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Merge pull request #1025 from facebook/huf

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Huf
This commit is contained in:
Yann Collet
2018-02-27 09:57:01 -08:00
committed by GitHub
parent d18d43aaf9 33a3f18848
commit 2c4d3f339a
5 changed files with 87 additions and 59 deletions
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lib/compress/huf_compress.c
+68 -44
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@@ -335,10 +335,10 @@ static void HUF_sort(nodeElt* huffNode, const U32* count, U32 maxSymbolValue)
/** HUF_buildCTable_wksp() :
* Same as HUF_buildCTable(), but using externally allocated scratch buffer.
* `workSpace` must be aligned on 4-bytes boundaries, and be at least as large as a table of 1024 unsigned.
* `workSpace` must be aligned on 4-bytes boundaries, and be at least as large as a table of HUF_CTABLE_WORKSPACE_SIZE_U32 unsigned.
*/
#define STARTNODE (HUF_SYMBOLVALUE_MAX+1)
typedef nodeElt huffNodeTable[2*HUF_SYMBOLVALUE_MAX+1 +1];
typedef nodeElt huffNodeTable[HUF_CTABLE_WORKSPACE_SIZE_U32];
size_t HUF_buildCTable_wksp (HUF_CElt* tree, const U32* count, U32 maxSymbolValue, U32 maxNbBits, void* workSpace, size_t wkspSize)
{
nodeElt* const huffNode0 = (nodeElt*)workSpace;
@@ -349,9 +349,10 @@ size_t HUF_buildCTable_wksp (HUF_CElt* tree, const U32* count, U32 maxSymbolValu
U32 nodeRoot;
/* safety checks */
if (wkspSize < sizeof(huffNodeTable)) return ERROR(GENERIC); /* workSpace is not large enough */
if (((size_t)workSpace & 3) != 0) return ERROR(GENERIC); /* must be aligned on 4-bytes boundaries */
if (wkspSize < sizeof(huffNodeTable)) return ERROR(workSpace_tooSmall);
if (maxNbBits == 0) maxNbBits = HUF_TABLELOG_DEFAULT;
if (maxSymbolValue > HUF_SYMBOLVALUE_MAX) return ERROR(GENERIC);
if (maxSymbolValue > HUF_SYMBOLVALUE_MAX) return ERROR(maxSymbolValue_tooLarge);
memset(huffNode0, 0, sizeof(huffNodeTable));
/* sort, decreasing order */
@@ -508,8 +509,14 @@ static size_t HUF_compressCTable_internal(
return op-ostart;
}
typedef struct {
U32 count[HUF_SYMBOLVALUE_MAX + 1];
HUF_CElt CTable[HUF_SYMBOLVALUE_MAX + 1];
huffNodeTable nodeTable;
} HUF_compress_tables_t;
/* `workSpace` must a table of at least 1024 unsigned */
/* HUF_compress_internal() :
* `workSpace` must a table of at least HUF_WORKSPACE_SIZE_U32 unsigned */
static size_t HUF_compress_internal (
void* dst, size_t dstSize,
const void* src, size_t srcSize,
@@ -519,76 +526,81 @@ static size_t HUF_compress_internal (
HUF_CElt* oldHufTable, HUF_repeat* repeat, int preferRepeat,
const int bmi2)
{
HUF_compress_tables_t* const table = (HUF_compress_tables_t*)workSpace;
BYTE* const ostart = (BYTE*)dst;
BYTE* const oend = ostart + dstSize;
BYTE* op = ostart;
U32* count;
size_t const countSize = sizeof(U32) * (HUF_SYMBOLVALUE_MAX + 1);
HUF_CElt* CTable;
size_t const CTableSize = sizeof(HUF_CElt) * (HUF_SYMBOLVALUE_MAX + 1);
/* checks & inits */
if (wkspSize < sizeof(huffNodeTable) + countSize + CTableSize) return ERROR(GENERIC);
if (!srcSize) return 0; /* Uncompressed (note : 1 means rle, so first byte must be correct) */
if (!dstSize) return 0; /* cannot fit within dst budget */
if (((size_t)workSpace & 3) != 0) return ERROR(GENERIC); /* must be aligned on 4-bytes boundaries */
if (wkspSize < sizeof(*table)) return ERROR(workSpace_tooSmall);
if (!srcSize) return 0; /* Uncompressed */
if (!dstSize) return 0; /* cannot fit anything within dst budget */
