* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
+#define LZ4_MEM_COMPRESS (4096 * sizeof(unsigned char *))
+#define LZ4HC_MEM_COMPRESS (65538 * sizeof(unsigned char *))
/*
* lz4_compressbound()
return isize + (isize / 255) + 16;
}
+/*
+ * lz4_compress()
+ * src : source address of the original data
+ * src_len : size of the original data
+ * dst : output buffer address of the compressed data
+ * This requires 'dst' of size LZ4_COMPRESSBOUND.
+ * dst_len : is the output size, which is returned after compress done
+ * workmem : address of the working memory.
+ * This requires 'workmem' of size LZ4_MEM_COMPRESS.
+ * return : Success if return 0
+ * Error if return (< 0)
+ * note : Destination buffer and workmem must be already allocated with
+ * the defined size.
+ */
+int lz4_compress(const unsigned char *src, size_t src_len,
+ unsigned char *dst, size_t *dst_len, void *wrkmem);
+
+ /*
+ * lz4hc_compress()
+ * src : source address of the original data
+ * src_len : size of the original data
+ * dst : output buffer address of the compressed data
+ * This requires 'dst' of size LZ4_COMPRESSBOUND.
+ * dst_len : is the output size, which is returned after compress done
+ * workmem : address of the working memory.
+ * This requires 'workmem' of size LZ4HC_MEM_COMPRESS.
+ * return : Success if return 0
+ * Error if return (< 0)
+ * note : Destination buffer and workmem must be already allocated with
+ * the defined size.
+ */
+int lz4hc_compress(const unsigned char *src, size_t src_len,
+ unsigned char *dst, size_t *dst_len, void *wrkmem);
+
/*
* lz4_decompress()
* src : source address of the compressed data
config LZO_DECOMPRESS
tristate
+config LZ4_COMPRESS
+ tristate
+
+config LZ4HC_COMPRESS
+ tristate
+
config LZ4_DECOMPRESS
tristate
obj-$(CONFIG_BCH) += bch.o
obj-$(CONFIG_LZO_COMPRESS) += lzo/
obj-$(CONFIG_LZO_DECOMPRESS) += lzo/
+obj-$(CONFIG_LZ4_COMPRESS) += lz4/
+obj-$(CONFIG_LZ4HC_COMPRESS) += lz4/
obj-$(CONFIG_LZ4_DECOMPRESS) += lz4/
obj-$(CONFIG_XZ_DEC) += xz/
obj-$(CONFIG_RAID6_PQ) += raid6/
+obj-$(CONFIG_LZ4_COMPRESS) += lz4_compress.o
+obj-$(CONFIG_LZ4HC_COMPRESS) += lz4hc_compress.o
obj-$(CONFIG_LZ4_DECOMPRESS) += lz4_decompress.o
--- /dev/null
+/*
+ * LZ4 - Fast LZ compression algorithm
+ * Copyright (C) 2011-2012, 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/
+ *
+ * Changed for kernel use by:
+ * Chanho Min <chanho.min@lge.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/lz4.h>
+#include <asm/unaligned.h>
+#include "lz4defs.h"
+
+/*
+ * LZ4_compressCtx :
+ * -----------------
+ * Compress 'isize' bytes from 'source' into an output buffer 'dest' of
+ * maximum size 'maxOutputSize'. * If it cannot achieve it, compression
+ * will stop, and result of the function will be zero.
