diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/README.md | 2 | ||||
| -rw-r--r-- | lib/dll/example/README.md | 2 | ||||
| -rw-r--r-- | lib/lz4.c | 396 | ||||
| -rw-r--r-- | lib/lz4hc.c | 8 |
4 files changed, 260 insertions, 148 deletions
diff --git a/lib/README.md b/lib/README.md index d08e0f1d..244d65ce 100644 --- a/lib/README.md +++ b/lib/README.md @@ -96,7 +96,7 @@ The following build macro can be selected to adjust source code behavior at comp by using bitcount instructions, generally implemented as fast single instructions in many cpus. In case the target cpus doesn't support it, or compiler intrinsic doesn't work, or feature bad performance, it's possible to use an optimized software path instead. - This is achieved by setting this build macros . + This is achieved by setting this build macros. In most cases, it's not expected to be necessary, but it can be legitimately considered for less common platforms. diff --git a/lib/dll/example/README.md b/lib/dll/example/README.md index 6d932480..b93914ba 100644 --- a/lib/dll/example/README.md +++ b/lib/dll/example/README.md @@ -51,7 +51,7 @@ The compiled executable will require LZ4 DLL which is available at `dll\msys-lz4 Open `example\fullbench-dll.sln` to compile `fullbench-dll` that uses a dynamic LZ4 library from the `dll` directory. The solution works with Visual C++ 2010 or newer. When one will open the solution with Visual C++ newer than 2010 -then the solution will upgraded to the current version. +then the solution will be upgraded to the current version. #### Using LZ4 DLL with Visual C++ @@ -210,7 +210,10 @@ void LZ4_free(void* p); #endif #include <string.h> /* memset, memcpy */ -#define MEM_INIT(p,v,s) memset((p),(v),(s)) +#if !defined(LZ4_memset) +# define LZ4_memset(p,v,s) memset((p),(v),(s)) +#endif +#define MEM_INIT(p,v,s) LZ4_memset((p),(v),(s)) /*-************************************ @@ -321,10 +324,20 @@ typedef enum { * memcpy() as if it were standard compliant, so it can inline it in freestanding * environments. This is needed when decompressing the Linux Kernel, for example. */ -#if defined(__GNUC__) && (__GNUC__ >= 4) -#define LZ4_memcpy(dst, src, size) __builtin_memcpy(dst, src, size) -#else -#define LZ4_memcpy(dst, src, size) memcpy(dst, src, size) +#if !defined(LZ4_memcpy) +# if defined(__GNUC__) && (__GNUC__ >= 4) +# define LZ4_memcpy(dst, src, size) __builtin_memcpy(dst, src, size) +# else +# define LZ4_memcpy(dst, src, size) memcpy(dst, src, size) +# endif +#endif + +#if !defined(LZ4_memmove) +# if defined(__GNUC__) && (__GNUC__ >= 4) +# define LZ4_memmove __builtin_memmove +# else +# define LZ4_memmove memmove +# endif #endif static unsigned LZ4_isLittleEndian(void) @@ -529,7 +542,7 @@ static unsigned LZ4_NbCommonBytes (reg_t val) * including _tzcnt_u64. Therefore, we need to neuter the _tzcnt_u64 code path for ARM64EC. ****************************************************************************************************/ # if defined(__clang__) && (__clang_major__ < 10) - /* Avoid undefined clang-cl intrinics issue. + /* Avoid undefined clang-cl intrinsics issue. * See https://github.com/lz4/lz4/pull/1017 for details. */ return (unsigned)__builtin_ia32_tzcnt_u64(val) >> 3; # else @@ -1711,7 +1724,7 @@ int LZ4_saveDict (LZ4_stream_t* LZ4_dict, char* safeBuffer, int dictSize) if (dictSize > 0) { const BYTE* const previousDictEnd = dict->dictionary + dict->dictSize; assert(dict->dictionary); - memmove(safeBuffer, previousDictEnd - dictSize, dictSize); + LZ4_memmove(safeBuffer, previousDictEnd - dictSize, (size_t)dictSize); } dict->dictionary = (const BYTE*)safeBuffer; @@ -1726,39 +1739,163 @@ int LZ4_saveDict (LZ4_stream_t* LZ4_dict, char* safeBuffer, int dictSize) * Decompression functions ********************************/ -typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive; typedef enum { decode_full_block = 0, partial_decode = 1 } earlyEnd_directive; #undef MIN #define