if (srcSize > HUF_BLOCKSIZE_MAX) return ERROR(srcSize_wrong); /* current block size limit */
if (huffLog > HUF_TABLELOG_MAX) return ERROR(tableLog_tooLarge);
if (maxSymbolValue > HUF_SYMBOLVALUE_MAX) return ERROR(maxSymbolValue_tooLarge);
if (!maxSymbolValue) maxSymbolValue = HUF_SYMBOLVALUE_MAX;
if (!huffLog) huffLog = HUF_TABLELOG_DEFAULT;
count = (U32*)workSpace;
workSpace = (BYTE*)workSpace + countSize;
wkspSize -= countSize;
CTable = (HUF_CElt*)workSpace;
workSpace = (BYTE*)workSpace + CTableSize;
wkspSize -= CTableSize;
/* Heuristic : If we don't need to check the validity of the old table use the old table for small inputs */
/* Heuristic : If old table is valid, use it for small inputs */
if (preferRepeat && repeat && *repeat == HUF_repeat_valid) {
return HUF_compressCTable_internal(ostart, op, oend, src, srcSize, singleStream, oldHufTable, bmi2);
return HUF_compressCTable_internal(ostart, op, oend,
src, srcSize,
singleStream, oldHufTable, bmi2);
}
/* Scan input and build symbol stats */
{ CHECK_V_F(largest, FSE_count_wksp (count, &maxSymbolValue, (const BYTE*)src, srcSize, (U32*)workSpace) );
{ CHECK_V_F(largest, FSE_count_wksp (table->count, &maxSymbolValue, (const BYTE*)src, srcSize, table->count) );
if (largest == srcSize) { *ostart = ((const BYTE*)src)[0]; return 1; } /* single symbol, rle */
if (largest <= (srcSize >> 7)+1) return 0; /* Fast heuristic : not compressible enough */
if (largest <= (srcSize >> 7)+1) return 0; /* heuristic : probably not compressible enough */
}
/* Check validity of previous table */
if (repeat && *repeat == HUF_repeat_check && !HUF_validateCTable(oldHufTable, count, maxSymbolValue)) {
if ( repeat
&& *repeat == HUF_repeat_check
&& !HUF_validateCTable(oldHufTable, table->count, maxSymbolValue)) {
*repeat = HUF_repeat_none;
}
/* Heuristic : use existing table for small inputs */
if (preferRepeat && repeat && *repeat != HUF_repeat_none) {
return HUF_compressCTable_internal(ostart, op, oend, src, srcSize, singleStream, oldHufTable, bmi2);
return HUF_compressCTable_internal(ostart, op, oend,
src, srcSize,
singleStream, oldHufTable, bmi2);
}
/* Build Huffman Tree */
huffLog = HUF_optimalTableLog(huffLog, srcSize, maxSymbolValue);
{ CHECK_V_F(maxBits, HUF_buildCTable_wksp (CTable, count, maxSymbolValue, huffLog, workSpace, wkspSize) );
{ CHECK_V_F(maxBits, HUF_buildCTable_wksp(table->CTable, table->count,
maxSymbolValue, huffLog,
table->nodeTable, sizeof(table->nodeTable)) );
huffLog = (U32)maxBits;
/* Zero the unused symbols so we can check it for validity */
memset(CTable + maxSymbolValue + 1, 0, CTableSize - (maxSymbolValue + 1) * sizeof(HUF_CElt));
/* Zero unused symbols in CTable, so we can check it for validity */
memset(table->CTable + (maxSymbolValue + 1), 0,
sizeof(table->CTable) - ((maxSymbolValue + 1) * sizeof(HUF_CElt)));
}
/* Write table description header */
{ CHECK_V_F(hSize, HUF_writeCTable (op, dstSize, CTable, maxSymbolValue, huffLog) );
/* Check if using the previous table will be beneficial */
{ CHECK_V_F(hSize, HUF_writeCTable (op, dstSize, table->CTable, maxSymbolValue, huffLog) );
/* Check if using previous huffman table is beneficial */
if (repeat && *repeat != HUF_repeat_none) {
size_t const oldSize = HUF_estimateCompressedSize(oldHufTable, count, maxSymbolValue);
size_t const newSize = HUF_estimateCompressedSize(CTable, count, maxSymbolValue);