+ * return : the number of bytes written in buffer 'dest', or 0 if the
+ * compression fails
+ */
+static inline int lz4_compressctx(void *ctx,
+ const char *source,
+ char *dest,
+ int isize,
+ int maxoutputsize)
+{
+ HTYPE *hashtable = (HTYPE *)ctx;
+ const u8 *ip = (u8 *)source;
+#if LZ4_ARCH64
+ const BYTE * const base = ip;
+#else
+ const int base = 0;
+#endif
+ const u8 *anchor = ip;
+ const u8 *const iend = ip + isize;
+ const u8 *const mflimit = iend - MFLIMIT;
+ #define MATCHLIMIT (iend - LASTLITERALS)
+
+ u8 *op = (u8 *) dest;
+ u8 *const oend = op + maxoutputsize;
+ int length;
+ const int skipstrength = SKIPSTRENGTH;
+ u32 forwardh;
+ int lastrun;
+
+ /* Init */
+ if (isize < MINLENGTH)
+ goto _last_literals;
+
+ memset((void *)hashtable, 0, LZ4_MEM_COMPRESS);
+
+ /* First Byte */
+ hashtable[LZ4_HASH_VALUE(ip)] = ip - base;
+ ip++;
+ forwardh = LZ4_HASH_VALUE(ip);
+
+ /* Main Loop */
+ for (;;) {
+ int findmatchattempts = (1U << skipstrength) + 3;
+ const u8 *forwardip = ip;
+ const u8 *ref;
+ u8 *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 > (u8 *)source) &&
+ unlikely(ip[-1] == ref[-1])) {
+ ip--;
+ ref--;
+ }
+
+ /* Encode Literal length */
+ length = (int)(ip - anchor);
+ token = op++;
+ /* check output limit */
+ if (unlikely(op + length + (2 + 1 + LASTLITERALS) +
+ (length >> 8) > oend))
+ return 0;
+
+ if (length >= (int)RUN_MASK) {
+ int len;
+ *token = (RUN_MASK << ML_BITS);
+ len = length - RUN_MASK;
+ for (; len > 254 ; len -= 255)
+ *op++ = 255;
+ *op++ = (u8)len;
+ } else
+ *token = (length << ML_BITS);
+
+ /* Copy Literals */
+ LZ4_BLINDCOPY(anchor, op, length);
+_next_match:
+ /* Encode Offset */
+ LZ4_WRITE_LITTLEENDIAN_16(op, (u16)(ip - ref));
+
+ /* Start Counting */
+ ip += MINMATCH;
+ /* MinMatch verified */
+ ref += MINMATCH;
+ anchor = ip;
+ while (likely(ip < MATCHLIMIT - (STEPSIZE - 1))) {
+ #if LZ4_ARCH64
+ u64 diff = A64(ref) ^ A64(ip);
+ #else
+ u32 diff = A32(ref) ^ A32(ip);
+ #endif
+ 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 */
+ length = (int)(ip - anchor);
+ /* Check output limit */
+ if (unlikely(op + (1 + LASTLITERALS) + (length >> 8) > oend))
+ return 0;
+ if (length >= (int)ML_MASK) {
+ *token += ML_MASK;
+ length -= ML_MASK;
+ for (; length > 509 ; length -= 510) {
+ *op++ = 255;
+ *op++ = 255;
+ }
+ if (length > 254) {
+ length -= 255;
+ *op++ = 255;
+ }
+ *op++ = (u8)length;
+ } else
+ *token += length;
+
+ /* 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 */
+ lastrun = (int)(iend - anchor);
+ if (((char *)op - dest) + lastrun + 1
+ + ((lastrun + 255 - RUN_MASK) / 255) > (u32)maxoutputsize)
+ return 0;
+
+ if (lastrun >= (int)RUN_MASK) {
+ *op++ = (RUN_MASK << ML_BITS);
+ lastrun -= RUN_MASK;
+ for (; lastrun > 254 ; lastrun -= 255)
+ *op++ = 255;
+ *op++ = (u8)lastrun;
+ } else
+ *op++ = (lastrun << ML_BITS);
+ memcpy(op, anchor, iend - anchor);
+ op += iend - anchor;
+
+ /* End */
+ return (int)(((char *)op) - dest);
+}
+
+static inline int lz4_compress64kctx(void *ctx,
