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improved dictbuilder notifications on selectivity

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This commit is contained in:
Yann Collet 2016-07-27 13:28:46 +02:00
parent f796f7ab45
commit 07626dfa51
1 changed files with 17 additions and 13 deletions
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30
lib/dictBuilder/zdict.c
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@ -489,14 +489,13 @@ static U32 ZDICT_dictSize(const dictItem* dictList)
static size_t ZDICT_trainBuffer(dictItem* dictList, U32 dictListSize,
const void* const buffer, size_t bufferSize, /* buffer must end with noisy guard band */
const size_t* fileSizes, unsigned nbFiles,
U32 shiftRatio)
U32 minRatio)
{
int* const suffix0 = (int*)malloc((bufferSize+2)*sizeof(*suffix0));
int* const suffix = suffix0+1;
U32* reverseSuffix = (U32*)malloc((bufferSize)*sizeof(*reverseSuffix));
BYTE* doneMarks = (BYTE*)malloc((bufferSize+16)*sizeof(*doneMarks)); /* +16 for overflow security */
U32* filePos = (U32*)malloc(nbFiles * sizeof(*filePos));
U32 minRatio = nbFiles >> shiftRatio;
size_t result = 0;
/* init */
@ -877,7 +876,8 @@ size_t ZDICT_trainFromBuffer_unsafe(
{
U32 const dictListSize = MAX(MAX(DICTLISTSIZE, nbSamples), (U32)(maxDictSize/16));
dictItem* const dictList = (dictItem*)malloc(dictListSize * sizeof(*dictList));
unsigned selectivity = params.selectivityLevel;
unsigned const selectivity = params.selectivityLevel == 0 ? g_selectivity_default : params.selectivityLevel;
unsigned const minRep = nbSamples >> selectivity;
size_t const targetDictSize = maxDictSize;
size_t const samplesBuffSize = ZDICT_totalSampleSize(samplesSizes, nbSamples);
size_t dictSize = 0;
@ -890,13 +890,12 @@ size_t ZDICT_trainFromBuffer_unsafe(
/* init */
ZDICT_initDictItem(dictList);
g_displayLevel = params.notificationLevel;
if (selectivity==0) selectivity = g_selectivity_default;
/* build dictionary */
ZDICT_trainBuffer(dictList, dictListSize,
samplesBuffer, samplesBuffSize,
samplesSizes, nbSamples,
selectivity);
minRep);
/* display best matches */
if (g_displayLevel>= 3) {
@ -920,16 +919,20 @@ size_t ZDICT_trainFromBuffer_unsafe(
{ U32 dictContentSize = ZDICT_dictSize(dictList);
if (dictContentSize < targetDictSize/2) {
DISPLAYLEVEL(2, "! warning : created dictionary significantly smaller than requested (%u < %u) \n", dictContentSize, (U32)maxDictSize);
DISPLAYLEVEL(2, "! consider increasing selectivity to produce larger dictionary (-s%u) \n", selectivity+1);
DISPLAYLEVEL(2, "! note : larger dictionaries are not necessarily better, test its efficiency on samples \n");
if (minRep > MINRATIO) {
DISPLAYLEVEL(2, "! consider increasing selectivity to produce larger dictionary (-s%u) \n", selectivity+1);
DISPLAYLEVEL(2, "! note : larger dictionaries are not necessarily better, test its efficiency on samples \n");
}
if (samplesBuffSize < 10 * targetDictSize)
DISPLAYLEVEL(2, "! consider also increasing the number of samples (total size : %u MB)\n", (U32)(samplesBuffSize>>20));
DISPLAYLEVEL(2, "! consider increasing the number of samples (total size : %u MB)\n", (U32)(samplesBuffSize>>20));
}
if (dictContentSize > targetDictSize*2) {
DISPLAYLEVEL(2, "! warning : calculated dictionary significantly larger than requested (%u > %u) \n", dictContentSize, (U32)maxDictSize);
DISPLAYLEVEL(2, "! consider decreasing selectivity to produce denser dictionary (-s%u) \n", selectivity-1);
DISPLAYLEVEL(2, "! test its efficiency on samples \n");
if ((dictContentSize > targetDictSize*2) && (nbSamples > 2*MINRATIO) && (selectivity>1)) {
U32 proposedSelectivity = selectivity-1;
while ((nbSamples >> proposedSelectivity) <= MINRATIO) { proposedSelectivity--; }
DISPLAYLEVEL(2, "! note : calculated dictionary significantly larger than requested (%u > %u) \n", dictContentSize, (U32)maxDictSize);
DISPLAYLEVEL(2, "! you may consider decreasing selectivity to produce denser dictionary (-s%u) \n", proposedSelectivity);
DISPLAYLEVEL(2, "! but test its efficiency on samples \n");
}
/* limit dictionary size */
@ -937,9 +940,10 @@ size_t ZDICT_trainFromBuffer_unsafe(
U32 currentSize = 0;
U32 n; for (n=1; n<max; n++) {
currentSize += dictList[n].length;
if (currentSize > targetDictSize) break;
if (currentSize > targetDictSize) { currentSize -= dictList[n].length; break; }
}
dictList->pos = n;
dictContentSize = currentSize;
}
/* build dict content */