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Fix : size estimation when some samples are very large

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This commit is contained in:
Yann Collet 2016-12-18 11:58:23 +01:00
parent 36321d2e32
commit 1496c3dc47
2 changed files with 26 additions and 5 deletions
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2
lib/dictBuilder/zdict.c
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@ -569,7 +569,7 @@ static void ZDICT_countEStats(EStats_ress_t esr, ZSTD_parameters params,
if (ZSTD_isError(errorCode)) { DISPLAYLEVEL(1, "warning : ZSTD_copyCCtx failed \n"); return; }
}
cSize = ZSTD_compressBlock(esr.zc, esr.workPlace, ZSTD_BLOCKSIZE_ABSOLUTEMAX, src, srcSize);
if (ZSTD_isError(cSize)) { DISPLAYLEVEL(1, "warning : could not compress sample size %u \n", (U32)srcSize); return; }
if (ZSTD_isError(cSize)) { DISPLAYLEVEL(3, "warning : could not compress sample size %u \n", (U32)srcSize); return; }
if (cSize) { /* if == 0; block is not compressible */
const seqStore_t* seqStorePtr = ZSTD_getSeqStore(esr.zc);

29
programs/dibio.c
View File

@ -31,7 +31,8 @@
#define MB *(1 <<20)
#define GB *(1U<<30)
#define MEMMULT 11
#define SAMPLESIZE_MAX (128 KB)
#define MEMMULT 11 /* rough estimation : memory cost to analyze 1 byte of sample */
static const size_t maxMemory = (sizeof(size_t) == 4) ? (2 GB - 64 MB) : ((size_t)(512 MB) << sizeof(size_t));
#define NOISELENGTH 32
@ -97,7 +98,7 @@ static unsigned DiB_loadFiles(void* buffer, size_t* bufferSizePtr,
for (n=0; n<nbFiles; n++) {
const char* const fileName = fileNamesTable[n];
unsigned long long const fs64 = UTIL_getFileSize(fileName);
size_t const fileSize = (size_t) MIN(fs64, 128 KB);
size_t const fileSize = (size_t) MIN(fs64, SAMPLESIZE_MAX);
if (fileSize > *bufferSizePtr-pos) break;
{ FILE* const f = fopen(fileName, "rb");
if (f==NULL) EXM_THROW(10, "zstd: dictBuilder: %s %s ", fileName, strerror(errno));
@ -163,6 +164,21 @@ static void DiB_saveDict(const char* dictFileName,
}
static int g_tooLargeSamples = 0;
static U64 DiB_getTotalCappedFileSize(const char** fileNamesTable, unsigned nbFiles)
{
U64 total = 0;
unsigned n;
for (n=0; n<nbFiles; n++) {
U64 const fileSize = UTIL_getFileSize(fileNamesTable[n]);
U64 const cappedFileSize = MIN(fileSize, SAMPLESIZE_MAX);
total += cappedFileSize;
g_tooLargeSamples |= (fileSize > 2*SAMPLESIZE_MAX);
}
return total;
}
/*! ZDICT_trainFromBuffer_unsafe() :
Strictly Internal use only !!
Same as ZDICT_trainFromBuffer_advanced(), but does not control `samplesBuffer`.
@ -181,7 +197,7 @@ int DiB_trainFromFiles(const char* dictFileName, unsigned maxDictSize,
{
void* const dictBuffer = malloc(maxDictSize);
size_t* const fileSizes = (size_t*)malloc(nbFiles * sizeof(size_t));
unsigned long long const totalSizeToLoad = UTIL_getTotalFileSize(fileNamesTable, nbFiles);
unsigned long long const totalSizeToLoad = DiB_getTotalCappedFileSize(fileNamesTable, nbFiles);
size_t const maxMem = DiB_findMaxMem(totalSizeToLoad * MEMMULT) / MEMMULT;
size_t benchedSize = (size_t) MIN ((unsigned long long)maxMem, totalSizeToLoad);
void* const srcBuffer = malloc(benchedSize+NOISELENGTH);
@ -190,7 +206,12 @@ int DiB_trainFromFiles(const char* dictFileName, unsigned maxDictSize,
/* Checks */
if ((!fileSizes) || (!srcBuffer) || (!dictBuffer)) EXM_THROW(12, "not enough memory for DiB_trainFiles"); /* should not happen */
g_displayLevel = params.notificationLevel;
if (nbFiles < 5) {
if (g_tooLargeSamples) {
DISPLAYLEVEL(2, "! Warning : some samples are very large \n");
DISPLAYLEVEL(2, "! Note that dictionary is only useful for small files or beginning of large files. \n");
DISPLAYLEVEL(2, "! As a consequence, only the first %u bytes of each file are loaded \n", SAMPLESIZE_MAX);
}
if ((nbFiles < 5) || (totalSizeToLoad < 9 * (unsigned long long)maxDictSize)) {
DISPLAYLEVEL(2, "! Warning : nb of samples too low for proper processing ! \n");
DISPLAYLEVEL(2, "! Please provide _one file per sample_. \n");
DISPLAYLEVEL(2, "! Do not concatenate samples together into a single file, \n");