--- /dev/null
+/*
+ * 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/
+ */
+
+#include <sys/zfs_context.h>
+
+static int real_LZ4_compress(const char *source, char *dest, int isize,
+ int osize);
+static int LZ4_uncompress_unknownOutputSize(const char *source, char *dest,
+ int isize, int maxOutputSize);
+static int LZ4_compressCtx(void *ctx, const char *source, char *dest,
+ int isize, int osize);
+static int LZ4_compress64kCtx(void *ctx, const char *source, char *dest,
+ int isize, int osize);
+
+static kmem_cache_t *lz4_cache;
+
+/*ARGSUSED*/
+size_t
+lz4_compress(void *s_start, void *d_start, size_t s_len, size_t d_len, int n)
+{
+ uint32_t bufsiz;
+ char *dest = d_start;
+
+ ASSERT(d_len >= sizeof (bufsiz));
+
+ bufsiz = real_LZ4_compress(s_start, &dest[sizeof (bufsiz)], s_len,
+ d_len - sizeof (bufsiz));
+
+ /* Signal an error if the compression routine returned zero. */
+ if (bufsiz == 0)
+ return (s_len);
+
+ /*
+ * Encode the compresed buffer size at the start. We'll need this in
+ * decompression to counter the effects of padding which might be
+ * added to the compressed buffer and which, if unhandled, would
+ * confuse the hell out of our decompression function.
+ */
+ *(uint32_t *)dest = BE_32(bufsiz);
+
+ return (bufsiz + sizeof (bufsiz));
+}
+
+/*ARGSUSED*/
+int
+lz4_decompress(void *s_start, void *d_start, size_t s_len, size_t d_len, int n)
+{
+ const char *src = s_start;
+ uint32_t bufsiz = BE_IN32(src);
+
+ /* invalid compressed buffer size encoded at start */
+ if (bufsiz + sizeof (bufsiz) > 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(&src[sizeof (bufsiz)],
+ d_start, bufsiz, d_len) < 0);
+}
+
+/*
+ * LZ4 API Description:
+ *
+ * Simple Functions:
+ * real_LZ4_compress() :
+ * isize : is the input size. Max supported value is ~1.9GB
+ * return : the number of bytes written in buffer dest
+ * or 0 if the compression fails (if LZ4_COMPRESSMIN is set).
+ * note : destination buffer must be already allocated.
+ * destination buffer must be sized to handle worst cases
+ * situations (input data not compressible) worst case size
+ * evaluation is provided by function LZ4_compressBound().
+ *
+ * real_LZ4_uncompress() :
+ * osize : is the output size, therefore the original size
+ * return : the number of bytes read in the source buffer.
+ * If the source stream is malformed, the function will stop
+ * decoding and return a negative result, indicating the byte
+ * position of the faulty instruction. This function never
+ * writes beyond dest + osize, and is therefore protected
+ * against malicious data packets.
+ * note : destination buffer must be already allocated
+ *
+ * Advanced Functions
+ *
+ * LZ4_compressBound() :
+ * Provides the maximum size that LZ4 may output in a "worst case"
+ * scenario (input data not compressible) primarily useful for memory
+ * allocation of output buffer.
+ *
+ * isize : is the input size. Max supported value is ~1.9GB
+ * return : maximum output size in a "worst case" scenario
+ * note : this function is limited by "int" range (2^31-1)
+ *
+ * LZ4_uncompress_unknownOutputSize() :
+ * isize : is the input size, therefore the compressed size
+ * maxOutputSize : is the size of the destination buffer (which must be
+ * already allocated)
+ * return : the number of bytes decoded in the destination buffer
+ * (necessarily <= maxOutputSize). If the source stream is
+ * malformed, the function will stop decoding and return a
+ * negative result, indicating the byte position of the faulty
+ * instruction. This function never writes beyond dest +
+ * maxOutputSize, and is therefore protected against malicious
+ * data packets.
+ * note : Destination buffer must be already allocated.
+ * This version is slightly slower than real_LZ4_uncompress()
+ *
+ * LZ4_compressCtx() :
+ * This function explicitly handles the CTX memory structure.
+ *
+ * ILLUMOS CHANGES: the CTX memory structure must be explicitly allocated
+ * by the caller (either on the stack or using kmem_cache_alloc). Passing NULL
+ * isn't valid.
