diff options
Diffstat (limited to 'vendor/github.com/DataDog/zstd/fastcover.c')
| -rw-r--r-- | vendor/github.com/DataDog/zstd/fastcover.c | 740 |
1 files changed, 740 insertions, 0 deletions
diff --git a/vendor/github.com/DataDog/zstd/fastcover.c b/vendor/github.com/DataDog/zstd/fastcover.c new file mode 100644 index 000000000..5b6b941a9 --- /dev/null +++ b/vendor/github.com/DataDog/zstd/fastcover.c @@ -0,0 +1,740 @@ +/*-************************************* +* Dependencies +***************************************/ +#include <stdio.h> /* fprintf */ +#include <stdlib.h> /* malloc, free, qsort */ +#include <string.h> /* memset */ +#include <time.h> /* clock */ + +#include "mem.h" /* read */ +#include "pool.h" +#include "threading.h" +#include "cover.h" +#include "zstd_internal.h" /* includes zstd.h */ +#ifndef ZDICT_STATIC_LINKING_ONLY +#define ZDICT_STATIC_LINKING_ONLY +#endif +#include "zdict.h" + + +/*-************************************* +* Constants +***************************************/ +#define FASTCOVER_MAX_SAMPLES_SIZE (sizeof(size_t) == 8 ? ((unsigned)-1) : ((unsigned)1 GB)) +#define FASTCOVER_MAX_F 31 +#define FASTCOVER_MAX_ACCEL 10 +#define DEFAULT_SPLITPOINT 0.75 +#define DEFAULT_F 20 +#define DEFAULT_ACCEL 1 + + +/*-************************************* +* Console display +***************************************/ +static int g_displayLevel = 2; +#define DISPLAY(...) \ + { \ + fprintf(stderr, __VA_ARGS__); \ + fflush(stderr); \ + } +#define LOCALDISPLAYLEVEL(displayLevel, l, ...) \ + if (displayLevel >= l) { \ + DISPLAY(__VA_ARGS__); \ + } /* 0 : no display; 1: errors; 2: default; 3: details; 4: debug */ +#define DISPLAYLEVEL(l, ...) LOCALDISPLAYLEVEL(g_displayLevel, l, __VA_ARGS__) + +#define LOCALDISPLAYUPDATE(displayLevel, l, ...) \ + if (displayLevel >= l) { \ + if ((clock() - g_time > refreshRate) || (displayLevel >= 4)) { \ + g_time = clock(); \ + DISPLAY(__VA_ARGS__); \ + } \ + } +#define DISPLAYUPDATE(l, ...) LOCALDISPLAYUPDATE(g_displayLevel, l, __VA_ARGS__) +static const clock_t refreshRate = CLOCKS_PER_SEC * 15 / 100; +static clock_t g_time = 0; + + +/*-************************************* +* Hash Functions +***************************************/ +static const U64 prime6bytes = 227718039650203ULL; +static size_t ZSTD_hash6(U64 u, U32 h) { return (size_t)(((u << (64-48)) * prime6bytes) >> (64-h)) ; } +static size_t ZSTD_hash6Ptr(const void* p, U32 h) { return ZSTD_hash6(MEM_readLE64(p), h); } + +static const U64 prime8bytes = 0xCF1BBCDCB7A56463ULL; +static size_t ZSTD_hash8(U64 u, U32 h) { return (size_t)(((u) * prime8bytes) >> (64-h)) ; } +static size_t ZSTD_hash8Ptr(const void* p, U32 h) { return ZSTD_hash8(MEM_readLE64(p), h); } + + +/** + * Hash the d-byte value pointed to by p and mod 2^f + */ +static size_t FASTCOVER_hashPtrToIndex(const void* p, U32 h, unsigned d) { + if (d == 6) { + return ZSTD_hash6Ptr(p, h) & ((1 << h) - 1); + } + return ZSTD_hash8Ptr(p, h) & ((1 << h) - 1); +} + + +/*-************************************* +* Acceleration +***************************************/ +typedef struct { + unsigned finalize; /* Percentage of training samples used for