size_t const oldSize = HUF_estimateCompressedSize(oldHufTable, table->count, maxSymbolValue);
size_t const newSize = HUF_estimateCompressedSize(table->CTable, table->count, maxSymbolValue);
if (oldSize <= hSize + newSize || hSize + 12 >= srcSize) {
return HUF_compressCTable_internal(ostart, op, oend, src, srcSize, singleStream, oldHufTable, bmi2);
}
}
/* Use the new table */
return HUF_compressCTable_internal(ostart, op, oend,
src, srcSize,
singleStream, oldHufTable, bmi2);
} }
/* Use the new huffman table */
if (hSize + 12ul >= srcSize) { return 0; }
op += hSize;
if (repeat) { *repeat = HUF_repeat_none; }
if (oldHufTable) { memcpy(oldHufTable, CTable, CTableSize); } /* Save the new table */
if (oldHufTable)
memcpy(oldHufTable, table->CTable, sizeof(table->CTable)); /* Save new table */
}
return HUF_compressCTable_internal(ostart, op, oend, src, srcSize, singleStream, CTable, bmi2);
return HUF_compressCTable_internal(ostart, op, oend,
src, srcSize,
singleStream, table->CTable, bmi2);
}
@@ -597,7 +609,10 @@ size_t HUF_compress1X_wksp (void* dst, size_t dstSize,
unsigned maxSymbolValue, unsigned huffLog,
void* workSpace, size_t wkspSize)
{
return HUF_compress_internal(dst, dstSize, src, srcSize, maxSymbolValue, huffLog, 1 /* single stream */, workSpace, wkspSize, NULL, NULL, 0, /* bmi2 */ 0);
return HUF_compress_internal(dst, dstSize, src, srcSize,
maxSymbolValue, huffLog, 1 /*single stream*/,
workSpace, wkspSize,
NULL, NULL, 0, 0 /*bmi2*/);
}
size_t HUF_compress1X_repeat (void* dst, size_t dstSize,
@@ -606,7 +621,10 @@ size_t HUF_compress1X_repeat (void* dst, size_t dstSize,
void* workSpace, size_t wkspSize,
HUF_CElt* hufTable, HUF_repeat* repeat, int preferRepeat, int bmi2)
{
return HUF_compress_internal(dst, dstSize, src, srcSize, maxSymbolValue, huffLog, 1 /* single stream */, workSpace, wkspSize, hufTable, repeat, preferRepeat, bmi2);
return HUF_compress_internal(dst, dstSize, src, srcSize,
maxSymbolValue, huffLog, 1 /*single stream*/,
workSpace, wkspSize, hufTable,
repeat, preferRepeat, bmi2);
}
size_t HUF_compress1X (void* dst, size_t dstSize,
@@ -625,7 +643,10 @@ size_t HUF_compress4X_wksp (void* dst, size_t dstSize,
unsigned maxSymbolValue, unsigned huffLog,
void* workSpace, size_t wkspSize)
{
return HUF_compress_internal(dst, dstSize, src, srcSize, maxSymbolValue, huffLog, 0 /* 4 streams */, workSpace, wkspSize, NULL, NULL, 0, /* bmi2 */ 0);
return HUF_compress_internal(dst, dstSize, src, srcSize,
maxSymbolValue, huffLog, 0 /*4 streams*/,
workSpace, wkspSize,
NULL, NULL, 0, 0 /*bmi2*/);
}
/* HUF_compress4X_repeat():
@@ -637,7 +658,10 @@ size_t HUF_compress4X_repeat (void* dst, size_t dstSize,
void* workSpace, size_t wkspSize,
HUF_CElt* hufTable, HUF_repeat* repeat, int preferRepeat, int bmi2)
{
return HUF_compress_internal(dst, dstSize, src, srcSize, maxSymbolValue, huffLog, 0 /* 4 streams */, workSpace, wkspSize, hufTable, repeat, preferRepeat, bmi2);
return HUF_compress_internal(dst, dstSize, src, srcSize,
maxSymbolValue, huffLog, 0 /* 4 streams */,
workSpace, wkspSize,
hufTable, repeat, preferRepeat, bmi2);
}
size_t HUF_compress2 (void* dst, size_t dstSize,
@@ -650,5 +674,5 @@ size_t HUF_compress2 (void* dst, size_t dstSize,
size_t HUF_compress (void* dst, size_t maxDstSize, const void* src, size_t srcSize)
{
return HUF_compress2(dst, maxDstSize, src, (U32)srcSize, 255, HUF_TABLELOG_DEFAULT);
return HUF_compress2(dst, maxDstSize, src, srcSize, 255, HUF_TABLELOG_DEFAULT);
}