+ *
+ * LZ4_compress64kCtx() :
+ * Same as LZ4_compressCtx(), but specific to small inputs (<64KB).
+ * isize *Must* be <64KB, otherwise the output will be corrupted.
+ *
+ * ILLUMOS CHANGES: the CTX memory structure must be explicitly allocated
+ * by the caller (either on the stack or using kmem_cache_alloc). Passing NULL
+ * isn't valid.
+ */
+
+/*
+ * Tuning parameters
+ */
+
+/*
+ * COMPRESSIONLEVEL: Increasing this value improves compression ratio
+ * Lowering this value reduces memory usage. Reduced memory usage
+ * typically improves speed, due to cache effect (ex: L1 32KB for Intel,
+ * L1 64KB for AMD). Memory usage formula : N->2^(N+2) Bytes
+ * (examples : 12 -> 16KB ; 17 -> 512KB)
+ */
+#define COMPRESSIONLEVEL 12
+
+/*
+ * NOTCOMPRESSIBLE_CONFIRMATION: Decreasing this value will make the
+ * algorithm skip faster data segments considered "incompressible".
+ * This may decrease compression ratio dramatically, but will be
+ * faster on incompressible data. Increasing this value will make
+ * the algorithm search more before declaring a segment "incompressible".
+ * This could improve compression a bit, but will be slower on
+ * incompressible data. The default value (6) is recommended.
+ */
+#define NOTCOMPRESSIBLE_CONFIRMATION 6
+
+/*
+ * BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE: This will provide a boost to
+ * performance for big endian cpu, but the resulting compressed stream
+ * will be incompatible with little-endian CPU. You can set this option
+ * to 1 in situations where data will stay within closed environment.
+ * This option is useless on Little_Endian CPU (such as x86).
+ */
+/* #define BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE 1 */
+
+/*
+ * 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 (defined(__BIG_ENDIAN__) || defined(__BIG_ENDIAN) || \
+ defined(_BIG_ENDIAN) || defined(_ARCH_PPC) || defined(__PPC__) || \
+ defined(__PPC) || defined(PPC) || defined(__powerpc__) || \
+ defined(__powerpc) || defined(powerpc) || \
+ ((defined(__BYTE_ORDER__)&&(__BYTE_ORDER__ == __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
+
+/*
+ * Illumos : we can't use GCC's __builtin_ctz family of builtins in the
+ * kernel
+ * Linux : we can use GCC's __builtin_ctz family of builtins in the
+ * kernel
+ */
+#undef LZ4_FORCE_SW_BITCOUNT
+
+/*
+ * Compiler Options
+ */
+/* Disable restrict */
+#define restrict
+
+#define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
+
+#if (GCC_VERSION >= 302) || (__INTEL_COMPILER >= 800) || defined(__clang__)
+#define expect(expr, value) (__builtin_expect((expr), (value)))
+#else
+#define expect(expr, value) (expr)
+#endif
+
+#ifndef likely
+#define likely(expr) expect((expr) != 0, 1)
+#endif
+
+#ifndef unlikely
+#define unlikely(expr) expect((expr) != 0, 0)
+#endif
+
+#define lz4_bswap16(x) ((unsigned short int) ((((x) >> 8) & 0xffu) | \
+ (((x) & 0xffu) << 8)))
+
