table[u];
426            while ((u>1) && (table[u-1].savings < elt.savings))
427                table[u] = table[u-1], u--;
428            table[u] = elt;
429            return u;
430        }
431
432        if (MEM_read64(buf + table[u].pos) == MEM_read64(buf + elt.pos + 1)) {
433            if (isIncluded(buf + table[u].pos, buf + elt.pos + 1, table[u].length)) {
434                size_t const addedLength = MAX( (int)elt.length - (int)table[u].length , 1 );
435                table[u].pos = elt.pos;
436                table[u].savings += (U32)(elt.savings * addedLength / elt.length);
437                table[u].length = MIN(elt.length, table[u].length + 1);
438                return u;
439            }
440        }
441    }
442
443    return 0;
444}
445
446
447static void ZDICT_removeDictItem(dictItem* table, U32 id)
448{
449    /* convention : table[0].pos stores nb of elts */
450    U32 const max = table[0].pos;
451    U32 u;
452    if (!id) return;   /* protection, should never happen */
453    for (u=id; u<max-1; u++)
454        table[u] = table[u+1];
455    table->pos--;
456}
457
458
459static void ZDICT_insertDictItem(dictItem* table, U32 maxSize, dictItem elt, const void* buffer)
460{
461    /* merge if possible */
462    U32 mergeId = ZDICT_tryMerge(table, elt, 0, buffer);
463    if (mergeId) {
464        U32 newMerge = 1;
465        while (newMerge) {
466            newMerge = ZDICT_tryMerge(table, table[mergeId], mergeId, buffer);
467            if (newMerge) ZDICT_removeDictItem(table, mergeId);
468            mergeId = newMerge;
469        }
470        return;
471    }
472
473    /* insert */
474    {   U32 current;
475        U32 nextElt = table->pos;
476        if (nextElt >= maxSize) nextElt = maxSize-1;
477        current = nextElt-1;
478        while (table[current].savings < elt.savings) {
479            table[current+1] = table[current];
480            current--;
481        }
482        table[current+1] = elt;
483        table->pos = nextElt+1;
484    }
485}
486
487
488static U32 ZDICT_dictSize(const dictItem* dictList)
489{
490    U32 u, dictSize = 0;
491    for (u=1; u<dictList[0].pos; u++)
492        dictSize += dictList[u].length;
493    return dictSize;
494}
495
496
497static size_t ZDICT_trainBuffer_legacy(dictItem* dictList, U32 dictListSize,
498                            const void* const buffer, size_t bufferSize,   /* buffer must end with noisy guard band */
499                            const size_t* fileSizes, unsigned nbFiles,
500                            U32 minRatio, U32 notificationLevel)
501{
502    int* const suffix0 = (int*)malloc((bufferSize+2)*sizeof(*suffix0));
503    int* const suffix = suffix0+1;
504    U32* reverseSuffix = (U32*)malloc((bufferSize)*sizeof(*reverseSuffix));
505    BYTE* doneMarks = (BYTE*)malloc((bufferSize+16)*sizeof(*doneMarks));   /* +16 for overflow security */
506    U32* filePos = (U32*)malloc(nbFiles * sizeof(*filePos));
507    size_t result = 0;
508    clock_t displayClock = 0;
509    clock_t const refreshRate = CLOCKS_PER_SEC * 3 / 10;
510
511#   define DISPLAYUPDATE(l, ...) if (notificationLevel>=l) { \
512            if (ZDICT_clockSpan(displayClock) > refreshRate)  \
513            { displayClock = clock(); DISPLAY(__VA_ARGS__); \
514            if (notificationLevel>=4) fflush(stderr); } }
515
516    /* init */
517    DISPLAYLEVEL(2, "\r%70s\r", "");   /* clean display line */
518    if (!suffix0 || !reverseSuffix || !doneMarks || !filePos) {
519        result = ERROR(memory_allocation);
520        goto _cleanup;
521    }
522    if (minRatio < MINRATIO) minRatio = MINRATIO;
523    memset(doneMarks, 0, bufferSize+16);
524
525    /* limit sample set size (divsufsort limitation)*/
526    if (bufferSize > ZDICT_MAX_SAMPLES_SIZE) DISPLAYLEVEL(3, "sample set too large : reduced to %u MB ...\n", (U32)(ZDICT_MAX_SAMPLES_SIZE>>20));
527    while (bufferSize > ZDICT_MAX_SAMPLES_SIZE) bufferSize -= fileSizes[--nbFiles];
528
529    /* sort */
530    DISPLAYLEVEL(2, "sorting %u files of total size %u MB ...\n", nbFiles, (U32)(bufferSize>>20));
531    {   int const divSuftSortResult = divsufsort((const unsigned char*)buffer, suffix, (int)bufferSize, 0);
532        if (divSuftSortResult != 0) { result = ERROR(GENERIC); goto _cleanup; }
533    }
534    suffix[bufferSize] = (int)bufferSize;   /* leads into noise */
535    suffix0[0] = (int)bufferSize;           /* leads into noise */
536    /* build reverse suffix sort */
537    {   size_t pos;
538        for (pos=0; pos < bufferSize; pos++)
539            reverseSuffix[suffix[pos]] = (U32)pos;
540        /* note filePos tracks borders between samples.