ZDICT_finalizeDictionary */ + unsigned skip; /* Number of dmer skipped between each dmer counted in computeFrequency */ +} FASTCOVER_accel_t; + + +static const FASTCOVER_accel_t FASTCOVER_defaultAccelParameters[FASTCOVER_MAX_ACCEL+1] = { + { 100, 0 }, /* accel = 0, should not happen because accel = 0 defaults to accel = 1 */ + { 100, 0 }, /* accel = 1 */ + { 50, 1 }, /* accel = 2 */ + { 34, 2 }, /* accel = 3 */ + { 25, 3 }, /* accel = 4 */ + { 20, 4 }, /* accel = 5 */ + { 17, 5 }, /* accel = 6 */ + { 14, 6 }, /* accel = 7 */ + { 13, 7 }, /* accel = 8 */ + { 11, 8 }, /* accel = 9 */ + { 10, 9 }, /* accel = 10 */ +}; + + +/*-************************************* +* Context +***************************************/ +typedef struct { + const BYTE *samples; + size_t *offsets; + const size_t *samplesSizes; + size_t nbSamples; + size_t nbTrainSamples; + size_t nbTestSamples; + size_t nbDmers; + U32 *freqs; + unsigned d; + unsigned f; + FASTCOVER_accel_t accelParams; +} FASTCOVER_ctx_t; + + +/*-************************************* +* Helper functions +***************************************/ +/** + * Selects the best segment in an epoch. + * Segments of are scored according to the function: + * + * Let F(d) be the frequency of all dmers with hash value d. + * Let S_i be hash value of the dmer at position i of segment S which has length k. + * + * Score(S) = F(S_1) + F(S_2) + ... + F(S_{k-d+1}) + * + * Once the dmer with hash value d is in the dictionary we set F(d) = 0. + */ +static COVER_segment_t FASTCOVER_selectSegment(const FASTCOVER_ctx_t *ctx, + U32 *freqs, U32 begin, U32 end, + ZDICT_cover_params_t parameters, + U16* segmentFreqs) { + /* Constants */ + const U32 k = parameters.k; + const U32 d = parameters.d; + const U32 f = ctx->f; + const U32 dmersInK = k - d + 1; + + /* Try each segment (activeSegment) and save the best (bestSegment) */ + COVER_segment_t bestSegment = {0, 0, 0}; + COVER_segment_t activeSegment; + + /* Reset the activeDmers in the segment */ + /* The activeSegment starts at the beginning of the epoch. */ + activeSegment.begin = begin; + activeSegment.end = begin; + activeSegment.score = 0; + + /* Slide the activeSegment through the whole epoch. + * Save the best segment in bestSegment. + */ + while (activeSegment.end < end) { + /* Get hash value of current dmer */ + const size_t idx = FASTCOVER_hashPtrToIndex(ctx->samples + activeSegment.end, f, d); + + /* Add frequency of this index to score if this is the first occurrence of index in active segment */ + if (segmentFreqs[idx] == 0) { + activeSegment.score += freqs[idx]; + } + /* Increment end of segment and segmentFreqs*/ + activeSegment.end += 1; + segmentFreqs[idx] += 1; + /* If the window is now too large, drop the first position */ + if (activeSegment.end - activeSegment.begin == dmersInK + 1) { + /* Get hash value of the dmer to be eliminated from active segment */ + const size_t delIndex = FASTCOVER_hashPtrToIndex(ctx->samples + activeSegment.begin, f, d); + segmentFreqs[delIndex] -= 1; + /* Subtract frequency of this index from score if this is the last occurrence of this index in active segment */ + if (segmentFreqs[delIndex] == 