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minor : added assert in bt

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This commit is contained in:
Yann Collet 2017-09-16 23:40:14 -07:00
parent 4a52a89026
commit 539b91ee9b
1 changed files with 8 additions and 6 deletions
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14
lib/compress/zstd_lazy.c
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@ -49,6 +49,7 @@ static U32 ZSTD_insertBt1(ZSTD_CCtx* zc, const BYTE* const ip, const U32 mls, co
predictedLarge += (predictedLarge>0); predictedLarge += (predictedLarge>0);
#endif /* ZSTD_C_PREDICT */ #endif /* ZSTD_C_PREDICT */
assert(ip <= iend-8); /* required for h calculation */
hashTable[h] = current; /* Update Hash Table */ hashTable[h] = current; /* Update Hash Table */
while (nbCompares-- && (matchIndex > windowLow)) { while (nbCompares-- && (matchIndex > windowLow)) {
@ -93,27 +94,27 @@ static U32 ZSTD_insertBt1(ZSTD_CCtx* zc, const BYTE* const ip, const U32 mls, co
} }
if (ip+matchLength == iend) /* equal : no way to know if inf or sup */ if (ip+matchLength == iend) /* equal : no way to know if inf or sup */
break; /* drop , to guarantee consistency ; miss a bit of compression, but other solutions can corrupt the tree */ break; /* drop , to guarantee consistency ; miss a bit of compression, but other solutions can corrupt tree */
if (match[matchLength] < ip[matchLength]) { /* necessarily within correct buffer */ if (match[matchLength] < ip[matchLength]) { /* necessarily within buffer */
/* match is smaller than current */ /* match+1 is smaller than current */
*smallerPtr = matchIndex; /* update smaller idx */ *smallerPtr = matchIndex; /* update smaller idx */
commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */ commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */
if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop the search */ if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop searching */
smallerPtr = nextPtr+1; /* new "smaller" => larger of match */ smallerPtr = nextPtr+1; /* new "smaller" => larger of match */
matchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */ matchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to current) */
} else { } else {
/* match is larger than current */ /* match is larger than current */
*largerPtr = matchIndex; *largerPtr = matchIndex;
commonLengthLarger = matchLength; commonLengthLarger = matchLength;
if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop the search */ if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop searching */
largerPtr = nextPtr; largerPtr = nextPtr;
matchIndex = nextPtr[0]; matchIndex = nextPtr[0];
} } } }
*smallerPtr = *largerPtr = 0; *smallerPtr = *largerPtr = 0;
if (bestLength > 384) return MIN(192, (U32)(bestLength - 384)); /* speed optimization */ if (bestLength > 384) return MIN(192, (U32)(bestLength - 384)); /* speed optimization */
if (matchEndIdx > current + 8) return matchEndIdx - current - 8; if (matchEndIdx > current + 8) return matchEndIdx - (current + 8);
return 1; return 1;
} }
@ -147,6 +148,7 @@ static size_t ZSTD_insertBtAndFindBestMatch (
U32 dummy32; /* to be nullified at the end */ U32 dummy32; /* to be nullified at the end */
size_t bestLength = 0; size_t bestLength = 0;
assert(ip <= iend-8); /* required for h calculation */
hashTable[h] = current; /* Update Hash Table */ hashTable[h] = current; /* Update Hash Table */
while (nbCompares-- && (matchIndex > windowLow)) { while (nbCompares-- && (matchIndex > windowLow)) {