541           It's not used at this stage, but planned to become useful in a later update */
542        filePos[0] = 0;
543        for (pos=1; pos<nbFiles; pos++)
544            filePos[pos] = (U32)(filePos[pos-1] + fileSizes[pos-1]);
545    }
546
547    DISPLAYLEVEL(2, "finding patterns ... \n");
548    DISPLAYLEVEL(3, "minimum ratio : %u \n", minRatio);
549
550    {   U32 cursor; for (cursor=0; cursor < bufferSize; ) {
551            dictItem solution;
552            if (doneMarks[cursor]) { cursor++; continue; }
553            solution = ZDICT_analyzePos(doneMarks, suffix, reverseSuffix[cursor], buffer, minRatio, notificationLevel);
554            if (solution.length==0) { cursor++; continue; }
555            ZDICT_insertDictItem(dictList, dictListSize, solution, buffer);
556            cursor += solution.length;
557            DISPLAYUPDATE(2, "\r%4.2f %% \r", (double)cursor / bufferSize * 100);
558    }   }
559
560_cleanup:
561    free(suffix0);
562    free(reverseSuffix);
563    free(doneMarks);
564    free(filePos);
565    return result;
566}
567
568
569static void ZDICT_fillNoise(void* buffer, size_t length)
570{
571    unsigned const prime1 = 2654435761U;
572    unsigned const prime2 = 2246822519U;
573    unsigned acc = prime1;
574    size_t p=0;;
575    for (p=0; p<length; p++) {
576        acc *= prime2;
577        ((unsigned char*)buffer)[p] = (unsigned char)(acc >> 21);
578    }
579}
580
581
582typedef struct
583{
584    ZSTD_CCtx* ref;    /* contains reference to dictionary */
585    ZSTD_CCtx* zc;     /* working context */
586    void* workPlace;   /* must be ZSTD_BLOCKSIZE_MAX allocated */
587} EStats_ress_t;
588
589#define MAXREPOFFSET 1024
590
591static void ZDICT_countEStats(EStats_ress_t esr, ZSTD_parameters params,
592                              U32* countLit, U32* offsetcodeCount, U32* matchlengthCount, U32* litlengthCount, U32* repOffsets,
593                              const void* src, size_t srcSize,
594                              U32 notificationLevel)
595{
596    size_t const blockSizeMax = MIN (ZSTD_BLOCKSIZE_MAX, 1 << params.cParams.windowLog);
597    size_t cSize;
598
599    if (srcSize > blockSizeMax) srcSize = blockSizeMax;   /* protection vs large samples */
600    {   size_t const errorCode = ZSTD_copyCCtx(esr.zc, esr.ref, 0);
601        if (ZSTD_isError(errorCode)) { DISPLAYLEVEL(1, "warning : ZSTD_copyCCtx failed \n"); return; }
602    }
603    cSize = ZSTD_compressBlock(esr.zc, esr.workPlace, ZSTD_BLOCKSIZE_MAX, src, srcSize);
604    if (ZSTD_isError(cSize)) { DISPLAYLEVEL(3, "warning : could not compress sample size %u \n", (U32)srcSize); return; }
605
606    if (cSize) {  /* if == 0; block is not compressible */
607        const seqStore_t* const seqStorePtr = ZSTD_getSeqStore(esr.zc);
608
609        /* literals stats */
610        {   const BYTE* bytePtr;
611            for(bytePtr = seqStorePtr->litStart; bytePtr < seqStorePtr->lit; bytePtr++)
612                countLit[*bytePtr]++;
613        }
614
615        /* seqStats */
616        {   U32 const nbSeq = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart);
617            ZSTD_seqToCodes(seqStorePtr);
618
619            {   const BYTE* codePtr = seqStorePtr->ofCode;
620                U32 u;
621                for (u=0; u<nbSeq; u++) offsetcodeCount[codePtr[u]]++;
622            }
623
624            {   const BYTE* codePtr = seqStorePtr->mlCode;
625                U32 u;
626                for (u=0; u<nbSeq; u++) matchlengthCount[codePtr[u]]++;
627            }
628