MIN(a,b) ( (a) < (b) ? (a) : (b) ) + +/* variant for decompress_unsafe() + * does not know end of input + * presumes input is well formed + * note : will consume at least one byte */ +size_t read_long_length_no_check(const BYTE** pp) +{ + size_t b, l = 0; + do { b = **pp; (*pp)++; l += b; } while (b==255); + DEBUGLOG(6, "read_long_length_no_check: +length=%zu using %zu input bytes", l, l/255 + 1) + return l; +} + +/* core decoder variant for LZ4_decompress_fast*() + * for legacy support only : these entry points are deprecated. + * - Presumes input is correctly formed (no defense vs malformed inputs) + * - Does not know input size (presume input buffer is "large enough") + * - Decompress a full block (only) + * @return : nb of bytes read from input. + * Note : this variant is not optimized for speed, just for maintenance. + * the goal is to remove support of decompress_fast*() variants by v2.0 +**/ +LZ4_FORCE_INLINE int +LZ4_decompress_unsafe_generic( + const BYTE* const istart, + BYTE* const ostart, + int decompressedSize, + + size_t prefixSize, + const BYTE* const dictStart, /* only if dict==usingExtDict */ + const size_t dictSize /* note: =0 if dictStart==NULL */ + ) +{ + const BYTE* ip = istart; + BYTE* op = (BYTE*)ostart; + BYTE* const oend = ostart + decompressedSize; + const BYTE* const prefixStart = ostart - prefixSize; + + DEBUGLOG(5, "LZ4_decompress_unsafe_generic"); + if (dictStart == NULL) assert(dictSize == 0); + + while (1) { + /* start new sequence */ + unsigned token = *ip++; + + /* literals */ + { size_t ll = token >> ML_BITS; + if (ll==15) { + /* long literal length */ + ll += read_long_length_no_check(&ip); + } + if ((size_t)(oend-op) < ll) return -1; /* output buffer overflow */ + LZ4_memmove(op, ip, ll); /* support in-place decompression */ + op += ll; + ip += ll; + if ((size_t)(oend-op) < MFLIMIT) { + if (op==oend) break; /* end of block */ + DEBUGLOG(5, "invalid: literals end at distance %zi from end of block", oend-op); + /* incorrect end of block : + * last match must start at least MFLIMIT==12 bytes before end of output block */ + return -1; + } } + + /* match */ + { size_t ml = token & 15; + size_t const offset = LZ4_readLE16(ip); + ip+=2; + + if (ml==15) { + /* long literal length */ + ml += read_long_length_no_check(&ip); + } + ml += MINMATCH; + + if ((size_t)(oend-op) < ml) return -1; /* output buffer overflow */ + + { const BYTE* match = op - offset; + + /* out of range */ + if (offset > (size_t)(op - prefixStart) + dictSize) { + DEBUGLOG(6, "offset out of range"); + return -1; + } + + /* check special case : extDict */ + if (offset > (size_t)(op - prefixStart)) { + /* extDict scenario */ + const BYTE* const dictEnd = dictStart + dictSize; + const BYTE* extMatch = dictEnd - (offset - (size_t)(op-prefixStart)); + size_t const extml = (size_t)(dictEnd - extMatch); + if (extml > ml) { + /* match entirely within extDict */ + LZ4_memmove(op, extMatch, ml); + op += ml; + ml = 0; + } else { + /* match split between extDict & prefix */ + LZ4_memmove(op, extMatch, extml); + op += extml; + ml -= extml; + } + match = prefixStart; + } + + /* match copy - slow variant, supporting overlap copy */ + { size_t u; + for (u=0; u<ml; u++) { + op[u] = match[u]; + } } } + op += ml; + if ((size_t)(oend-op) < LASTLITERALS) { + DEBUGLOG(5, "invalid: match ends at distance %zi from end of block", oend-op); + /* incorrect end of block : + * last match must stop at least LASTLITERALS==5 bytes before end of output block */ + return -1; + } + } /* match */ + } /* main loop */ + return (int)(ip - istart); +} + + /* Read the variable-length literal or match length. * - * ip - pointer to use as input. - * lencheck - end ip. Return an error if ip advances >= lencheck. - * loop_check - check ip >= lencheck in body of loop. Returns loop_error if so. - * initial_check - check ip >= lencheck before start of loop. Returns initial_error if so. - * error (output) - error code. Should