diff options
| -rw-r--r-- | lib/lz4.c | 45 |
1 files changed, 23 insertions, 22 deletions
@@ -546,7 +546,10 @@ LZ4_FORCE_INLINE void LZ4_resetTable( cctx->currentOffset = 0; cctx->tableType = unusedTable; } - if (dictDirective == usingExtDictCtx && cctx->currentOffset == 0) { + if (dictDirective == usingExtDictCtx && + tableType != byPtr && + cctx->currentOffset == 0) + { cctx->currentOffset = 1; } } @@ -842,11 +845,8 @@ int LZ4_compress_fast_safeExtState(void* state, const char* source, char* dest, } else { const tableType_t tableType = (sizeof(void*)==8) ? byU32 : byPtr; LZ4_resetTable(ctx, inputSize, tableType, noDict); - if (ctx->currentOffset) { - return LZ4_compress_generic(ctx, source, dest, inputSize, 0, notLimited, tableType, noDict, dictSmall, acceleration); - } else { - return LZ4_compress_generic(ctx, source, dest, inputSize, 0, notLimited, tableType, noDict, noDictIssue, acceleration); - } + ctx->currentOffset += 64 KB; + return LZ4_compress_generic(ctx, source, dest, inputSize, 0, notLimited, tableType, noDict, noDictIssue, acceleration); } } else { if (inputSize < LZ4_64Klimit) { @@ -860,11 +860,8 @@ int LZ4_compress_fast_safeExtState(void* state, const char* source, char* dest, } else { const tableType_t tableType = (sizeof(void*)==8) ? byU32 : byPtr; LZ4_resetTable(ctx, inputSize, tableType, noDict); - if (ctx->currentOffset) { - return LZ4_compress_generic(ctx, source, dest, inputSize, maxOutputSize, limitedOutput, tableType, noDict, dictSmall, acceleration); - } else { - return LZ4_compress_generic(ctx, source, dest, inputSize, maxOutputSize, limitedOutput, tableType, noDict, noDictIssue, acceleration); - } + ctx->currentOffset += 64 KB; + return LZ4_compress_generic(ctx, source, dest, inputSize, maxOutputSize, limitedOutput, tableType, noDict, noDictIssue, acceleration); } } } @@ -1222,21 +1219,25 @@ int LZ4_compress_fast_continue (LZ4_stream_t* LZ4_stream, const char* source, ch /* external dictionary mode */ { int result; - if (streamPtr->dictCtx && inputSize < 2 KB) { - LZ4_resetTable(streamPtr, inputSize, tableType, usingExtDictCtx); - if ((streamPtr->dictCtx->dictSize < 64 KB) && (streamPtr->dictCtx->dictSize < streamPtr->currentOffset)) { - result = LZ4_compress_generic(streamPtr, source, dest, inputSize, maxOutputSize, limitedOutput, tableType, usingExtDictCtx, dictSmall, acceleration); + if (streamPtr->dictCtx) { + /* We depend here on the fact that dictCtx'es (produced by + * LZ4_loadDict) guarantee that their tables contain no references + * to offsets between dictCtx->currentOffset - 64 KB and + * dictCtx->currentOffset - dictCtx->dictSize. This makes it safe + * to use noDictIssue even when the dict isn't a full 64 KB. + */ + if (inputSize > 2 KB) { + /* For compressing large blobs, it is faster to pay the setup + * cost to copy the dictionary's tables into the active context, + * so that the compression loop is only looking in one table. + */ + memcpy(streamPtr, streamPtr->dictCtx, sizeof(LZ4_stream_t)); + result = LZ4_compress_generic(streamPtr, source, dest, inputSize, maxOutputSize, limitedOutput, tableType, usingExtDict, noDictIssue, acceleration); } else { + LZ4_resetTable(streamPtr, inputSize, tableType, usingExtDictCtx); result = LZ4_compress_generic(streamPtr, source, dest, inputSize, maxOutputSize, limitedOutput, tableType, usingExtDictCtx, noDictIssue, acceleration); } } else { - if (streamPtr->dictCtx) { - /* For compressing large blobs, it is faster to pay the setup - * cost to copy the dictionary's tables into the active context, - * so that the compression loop is only looking in one table. - */ - memcpy(streamPtr, streamPtr->dictCtx, sizeof(LZ4_stream_t)); - } LZ4_resetTable(streamPtr, inputSize, tableType, usingExtDict); if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset)) { result = LZ4_compress_generic(streamPtr, source, dest, inputSize, maxOutputSize, limitedOutput, tableType, usingExtDict, dictSmall, acceleration); |