629            {   const BYTE* codePtr = seqStorePtr->llCode;
630                U32 u;
631                for (u=0; u<nbSeq; u++) litlengthCount[codePtr[u]]++;
632            }
633
634            if (nbSeq >= 2) { /* rep offsets */
635                const seqDef* const seq = seqStorePtr->sequencesStart;
636                U32 offset1 = seq[0].offset - 3;
637                U32 offset2 = seq[1].offset - 3;
638                if (offset1 >= MAXREPOFFSET) offset1 = 0;
639                if (offset2 >= MAXREPOFFSET) offset2 = 0;
640                repOffsets[offset1] += 3;
641                repOffsets[offset2] += 1;
642    }   }   }
643}
644
645static size_t ZDICT_totalSampleSize(const size_t* fileSizes, unsigned nbFiles)
646{
647    size_t total=0;
648    unsigned u;
649    for (u=0; u<nbFiles; u++) total += fileSizes[u];
650    return total;
651}
652
653typedef struct { U32 offset; U32 count; } offsetCount_t;
654
655static void ZDICT_insertSortCount(offsetCount_t table[ZSTD_REP_NUM+1], U32 val, U32 count)
656{
657    U32 u;
658    table[ZSTD_REP_NUM].offset = val;
659    table[ZSTD_REP_NUM].count = count;
660    for (u=ZSTD_REP_NUM; u>0; u--) {
661        offsetCount_t tmp;
662        if (table[u-1].count >= table[u].count) break;
663        tmp = table[u-1];
664        table[u-1] = table[u];
665        table[u] = tmp;
666    }
667}
668
669/* ZDICT_flatLit() :
670 * rewrite `countLit` to contain a mostly flat but still compressible distribution of literals.
671 * necessary to avoid generating a non-compressible distribution that HUF_writeCTable() cannot encode.
672 */
673static void ZDICT_flatLit(U32* countLit)
674{
675    int u;
676    for (u=1; u<256; u++) countLit[u] = 2;
677    countLit[0]   = 4;
678    countLit[253] = 1;
679    countLit[254] = 1;
680}
681
682#define OFFCODE_MAX 30  /* only applicable to first block */
683static size_t ZDICT_analyzeEntropy(void*  dstBuffer, size_t maxDstSize,
684                                   unsigned compressionLevel,
685                             const void*  srcBuffer, const size_t* fileSizes, unsigned nbFiles,
686                             const void* dictBuffer, size_t  dictBufferSize,
687                                   unsigned notificationLevel)
688{
689    U32 countLit[256];
690    HUF_CREATE_STATIC_CTABLE(hufTable, 255);
691    U32 offcodeCount[OFFCODE_MAX+1];
692    short offcodeNCount[OFFCODE_MAX+1];
693    U32 offcodeMax = ZSTD_highbit32((U32)(dictBufferSize + 128 KB));
694    U32 matchLengthCount[MaxML+1];
695    short matchLengthNCount[MaxML+1];
696    U32 litLengthCount[MaxLL+1];
697    short litLengthNCount[MaxLL+1];
698    U32 repOffset[MAXREPOFFSET];
699    offsetCount_t bestRepOffset[ZSTD_REP_NUM+1];
700    EStats_ress_t esr;
701    ZSTD_parameters params;
702    U32 u, huffLog = 11, Offlog = OffFSELog, mlLog = MLFSELog, llLog = LLFSELog, total;
703    size_t pos = 0, errorCode;
704    size_t eSize = 0;
705    size_t const totalSrcSize = ZDICT_totalSampleSize(fileSizes, nbFiles);
706    size_t const averageSampleSize = totalSrcSize / (nbFiles + !nbFiles);
707    BYTE* dstPtr = (BYTE*)dstBuffer;
708
709    /* init */
710    DEBUGLOG(4, "ZDICT_analyzeEntropy");
711    esr.ref = ZSTD_createCCtx();
712    esr.zc = ZSTD_createCCtx();
713    esr.workPlace = malloc(ZSTD_BLOCKSIZE_MAX);
714    if (!esr.ref || !esr.zc || !esr.workPlace) {
715        eSize = ERROR(memory_allocation);
716        DISPLAYLEVEL(1, "Not enough memory \n");
717        goto _cleanup;
718    }
719    if (offcodeMax>OFFCODE_MAX) { eSize = ERROR(dictionaryCreation_failed); goto _cleanup; }   /* too large dictionary */