+/* 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 HASH_LOG COMPRESSIONLEVEL
+#define HASHTABLESIZE (1 << HASH_LOG)
+#define HASH_MASK (HASHTABLESIZE - 1)
+
+#define SKIPSTRENGTH (NOTCOMPRESSIBLE_CONFIRMATION > 2 ? \
+ NOTCOMPRESSIBLE_CONFIRMATION : 2)
+
+#define COPYLENGTH 8
+#define LASTLITERALS 5
+#define MFLIMIT (COPYLENGTH + MINMATCH)
+#define MINLENGTH (MFLIMIT + 1)
+
+#define MAXD_LOG 16
+#define MAX_DISTANCE ((1 << MAXD_LOG) - 1)
+
+#define ML_BITS 4
+#define ML_MASK ((1U<<ML_BITS)-1)
+#define RUN_BITS (8-ML_BITS)
+#define RUN_MASK ((1U<<RUN_BITS)-1)
+
+
+/*
+ * Architecture-specific macros
+ */
+#if LZ4_ARCH64
+#define STEPSIZE 8
+#define UARCH U64
+#define AARCH A64
+#define LZ4_COPYSTEP(s, d) A64(d) = A64(s); d += 8; s += 8;
+#define LZ4_COPYPACKET(s, d) LZ4_COPYSTEP(s, d)
+#define LZ4_SECURECOPY(s, d, e) if (d < e) LZ4_WILDCOPY(s, d, e)
+#define HTYPE U32
+#define INITBASE(base) const BYTE* const base = ip
+#else /* !LZ4_ARCH64 */
+#define STEPSIZE 4
+#define UARCH U32
+#define AARCH A32
+#define LZ4_COPYSTEP(s, d) A32(d) = A32(s); d += 4; s += 4;
+#define LZ4_COPYPACKET(s, d) LZ4_COPYSTEP(s, d); LZ4_COPYSTEP(s, d);
+#define LZ4_SECURECOPY LZ4_WILDCOPY
+#define HTYPE const BYTE *
+#define INITBASE(base) const int base = 0
+#endif /* !LZ4_ARCH64 */
+
+#if (defined(LZ4_BIG_ENDIAN) && !defined(BIG_ENDIAN_NATIVE_BUT_INCOMPATIBLE))
+#define LZ4_READ_LITTLEENDIAN_16(d, s, p) \
+ { U16 v = A16(p); v = lz4_bswap16(v); d = (s) - v; }
+#define LZ4_WRITE_LITTLEENDIAN_16(p, i) \
+ { U16 v = (U16)(i); v = lz4_bswap16(v); A16(p) = v; p += 2; }
+#else
+#define LZ4_READ_LITTLEENDIAN_16(d, s, p) { d = (s) - A16(p); }
+#define LZ4_WRITE_LITTLEENDIAN_16(p, v) { A16(p) = v; p += 2; }
+#endif
+
+
+/* Local structures */
+struct refTables {
+ HTYPE hashTable[HASHTABLESIZE];
+};
+
+
+/* Macros */
+#define LZ4_HASH_FUNCTION(i) (((i) * 2654435761U) >> ((MINMATCH * 8) - \
+ HASH_LOG))
+#define LZ4_HASH_VALUE(p) LZ4_HASH_FUNCTION(A32(p))
+#define LZ4_WILDCOPY(s, d, e) do { LZ4_COPYPACKET(s, d) } while (d < e);
+#define LZ4_BLINDCOPY(s, d, l) { BYTE* e = (d) + l; LZ4_WILDCOPY(s, d, e); \
+ d = e; }
+
+
+/* Private functions */
+#if LZ4_ARCH64
+
+static inline int
+LZ4_NbCommonBytes(register U64 val)
+{
+#if defined(LZ4_BIG_ENDIAN)
+#if defined(__GNUC__) && (GCC_VERSION >= 304) && \
+ !defined(LZ4_FORCE_SW_BITCOUNT)
+ return (__builtin_clzll(val) >> 3);
+#else
+ int r;
+ if (!(val >> 32)) {
+ r = 4;
+ } else {
+ r = 0;
+ val >>= 32;
+ }
+ if (!(val >> 16)) {
+ r += 2;
+ val >>= 8;
+ } else {
+ val >>= 24;
+ }
+ r += (!val);
+ return (r);
+#endif
+#else
+#if defined(__GNUC__) && (GCC_VERSION >= 304) && \
+ !defined(LZ4_FORCE_SW_BITCOUNT)
+ return (__builtin_ctzll(val) >> 3);
+#else
+ static const int DeBruijnBytePos[64] =
+ { 0, 0, 0, 0, 0, 1, 1, 2, 0, 3, 1, 3, 1, 4, 2, 7, 0, 2, 3, 6, 1, 5,
+ 3, 5, 1, 3, 4, 4, 2, 5, 6, 7, 7, 0, 1, 2, 3, 3, 4, 6, 2, 6, 5,
+ 5, 3, 4, 5, 6, 7, 1, 2, 4, 6, 4,