0) { + activeSegment.score -= freqs[delIndex]; + } + /* Increment start of segment */ + activeSegment.begin += 1; + } + + /* If this segment is the best so far save it */ + if (activeSegment.score > bestSegment.score) { + bestSegment = activeSegment; + } + } + + /* Zero out rest of segmentFreqs array */ + while (activeSegment.begin < end) { + const size_t delIndex = FASTCOVER_hashPtrToIndex(ctx->samples + activeSegment.begin, f, d); + segmentFreqs[delIndex] -= 1; + activeSegment.begin += 1; + } + + { + /* Zero the frequency of hash value of each dmer covered by the chosen segment. */ + U32 pos; + for (pos = bestSegment.begin; pos != bestSegment.end; ++pos) { + const size_t i = FASTCOVER_hashPtrToIndex(ctx->samples + pos, f, d); + freqs[i] = 0; + } + } + + return bestSegment; +} + + +static int FASTCOVER_checkParameters(ZDICT_cover_params_t parameters, + size_t maxDictSize, unsigned f, + unsigned accel) { + /* k, d, and f are required parameters */ + if (parameters.d == 0 || parameters.k == 0) { + return 0; + } + /* d has to be 6 or 8 */ + if (parameters.d != 6 && parameters.d != 8) { + return 0; + } + /* k <= maxDictSize */ + if (parameters.k > maxDictSize) { + return 0; + } + /* d <= k */ + if (parameters.d > parameters.k) { + return 0; + } + /* 0 < f <= FASTCOVER_MAX_F*/ + if (f > FASTCOVER_MAX_F || f == 0) { + return 0; + } + /* 0 < splitPoint <= 1 */ + if (parameters.splitPoint <= 0 || parameters.splitPoint > 1) { + return 0; + } + /* 0 < accel <= 10 */ + if (accel > 10 || accel == 0) { + return 0; + } + return 1; +} + + +/** + * Clean up a context initialized with `FASTCOVER_ctx_init()`. + */ +static void +FASTCOVER_ctx_destroy(FASTCOVER_ctx_t* ctx) +{ + if (!ctx) return; + + free(ctx->freqs); + ctx->freqs = NULL; + + free(ctx->offsets); + ctx->offsets = NULL; +} + + +/** + * Calculate for frequency of hash value of each dmer in ctx->samples + */ +static void +FASTCOVER_computeFrequency(U32* freqs, const FASTCOVER_ctx_t* ctx) +{ + const unsigned f = ctx->f; + const unsigned d = ctx->d; + const unsigned skip = ctx->accelParams.skip; + const unsigned readLength = MAX(d, 8); + size_t i; + assert(ctx->nbTrainSamples >= 5); + assert(ctx->nbTrainSamples <= ctx->nbSamples); + for (i = 0; i < ctx->nbTrainSamples; i++) { + size_t start = ctx->offsets[i]; /* start of current dmer */ + size_t const currSampleEnd = ctx->offsets[i+1]; + while (start + readLength <= currSampleEnd) { + const size_t dmerIndex = FASTCOVER_hashPtrToIndex(ctx->samples + start, f, d); + freqs[dmerIndex]++; + start = start + skip + 1; + } + } +} + + +/** + * Prepare a context for dictionary building. + * The context is only dependent on the parameter `d` and can used multiple + * times. + * Returns 1 on success or zero on error. + * The context must be destroyed with `FASTCOVER_ctx_destroy()`. + */ +static int +FASTCOVER_ctx_init(FASTCOVER_ctx_t* ctx, + const void* samplesBuffer, + const size_t* samplesSizes, unsigned nbSamples, + unsigned d, double splitPoint, unsigned f, + FASTCOVER_accel_t accelParams) +{ + const BYTE* const samples = (const BYTE*)samplesBuffer; + const size_t totalSamplesSize = COVER_sum(samplesSizes, nbSamples); + /* Split