720    for (u=0; u<256; u++) countLit[u] = 1;   /* any character must be described */
721    for (u=0; u<=offcodeMax; u++) offcodeCount[u] = 1;
722    for (u=0; u<=MaxML; u++) matchLengthCount[u] = 1;
723    for (u=0; u<=MaxLL; u++) litLengthCount[u] = 1;
724    memset(repOffset, 0, sizeof(repOffset));
725    repOffset[1] = repOffset[4] = repOffset[8] = 1;
726    memset(bestRepOffset, 0, sizeof(bestRepOffset));
727    if (compressionLevel<=0) compressionLevel = g_compressionLevel_default;
728    params = ZSTD_getParams(compressionLevel, averageSampleSize, dictBufferSize);
729    {   size_t const beginResult = ZSTD_compressBegin_advanced(esr.ref, dictBuffer, dictBufferSize, params, 0);
730        if (ZSTD_isError(beginResult)) {
731            DISPLAYLEVEL(1, "error : ZSTD_compressBegin_advanced() failed : %s \n", ZSTD_getErrorName(beginResult));
732            eSize = ERROR(GENERIC);
733            goto _cleanup;
734    }   }
735
736    /* collect stats on all samples */
737    for (u=0; u<nbFiles; u++) {
738        ZDICT_countEStats(esr, params,
739                          countLit, offcodeCount, matchLengthCount, litLengthCount, repOffset,
740                         (const char*)srcBuffer + pos, fileSizes[u],
741                          notificationLevel);
742        pos += fileSizes[u];
743    }
744
745    /* analyze, build stats, starting with literals */
746    {   size_t maxNbBits = HUF_buildCTable (hufTable, countLit, 255, huffLog);
747        if (HUF_isError(maxNbBits)) {
748            eSize = ERROR(GENERIC);
749            DISPLAYLEVEL(1, " HUF_buildCTable error \n");
750            goto _cleanup;
751        }
752        if (maxNbBits==8) {  /* not compressible : will fail on HUF_writeCTable() */
753            DISPLAYLEVEL(2, "warning : pathological dataset : literals are not compressible : samples are noisy or too regular \n");
754            ZDICT_flatLit(countLit);  /* replace distribution by a fake "mostly flat but still compressible" distribution, that HUF_writeCTable() can encode */
755            maxNbBits = HUF_buildCTable (hufTable, countLit, 255, huffLog);
756            assert(maxNbBits==9);
757        }
758        huffLog = (U32)maxNbBits;
759    }
760
761    /* looking for most common first offsets */
762    {   U32 offset;
763        for (offset=1; offset<MAXREPOFFSET; offset++)
764            ZDICT_insertSortCount(bestRepOffset, offset, repOffset[offset]);
765    }
766    /* note : the result of this phase should be used to better appreciate the impact on statistics */
767
768    total=0; for (u=0; u<=offcodeMax; u++) total+=offcodeCount[u];
769    errorCode = FSE_normalizeCount(offcodeNCount, Offlog, offcodeCount, total, offcodeMax);
770    if (FSE_isError(errorCode)) {
771        eSize = ERROR(GENERIC);
772        DISPLAYLEVEL(1, "FSE_normalizeCount error with offcodeCount \n");
773        goto _cleanup;
774    }
775    Offlog = (U32)errorCode;
776
777    total=0; for (u=0; u<=MaxML; u++) total+=matchLengthCount[u];
778    errorCode = FSE_normalizeCount(matchLengthNCount, mlLog, matchLengthCount, total, MaxML);
779    if (FSE_isError(errorCode)) {
780        eSize = ERROR(GENERIC);
781        DISPLAYLEVEL(1, "FSE_normalizeCount error with matchLengthCount \n");
782        goto _cleanup;
783    }
784    mlLog = (U32)errorCode;
785
786    total=0; for (u=0; u<=MaxLL; u++) total+=litLengthCount[u];
787    errorCode = FSE_normalizeCount(litLengthNCount, llLog, litLengthCount, total, MaxLL);
