/* * LZ4 - Fast LZ compression algorithm * Header File * Copyright (C) 2011-2013, Yann Collet. * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following disclaimer * in the documentation and/or other materials provided with the * distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * You can contact the author at : * - LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html * - LZ4 source repository : http://code.google.com/p/lz4/ * * $FreeBSD: head/sys/cddl/boot/zfs/lz4.c 272389 2014-10-02 00:13:08Z delphij $ */ static int LZ4_uncompress_unknownOutputSize(const char *source, char *dest, int isize, int maxOutputSize); /* ARGSUSED */ static int lz4_decompress(void *s_start, void *d_start, size_t s_len, size_t d_len, int dummy __unused) { const uint8_t *src = s_start; uint32_t bufsiz = htonl(*(uint32_t *)src); /* invalid compressed buffer size encoded at start */ if (bufsiz + 4 > s_len) return (1); /* * Returns 0 on success (decompression function returned non-negative) * and non-zero on failure (decompression function returned negative). */ return (LZ4_uncompress_unknownOutputSize(s_start + 4, d_start, bufsiz, d_len) < 0); } /* * CPU Feature Detection */ /* 32 or 64 bits ? */ #if (defined(__x86_64__) || defined(__x86_64) || defined(__amd64__) || \ defined(__amd64) || defined(__ppc64__) || defined(_WIN64) || \ defined(__LP64__) || defined(_LP64)) #define LZ4_ARCH64 1 #else #define LZ4_ARCH64 0 #endif /* * Little Endian or Big Endian? * Note: overwrite the below #define if you know your architecture endianess. */ #if BYTE_ORDER == BIG_ENDIAN #define LZ4_BIG_ENDIAN 1 #else /* * Little Endian assumed. PDP Endian and other very rare endian format * are unsupported. */ #endif /* * Unaligned memory access is automatically enabled for "common" CPU, * such as x86. For others CPU, the compiler will be more cautious, and * insert extra code to ensure aligned access is respected. If you know * your target CPU supports unaligned memory access, you may want to * force this option manually to improve performance */ #if defined(__ARM_FEATURE_UNALIGNED) #define LZ4_FORCE_UNALIGNED_ACCESS 1 #endif /* * Compiler Options */ #if __STDC_VERSION__ >= 199901L /* C99 */ /* "restrict" is a known keyword */ #else /* Disable restrict */ #define restrict #endif #define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__) #define lz4_bswap16(x) ((unsigned short int) ((((x) >> 8) & 0xffu) \ | (((x) & 0xffu) << 8))) #if (GCC_VERSION >= 302) || (__INTEL_COMPILER >= 800) || defined(__clang__) #define expect(expr, value) (__builtin_expect((expr), (value))) #else #define expect(expr, value) (expr) #endif #define likely(expr) expect((expr) != 0, 1) #define unlikely(expr) expect((expr) != 0, 0) /* Basic types */ #define BYTE uint8_t #define U16 uint16_t #define U32 uint32_t #define S32 int32_t #define U64 uint64_t #ifndef LZ4_FORCE_UNALIGNED_ACCESS #pragma pack(1) #endif typedef struct _U16_S { U16 v; } U16_S; typedef struct _U32_S { U32 v; } U32_S; typedef struct _U64_S { U64 v; } U64_S; #ifndef LZ4_FORCE_UNALIGNED_ACCESS #pragma pack() #endif #define A64(x) (((U64_S *)(x))->v) #define A32(x) (((U32_S *)(x))->v) #define A16(x) (((U16_S *)(x))->v) /* * Constants */ #define MINMATCH 4 #define COPYLENGTH 8 #define LASTLITERALS 5 #define ML_BITS 4 #define ML_MASK ((1U<> ML_BITS)) == RUN_MASK) { int s = 255; while ((ip < iend) && (s == 255)) { s = *ip++; length += s; } } /* copy literals */ cpy = op + length; if ((cpy > oend - COPYLENGTH) || (ip + length > iend - COPYLENGTH)) { if (cpy > oend) /* * Error: request to write beyond destination * buffer. */ goto _output_error; if (ip + length > iend) /* * Error : request to read beyond source * buffer. */ goto _output_error; memcpy(op, ip, length); op += length; ip += length; if (ip < iend) /* Error : LZ4 format violation */ goto _output_error; /* Necessarily EOF, due to parsing restrictions. */ break; } LZ4_WILDCOPY(ip, op, cpy); ip -= (op - cpy); op = cpy; /* get offset */ LZ4_READ_LITTLEENDIAN_16(ref, cpy, ip); ip += 2; if (ref < (BYTE * const) dest) /* * Error: offset creates reference outside of * destination buffer. */ goto _output_error; /* get matchlength */ if ((length = (token & ML_MASK)) == ML_MASK) { while (ip < iend) { int s = *ip++; length += s; if (s == 255) continue; break; } } /* copy repeated sequence */ if unlikely(op - ref < STEPSIZE) { #if LZ4_ARCH64 size_t dec2table[] = { 0, 0, 0, -1, 0, 1, 2, 3 }; size_t dec2 = dec2table[op - ref]; #else const int dec2 = 0; #endif *op++ = *ref++; *op++ = *ref++; *op++ = *ref++; *op++ = *ref++; ref -= dec[op - ref]; A32(op) = A32(ref); op += STEPSIZE - 4; ref -= dec2; } else { LZ4_COPYSTEP(ref, op); } cpy = op + length - (STEPSIZE - 4); if (cpy > oend - COPYLENGTH) { if (cpy > oend) /* * Error: request to write outside of * destination buffer. */ goto _output_error; LZ4_SECURECOPY(ref, op, (oend - COPYLENGTH)); while (op < cpy) *op++ = *ref++; op = cpy; if (op == oend) /* * Check EOF (should never happen, since last * 5 bytes are supposed to be literals). */ break; continue; } LZ4_SECURECOPY(ref, op, cpy); op = cpy; /* correction */ } /* end of decoding */ return (int)(((char *)op) - dest); /* write overflow error detected */ _output_error: return (int)(-(((char *)ip) - source)); }