simplifications
diff --git a/lib/zstd_decompress.c b/lib/zstd_decompress.c
index 7a38bf9..d8d7837 100644
--- a/lib/zstd_decompress.c
+++ b/lib/zstd_decompress.c
@@ -508,6 +508,39 @@
}
+/*! ZSTD_buildSeqTable() :
+ @return : nb bytes read from src,
+ or an error code if it fails, testable with ZSTD_isError()
+*/
+static size_t ZSTD_buildSeqTable(FSE_DTable* DTable, U32 type, U32 rawBits, U32 maxLog,
+ const void* src, size_t srcSize)
+{
+ switch(type)
+ {
+ case FSE_ENCODING_RLE :
+ if (!srcSize) return ERROR(srcSize_wrong);
+ FSE_buildDTable_rle(DTable, *(const BYTE*)src);
+ return 1;
+ case FSE_ENCODING_RAW :
+ FSE_buildDTable_raw(DTable, rawBits);
+ return 0;
+ case FSE_ENCODING_STATIC:
+ return 0;
+ default : /* impossible */
+ case FSE_ENCODING_DYNAMIC :
+ { U32 tableLog, max = (1<<rawBits)-1;
+ S16 norm[MaxSeq+1];
+ size_t const headerSize = FSE_readNCount(norm, &max, &tableLog, src, srcSize);
+ if (FSE_isError(headerSize)) return ERROR(GENERIC);
+ if (tableLog > maxLog) return ERROR(corruption_detected);
+ FSE_buildDTable(DTable, norm, max, tableLog);
+ return headerSize;
+ } }
+}
+
+
+
+
size_t ZSTD_decodeSeqHeaders(int* nbSeq, const BYTE** dumpsPtr, size_t* dumpsLengthPtr,
FSE_DTable* DTableLL, FSE_DTable* DTableML, FSE_DTable* DTableOffb,
const void* src, size_t srcSize)
@@ -516,11 +549,9 @@
const BYTE* ip = istart;
const BYTE* const iend = istart + srcSize;
U32 LLtype, Offtype, MLtype;
- size_t dumpsLength;
/* check */
- if (srcSize < MIN_SEQUENCES_SIZE)
- return ERROR(srcSize_wrong);
+ if (srcSize < MIN_SEQUENCES_SIZE) return ERROR(srcSize_wrong);
/* SeqHead */
*nbSeq = *ip++;
@@ -536,91 +567,37 @@
LLtype = *ip >> 6;
Offtype = (*ip >> 4) & 3;
MLtype = (*ip >> 2) & 3;
- if (*ip & 2) {
- dumpsLength = ip[2];
- dumpsLength += ip[1] << 8;
- ip += 3;
- } else {
- dumpsLength = ip[1];
- dumpsLength += (ip[0] & 1) << 8;
- ip += 2;
+ { size_t dumpsLength;
+ if (*ip & 2) {
+ dumpsLength = ip[2];
+ dumpsLength += ip[1] << 8;
+ ip += 3;
+ } else {
+ dumpsLength = ip[1];
+ dumpsLength += (ip[0] & 1) << 8;
+ ip += 2;
+ }
+ *dumpsPtr = ip;
+ ip += dumpsLength;
+ *dumpsLengthPtr = dumpsLength;
}
- *dumpsPtr = ip;
- ip += dumpsLength;
- *dumpsLengthPtr = dumpsLength;
/* check */
if (ip > iend-3) return ERROR(srcSize_wrong); /* min : all 3 are "raw", hence no header, but at least xxLog bits per type */
/* Build DTables */
- {
- S16 norm[MaxML+1]; /* assumption : MaxML >= MaxLL >= MaxOff */
-
- switch(LLtype)
- {
- case FSE_ENCODING_RLE :
- FSE_buildDTable_rle(DTableLL, *ip++);
- break;
- case FSE_ENCODING_RAW :
- FSE_buildDTable_raw(DTableLL, LLbits);
- break;
- case FSE_ENCODING_STATIC:
- break;
- default : /* impossible */
- case FSE_ENCODING_DYNAMIC :
- { U32 LLlog, max = MaxLL;
- size_t const headerSize = FSE_readNCount(norm, &max, &LLlog, ip, iend-ip);
- if (FSE_isError(headerSize)) return ERROR(GENERIC);
- if (LLlog > LLFSELog) return ERROR(corruption_detected);
- ip += headerSize;
- FSE_buildDTable(DTableLL, norm, max, LLlog);
- }
- }
-
- switch(Offtype)
- {
- case FSE_ENCODING_RLE :
- if (ip > iend-2) return ERROR(srcSize_wrong); /* min : "raw", hence no header, but at least xxLog bits */
- FSE_buildDTable_rle(DTableOffb, *ip++ & MaxOff); /* if *ip > MaxOff, data is corrupted */
- break;
- case FSE_ENCODING_RAW :
- FSE_buildDTable_raw(DTableOffb, Offbits);
- break;
- case FSE_ENCODING_STATIC:
- break;
- default : /* impossible */
- case FSE_ENCODING_DYNAMIC :
- {
- U32 Offlog, max = MaxOff;
- size_t const headerSize = FSE_readNCount(norm, &max, &Offlog, ip, iend-ip);
- if (FSE_isError(headerSize)) return ERROR(GENERIC);
- if (Offlog > OffFSELog) return ERROR(corruption_detected);
- ip += headerSize;
- FSE_buildDTable(DTableOffb, norm, max, Offlog);
- }
- }
-
- switch(MLtype)
- {
- case FSE_ENCODING_RLE :
- if (ip > iend-2) return ERROR(srcSize_wrong); /* min : "raw", hence no header, but at least xxLog bits */
- FSE_buildDTable_rle(DTableML, *ip++);
- break;
- case FSE_ENCODING_RAW :
- FSE_buildDTable_raw(DTableML, MLbits);
- break;
- case FSE_ENCODING_STATIC:
- break;
- default : /* impossible */
- case FSE_ENCODING_DYNAMIC :
- { U32 MLlog, max = MaxML;
- size_t const headerSize = FSE_readNCount(norm, &max, &MLlog, ip, iend-ip);
- if (FSE_isError(headerSize)) return ERROR(GENERIC);
- if (MLlog > MLFSELog) return ERROR(corruption_detected);
- ip += headerSize;
- FSE_buildDTable(DTableML, norm, max, MLlog);
- }
- } } /* Build DTables */
+ { size_t const bhSize = ZSTD_buildSeqTable(DTableLL, LLtype, LLbits, LLFSELog, ip, iend-ip);
+ if (ZSTD_isError(bhSize)) return ERROR(corruption_detected);
+ ip += bhSize;
+ }
+ { size_t const bhSize = ZSTD_buildSeqTable(DTableOffb, Offtype, Offbits, OffFSELog, ip, iend-ip);
+ if (ZSTD_isError(bhSize)) return ERROR(corruption_detected);
+ ip += bhSize;
+ }
+ { size_t const bhSize = ZSTD_buildSeqTable(DTableML, MLtype, MLbits, MLFSELog, ip, iend-ip);
+ if (ZSTD_isError(bhSize)) return ERROR(corruption_detected);
+ ip += bhSize;
+ }
return ip-istart;
}