788    if (FSE_isError(errorCode)) {
789        eSize = ERROR(GENERIC);
790        DISPLAYLEVEL(1, "FSE_normalizeCount error with litLengthCount \n");
791        goto _cleanup;
792    }
793    llLog = (U32)errorCode;
794
795    /* write result to buffer */
796    {   size_t const hhSize = HUF_writeCTable(dstPtr, maxDstSize, hufTable, 255, huffLog);
797        if (HUF_isError(hhSize)) {
798            eSize = ERROR(GENERIC);
799            DISPLAYLEVEL(1, "HUF_writeCTable error \n");
800            goto _cleanup;
801        }
802        dstPtr += hhSize;
803        maxDstSize -= hhSize;
804        eSize += hhSize;
805    }
806
807    {   size_t const ohSize = FSE_writeNCount(dstPtr, maxDstSize, offcodeNCount, OFFCODE_MAX, Offlog);
808        if (FSE_isError(ohSize)) {
809            eSize = ERROR(GENERIC);
810            DISPLAYLEVEL(1, "FSE_writeNCount error with offcodeNCount \n");
811            goto _cleanup;
812        }
813        dstPtr += ohSize;
814        maxDstSize -= ohSize;
815        eSize += ohSize;
816    }
817
818    {   size_t const mhSize = FSE_writeNCount(dstPtr, maxDstSize, matchLengthNCount, MaxML, mlLog);
819        if (FSE_isError(mhSize)) {
820            eSize = ERROR(GENERIC);
821            DISPLAYLEVEL(1, "FSE_writeNCount error with matchLengthNCount \n");
822            goto _cleanup;
823        }
824        dstPtr += mhSize;
825        maxDstSize -= mhSize;
826        eSize += mhSize;
827    }
828
829    {   size_t const lhSize = FSE_writeNCount(dstPtr, maxDstSize, litLengthNCount, MaxLL, llLog);
830        if (FSE_isError(lhSize)) {
831            eSize = ERROR(GENERIC);
832            DISPLAYLEVEL(1, "FSE_writeNCount error with litlengthNCount \n");
833            goto _cleanup;
834        }
835        dstPtr += lhSize;
836        maxDstSize -= lhSize;
837        eSize += lhSize;
838    }
839
840    if (maxDstSize<12) {
841        eSize = ERROR(GENERIC);
842        DISPLAYLEVEL(1, "not enough space to write RepOffsets \n");
843        goto _cleanup;
844    }
845# if 0
846    MEM_writeLE32(dstPtr+0, bestRepOffset[0].offset);
847    MEM_writeLE32(dstPtr+4, bestRepOffset[1].offset);
848    MEM_writeLE32(dstPtr+8, bestRepOffset[2].offset);
849#else
850    /* at this stage, we don't use the result of "most common first offset",
851       as the impact of statistics is not properly evaluated */
852    MEM_writeLE32(dstPtr+0, repStartValue[0]);
853    MEM_writeLE32(dstPtr+4, repStartValue[1]);
854    MEM_writeLE32(dstPtr+8, repStartValue[2]);
855#endif
856    eSize += 12;
857
858_cleanup:
859    ZSTD_freeCCtx(esr.ref);
860    ZSTD_freeCCtx(esr.zc);
861    free(esr.workPlace);
862
863    return eSize;
864}
865
866
867
868size_t ZDICT_finalizeDictionary(void* dictBuffer, size_t dictBufferCapacity,
869                          const void* customDictContent, size_t dictContentSize,
870                          const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
871                          ZDICT_params_t params)
872{
873    size_t hSize;
874#define HBUFFSIZE 256   /* should prove large enough for all entropy headers */
875    BYTE header[HBUFFSIZE];
876    int const compressionLevel = (params.compressionLevel <= 0) ? g_compressionLevel_default : params.compressionLevel;
877    U32 const notificationLevel = params.notificationLevel;
878
879    /* check conditions */
880    DEBUGLOG(4, "ZDICT_finalizeDictionary");
881    if (dictBufferCapacity < dictContentSize) return ERROR(dstSize_tooSmall);
882    if (dictContentSize < ZDICT_CONTENTSIZE_MIN) return ERROR(srcSize_wrong);