+ const char *source,
+ char *dest,
+ int isize,
+ int maxoutputsize)
+{
+ u16 *hashtable = (u16 *)ctx;
+ const u8 *ip = (u8 *) source;
+ const u8 *anchor = ip;
+ const u8 *const base = ip;
+ const u8 *const iend = ip + isize;
+ const u8 *const mflimit = iend - MFLIMIT;
+ #define MATCHLIMIT (iend - LASTLITERALS)
+
+ u8 *op = (u8 *) dest;
+ u8 *const oend = op + maxoutputsize;
+ int len, length;
+ const int skipstrength = SKIPSTRENGTH;
+ u32 forwardh;
+ int lastrun;
+
+ /* Init */
+ if (isize < MINLENGTH)
+ goto _last_literals;
+
+ memset((void *)hashtable, 0, LZ4_MEM_COMPRESS);
+
+ /* First Byte */
+ ip++;
+ forwardh = LZ4_HASH64K_VALUE(ip);
+
+ /* Main Loop */
+ for (;;) {
+ int findmatchattempts = (1U << skipstrength) + 3;
+ const u8 *forwardip = ip;
+ const u8 *ref;
+ u8 *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] = (u16)(ip - base);
+ } while (A32(ref) != A32(ip));
+
+ /* Catch up */
+ while ((ip > anchor) && (ref > (u8 *)source)
+ && (ip[-1] == ref[-1])) {
+ ip--;
+ ref--;
+ }
+
+ /* Encode Literal length */
+ length = (int)(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++ = (u8)len;
+ } else
+ *token = (length << ML_BITS);
+
+ /* Copy Literals */
+ LZ4_BLINDCOPY(anchor, op, length);
+
+_next_match:
+ /* Encode Offset */
+ LZ4_WRITE_LITTLEENDIAN_16(op, (u16)(ip - ref));
+
+ /* Start Counting */
+ ip += MINMATCH;
+ /* MinMatch verified */
+ ref += MINMATCH;
+ anchor = ip;
+
+ while (ip < MATCHLIMIT - (STEPSIZE - 1)) {
+ #if LZ4_ARCH64
+ u64 diff = A64(ref) ^ A64(ip);
+ #else
+ u32 diff = A32(ref) ^ A32(ip);
+ #endif
+
+ 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 = (int)(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++ = (u8)len;
+ } else
+ *token += len;
+
+ /* Test end of chunk */
+ if (ip > mflimit) {
+ anchor = ip;
+ break;
+ }
+
+ /* Fill table */
+ hashtable[LZ4_HASH64K_VALUE(ip-2)] = (u16)(ip - 2 - base);
+
+ /* Test next position */
+ ref = base + hashtable[LZ4_HASH64K_VALUE(ip)];
+ hashtable[LZ4_HASH64K_VALUE(ip)] = (u16)(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 */
+ lastrun = (int)(iend - anchor);
+ if (op + lastrun + 1 + (lastrun - RUN_MASK + 255) / 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++ = (u8)lastrun;
+ } else
+ *op++ = (lastrun << ML_BITS);
+ memcpy(op, anchor, iend - anchor);
+ op += iend - anchor;
+ /* End */
+ return (int)(((char *)op) - dest);
+}
+
+int lz4_compress(const unsigned char *src, size_t src_len,
+ unsigned char *dst, size_t *dst_len, void *wrkmem)
+{
+ int ret = -1;
+ int out_len = 0;
+
+ if (src_len < LZ4_64KLIMIT)
+ out_len = lz4_compress64kctx(wrkmem, src, dst, src_len,
+ lz4_compressbound(src_len));
+ else
+ out_len = lz4_compressctx(wrkmem, src, dst, src_len,
+ lz4_compressbound(src_len));
+
+ if (out_len < 0)
+ goto exit;
+
+ *dst_len = out_len;
+
+ return 0;
+exit:
+ return ret;
+}
+EXPORT_SYMBOL_GPL(lz4_compress);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("LZ4 compressor");
* Architecture-specific macros
*/
#define BYTE u8