+ 4, 5, 7, 2, 6, 5, 7, 6, 7, 7
+ };
+ return DeBruijnBytePos[((U64) ((val & -val) * 0x0218A392CDABBD3F)) >>
+ 58];
+#endif
+#endif
+}
+
+#else
+
+static inline int
+LZ4_NbCommonBytes(register U32 val)
+{
+#if defined(LZ4_BIG_ENDIAN)
+#if defined(__GNUC__) && (GCC_VERSION >= 304) && \
+ !defined(LZ4_FORCE_SW_BITCOUNT)
+ return (__builtin_clz(val) >> 3);
+#else
+ int r;
+ if (!(val >> 16)) {
+ r = 2;
+ val >>= 8;
+ } else {
+ r = 0;
+ val >>= 24;
+ }
+ r += (!val);
+ return (r);
+#endif
+#else
+#if defined(__GNUC__) && (GCC_VERSION >= 304) && \
+ !defined(LZ4_FORCE_SW_BITCOUNT)
+ return (__builtin_ctz(val) >> 3);
+#else
+ static const int DeBruijnBytePos[32] = {
+ 0, 0, 3, 0, 3, 1, 3, 0,
+ 3, 2, 2, 1, 3, 2, 0, 1,
+ 3, 3, 1, 2, 2, 2, 2, 0,
+ 3, 1, 2, 0, 1, 0, 1, 1
+ };
+ return DeBruijnBytePos[((U32) ((val & -(S32) val) * 0x077CB531U)) >>
+ 27];
+#endif
+#endif
+}
+
+#endif
+
+/* Compression functions */
+
+/*ARGSUSED*/
+static int
+LZ4_compressCtx(void *ctx, const char *source, char *dest, int isize,
+ int osize)
+{
+ struct refTables *srt = (struct refTables *)ctx;
+ HTYPE *HashTable = (HTYPE *) (srt->hashTable);
+
+ const BYTE *ip = (BYTE *) source;
+ INITBASE(base);
+ const BYTE *anchor = ip;
+ const BYTE *const iend = ip + isize;
+ const BYTE *const oend = (BYTE *) dest + osize;
+ const BYTE *const mflimit = iend - MFLIMIT;
+#define matchlimit (iend - LASTLITERALS)
+
+ BYTE *op = (BYTE *) dest;
+
+ int len, length;
+ const int skipStrength = SKIPSTRENGTH;
+ U32 forwardH;
+
+
+ /* Init */
+ if (isize < MINLENGTH)
+ goto _last_literals;
+
+ /* First Byte */
+ HashTable[LZ4_HASH_VALUE(ip)] = ip - base;
+ ip++;
+ forwardH = LZ4_HASH_VALUE(ip);
+
+ /* Main Loop */
+ for (;;) {
+ int findMatchAttempts = (1U << skipStrength) + 3;
+ const BYTE *forwardIp = ip;
+ const BYTE *ref;
+ BYTE *token;
+
+ /* Find a match */
+ do {
+ U32 h = forwardH;
+ int step = findMatchAttempts++ >> skipStrength;
+ ip = forwardIp;
+ forwardIp = ip + step;
+
+ if (unlikely(forwardIp > mflimit)) {
+ goto _last_literals;
+ }
+
+ forwardH = LZ4_HASH_VALUE(forwardIp);
+ ref = base + HashTable[h];
+ HashTable[h] = ip - base;
+
+ } while ((ref < ip - MAX_DISTANCE) || (A32(ref) != A32(ip)));
+
+ /* Catch up */
+ while ((ip > anchor) && (ref > (BYTE *) source) &&
+ unlikely(ip[-1] == ref[-1])) {
+ ip--;
+ ref--;
+ }
+
+ /* Encode Literal length */
+ length = ip - anchor;
+ token = op++;
+
+ /* Check output limit */
+ if (unlikely(op + length + (2 + 1 + LASTLITERALS) +
+ (length >> 8) > oend))
+ return (0);
+
+ if (length >= (int)RUN_MASK) {
+ *token = (RUN_MASK << ML_BITS);
+ len = length - RUN_MASK;
+ for (; len > 254; len -= 255)
+ *op++ = 255;
+ *op++ = (BYTE)len;
+ } else
+ *token = (length << ML_BITS);
+
+ /* Copy Literals */
+ LZ4_BLINDCOPY(anchor, op, length);
+
+ _next_match:
+ /* Encode Offset */
+ LZ4_WRITE_LITTLEENDIAN_16(op, ip - ref);
+
+ /* Start Counting */
+ ip += MINMATCH;
+ ref += MINMATCH; /* MinMatch verified */
