1 #include <stdio.h> /* fprintf */ 2 #include <stdlib.h> /* malloc, free, qsort */ 3 #include <string.h> /* memset */ 4 #include <time.h> /* clock */ 5 #include "mem.h" /* read */ 6 #include "pool.h" 7 #include "threading.h" 8 #include "zstd_internal.h" /* includes zstd.h */ 9 #ifndef ZDICT_STATIC_LINKING_ONLY 10 #define ZDICT_STATIC_LINKING_ONLY 11 #endif 12 #include "zdict.h" 13 14 /** 15 * COVER_best_t is used for two purposes: 16 * 1. Synchronizing threads. 17 * 2. Saving the best parameters and dictionary. 18 * 19 * All of the methods except COVER_best_init() are thread safe if zstd is 20 * compiled with multithreaded support. 21 */ 22 typedef struct COVER_best_s { 23 ZSTD_pthread_mutex_t mutex; 24 ZSTD_pthread_cond_t cond; 25 size_t liveJobs; 26 void *dict; 27 size_t dictSize; 28 ZDICT_cover_params_t parameters; 29 size_t compressedSize; 30 } COVER_best_t; 31 32 /** 33 * A segment is a range in the source as well as the score of the segment. 34 */ 35 typedef struct { 36 U32 begin; 37 U32 end; 38 U32 score; 39 } COVER_segment_t; 40 41 /** 42 *Number of epochs and size of each epoch. 43 */ 44 typedef struct { 45 U32 num; 46 U32 size; 47 } COVER_epoch_info_t; 48 49 /** 50 * Computes the number of epochs and the size of each epoch. 51 * We will make sure that each epoch gets at least 10 * k bytes. 52 * 53 * The COVER algorithms divide the data up into epochs of equal size and 54 * select one segment from each epoch. 55 * 56 * @param maxDictSize The maximum allowed dictionary size. 57 * @param nbDmers The number of dmers we are training on. 58 * @param k The parameter k (segment size). 59 * @param passes The target number of passes over the dmer corpus. 60 * More passes means a better dictionary. 61 */ 62 COVER_epoch_info_t COVER_computeEpochs(U32 maxDictSize, U32 nbDmers, 63 U32 k, U32 passes); 64 65 /** 66 * Warns the user when their corpus is too small. 67 */ 68 void COVER_warnOnSmallCorpus(size_t maxDictSize, size_t nbDmers, int displayLevel); 69 70 /** 71 * Checks total compressed size of a dictionary 72 */ 73 size_t COVER_checkTotalCompressedSize(const ZDICT_cover_params_t parameters, 74 const size_t *samplesSizes, const BYTE *samples, 75 size_t *offsets, 76 size_t nbTrainSamples, size_t nbSamples, 77 BYTE *const dict, size_t dictBufferCapacity); 78 79 /** 80 * Returns the sum of the sample sizes. 81 */ 82 size_t COVER_sum(const size_t *samplesSizes, unsigned nbSamples) ; 83 84 /** 85 * Initialize the `COVER_best_t`. 86 */ 87 void COVER_best_init(COVER_best_t *best); 88 89 /** 90 * Wait until liveJobs == 0. 91 */ 92 void COVER_best_wait(COVER_best_t *best); 93 94 /** 95 * Call COVER_best_wait() and then destroy the COVER_best_t. 96 */ 97 void COVER_best_destroy(COVER_best_t *best); 98 99 /** 100 * Called when a thread is about to be launched. 101 * Increments liveJobs. 102 */ 103 void COVER_best_start(COVER_best_t *best); 104 105 /** 106 * Called when a thread finishes executing, both on error or success. 107 * Decrements liveJobs and signals any waiting threads if liveJobs == 0. 108 * If this dictionary is the best so far save it and its parameters. 109 */ 110 void COVER_best_finish(COVER_best_t *best, size_t compressedSize, 111 ZDICT_cover_params_t parameters, void *dict, 112 size_t dictSize); 113