be set to 0 before call. - */ -typedef enum { loop_error = -2, initial_error = -1, ok = 0 } variable_length_error; -LZ4_FORCE_INLINE unsigned -read_variable_length(const BYTE**ip, const BYTE* lencheck, - int loop_check, int initial_check, - variable_length_error* error) -{ - U32 length = 0; - U32 s; - if (initial_check && unlikely((*ip) >= lencheck)) { /* overflow detection */ - *error = initial_error; - return length; + * @ip : input pointer + * @ilimit : position after which if length is not decoded, the input is necessarily corrupted. + * @initial_check - check ip >= ipmax before start of loop. Returns initial_error if so. + * @error (output) - error code. Must be set to 0 before call. +**/ +typedef size_t Rvl_t; +static const Rvl_t rvl_error = (Rvl_t)(-1); +LZ4_FORCE_INLINE Rvl_t +read_variable_length(const BYTE** ip, const BYTE* ilimit, + int initial_check) +{ + Rvl_t s, length = 0; + assert(ip != NULL); + assert(*ip != NULL); + assert(ilimit != NULL); + if (initial_check && unlikely((*ip) >= ilimit)) { /* read limit reached */ + return rvl_error; } do { s = **ip; (*ip)++; length += s; - if (loop_check && unlikely((*ip) >= lencheck)) { /* overflow detection */ - *error = loop_error; - return length; + if (unlikely((*ip) > ilimit)) { /* read limit reached */ + return rvl_error; + } + /* accumulator overflow detection (32-bit mode only) */ + if ((sizeof(length)<8) && unlikely(length > ((Rvl_t)(-1)/2)) ) { + return rvl_error; } } while (s==255); @@ -1778,7 +1915,6 @@ LZ4_decompress_generic( int srcSize, int outputSize, /* If endOnInput==endOnInputSize, this value is `dstCapacity` */ - endCondition_directive endOnInput, /* endOnOutputSize, endOnInputSize */ earlyEnd_directive partialDecoding, /* full, partial */ dict_directive dict, /* noDict, withPrefix64k, usingExtDict */ const BYTE* const lowPrefix, /* always <= dst, == dst when no prefix */ @@ -1797,13 +1933,12 @@ LZ4_decompress_generic( const BYTE* const dictEnd = (dictStart == NULL) ? NULL : dictStart + dictSize; - const int safeDecode = (endOnInput==endOnInputSize); - const int checkOffset = ((safeDecode) && (dictSize < (int)(64 KB))); + const int checkOffset = (dictSize < (int)(64 KB)); /* Set up the "end" pointers for the shortcut. */ - const BYTE* const shortiend = iend - (endOnInput ? 14 : 8) /*maxLL*/ - 2 /*offset*/; - const BYTE* const shortoend = oend - (endOnInput ? 14 : 8) /*maxLL*/ - 18 /*maxML*/; + const BYTE* const shortiend = iend - 14 /*maxLL*/ - 2 /*offset*/; + const BYTE* const shortoend = oend - 14 /*maxLL*/ - 18 /*maxML*/; const BYTE* match; size_t offset; @@ -1815,83 +1950,70 @@ LZ4_decompress_generic( /* Special cases */ assert(lowPrefix <= op); - if ((endOnInput) && (unlikely(outputSize==0))) { + if (unlikely(outputSize==0)) { /* Empty output buffer */ if (partialDecoding) return 0; return ((srcSize==1) && (*ip==0)) ? 0 : -1; } - if ((!endOnInput) && (unlikely(outputSize==0))) { return (*ip==0 ? 1 : -1); } - if ((endOnInput) && unlikely(srcSize==0)) { return -1; } + if (unlikely(srcSize==0)) { return -1; } - /* Currently the fast loop shows a regression on qualcomm arm chips. */ + /* LZ4_FAST_DEC_LOOP: + * designed for modern OoO performance cpus, + * where copying reliably 32-bytes is preferable to an unpredictable branch. + * note : fast loop may show a regression for some client arm chips. */ #if LZ4_FAST_DEC_LOOP if ((oend - op) < FASTLOOP_SAFE_DISTANCE) { DEBUGLOG(6, "skip fast decode loop"); goto safe_decode; } - /* Fast loop : decode sequences as long as output < iend-FASTLOOP_SAFE_DISTANCE */ + /* Fast loop : decode sequences as long as output < oend-FASTLOOP_SAFE_DISTANCE */ while (1) { /* Main fastloop assertion: We can always wildcopy FASTLOOP_SAFE_DISTANCE */ assert(oend - op >= FASTLOOP_SAFE_DISTANCE); - if (endOnInput) { assert(ip < iend); } + assert(ip < iend); token = *ip++; length = token >> ML_BITS; /* literal length */ - assert(!endOnInput || ip <= iend); /* ip < iend before the increment */ - /* decode literal length */ if (length == RUN_MASK) { - variable_length_error error = ok; - length += read_variable_length(&ip, iend-RUN_MASK, (int)endOnInput, (int)endOnInput, &error); - if (error == initial_error) { goto _output_error; } - if ((safeDecode) && unlikely((uptrval)(op)+length<(uptrval)(op))) { goto _output_error; } /* overflow detection */ - if ((safeDecode) && unlikely((uptrval)(ip)+length<(uptrval)(ip))) { goto _output_error; } /* overflow detection */ + size_t const addl = read_variable_length(&ip, iend-RUN_MASK, 1); + if (addl == rvl_error) { goto _output_error; } + length += addl; + if (unlikely((uptrval)(op)+length<(uptrval)(op))) { goto _output_error; } /* overflow detection */ + if (unlikely((uptrval)(ip)+length<(uptrval)(ip))) { goto _output_error; } /* overflow detection */ /* copy literals */ cpy = op+length; LZ4_STATIC_ASSERT(MFLIMIT >= WILDCOPYLENGTH); - if (endOnInput) { /* LZ4_decompress_safe() */ - if ((cpy>oend-32) || (ip+length>iend-32)) { goto safe_literal_copy; } - LZ4_wildCopy32(op, ip, cpy); - } else { /* LZ4_decompress_fast() */ - if (cpy>oend-8) { goto safe_literal_copy; } - LZ4_wildCopy8(op, ip, cpy); /* LZ4_decompress_fast() cannot copy more than 8 bytes at a time : - * it doesn't know input length, and only relies on end-of-block properties */ - } + if ((cpy>oend-32) || (ip+length>iend-32)) { goto safe_literal_copy; } + LZ4_wildCopy32(op, ip, cpy); ip += length; op = cpy; } else { cpy = op+length; - if (endOnInput) { /* LZ4_decompress_safe() */ - DEBUGLOG(7, "copy %u bytes in a 16-bytes stripe", (unsigned)length); - /* We don't need to check oend, since we check it once for each loop below */ - if (ip > iend-(16 + 1/*max lit + offset + nextToken*/)) { goto safe_literal_copy; } - /* Literals can only be 14, but hope compilers optimize if we copy by a register size */ - LZ4_memcpy(op, ip, 16); - } else { /* LZ4_decompress_fast() */ - /* LZ4_decompress_fast() cannot copy more than 8 bytes at a time : - * it doesn't know input length, and relies on end-of-block properties */ - LZ4_memcpy(op, ip, 8); - if (length > 8) { LZ4_memcpy(op+8, ip+8, 8); } - } + DEBUGLOG(7, "copy %u bytes in a 16-bytes stripe", (unsigned)length); + /* We don't need to check oend, since we check it once for each loop below */ + if (ip > iend-(16 + 1/*max lit + offset + nextToken*/)) { goto safe_literal_copy; } + /* Literals can only be <= 14, but hope compilers optimize better when copy by a register size */ + LZ4_memcpy(op, ip, 16); ip += length; op = cpy; } /* get offset */ offset = LZ4_readLE16(ip); ip+=2; match = op - offset; - assert(match <= op); + assert(match <= op); /* overflow check */ /* get matchlength */ length = token & ML_MASK; if (length == ML_MASK) { - variable_length_error error = ok; - if ((checkOffset) && (unlikely(match + dictSize < lowPrefix))) { goto _output_error; } /* Error : offset outside buffers */ - length += read_variable_length(&ip, iend - LASTLITERALS + 1, (int)endOnInput, 0, &error); - if (error != ok) { goto _output_error; } - if ((safeDecode) && unlikely((uptrval)(op)+length<(uptrval)op)) { goto _output_error; } /* overflow detection */ + size_t const addl = read_variable_length(&ip, iend - LASTLITERALS + 1, 0); + if (addl == rvl_error) { goto _output_error; } + length += addl; length += MINMATCH; + if (unlikely((uptrval)(op)+length<(uptrval)op)) { goto _output_error; } /* overflow detection */ + if ((checkOffset) && (unlikely(match + dictSize < lowPrefix))) { goto _output_error; } /* Error : offset outside buffers */ if (op + length >= oend - FASTLOOP_SAFE_DISTANCE) { goto safe_match_copy; } @@ -1901,7 +2023,7 @@ LZ4_decompress_generic( goto safe_match_copy; } - /* Fastpath check: Avoids a branch in LZ4_wildCopy32 if true */ + /* Fastpath check: skip LZ4_wildCopy32 when true */ if ((dict == withPrefix64k) || (match >= lowPrefix)) { if (offset >= 8) { assert(match >= lowPrefix); @@ -1918,6 +2040,7 @@ LZ4_decompress_generic( if (checkOffset && (unlikely(match + dictSize < lowPrefix))) { goto _output_error; } /* Error : offset outside buffers */ /* match starting within external dictionary */ if ((dict==usingExtDict) && (match < lowPrefix)) { + assert(dictEnd != NULL); if (unlikely(op+length > oend-LASTLITERALS)) { if (partialDecoding) { DEBUGLOG(7, "partialDecoding: dictionary match, close to dstEnd"); @@ -1928,7 +2051,7 @@ LZ4_decompress_generic( if (length <= (size_t)(lowPrefix-match)) { /* match fits entirely within external dictionary : just copy */ - memmove(op, dictEnd - (lowPrefix-match), length); + LZ4_memmove(op, dictEnd - (lowPrefix-match), length); op += length; } else { /* match stretches into both external dictionary and current block */ @@ -1964,11 +2087,10 @@ LZ4_decompress_generic( /* Main Loop : decode remaining sequences where output < FASTLOOP_SAFE_DISTANCE */ while (1) { + assert(ip < iend); token = *ip++; length = token >> ML_BITS; /* literal length */ - assert(!endOnInput || ip <= iend); /* ip < iend before the increment */ - /* A two-stage shortcut for the most common case: * 1) If the literal length is 0..14, and there is enough space, * enter the shortcut and copy 16 bytes on behalf of the literals @@ -1978,11 +2100,11 @@ LZ4_decompress_generic( * those 18 bytes earlier, upon entering the shortcut (in other words, * there is a combined check for both stages). */ - if ( (endOnInput ? length != RUN_MASK : length <= 8) + if ( (length != RUN_MASK) /* strictly "less than" on input, to re-enter the loop with at least one byte */ - && likely((endOnInput ? ip < shortiend : 1) & (op <= shortoend)) ) { + && likely((ip < shortiend) & (op <= shortoend)) ) { /* Copy the literals */ - LZ4_memcpy(op, ip, endOnInput ? 16 : 8); + LZ4_memcpy(op, ip, 16); op += length; ip += length; /* The second stage: prepare for match copying, decode full info. @@ -2012,11 +2134,11 @@ LZ4_decompress_generic( /* decode literal length */ if (length == RUN_MASK) { - variable_length_error error = ok; - length += read_variable_length(&ip, iend-RUN_MASK, (int)endOnInput, (int)endOnInput, &error); - if (error == initial_error) { goto _output_error; } - if ((safeDecode) && unlikely((uptrval)(op)+length<(uptrval)(op))) { goto _output_error; } /* overflow detection */ - if ((safeDecode) && unlikely((uptrval)(ip)+length<(uptrval)(ip))) { goto _output_error; } /* overflow detection */ + size_t const addl = read_variable_length(&ip, iend-RUN_MASK, 1); + if (addl == rvl_error) { goto _output_error; } + length += addl; + if (unlikely((uptrval)(op)+length<(uptrval)(op))) { goto _output_error; } /* overflow detection */ + if (unlikely((uptrval)(ip)+length<(uptrval)(ip))) { goto _output_error; } /* overflow detection */ } /* copy literals */ @@ -2025,9 +2147,7 @@ LZ4_decompress_generic( safe_literal_copy: #endif LZ4_STATIC_ASSERT(MFLIMIT >= WILDCOPYLENGTH); - if ( ((endOnInput) && ((cpy>oend-MFLIMIT) || (ip+length>iend-(2+1+LASTLITERALS))) ) - || ((!endOnInput) && (cpy>oend-WILDCOPYLENGTH)) ) - { + if ((cpy>oend-MFLIMIT) || (ip+length>iend-(2+1+LASTLITERALS))) { /* We've either hit the input parsing restriction or the output parsing restriction. * In the normal scenario, decoding a full block, it must be the last sequence, * otherwise it's an error (invalid input or dimensions). @@ -2037,7 +2157,6 @@ LZ4_decompress_generic( /* Since we are partial decoding we may be in this block because of the output parsing * restriction, which is not valid since the output buffer is allowed to be undersized. */ - assert(endOnInput); DEBUGLOG(7, "partialDecoding: copying literals, close to input or output end") DEBUGLOG(7, "partialDecoding: literal length = %u", (unsigned)length); DEBUGLOG(7, "partialDecoding: remaining space in dstBuffer : %i", (int)(oend - op)); @@ -2058,21 +2177,17 @@ LZ4_decompress_generic( length = (size_t)(oend-op); } } else { - /* We must be on the last sequence because