+ anchor = ip;
+ while (likely(ip < matchlimit - (STEPSIZE - 1))) {
+ UARCH diff = AARCH(ref) ^ AARCH(ip);
+ if (!diff) {
+ ip += STEPSIZE;
+ ref += STEPSIZE;
+ continue;
+ }
+ ip += LZ4_NbCommonBytes(diff);
+ goto _endCount;
+ }
+#if LZ4_ARCH64
+ if ((ip < (matchlimit - 3)) && (A32(ref) == A32(ip))) {
+ ip += 4;
+ ref += 4;
+ }
+#endif
+ if ((ip < (matchlimit - 1)) && (A16(ref) == A16(ip))) {
+ ip += 2;
+ ref += 2;
+ }
+ if ((ip < matchlimit) && (*ref == *ip))
+ ip++;
+ _endCount:
+
+ /* Encode MatchLength */
+ len = (ip - anchor);
+ /* Check output limit */
+ if (unlikely(op + (1 + LASTLITERALS) + (len >> 8) > oend))
+ return (0);
+ if (len >= (int)ML_MASK) {
+ *token += ML_MASK;
+ len -= ML_MASK;
+ for (; len > 509; len -= 510) {
+ *op++ = 255;
+ *op++ = 255;
+ }
+ if (len > 254) {
+ len -= 255;
+ *op++ = 255;
+ }
+ *op++ = (BYTE)len;
+ } else
+ *token += len;
+
+ /* Test end of chunk */
+ if (ip > mflimit) {
+ anchor = ip;
+ break;
+ }
+ /* Fill table */
+ HashTable[LZ4_HASH_VALUE(ip - 2)] = ip - 2 - base;
+
+ /* Test next position */
+ ref = base + HashTable[LZ4_HASH_VALUE(ip)];
+ HashTable[LZ4_HASH_VALUE(ip)] = ip - base;
+ if ((ref > ip - (MAX_DISTANCE + 1)) && (A32(ref) == A32(ip))) {
+ token = op++;
+ *token = 0;
+ goto _next_match;
+ }
+ /* Prepare next loop */
+ anchor = ip++;
+ forwardH = LZ4_HASH_VALUE(ip);
+ }
+
+ _last_literals:
+ /* Encode Last Literals */
+ {
+ int lastRun = iend - anchor;
+ if (op + lastRun + 1 + ((lastRun + 255 - RUN_MASK) / 255) >
+ oend)
+ return (0);
+ if (lastRun >= (int)RUN_MASK) {
+ *op++ = (RUN_MASK << ML_BITS);
+ lastRun -= RUN_MASK;
+ for (; lastRun > 254; lastRun -= 255) {
+ *op++ = 255;
+ }
+ *op++ = (BYTE)lastRun;
+ } else
+ *op++ = (lastRun << ML_BITS);
+ (void) memcpy(op, anchor, iend - anchor);
+ op += iend - anchor;
+ }
+
+ /* End */
+ return (int)(((char *)op) - dest);
+}
+
+
+
+/* Note : this function is valid only if isize < LZ4_64KLIMIT */
+#define LZ4_64KLIMIT ((1 << 16) + (MFLIMIT - 1))
+#define HASHLOG64K (HASH_LOG + 1)
+#define HASH64KTABLESIZE (1U << HASHLOG64K)
+#define LZ4_HASH64K_FUNCTION(i) (((i) * 2654435761U) >> ((MINMATCH*8) - \
+ HASHLOG64K))
+#define LZ4_HASH64K_VALUE(p) LZ4_HASH64K_FUNCTION(A32(p))
+
+/*ARGSUSED*/
+static int
+LZ4_compress64kCtx(void *ctx, const char *source, char *dest, int isize,
+ int osize)
+{
+ struct refTables *srt = (struct refTables *)ctx;
+ U16 *HashTable = (U16 *) (srt->hashTable);
+
+ const BYTE *ip = (BYTE *) source;
+ const BYTE *anchor = ip;
+ const BYTE *const base = ip;
+ const BYTE *const iend = ip + isize;
+ const BYTE *const oend = (BYTE *) dest + osize;
+ const BYTE *const mflimit = iend - MFLIMIT;
+#define matchlimit (iend - LASTLITERALS)
+
+ BYTE *op = (BYTE *) dest;
+
+ int len, length;
+ const int skipStrength = SKIPSTRENGTH;
+ U32 forwardH;
+
+ /* Init */
+ if (isize < MINLENGTH)
+ goto _last_literals;
+
+ /* First Byte */
+ ip++;