samples into testing and training sets */ + const unsigned nbTrainSamples = splitPoint < 1.0 ? (unsigned)((double)nbSamples * splitPoint) : nbSamples; + const unsigned nbTestSamples = splitPoint < 1.0 ? nbSamples - nbTrainSamples : nbSamples; + const size_t trainingSamplesSize = splitPoint < 1.0 ? COVER_sum(samplesSizes, nbTrainSamples) : totalSamplesSize; + const size_t testSamplesSize = splitPoint < 1.0 ? COVER_sum(samplesSizes + nbTrainSamples, nbTestSamples) : totalSamplesSize; + + /* Checks */ + if (totalSamplesSize < MAX(d, sizeof(U64)) || + totalSamplesSize >= (size_t)FASTCOVER_MAX_SAMPLES_SIZE) { + DISPLAYLEVEL(1, "Total samples size is too large (%u MB), maximum size is %u MB\n", + (unsigned)(totalSamplesSize >> 20), (FASTCOVER_MAX_SAMPLES_SIZE >> 20)); + return 0; + } + + /* Check if there are at least 5 training samples */ + if (nbTrainSamples < 5) { + DISPLAYLEVEL(1, "Total number of training samples is %u and is invalid\n", nbTrainSamples); + return 0; + } + + /* Check if there's testing sample */ + if (nbTestSamples < 1) { + DISPLAYLEVEL(1, "Total number of testing samples is %u and is invalid.\n", nbTestSamples); + return 0; + } + + /* Zero the context */ + memset(ctx, 0, sizeof(*ctx)); + DISPLAYLEVEL(2, "Training on %u samples of total size %u\n", nbTrainSamples, + (unsigned)trainingSamplesSize); + DISPLAYLEVEL(2, "Testing on %u samples of total size %u\n", nbTestSamples, + (unsigned)testSamplesSize); + + ctx->samples = samples; + ctx->samplesSizes = samplesSizes; + ctx->nbSamples = nbSamples; + ctx->nbTrainSamples = nbTrainSamples; + ctx->nbTestSamples = nbTestSamples; + ctx->nbDmers = trainingSamplesSize - MAX(d, sizeof(U64)) + 1; + ctx->d = d; + ctx->f = f; + ctx->accelParams = accelParams; + + /* The offsets of each file */ + ctx->offsets = (size_t*)calloc((nbSamples + 1), sizeof(size_t)); + if (ctx->offsets == NULL) { + DISPLAYLEVEL(1, "Failed to allocate scratch buffers \n"); + FASTCOVER_ctx_destroy(ctx); + return 0; + } + + /* Fill offsets from the samplesSizes */ + { U32 i; + ctx->offsets[0] = 0; + assert(nbSamples >= 5); + for (i = 1; i <= nbSamples; ++i) { + ctx->offsets[i] = ctx->offsets[i - 1] + samplesSizes[i - 1]; + } + } + + /* Initialize frequency array of size 2^f */ + ctx->freqs = (U32*)calloc(((U64)1 << f), sizeof(U32)); + if (ctx->freqs == NULL) { + DISPLAYLEVEL(1, "Failed to allocate frequency table \n"); + FASTCOVER_ctx_destroy(ctx); + return 0; + } + + DISPLAYLEVEL(2, "Computing frequencies\n"); + FASTCOVER_computeFrequency(ctx->freqs, ctx); + + return 1; +} + + +/** + * Given the prepared context build the dictionary. + */ +static size_t +FASTCOVER_buildDictionary(const FASTCOVER_ctx_t* ctx, + U32* freqs, + void* dictBuffer, size_t dictBufferCapacity, + ZDICT_cover_params_t parameters, + U16* segmentFreqs) +{ + BYTE *const dict = (BYTE *)dictBuffer; + size_t tail = dictBufferCapacity; + /* Divide the data into epochs. We will select one segment from each epoch. */ + const COVER_epoch_info_t epochs = COVER_computeEpochs( + (U32)dictBufferCapacity, (U32)ctx->nbDmers, parameters.k, 1); + const size_t maxZeroScoreRun = 10; + size_t zeroScoreRun = 0; + size_t