of the parsing limitations so check - * that we exactly regenerate the original size (must be exact when !endOnInput). - */ - if ((!endOnInput) && (cpy != oend)) { goto _output_error; } /* We must be on the last sequence (or invalid) because of the parsing limitations * so check that we exactly consume the input and don't overrun the output buffer. */ - if ((endOnInput) && ((ip+length != iend) || (cpy > oend))) { + if ((ip+length != iend) || (cpy > oend)) { DEBUGLOG(6, "should have been last run of literals") DEBUGLOG(6, "ip(%p) + length(%i) = %p != iend (%p)", ip, (int)length, ip+length, iend); DEBUGLOG(6, "or cpy(%p) > oend(%p)", cpy, oend); goto _output_error; } } - memmove(op, ip, length); /* supports overlapping memory regions; only matters for in-place decompression scenarios */ + LZ4_memmove(op, ip, length); /* supports overlapping memory regions, for in-place decompression scenarios */ ip += length; op += length; /* Necessarily EOF when !partialDecoding. @@ -2084,7 +2199,7 @@ LZ4_decompress_generic( break; } } else { - LZ4_wildCopy8(op, ip, cpy); /* may overwrite up to WILDCOPYLENGTH beyond cpy */ + LZ4_wildCopy8(op, ip, cpy); /* can overwrite up to 8 bytes beyond cpy */ ip += length; op = cpy; } @@ -2097,10 +2212,10 @@ LZ4_decompress_generic( _copy_match: if (length == ML_MASK) { - variable_length_error error = ok; - length += read_variable_length(&ip, iend - LASTLITERALS + 1, (int)endOnInput, 0, &error); - if (error != ok) goto _output_error; - if ((safeDecode) && unlikely((uptrval)(op)+length<(uptrval)op)) goto _output_error; /* overflow detection */ + size_t const addl = read_variable_length(&ip, iend - LASTLITERALS + 1, 0); + if (addl == rvl_error) { goto _output_error; } + length += addl; + if (unlikely((uptrval)(op)+length<(uptrval)op)) goto _output_error; /* overflow detection */ } length += MINMATCH; @@ -2110,6 +2225,7 @@ LZ4_decompress_generic( if ((checkOffset) && (unlikely(match + dictSize < lowPrefix))) goto _output_error; /* Error : offset outside buffers */ /* match starting within external dictionary */ if ((dict==usingExtDict) && (match < lowPrefix)) { + assert(dictEnd != NULL); if (unlikely(op+length > oend-LASTLITERALS)) { if (partialDecoding) length = MIN(length, (size_t)(oend-op)); else goto _output_error; /* doesn't respect parsing restriction */ @@ -2117,7 +2233,7 @@ LZ4_decompress_generic( if (length <= (size_t)(lowPrefix-match)) { /* match fits entirely within external dictionary : just copy */ - memmove(op, dictEnd - (lowPrefix-match), length); + LZ4_memmove(op, dictEnd - (lowPrefix-match), length); op += length; } else { /* match stretches into both external dictionary and current block */ @@ -2188,12 +2304,8 @@ LZ4_decompress_generic( } /* end of decoding */ - if (endOnInput) { - DEBUGLOG(5, "decoded %i bytes", (int) (((char*)op)-dst)); - return (int) (((char*)op)-dst); /* Nb of output bytes decoded */ - } else { - return (int) (((const char*)ip)-src); /* Nb of input bytes read */ - } + DEBUGLOG(5, "decoded %i bytes", (int) (((char*)op)-dst)); + return (int) (((char*)op)-dst); /* Nb of output bytes decoded */ /* Overflow error detected */ _output_error: @@ -2208,7 +2320,7 @@ LZ4_FORCE_O2 int LZ4_decompress_safe(const char* source, char* dest, int compressedSize, int maxDecompressedSize) { return LZ4_decompress_generic(source, dest, compressedSize, maxDecompressedSize, - endOnInputSize, decode_full_block, noDict, + decode_full_block, noDict, (BYTE*)dest, NULL, 0); } @@ -2217,16 +2329,17 @@ int LZ4_decompress_safe_partial(const char* src, char* dst, int compressedSize, { dstCapacity = MIN(targetOutputSize, dstCapacity); return LZ4_decompress_generic(src, dst, compressedSize, dstCapacity, - endOnInputSize, partial_decode, + partial_decode, noDict, (BYTE*)dst, NULL, 0); } LZ4_FORCE_O2 int LZ4_decompress_fast(const char* source, char* dest, int originalSize) { - return LZ4_decompress_generic(source, dest, 