diff options
Diffstat (limited to 'lib/compress/hist.c')
| -rw-r--r-- | lib/compress/hist.c | 30 |
1 files changed, 19 insertions, 11 deletions
diff --git a/lib/compress/hist.c b/lib/compress/hist.c index 16524756b8dc..45b7babc1e23 100644 --- a/lib/compress/hist.c +++ b/lib/compress/hist.c @@ -73,6 +73,7 @@ unsigned HIST_count_simple(unsigned* count, unsigned* maxSymbolValuePtr, return largestCount; } +typedef enum { trustInput, checkMaxSymbolValue } HIST_checkInput_e; /* HIST_count_parallel_wksp() : * store histogram into 4 intermediate tables, recombined at the end. @@ -85,8 +86,8 @@ unsigned HIST_count_simple(unsigned* count, unsigned* maxSymbolValuePtr, static size_t HIST_count_parallel_wksp( unsigned* count, unsigned* maxSymbolValuePtr, const void* source, size_t sourceSize, - unsigned checkMax, - unsigned* const workSpace) + HIST_checkInput_e check, + U32* const workSpace) { const BYTE* ip = (const BYTE*)source; const BYTE* const iend = ip+sourceSize; @@ -137,7 +138,7 @@ static size_t HIST_count_parallel_wksp( /* finish last symbols */ while (ip<iend) Counting1[*ip++]++; - if (checkMax) { /* verify stats will fit into destination table */ + if (check) { /* verify stats will fit into destination table */ U32 s; for (s=255; s>maxSymbolValue; s--) { Counting1[s] += Counting2[s] + Counting3[s] + Counting4[s]; if (Counting1[s]) return ERROR(maxSymbolValue_tooSmall); @@ -157,14 +158,18 @@ static size_t HIST_count_parallel_wksp( /* HIST_countFast_wksp() : * Same as HIST_countFast(), but using an externally provided scratch buffer. - * `workSpace` size must be table of >= HIST_WKSP_SIZE_U32 unsigned */ + * `workSpace` is a writable buffer which must be 4-bytes aligned, + * `workSpaceSize` must be >= HIST_WKSP_SIZE + */ size_t HIST_countFast_wksp(unsigned* count, unsigned* maxSymbolValuePtr, const void* source, size_t sourceSize, - unsigned* workSpace) + void* workSpace, size_t workSpaceSize) { if (sourceSize < 1500) /* heuristic threshold */ return HIST_count_simple(count, maxSymbolValuePtr, source, sourceSize); - return HIST_count_parallel_wksp(count, maxSymbolValuePtr, source, sourceSize, 0, workSpace); + if ((size_t)workSpace & 3) return ERROR(GENERIC); /* must be aligned on 4-bytes boundaries */ + if (workSpaceSize < HIST_WKSP_SIZE) return ERROR(workSpace_tooSmall); + return HIST_count_parallel_wksp(count, maxSymbolValuePtr, source, sourceSize, trustInput, (U32*)workSpace); } /* fast variant (unsafe : won't check if src contains values beyond count[] limit) */ @@ -172,24 +177,27 @@ size_t HIST_countFast(unsigned* count, unsigned* maxSymbolValuePtr, const void* source, size_t sourceSize) { unsigned tmpCounters[HIST_WKSP_SIZE_U32]; - return HIST_countFast_wksp(count, maxSymbolValuePtr, source, sourceSize, tmpCounters); + return HIST_countFast_wksp(count, maxSymbolValuePtr, source, sourceSize, tmpCounters, sizeof(tmpCounters)); } /* HIST_count_wksp() : * Same as HIST_count(), but using an externally provided scratch buffer. * `workSpace` size must be table of >= HIST_WKSP_SIZE_U32 unsigned */ size_t HIST_count_wksp(unsigned* count, unsigned* maxSymbolValuePtr, - const void* source, size_t sourceSize, unsigned* workSpace) + const void* source, size_t sourceSize, + void* workSpace, size_t workSpaceSize) { + if ((size_t)workSpace & 3) return ERROR(GENERIC); /* must be aligned on 4-bytes boundaries */ + if (workSpaceSize < HIST_WKSP_SIZE) return ERROR(workSpace_tooSmall); if (*maxSymbolValuePtr < 255) - return HIST_count_parallel_wksp(count, maxSymbolValuePtr, source, sourceSize, 1, workSpace); + return HIST_count_parallel_wksp(count, maxSymbolValuePtr, source, sourceSize, checkMaxSymbolValue, (U32*)workSpace); *maxSymbolValuePtr = 255; - return HIST_countFast_wksp(count, maxSymbolValuePtr, source, sourceSize, workSpace); + return HIST_countFast_wksp(count, maxSymbolValuePtr, source, sourceSize, workSpace, workSpaceSize); } size_t HIST_count(unsigned* count, unsigned* maxSymbolValuePtr, const void* src, size_t srcSize) { unsigned tmpCounters[HIST_WKSP_SIZE_U32]; - return HIST_count_wksp(count, maxSymbolValuePtr, src, srcSize, tmpCounters); + return HIST_count_wksp(count, maxSymbolValuePtr, src, srcSize, tmpCounters, sizeof(tmpCounters)); } |