+typedef struct _U16_S { u16 v; } U16_S;
+typedef struct _U32_S { u32 v; } U32_S;
+typedef struct _U64_S { u64 v; } U64_S;
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) \
|| defined(CONFIG_ARM) && __LINUX_ARM_ARCH__ >= 6 \
&& defined(ARM_EFFICIENT_UNALIGNED_ACCESS)
-typedef struct _U32_S { u32 v; } U32_S;
-typedef struct _U64_S { u64 v; } U64_S;
+#define A16(x) (((U16_S *)(x))->v)
#define A32(x) (((U32_S *)(x))->v)
#define A64(x) (((U64_S *)(x))->v)
#define PUT4(s, d) (A32(d) = A32(s))
#define PUT8(s, d) (A64(d) = A64(s))
+#define LZ4_WRITE_LITTLEENDIAN_16(p, v) \
+ do { \
+ A16(p) = v; \
+ p += 2; \
+ } while (0)
#else /* CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS */
+#define A64(x) get_unaligned((u64 *)&(((U16_S *)(x))->v))
+#define A32(x) get_unaligned((u32 *)&(((U16_S *)(x))->v))
+#define A16(x) get_unaligned((u16 *)&(((U16_S *)(x))->v))
+
#define PUT4(s, d) \
put_unaligned(get_unaligned((const u32 *) s), (u32 *) d)
#define PUT8(s, d) \
put_unaligned(get_unaligned((const u64 *) s), (u64 *) d)
+
+#define LZ4_WRITE_LITTLEENDIAN_16(p, v) \
+ do { \
+ put_unaligned(v, (u16 *)(p)); \
+ p += 2; \
+ } while (0)
#endif
#define COPYLENGTH 8
#define ML_MASK ((1U << ML_BITS) - 1)
#define RUN_BITS (8 - ML_BITS)
#define RUN_MASK ((1U << RUN_BITS) - 1)
+#define MEMORY_USAGE 14
+#define MINMATCH 4
+#define SKIPSTRENGTH 6
+#define LASTLITERALS 5
+#define MFLIMIT (COPYLENGTH + MINMATCH)
+#define MINLENGTH (MFLIMIT + 1)
+#define MAXD_LOG 16
+#define MAXD (1 << MAXD_LOG)
+#define MAXD_MASK (u32)(MAXD - 1)
+#define MAX_DISTANCE (MAXD - 1)
+#define HASH_LOG (MAXD_LOG - 1)
+#define HASHTABLESIZE (1 << HASH_LOG)
+#define MAX_NB_ATTEMPTS 256
+#define OPTIMAL_ML (int)((ML_MASK-1)+MINMATCH)
+#define LZ4_64KLIMIT ((1<<16) + (MFLIMIT - 1))
+#define HASHLOG64K ((MEMORY_USAGE - 2) + 1)
+#define HASH64KTABLESIZE (1U << HASHLOG64K)
+#define LZ4_HASH_VALUE(p) (((A32(p)) * 2654435761U) >> \
+ ((MINMATCH * 8) - (MEMORY_USAGE-2)))
+#define LZ4_HASH64K_VALUE(p) (((A32(p)) * 2654435761U) >> \
+ ((MINMATCH * 8) - HASHLOG64K))
+#define HASH_VALUE(p) (((A32(p)) * 2654435761U) >> \
+ ((MINMATCH * 8) - HASH_LOG))
#if LZ4_ARCH64/* 64-bit */
#define STEPSIZE 8
LZ4_WILDCOPY(s, d, e); \
} \
} while (0)
+#define HTYPE u32
+
+#ifdef __BIG_ENDIAN
+#define LZ4_NBCOMMONBYTES(val) (__builtin_clzll(val) >> 3)
+#else
+#define LZ4_NBCOMMONBYTES(val) (__builtin_ctzll(val) >> 3)
+#endif
#else /* 32-bit */
#define STEPSIZE 4
} while (0)
#define LZ4_SECURECOPY LZ4_WILDCOPY
+#define HTYPE const u8*
+
+#ifdef __BIG_ENDIAN
+#define LZ4_NBCOMMONBYTES(val) (__builtin_clz(val) >> 3)
+#else
+#define LZ4_NBCOMMONBYTES(val) (__builtin_ctz(val) >> 3)
+#endif
+
#endif
#define LZ4_READ_LITTLEENDIAN_16(d, s, p) \
do { \
LZ4_COPYPACKET(s, d); \
} while (d < e)
+
+#define LZ4_BLINDCOPY(s, d, l) \
+ do { \
+ u8 *e = (d) + l; \
+ LZ4_WILDCOPY(s, d, e); \
+ d = e; \
+ } while (0)
--- /dev/null
+/*
+ * LZ4 HC - High Compression Mode of LZ4
+ * Copyright (C) 2011-2012, 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/
