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Merge pull request #3302 from daniellerozenblit/optimal-huff-depth-speed

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Optimal huff depth speed improvements
This commit is contained in:
daniellerozenblit
2023-01-03 12:51:51 -05:00
committed by GitHub
parent 3248910432 87becc567d
commit 1c818e3a0a
2 changed files with 27 additions and 20 deletions
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lib/compress/huf_compress.c
+17 -10
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@@ -1261,28 +1261,35 @@ unsigned HUF_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxS
if (depthMode == HUF_depth_optimal) { /** Test valid depths and return optimal **/
BYTE* dst = (BYTE*)workSpace + sizeof(HUF_WriteCTableWksp);
size_t dstSize = wkspSize - sizeof(HUF_WriteCTableWksp);
size_t optSize = ((size_t) ~0);
unsigned huffLog;
size_t maxBits, hSize, newSize;
const unsigned symbolCardinality = HUF_cardinality(count, maxSymbolValue);
const unsigned minTableLog = HUF_minTableLog(symbolCardinality);
size_t optSize = ((size_t) ~0) - 1;
unsigned optLogGuess;
if (wkspSize < sizeof(HUF_buildCTable_wksp_tables)) return optLog;
if (wkspSize < sizeof(HUF_buildCTable_wksp_tables)) return optLog; /** Assert workspace is large enough **/
/* Search until size increases */
for (optLogGuess = minTableLog; optLogGuess <= maxTableLog; optLogGuess++) {
maxBits = HUF_buildCTable_wksp(table, count, maxSymbolValue, optLogGuess, workSpace, wkspSize);
for (huffLog = HUF_minTableLog(symbolCardinality); huffLog <= maxTableLog; huffLog++) {
maxBits = HUF_buildCTable_wksp(table, count,
maxSymbolValue, huffLog,
workSpace, wkspSize);
if (ERR_isError(maxBits)) continue;
hSize = HUF_writeCTable_wksp(dst, dstSize, table, maxSymbolValue, (U32)maxBits,
workSpace, wkspSize);
if (maxBits < optLogGuess && optLogGuess > minTableLog) break;
hSize = HUF_writeCTable_wksp(dst, dstSize, table, maxSymbolValue, (U32)maxBits, workSpace, wkspSize);
if (ERR_isError(hSize)) continue;
newSize = HUF_estimateCompressedSize(table, count, maxSymbolValue) + hSize;
if (newSize > optSize + 1) {
break;
}
if (newSize < optSize) {
optSize = newSize;
optLog = huffLog;
optLog = optLogGuess;
}
}
}