883    if (dictBufferCapacity < ZDICT_DICTSIZE_MIN) return ERROR(dstSize_tooSmall);
884
885    /* dictionary header */
886    MEM_writeLE32(header, ZSTD_MAGIC_DICTIONARY);
887    {   U64 const randomID = XXH64(customDictContent, dictContentSize, 0);
888        U32 const compliantID = (randomID % ((1U<<31)-32768)) + 32768;
889        U32 const dictID = params.dictID ? params.dictID : compliantID;
890        MEM_writeLE32(header+4, dictID);
891    }
892    hSize = 8;
893
894    /* entropy tables */
895    DISPLAYLEVEL(2, "\r%70s\r", "");   /* clean display line */
896    DISPLAYLEVEL(2, "statistics ... \n");
897    {   size_t const eSize = ZDICT_analyzeEntropy(header+hSize, HBUFFSIZE-hSize,
898                                  compressionLevel,
899                                  samplesBuffer, samplesSizes, nbSamples,
900                                  customDictContent, dictContentSize,
901                                  notificationLevel);
902        if (ZDICT_isError(eSize)) return eSize;
903        hSize += eSize;
904    }
905
906    /* copy elements in final buffer ; note : src and dst buffer can overlap */
907    if (hSize + dictContentSize > dictBufferCapacity) dictContentSize = dictBufferCapacity - hSize;
908    {   size_t const dictSize = hSize + dictContentSize;
909        char* dictEnd = (char*)dictBuffer + dictSize;
910        memmove(dictEnd - dictContentSize, customDictContent, dictContentSize);
911        memcpy(dictBuffer, header, hSize);
912        return dictSize;
913    }
914}
915
916
917size_t ZDICT_addEntropyTablesFromBuffer_advanced(void* dictBuffer, size_t dictContentSize, size_t dictBufferCapacity,
918                                                 const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
919                                                 ZDICT_params_t params)
920{
921    int const compressionLevel = (params.compressionLevel <= 0) ? g_compressionLevel_default : params.compressionLevel;
922    U32 const notificationLevel = params.notificationLevel;
923    size_t hSize = 8;
924
925    /* calculate entropy tables */
926    DISPLAYLEVEL(2, "\r%70s\r", "");   /* clean display line */
927    DISPLAYLEVEL(2, "statistics ... \n");
928    {   size_t const eSize = ZDICT_analyzeEntropy((char*)dictBuffer+hSize, dictBufferCapacity-hSize,
929                                  compressionLevel,
930                                  samplesBuffer, samplesSizes, nbSamples,
931                                  (char*)dictBuffer + dictBufferCapacity - dictContentSize, dictContentSize,
932                                  notificationLevel);
933        if (ZDICT_isError(eSize)) return eSize;
934        hSize += eSize;
935    }
936
937    /* add dictionary header (after entropy tables) */
938    MEM_writeLE32(dictBuffer, ZSTD_MAGIC_DICTIONARY);
939    {   U64 const randomID = XXH64((char*)dictBuffer + dictBufferCapacity - dictContentSize, dictContentSize, 0);
940        U32 const compliantID = (randomID % ((1U<<31)-32768)) + 32768;
941        U32 const dictID = params.dictID ? params.dictID : compliantID;
942        MEM_writeLE32((char*)dictBuffer+4, dictID);
943    }
944
945    if (hSize + dictContentSize < dictBufferCapacity)
946        memmove((char*)dictBuffer + hSize, (char*)dictBuffer + dictBufferCapacity - dictContentSize, dictContentSize);
947    return MIN(dictBufferCapacity, hSize+dictContentSize);
948}
949
950
951/*! ZDICT_trainFromBuffer_unsafe_legacy() :
952*   Warning : `samplesBuffer` must be followed by noisy guard band.