epoch; + DISPLAYLEVEL(2, "Breaking content into %u epochs of size %u\n", + (U32)epochs.num, (U32)epochs.size); + /* Loop through the epochs until there are no more segments or the dictionary + * is full. + */ + for (epoch = 0; tail > 0; epoch = (epoch + 1) % epochs.num) { + const U32 epochBegin = (U32)(epoch * epochs.size); + const U32 epochEnd = epochBegin + epochs.size; + size_t segmentSize; + /* Select a segment */ + COVER_segment_t segment = FASTCOVER_selectSegment( + ctx, freqs, epochBegin, epochEnd, parameters, segmentFreqs); + + /* If the segment covers no dmers, then we are out of content. + * There may be new content in other epochs, for continue for some time. + */ + if (segment.score == 0) { + if (++zeroScoreRun >= maxZeroScoreRun) { + break; + } + continue; + } + zeroScoreRun = 0; + + /* Trim the segment if necessary and if it is too small then we are done */ + segmentSize = MIN(segment.end - segment.begin + parameters.d - 1, tail); + if (segmentSize < parameters.d) { + break; + } + + /* We fill the dictionary from the back to allow the best segments to be + * referenced with the smallest offsets. + */ + tail -= segmentSize; + memcpy(dict + tail, ctx->samples + segment.begin, segmentSize); + DISPLAYUPDATE( + 2, "\r%u%% ", + (unsigned)(((dictBufferCapacity - tail) * 100) / dictBufferCapacity)); + } + DISPLAYLEVEL(2, "\r%79s\r", ""); + return tail; +} + + +/** + * Parameters for FASTCOVER_tryParameters(). + */ +typedef struct FASTCOVER_tryParameters_data_s { + const FASTCOVER_ctx_t* ctx; + COVER_best_t* best; + size_t dictBufferCapacity; + ZDICT_cover_params_t parameters; +} FASTCOVER_tryParameters_data_t; + + +/** + * Tries a set of parameters and updates the COVER_best_t with the results. + * This function is thread safe if zstd is compiled with multithreaded support. + * It takes its parameters as an *OWNING* opaque pointer to support threading. + */ +static void FASTCOVER_tryParameters(void *opaque) +{ + /* Save parameters as local variables */ + FASTCOVER_tryParameters_data_t *const data = (FASTCOVER_tryParameters_data_t *)opaque; + const FASTCOVER_ctx_t *const ctx = data->ctx; + const ZDICT_cover_params_t parameters = data->parameters; + size_t dictBufferCapacity = data->dictBufferCapacity; + size_t totalCompressedSize = ERROR(GENERIC); + /* Initialize array to keep track of frequency of dmer within activeSegment */ + U16* segmentFreqs = (U16 *)calloc(((U64)1 << ctx->f), sizeof(U16)); + /* Allocate space for hash table, dict, and freqs */ + BYTE *const dict = (BYTE * const)malloc(dictBufferCapacity); + U32 *freqs = (U32*) malloc(((U64)1 << ctx->f) * sizeof(U32)); + if (!segmentFreqs || !dict || !freqs) { + DISPLAYLEVEL(1, "Failed to allocate buffers: out of memory\n"); + goto _cleanup; + } + /* Copy the frequencies because we need to modify them */ + memcpy(freqs, ctx->freqs, ((U64)1 << ctx->f) * sizeof(U32)); + /* Build the dictionary */ + { const size_t tail = FASTCOVER_buildDictionary(ctx, freqs, dict, dictBufferCapacity, + parameters, segmentFreqs); + const unsigned nbFinalizeSamples = (unsigned)(ctx->nbTrainSamples * ctx->accelParams.finalize / 100); + dictBufferCapacity = ZDICT_finalizeDictionary( + dict, dictBufferCapacity, dict + tail, dictBufferCapacity - tail, + ctx->samples, ctx->samplesSizes, nbFinalizeSamples, parameters.zParams); + if (ZDICT_isError(dictBufferCapacity)) { + DISPLAYLEVEL(1, "Failed to finalize dictionary\n"); + goto _cleanup; + } + } + /* Check total compressed size */ + totalCompressedSize = COVER_checkTotalCompressedSize(parameters, ctx->samplesSizes, + ctx->samples, ctx->offsets, + ctx->nbTrainSamples, ctx->nbSamples, + dict, dictBufferCapacity); +_cleanup: + COVER_best_finish(data->best, totalCompressedSize, parameters, dict, + dictBufferCapacity); + free(data); + free(segmentFreqs); + free(dict); + free(freqs); +} + + +static void +FASTCOVER_convertToCoverParams(ZDICT_fastCover_params_t fastCoverParams, + ZDICT_cover_params_t* coverParams) +{ + coverParams->k = fastCoverParams.k; + coverParams->d = fastCoverParams.d; + coverParams->steps = fastCoverParams.steps; + coverParams->nbThreads = fastCoverParams.nbThreads; + coverParams->splitPoint = fastCoverParams.splitPoint; + coverParams->zParams = fastCoverParams.zParams; +} + + +static void +FASTCOVER_convertToFastCoverParams(ZDICT_cover_params_t coverParams, + ZDICT_fastCover_params_t* fastCoverParams, + unsigned f, unsigned accel) +{ + fastCoverParams->k = coverParams.k; + fastCoverParams->d = coverParams.d; + fastCoverParams->steps = coverParams.steps; + fastCoverParams->nbThreads = coverParams.nbThreads; + fastCoverParams->splitPoint = coverParams.splitPoint; + fastCoverParams->f = f; + fastCoverParams->accel = accel; + fastCoverParams->zParams = coverParams.zParams; +} + + +ZDICTLIB_API size_t +ZDICT_trainFromBuffer_fastCover(void* dictBuffer, size_t dictBufferCapacity, + const void* samplesBuffer, + const size_t* samplesSizes, unsigned nbSamples, + ZDICT_fastCover_params_t parameters) +{ + BYTE* const dict = (BYTE*)dictBuffer; + FASTCOVER_ctx_t ctx; + ZDICT_cover_params_t coverParams; + FASTCOVER_accel_t accelParams; + /* Initialize global data */ + g_displayLevel = parameters.zParams.notificationLevel; + /* Assign splitPoint and f if not provided */ + parameters.splitPoint = 1.0; + parameters.f = parameters.f == 0 ? DEFAULT_F : parameters.f; + parameters.accel = parameters.accel == 0 ? DEFAULT_ACCEL : parameters.accel; + /* Convert to cover parameter */ + memset(&coverParams, 0 , sizeof(coverParams)); + FASTCOVER_convertToCoverParams(parameters, &coverParams); + /* Checks */ + if (!FASTCOVER_checkParameters(coverParams, dictBufferCapacity, parameters.f, + parameters.accel)) { + DISPLAYLEVEL(1, "FASTCOVER parameters incorrect\n"); + return ERROR(GENERIC); + } + if (nbSamples == 0) { + DISPLAYLEVEL(1, "FASTCOVER must have at least one input file\n"); + return ERROR(GENERIC); + } + if (dictBufferCapacity < ZDICT_DICTSIZE_MIN) { + DISPLAYLEVEL(1, "dictBufferCapacity must be at least %u\n", + ZDICT_DICTSIZE_MIN); + return ERROR(dstSize_tooSmall); + } + /* Assign corresponding FASTCOVER_accel_t to accelParams*/ + accelParams = FASTCOVER_defaultAccelParameters[parameters.accel]; + /* Initialize context */ + if (!FASTCOVER_ctx_init(&ctx, samplesBuffer, samplesSizes, nbSamples, + coverParams.d, parameters.splitPoint, parameters.f, + accelParams)) { + DISPLAYLEVEL(1, "Failed