0, originalSize, - endOnOutputSize, decode_full_block, withPrefix64k, - (BYTE*)dest - 64 KB, NULL, 0); + DEBUGLOG(5, "LZ4_decompress_fast"); + return LZ4_decompress_unsafe_generic( + (const BYTE*)source, (BYTE*)dest, originalSize, + 0, NULL, 0); } /*===== Instantiate a few more decoding cases, used more than once. =====*/ @@ -2235,7 +2348,7 @@ LZ4_FORCE_O2 /* Exported, an obsolete API function. */ int LZ4_decompress_safe_withPrefix64k(const char* source, char* dest, int compressedSize, int maxOutputSize) { return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, - endOnInputSize, decode_full_block, withPrefix64k, + decode_full_block, withPrefix64k, (BYTE*)dest - 64 KB, NULL, 0); } @@ -2244,16 +2357,16 @@ static int LZ4_decompress_safe_partial_withPrefix64k(const char* source, char* d { dstCapacity = MIN(targetOutputSize, dstCapacity); return LZ4_decompress_generic(source, dest, compressedSize, dstCapacity, - endOnInputSize, partial_decode, withPrefix64k, + partial_decode, withPrefix64k, (BYTE*)dest - 64 KB, NULL, 0); } /* Another obsolete API function, paired with the previous one. */ int LZ4_decompress_fast_withPrefix64k(const char* source, char* dest, int originalSize) { - /* LZ4_decompress_fast doesn't validate match offsets, - * and thus serves well with any prefixed dictionary. */ - return LZ4_decompress_fast(source, dest, originalSize); + return LZ4_decompress_unsafe_generic( + (const BYTE*)source, (BYTE*)dest, originalSize, + 64 KB, NULL, 0); } LZ4_FORCE_O2 @@ -2261,7 +2374,7 @@ static int LZ4_decompress_safe_withSmallPrefix(const char* source, char* dest, i size_t prefixSize) { return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, - endOnInputSize, decode_full_block, noDict, + decode_full_block, noDict, (BYTE*)dest-prefixSize, NULL, 0); } @@ -2271,7 +2384,7 @@ static int LZ4_decompress_safe_partial_withSmallPrefix(const char* source, char* { dstCapacity = MIN(targetOutputSize, dstCapacity); return LZ4_decompress_generic(source, dest, compressedSize, dstCapacity, - endOnInputSize, partial_decode, noDict, + partial_decode, noDict, (BYTE*)dest-prefixSize, NULL, 0); } @@ -2281,7 +2394,7 @@ int LZ4_decompress_safe_forceExtDict(const char* source, char* dest, const void* dictStart, size_t dictSize) { return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, - endOnInputSize, decode_full_block, usingExtDict, + decode_full_block, usingExtDict, (BYTE*)dest, (const BYTE*)dictStart, dictSize); } @@ -2292,7 +2405,7 @@ int LZ4_decompress_safe_partial_forceExtDict(const char* source, char* dest, { dstCapacity = MIN(targetOutputSize, dstCapacity); return LZ4_decompress_generic(source, dest, compressedSize, dstCapacity, - endOnInputSize, partial_decode, usingExtDict, + partial_decode, usingExtDict, (BYTE*)dest, (const BYTE*)dictStart, dictSize); } @@ -2300,9 +2413,9 @@ LZ4_FORCE_O2 static int LZ4_decompress_fast_extDict(const char* source, char* dest, int originalSize, const void* dictStart, size_t dictSize) { - return LZ4_decompress_generic(source, dest, 0, originalSize, - endOnOutputSize, decode_full_block, usingExtDict, - (BYTE*)dest, (const BYTE*)dictStart, dictSize); + return LZ4_decompress_unsafe_generic( + (const BYTE*)source, (BYTE*)dest, originalSize, + 0, (const BYTE*)dictStart, dictSize); } /* The "double dictionary" mode, for use with e.g. ring buffers: the first part @@ -2314,16 +2427,7 @@ int LZ4_decompress_safe_doubleDict(const char* source, char* dest, int compresse size_t prefixSize, const void* dictStart, size_t dictSize) { return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, - endOnInputSize, decode_full_block, usingExtDict, - (BYTE*)dest-prefixSize, (const BYTE*)dictStart, dictSize); -} - -LZ4_FORCE_INLINE -int LZ4_decompress_fast_doubleDict(const char* source, char* dest, int originalSize, - size_t prefixSize, const void* dictStart, size_t dictSize) -{ - return LZ4_decompress_generic(source, dest, 0, originalSize, - endOnOutputSize, decode_full_block, usingExtDict, + decode_full_block, usingExtDict, (BYTE*)dest-prefixSize, (const BYTE*)dictStart, dictSize); } @@ -2431,29 +2535,35 @@ int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const ch return result; } -LZ4_FORCE_O2 -int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int originalSize) +LZ4_FORCE_O2 int +LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, + const char* source, char* dest, int originalSize) { - LZ4_streamDecode_t_internal* lz4sd = &LZ4_streamDecode->internal_donotuse; + LZ4_streamDecode_t_internal* const lz4sd = + (assert(LZ4_streamDecode!