953*   @return : size of dictionary, or an error code which can be tested with ZDICT_isError()
954*/
955size_t ZDICT_trainFromBuffer_unsafe_legacy(
956                            void* dictBuffer, size_t maxDictSize,
957                            const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
958                            ZDICT_legacy_params_t params)
959{
960    U32 const dictListSize = MAX(MAX(DICTLISTSIZE_DEFAULT, nbSamples), (U32)(maxDictSize/16));
961    dictItem* const dictList = (dictItem*)malloc(dictListSize * sizeof(*dictList));
962    unsigned const selectivity = params.selectivityLevel == 0 ? g_selectivity_default : params.selectivityLevel;
963    unsigned const minRep = (selectivity > 30) ? MINRATIO : nbSamples >> selectivity;
964    size_t const targetDictSize = maxDictSize;
965    size_t const samplesBuffSize = ZDICT_totalSampleSize(samplesSizes, nbSamples);
966    size_t dictSize = 0;
967    U32 const notificationLevel = params.zParams.notificationLevel;
968
969    /* checks */
970    if (!dictList) return ERROR(memory_allocation);
971    if (maxDictSize < ZDICT_DICTSIZE_MIN) { free(dictList); return ERROR(dstSize_tooSmall); }   /* requested dictionary size is too small */
972    if (samplesBuffSize < ZDICT_MIN_SAMPLES_SIZE) { free(dictList); return ERROR(dictionaryCreation_failed); }   /* not enough source to create dictionary */
973
974    /* init */
975    ZDICT_initDictItem(dictList);
976
977    /* build dictionary */
978    ZDICT_trainBuffer_legacy(dictList, dictListSize,
979                       samplesBuffer, samplesBuffSize,
980                       samplesSizes, nbSamples,
981                       minRep, notificationLevel);
982
983    /* display best matches */
984    if (params.zParams.notificationLevel>= 3) {
985        U32 const nb = MIN(25, dictList[0].pos);
986        U32 const dictContentSize = ZDICT_dictSize(dictList);
987        U32 u;
988        DISPLAYLEVEL(3, "\n %u segments found, of total size %u \n", dictList[0].pos-1, dictContentSize);
989        DISPLAYLEVEL(3, "list %u best segments \n", nb-1);
990        for (u=1; u<nb; u++) {
991            U32 const pos = dictList[u].pos;
992            U32 const length = dictList[u].length;
993            U32 const printedLength = MIN(40, length);
994            if ((pos > samplesBuffSize) || ((pos + length) > samplesBuffSize))
995                return ERROR(GENERIC);   /* should never happen */
996            DISPLAYLEVEL(3, "%3u:%3u bytes at pos %8u, savings %7u bytes |",
997                         u, length, pos, dictList[u].savings);
998            ZDICT_printHex((const char*)samplesBuffer+pos, printedLength);
999            DISPLAYLEVEL(3, "| \n");
1000    }   }
1001
1002
1003    /* create dictionary */
1004    {   U32 dictContentSize = ZDICT_dictSize(dictList);
1005        if (dictContentSize < ZDICT_CONTENTSIZE_MIN) { free(dictList); return ERROR(dictionaryCreation_failed); }   /* dictionary content too small */
1006        if (dictContentSize < targetDictSize/4) {
1007            DISPLAYLEVEL(2, "!  warning : selected content significantly smaller than requested (%u < %u) \n", dictContentSize, (U32)maxDictSize);
1008            if (samplesBuffSize < 10 * targetDictSize)
1009                DISPLAYLEVEL(2, "!  consider increasing the number of samples (total size : %u MB)\n", (U32)(samplesBuffSize>>20));
1010            if (minRep > MINRATIO) {
1011                DISPLAYLEVEL(2, "!  consider increasing selectivity to produce larger dictionary (-s%u) \n", selectivity+1);
1012                DISPLAYLEVEL(2, "!  note : larger dictionaries are not necessarily better, test its efficiency on samples \n");
1013            }
1014        }
1015
1016        if ((dictContentSize > targetDictSize*3) && (nbSamples > 2*MINRATIO) && (selectivity>1)) {
1017            U32 proposedSelectivity = selectivity-1;
1018            while ((nbSamples >> proposedSelectivity) <= MINRATIO) { proposedSelectivity--; }
1019            DISPLAYLEVEL(2, "!  note : calculated dictionary significantly larger than requested (%u > %u) \n", dictContentSize, (U32)maxDictSize);