to initialize context\n"); + return ERROR(GENERIC); + } + COVER_warnOnSmallCorpus(dictBufferCapacity, ctx.nbDmers, g_displayLevel); + /* Build the dictionary */ + DISPLAYLEVEL(2, "Building dictionary\n"); + { + /* Initialize array to keep track of frequency of dmer within activeSegment */ + U16* segmentFreqs = (U16 *)calloc(((U64)1 << parameters.f), sizeof(U16)); + const size_t tail = FASTCOVER_buildDictionary(&ctx, ctx.freqs, dictBuffer, + dictBufferCapacity, coverParams, segmentFreqs); + const unsigned nbFinalizeSamples = (unsigned)(ctx.nbTrainSamples * ctx.accelParams.finalize / 100); + const size_t dictionarySize = ZDICT_finalizeDictionary( + dict, dictBufferCapacity, dict + tail, dictBufferCapacity - tail, + samplesBuffer, samplesSizes, nbFinalizeSamples, coverParams.zParams); + if (!ZSTD_isError(dictionarySize)) { + DISPLAYLEVEL(2, "Constructed dictionary of size %u\n", + (unsigned)dictionarySize); + } + FASTCOVER_ctx_destroy(&ctx); + free(segmentFreqs); + return dictionarySize; + } +} + + +ZDICTLIB_API size_t +ZDICT_optimizeTrainFromBuffer_fastCover( + void* dictBuffer, size_t dictBufferCapacity, + const void* samplesBuffer, + const size_t* samplesSizes, unsigned nbSamples, + ZDICT_fastCover_params_t* parameters) +{ + ZDICT_cover_params_t coverParams; + FASTCOVER_accel_t accelParams; + /* constants */ + const unsigned nbThreads = parameters->nbThreads; + const double splitPoint = + parameters->splitPoint <= 0.0 ? DEFAULT_SPLITPOINT : parameters->splitPoint; + const unsigned kMinD = parameters->d == 0 ? 6 : parameters->d; + const unsigned kMaxD = parameters->d == 0 ? 8 : parameters->d; + const unsigned kMinK = parameters->k == 0 ? 50 : parameters->k; + const unsigned kMaxK = parameters->k == 0 ? 2000 : parameters->k; + const unsigned kSteps = parameters->steps == 0 ? 40 : parameters->steps; + const unsigned kStepSize = MAX((kMaxK - kMinK) / kSteps, 1); + const unsigned kIterations = + (1 + (kMaxD - kMinD) / 2) * (1 + (kMaxK - kMinK) / kStepSize); + const unsigned f = parameters->f == 0 ? DEFAULT_F : parameters->f; + const unsigned accel = parameters->accel == 0 ? DEFAULT_ACCEL : parameters->accel; + /* Local variables */ + const int displayLevel = parameters->zParams.notificationLevel; + unsigned iteration = 1; + unsigned d; + unsigned k; + COVER_best_t best; + POOL_ctx *pool = NULL; + int warned = 0; + /* Checks */ + if (splitPoint <= 0 || splitPoint > 1) { + LOCALDISPLAYLEVEL(displayLevel, 1, "Incorrect splitPoint\n"); + return ERROR(GENERIC); + } + if (accel == 0 || accel > FASTCOVER_MAX_ACCEL) { + LOCALDISPLAYLEVEL(displayLevel, 1, "Incorrect accel\n"); + return ERROR(GENERIC); + } + if (kMinK < kMaxD || kMaxK < kMinK) { + LOCALDISPLAYLEVEL(displayLevel, 1, "Incorrect k\n"); + return ERROR(GENERIC); + } + if (nbSamples == 0) { + LOCALDISPLAYLEVEL(displayLevel, 1, "FASTCOVER must have at least one input file\n"); + return ERROR(GENERIC); + } + if (dictBufferCapacity < ZDICT_DICTSIZE_MIN) { + LOCALDISPLAYLEVEL(displayLevel, 1, "dictBufferCapacity must be at least %u\n", + ZDICT_DICTSIZE_MIN); + return ERROR(dstSize_tooSmall); + } + if (nbThreads > 1) { + pool = POOL_create(nbThreads, 1); + if (!pool) { + return ERROR(memory_allocation); + } + } + /* Initialization */ + COVER_best_init(&best); + memset(&coverParams, 0 , sizeof(coverParams)); + FASTCOVER_convertToCoverParams(*parameters, &coverParams); + accelParams = FASTCOVER_defaultAccelParameters[accel]; + /* Turn down global display level to clean up display at level 2 and below */ + g_displayLevel = displayLevel == 0 ? 