+ *
+ * Changed for kernel use by:
+ * Chanho Min <chanho.min@lge.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/lz4.h>
+#include <asm/unaligned.h>
+#include "lz4defs.h"
+
+struct lz4hc_data {
+ const u8 *base;
+ HTYPE hashtable[HASHTABLESIZE];
+ u16 chaintable[MAXD];
+ const u8 *nexttoupdate;
+} __attribute__((__packed__));
+
+static inline int lz4hc_init(struct lz4hc_data *hc4, const u8 *base)
+{
+ memset((void *)hc4->hashtable, 0, sizeof(hc4->hashtable));
+ memset(hc4->chaintable, 0xFF, sizeof(hc4->chaintable));
+
+#if LZ4_ARCH64
+ hc4->nexttoupdate = base + 1;
+#else
+ hc4->nexttoupdate = base;
+#endif
+ hc4->base = base;
+ return 1;
+}
+
+/* Update chains up to ip (excluded) */
+static inline void lz4hc_insert(struct lz4hc_data *hc4, const u8 *ip)
+{
+ u16 *chaintable = hc4->chaintable;
+ HTYPE *hashtable = hc4->hashtable;
+#if LZ4_ARCH64
+ const BYTE * const base = hc4->base;
+#else
+ const int base = 0;
+#endif
+
+ while (hc4->nexttoupdate < ip) {
+ const u8 *p = hc4->nexttoupdate;
+ size_t delta = p - (hashtable[HASH_VALUE(p)] + base);
+ if (delta > MAX_DISTANCE)
+ delta = MAX_DISTANCE;
+ chaintable[(size_t)(p) & MAXD_MASK] = (u16)delta;
+ hashtable[HASH_VALUE(p)] = (p) - base;
+ hc4->nexttoupdate++;
+ }
+}
+
+static inline size_t lz4hc_commonlength(const u8 *p1, const u8 *p2,
+ const u8 *const matchlimit)
+{
+ const u8 *p1t = p1;
+
+ while (p1t < matchlimit - (STEPSIZE - 1)) {
+#if LZ4_ARCH64
+ u64 diff = A64(p2) ^ A64(p1t);
+#else
+ u32 diff = A32(p2) ^ A32(p1t);
+#endif
+ if (!diff) {
+ p1t += STEPSIZE;
+ p2 += STEPSIZE;
+ continue;
+ }
+ p1t += LZ4_NBCOMMONBYTES(diff);
+ return p1t - p1;
+ }
+#if LZ4_ARCH64
+ if ((p1t < (matchlimit-3)) && (A32(p2) == A32(p1t))) {
+ p1t += 4;
+ p2 += 4;
+ }
+#endif
+
+ if ((p1t < (matchlimit - 1)) && (A16(p2) == A16(p1t))) {
+ p1t += 2;
+ p2 += 2;
+ }
+ if ((p1t < matchlimit) && (*p2 == *p1t))
+ p1t++;
+ return p1t - p1;
+}
+
+static inline int lz4hc_insertandfindbestmatch(struct lz4hc_data *hc4,
+ const u8 *ip, const u8 *const matchlimit, const u8 **matchpos)
+{
+ u16 *const chaintable = hc4->chaintable;
+ HTYPE *const hashtable = hc4->hashtable;
+ const u8 *ref;
+#if LZ4_ARCH64
+ const BYTE * const base = hc4->base;
+#else
+ const int base = 0;
+#endif
+ int nbattempts = MAX_NB_ATTEMPTS;
+ size_t repl = 0, ml = 0;
+ u16 delta;
+
+ /* HC4 match finder */
+ lz4hc_insert(hc4, ip);
+ ref = hashtable[HASH_VALUE(ip)] + base;
+
+ /* potential repetition */
+ if (ref >= ip-4) {
+ /* confirmed */
+ if (A32(ref) == A32(ip)) {
+ delta = (u16)(ip-ref);
+ repl = ml = lz4hc_commonlength(ip + MINMATCH,
+ ref + MINMATCH, matchlimit) + MINMATCH;
+ *matchpos = ref;
+ }
+ ref -= (size_t)chaintable[(size_t)(ref) & MAXD_MASK];
+ }
+
+ while ((ref >= ip - MAX_DISTANCE) && nbattempts) {
+ nbattempts--;
+ if (*(ref + ml) == *(ip + ml)) {
+ if (A32(ref) == A32(ip)) {
+ size_t mlt =
+ lz4hc_commonlength(ip + MINMATCH,
+ ref + MINMATCH, matchlimit) + MINMATCH;
+ if (mlt > ml) {
+ ml = mlt;
+ *matchpos = ref;
+ }