1020            DISPLAYLEVEL(2, "!  consider increasing dictionary size, or produce denser dictionary (-s%u) \n", proposedSelectivity);
1021            DISPLAYLEVEL(2, "!  always test dictionary efficiency on real samples \n");
1022        }
1023
1024        /* limit dictionary size */
1025        {   U32 const max = dictList->pos;   /* convention : nb of useful elts within dictList */
1026            U32 currentSize = 0;
1027            U32 n; for (n=1; n<max; n++) {
1028                currentSize += dictList[n].length;
1029                if (currentSize > targetDictSize) { currentSize -= dictList[n].length; break; }
1030            }
1031            dictList->pos = n;
1032            dictContentSize = currentSize;
1033        }
1034
1035        /* build dict content */
1036        {   U32 u;
1037            BYTE* ptr = (BYTE*)dictBuffer + maxDictSize;
1038            for (u=1; u<dictList->pos; u++) {
1039                U32 l = dictList[u].length;
1040                ptr -= l;
1041                if (ptr<(BYTE*)dictBuffer) { free(dictList); return ERROR(GENERIC); }   /* should not happen */
1042                memcpy(ptr, (const char*)samplesBuffer+dictList[u].pos, l);
1043        }   }
1044
1045        dictSize = ZDICT_addEntropyTablesFromBuffer_advanced(dictBuffer, dictContentSize, maxDictSize,
1046                                                             samplesBuffer, samplesSizes, nbSamples,
1047                                                             params.zParams);
1048    }
1049
1050    /* clean up */
1051    free(dictList);
1052    return dictSize;
1053}
1054
1055
1056/* ZDICT_trainFromBuffer_legacy() :
1057 * issue : samplesBuffer need to be followed by a noisy guard band.
1058 * work around : duplicate the buffer, and add the noise */
1059size_t ZDICT_trainFromBuffer_legacy(void* dictBuffer, size_t dictBufferCapacity,
1060                              const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
1061                              ZDICT_legacy_params_t params)
1062{
1063    size_t result;
1064    void* newBuff;
1065    size_t const sBuffSize = ZDICT_totalSampleSize(samplesSizes, nbSamples);
1066    if (sBuffSize < ZDICT_MIN_SAMPLES_SIZE) return 0;   /* not enough content => no dictionary */
1067
1068    newBuff = malloc(sBuffSize + NOISELENGTH);
1069    if (!newBuff) return ERROR(memory_allocation);
1070
1071    memcpy(newBuff, samplesBuffer, sBuffSize);
1072    ZDICT_fillNoise((char*)newBuff + sBuffSize, NOISELENGTH);   /* guard band, for end of buffer condition */
1073
1074    result =
1075        ZDICT_trainFromBuffer_unsafe_legacy(dictBuffer, dictBufferCapacity, newBuff,
1076                                            samplesSizes, nbSamples, params);
1077    free(newBuff);
1078    return result;
1079}
1080
1081
1082size_t ZDICT_trainFromBuffer(void* dictBuffer, size_t dictBufferCapacity,
1083                             const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples)
1084{
1085    ZDICT_cover_params_t params;
1086    DEBUGLOG(3, "ZDICT_trainFromBuffer");
1087    memset(&params, 0, sizeof(params));
1088    params.d = 8;
1089    params.steps = 4;
1090    /* Default to level 6 since no compression level information is available */
1091    params.zParams.compressionLevel = 6;
1092#if defined(ZSTD_DEBUG) && (ZSTD_DEBUG>=1)
1093    params.zParams.notificationLevel = ZSTD_DEBUG;
1094#endif
1095    return ZDICT_optimizeTrainFromBuffer_cover(dictBuffer, dictBufferCapacity,
1096                                               samplesBuffer, samplesSizes, nbSamples,
1097                                               &params);
1098}
1099
1100size_t ZDICT_addEntropyTablesFromBuffer(void* dictBuffer, size_t dictContentSize, size_t dictBufferCapacity,
1101                                  const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples)
1102{
1103    ZDICT_params_t params;
1104    memset(&params, 0, sizeof(params));
1105    return ZDICT_addEntropyTablesFromBuffer_advanced(dictBuffer, dictContentSize, dictBufferCapacity,
1106                                                     samplesBuffer, samplesSizes, nbSamples,
1107                                                     params);
1108}
1109