+ forwardH = LZ4_HASH64K_VALUE(ip);
+
+ /* Main Loop */
+ for (;;) {
+ int findMatchAttempts = (1U << skipStrength) + 3;
+ const BYTE *forwardIp = ip;
+ const BYTE *ref;
+ BYTE *token;
+
+ /* Find a match */
+ do {
+ U32 h = forwardH;
+ int step = findMatchAttempts++ >> skipStrength;
+ ip = forwardIp;
+ forwardIp = ip + step;
+
+ if (forwardIp > mflimit) {
+ goto _last_literals;
+ }
+
+ forwardH = LZ4_HASH64K_VALUE(forwardIp);
+ ref = base + HashTable[h];
+ HashTable[h] = ip - base;
+
+ } while (A32(ref) != A32(ip));
+
+ /* Catch up */
+ while ((ip > anchor) && (ref > (BYTE *) source) &&
+ (ip[-1] == ref[-1])) {
+ ip--;
+ ref--;
+ }
+
+ /* Encode Literal length */
+ length = ip - anchor;
+ token = op++;
+
+ /* Check output limit */
+ if (unlikely(op + length + (2 + 1 + LASTLITERALS) +
+ (length >> 8) > oend))
+ return (0);
+
+ if (length >= (int)RUN_MASK) {
+ *token = (RUN_MASK << ML_BITS);
+ len = length - RUN_MASK;
+ for (; len > 254; len -= 255)
+ *op++ = 255;
+ *op++ = (BYTE)len;
+ } else
+ *token = (length << ML_BITS);
+
+ /* Copy Literals */
+ LZ4_BLINDCOPY(anchor, op, length);
+
+ _next_match:
+ /* Encode Offset */
+ LZ4_WRITE_LITTLEENDIAN_16(op, ip - ref);
+
+ /* Start Counting */
+ ip += MINMATCH;
+ ref += MINMATCH; /* MinMatch verified */
+ anchor = ip;
+ while (ip < matchlimit - (STEPSIZE - 1)) {
+ UARCH diff = AARCH(ref) ^ AARCH(ip);
+ if (!diff) {
+ ip += STEPSIZE;
+ ref += STEPSIZE;
+ continue;
+ }
+ ip += LZ4_NbCommonBytes(diff);
+ goto _endCount;
+ }
+#if LZ4_ARCH64
+ if ((ip < (matchlimit - 3)) && (A32(ref) == A32(ip))) {
+ ip += 4;
+ ref += 4;
+ }
+#endif
+ if ((ip < (matchlimit - 1)) && (A16(ref) == A16(ip))) {
+ ip += 2;
+ ref += 2;
+ }
+ if ((ip < matchlimit) && (*ref == *ip))
+ ip++;
+ _endCount:
+
+ /* Encode MatchLength */
+ len = (ip - anchor);
+ /* Check output limit */
+ if (unlikely(op + (1 + LASTLITERALS) + (len >> 8) > oend))
+ return (0);
+ if (len >= (int)ML_MASK) {
+ *token += ML_MASK;
+ len -= ML_MASK;
+ for (; len > 509; len -= 510) {
+ *op++ = 255;
+ *op++ = 255;
+ }
+ if (len > 254) {
+ len -= 255;
+ *op++ = 255;
+ }
+ *op++ = (BYTE)len;
+ } else
+ *token += len;
+
+ /* Test end of chunk */
+ if (ip > mflimit) {
+ anchor = ip;
+ break;
+ }
+ /* Fill table */
+ HashTable[LZ4_HASH64K_VALUE(ip - 2)] = ip - 2 - base;
+
+ /* Test next position */
+ ref = base + HashTable[LZ4_HASH64K_VALUE(ip)];
+ HashTable[LZ4_HASH64K_VALUE(ip)] = ip - base;
+ if (A32(ref) == A32(ip)) {
+ token = op++;
+ *token = 0;
+ goto _next_match;
+ }
+ /* Prepare next loop */
+ anchor = ip++;
+ forwardH = LZ4_HASH64K_VALUE(ip);
+ }
+
+ _last_literals:
+ /* Encode Last Literals */
+ {
+ int lastRun = iend - anchor;
+ if (op + lastRun + 1 + ((lastRun + 255 - RUN_MASK) / 255) >
+ oend)
+ return (0);
+ if (lastRun >= (int)RUN_MASK) {
+ *op++ = (RUN_MASK << ML_BITS);
+ lastRun -= RUN_MASK;
+ for (; lastRun > 254; lastRun -= 255)
+ *op++ = 255;
+ *op++ = (BYTE)lastRun;
+ } else