=NULL), &LZ4_streamDecode->internal_donotuse); int result; + + DEBUGLOG(5, "LZ4_decompress_fast_continue (toDecodeSize=%i)", originalSize); assert(originalSize >= 0); if (lz4sd->prefixSize == 0) { + DEBUGLOG(5, "first invocation : no prefix nor extDict"); assert(lz4sd->extDictSize == 0); result = LZ4_decompress_fast(source, dest, originalSize); if (result <= 0) return result; lz4sd->prefixSize = (size_t)originalSize; lz4sd->prefixEnd = (BYTE*)dest + originalSize; } else if (lz4sd->prefixEnd == (BYTE*)dest) { - if (lz4sd->prefixSize >= 64 KB - 1 || lz4sd->extDictSize == 0) - result = LZ4_decompress_fast(source, dest, originalSize); - else - result = LZ4_decompress_fast_doubleDict(source, dest, originalSize, - lz4sd->prefixSize, lz4sd->externalDict, lz4sd->extDictSize); + DEBUGLOG(5, "continue using existing prefix"); + result = LZ4_decompress_unsafe_generic( + (const BYTE*)source, (BYTE*)dest, originalSize, + lz4sd->prefixSize, + lz4sd->externalDict, lz4sd->extDictSize); if (result <= 0) return result; lz4sd->prefixSize += (size_t)originalSize; lz4sd->prefixEnd += originalSize; } else { + DEBUGLOG(5, "prefix becomes extDict"); lz4sd->extDictSize = lz4sd->prefixSize; lz4sd->externalDict = lz4sd->prefixEnd - lz4sd->extDictSize; result = LZ4_decompress_fast_extDict(source, dest, originalSize, @@ -2507,7 +2617,9 @@ int LZ4_decompress_safe_partial_usingDict(const char* source, char* dest, int co int LZ4_decompress_fast_usingDict(const char* source, char* dest, int originalSize, const char* dictStart, int dictSize) { if (dictSize==0 || dictStart+dictSize == dest) - return LZ4_decompress_fast(source, dest, originalSize); + return LZ4_decompress_unsafe_generic( + (const BYTE*)source, (BYTE*)dest, originalSize, + (size_t)dictSize, NULL, 0); assert(dictSize >= 0); return LZ4_decompress_fast_extDict(source, dest, originalSize, dictStart, (size_t)dictSize); } diff --git a/lib/lz4hc.c b/lib/lz4hc.c index 8122bd80..4771ef8f 100644 --- a/lib/lz4hc.c +++ b/lib/lz4hc.c @@ -755,7 +755,7 @@ _last_literals: } else { *op++ = (BYTE)(lastRunSize << ML_BITS); } - memcpy(op, anchor, lastRunSize); + LZ4_memcpy(op, anchor, lastRunSize); op += lastRunSize; } @@ -894,7 +894,7 @@ LZ4HC_compress_generic_dictCtx ( ctx->dictCtx = NULL; return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit); } else if (position == 0 && *srcSizePtr > 4 KB) { - memcpy(ctx, ctx->dictCtx, sizeof(LZ4HC_CCtx_internal)); + LZ4_memcpy(ctx, ctx->dictCtx, sizeof(LZ4HC_CCtx_internal)); LZ4HC_setExternalDict(ctx, (const BYTE *)src); ctx->compressionLevel = (short)cLevel; return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit); @@ -1179,7 +1179,7 @@ int LZ4_saveDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, char* safeBuffer, int dictS if (dictSize > prefixSize) dictSize = prefixSize; if (safeBuffer == NULL) assert(dictSize == 0); if (dictSize > 0) - memmove(safeBuffer, streamPtr->end - dictSize, dictSize); + LZ4_memmove(safeBuffer, streamPtr->end - dictSize, dictSize); { U32 const endIndex = (U32)(streamPtr->end - streamPtr->prefixStart) + streamPtr->dictLimit; streamPtr->end = (const BYTE*)safeBuffer + dictSize; streamPtr->prefixStart = streamPtr->end - dictSize; @@ -1589,7 +1589,7 @@ _last_literals: } else { *op++ = (BYTE)(lastRunSize << ML_BITS); } - memcpy(op, anchor, lastRunSize); + LZ4_memcpy(op, anchor, lastRunSize); op += lastRunSize; } |