0 : displayLevel - 1; + /* Loop through d first because each new value needs a new context */ + LOCALDISPLAYLEVEL(displayLevel, 2, "Trying %u different sets of parameters\n", + kIterations); + for (d = kMinD; d <= kMaxD; d += 2) { + /* Initialize the context for this value of d */ + FASTCOVER_ctx_t ctx; + LOCALDISPLAYLEVEL(displayLevel, 3, "d=%u\n", d); + if (!FASTCOVER_ctx_init(&ctx, samplesBuffer, samplesSizes, nbSamples, d, splitPoint, f, accelParams)) { + LOCALDISPLAYLEVEL(displayLevel, 1, "Failed to initialize context\n"); + COVER_best_destroy(&best); + POOL_free(pool); + return ERROR(GENERIC); + } + if (!warned) { + COVER_warnOnSmallCorpus(dictBufferCapacity, ctx.nbDmers, displayLevel); + warned = 1; + } + /* Loop through k reusing the same context */ + for (k = kMinK; k <= kMaxK; k += kStepSize) { + /* Prepare the arguments */ + FASTCOVER_tryParameters_data_t *data = (FASTCOVER_tryParameters_data_t *)malloc( + sizeof(FASTCOVER_tryParameters_data_t)); + LOCALDISPLAYLEVEL(displayLevel, 3, "k=%u\n", k); + if (!data) { + LOCALDISPLAYLEVEL(displayLevel, 1, "Failed to allocate parameters\n"); + COVER_best_destroy(&best); + FASTCOVER_ctx_destroy(&ctx); + POOL_free(pool); + return ERROR(GENERIC); + } + data->ctx = &ctx; + data->best = &best; + data->dictBufferCapacity = dictBufferCapacity; + data->parameters = coverParams; + data->parameters.k = k; + data->parameters.d = d; + data->parameters.splitPoint = splitPoint; + data->parameters.steps = kSteps; + data->parameters.zParams.notificationLevel = g_displayLevel; + /* Check the parameters */ + if (!FASTCOVER_checkParameters(data->parameters, dictBufferCapacity, + data->ctx->f, accel)) { + DISPLAYLEVEL(1, "FASTCOVER parameters incorrect\n"); + free(data); + continue; + } + /* Call the function and pass ownership of data to it */ + COVER_best_start(&best); + if (pool) { + POOL_add(pool, &FASTCOVER_tryParameters, data); + } else { + FASTCOVER_tryParameters(data); + } + /* Print status */ + LOCALDISPLAYUPDATE(displayLevel, 2, "\r%u%% ", + (unsigned)((iteration * 100) / kIterations)); + ++iteration; + } + COVER_best_wait(&best); + FASTCOVER_ctx_destroy(&ctx); + } + LOCALDISPLAYLEVEL(displayLevel, 2, "\r%79s\r", ""); + /* Fill the output buffer and parameters with output of the best parameters */ + { + const size_t dictSize = best.dictSize; + if (ZSTD_isError(best.compressedSize)) { + const size_t compressedSize = best.compressedSize; + COVER_best_destroy(&best); + POOL_free(pool); + return compressedSize; + } + FASTCOVER_convertToFastCoverParams(best.parameters, parameters, f, accel); + memcpy(dictBuffer, best.dict, dictSize); + COVER_best_destroy(&best); + POOL_free(pool); + return dictSize; + } + +} |