+ *op++ = (lastRun << ML_BITS);
+ (void) memcpy(op, anchor, iend - anchor);
+ op += iend - anchor;
+ }
+
+ /* End */
+ return (int)(((char *)op) - dest);
+}
+
+static int
+real_LZ4_compress(const char *source, char *dest, int isize, int osize)
+{
+ void *ctx;
+ int result;
+
+ ASSERT(lz4_cache != NULL);
+ ctx = kmem_cache_alloc(lz4_cache, KM_PUSHPAGE);
+
+ /*
+ * out of kernel memory, gently fall through - this will disable
+ * compression in zio_compress_data
+ */
+ if (ctx == NULL)
+ return (0);
+
+ memset(ctx, 0, sizeof (struct refTables));
+
+ if (isize < LZ4_64KLIMIT)
+ result = LZ4_compress64kCtx(ctx, source, dest, isize, osize);
+ else
+ result = LZ4_compressCtx(ctx, source, dest, isize, osize);
+
+ kmem_cache_free(lz4_cache, ctx);
+ return (result);
+}
+
+/* Decompression functions */
+
+/*
+ * Note: The decoding functions real_LZ4_uncompress() and
+ * LZ4_uncompress_unknownOutputSize() are safe against "buffer overflow"
+ * attack type. They will never write nor read outside of the provided
+ * output buffers. LZ4_uncompress_unknownOutputSize() also insures that
+ * it will never read outside of the input buffer. A corrupted input
+ * will produce an error result, a negative int, indicating the position
+ * of the error within input stream.
+ */
+
+static int
+LZ4_uncompress_unknownOutputSize(const char *source, char *dest, int isize,
+ int maxOutputSize)
+{
+ /* Local Variables */
+ const BYTE *restrict ip = (const BYTE *) source;
+ const BYTE *const iend = ip + isize;
+ const BYTE *ref;
+
+ BYTE *op = (BYTE *) dest;
+ BYTE *const oend = op + maxOutputSize;
+ BYTE *cpy;
+
+ size_t dec32table[] = {0, 3, 2, 3, 0, 0, 0, 0};
+#if LZ4_ARCH64
+ size_t dec64table[] = {0, 0, 0, (size_t)-1, 0, 1, 2, 3};
+#endif
+
+ /* Main Loop */
+ while (ip < iend) {
+ unsigned token;
+ size_t length;
+
+ /* get runlength */
+ token = *ip++;
+ if ((length = (token >> 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: writes beyond output buffer */
+ goto _output_error;
+ if (ip + length != iend)
+ /*
+ * Error: LZ4 format requires to consume all
+ * input at this stage
+ */
+ goto _output_error;
+ (void) memcpy(op, ip, length);
+ op += length;
+ /* 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 dec64 = dec64table[op-ref];
+#else
+ const int dec64 = 0;
+#endif
+ op[0] = ref[0];
+ op[1] = ref[1];
+ op[2] = ref[2];
+ op[3] = ref[3];
+ op += 4;
+ ref += 4;
+ ref -= dec32table[op-ref];
+ A32(op) = A32(ref);
+ op += STEPSIZE - 4;
+ ref -= dec64;
+ } 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)
+ */
+ goto _output_error;
+ 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));
+}
+
+void
+lz4_init(void)
+{
+ lz4_cache = kmem_cache_create("lz4_cache",
+ sizeof (struct refTables), 0, NULL, NULL, NULL, NULL, NULL, 0);
+}
+
+void
+lz4_fini(void)
+{
+ if (lz4_cache) {
+ kmem_cache_destroy(lz4_cache);
+ lz4_cache = NULL;
+ }
+}
+
projects / mirror_zfs-debian.git / commitdiff