+ }
+ }
+ ref -= (size_t)chaintable[(size_t)(ref) & MAXD_MASK];
+ }
+
+ /* Complete table */
+ if (repl) {
+ const BYTE *ptr = ip;
+ const BYTE *end;
+ end = ip + repl - (MINMATCH-1);
+ /* Pre-Load */
+ while (ptr < end - delta) {
+ chaintable[(size_t)(ptr) & MAXD_MASK] = delta;
+ ptr++;
+ }
+ do {
+ chaintable[(size_t)(ptr) & MAXD_MASK] = delta;
+ /* Head of chain */
+ hashtable[HASH_VALUE(ptr)] = (ptr) - base;
+ ptr++;
+ } while (ptr < end);
+ hc4->nexttoupdate = end;
+ }
+
+ return (int)ml;
+}
+
+static inline int lz4hc_insertandgetwidermatch(struct lz4hc_data *hc4,
+ const u8 *ip, const u8 *startlimit, const u8 *matchlimit, int longest,
+ const u8 **matchpos, const u8 **startpos)
+{
+ u16 *const chaintable = hc4->chaintable;
+ HTYPE *const hashtable = hc4->hashtable;
+#if LZ4_ARCH64
+ const BYTE * const base = hc4->base;
+#else
+ const int base = 0;
+#endif
+ const u8 *ref;
+ int nbattempts = MAX_NB_ATTEMPTS;
+ int delta = (int)(ip - startlimit);
+
+ /* First Match */
+ lz4hc_insert(hc4, ip);
+ ref = hashtable[HASH_VALUE(ip)] + base;
+
+ while ((ref >= ip - MAX_DISTANCE) && (ref >= hc4->base)
+ && (nbattempts)) {
+ nbattempts--;
+ if (*(startlimit + longest) == *(ref - delta + longest)) {
+ if (A32(ref) == A32(ip)) {
+ const u8 *reft = ref + MINMATCH;
+ const u8 *ipt = ip + MINMATCH;
+ const u8 *startt = ip;
+
+ while (ipt < matchlimit-(STEPSIZE - 1)) {
+ #if LZ4_ARCH64
+ u64 diff = A64(reft) ^ A64(ipt);
+ #else
+ u32 diff = A32(reft) ^ A32(ipt);
+ #endif
+
+ if (!diff) {
+ ipt += STEPSIZE;
+ reft += STEPSIZE;
+ continue;
+ }
+ ipt += LZ4_NBCOMMONBYTES(diff);
+ goto _endcount;
+ }
+ #if LZ4_ARCH64
+ if ((ipt < (matchlimit - 3))
+ && (A32(reft) == A32(ipt))) {
+ ipt += 4;
+ reft += 4;
+ }
+ ipt += 2;
+ #endif
+ if ((ipt < (matchlimit - 1))
+ && (A16(reft) == A16(ipt))) {
+ reft += 2;
+ }
+ if ((ipt < matchlimit) && (*reft == *ipt))
+ ipt++;
+_endcount:
+ reft = ref;
+
+ while ((startt > startlimit)
+ && (reft > hc4->base)
+ && (startt[-1] == reft[-1])) {
+ startt--;
+ reft--;
+ }
+
+ if ((ipt - startt) > longest) {
+ longest = (int)(ipt - startt);
+ *matchpos = reft;
+ *startpos = startt;
+ }
+ }
+ }
+ ref -= (size_t)chaintable[(size_t)(ref) & MAXD_MASK];
+ }
+ return longest;
+}
+
+static inline int lz4_encodesequence(const u8 **ip, u8 **op, const u8 **anchor,
+ int ml, const u8 *ref)
+{
+ int length, len;
+ u8 *token;
+
+ /* Encode Literal length */
+ length = (int)(*ip - *anchor);
+ token = (*op)++;
+ if (length >= (int)RUN_MASK) {
+ *token = (RUN_MASK << ML_BITS);
+ len = length - RUN_MASK;
+ for (; len > 254 ; len -= 255)
+ *(*op)++ = 255;
+ *(*op)++ = (u8)len;
+ } else
+ *token = (length << ML_BITS);
+
+ /* Copy Literals */
+ LZ4_BLINDCOPY(*anchor, *op, length);
+
+ /* Encode Offset */
+ LZ4_WRITE_LITTLEENDIAN_16(*op, (u16)(*ip - ref));
+
+ /* Encode MatchLength */
+ len = (int)(ml - MINMATCH);
+ 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)++ = (u8)len;
+ } else
+ *token += len;
+
+ /* Prepare next loop */
+ *ip += ml;
+ *anchor = *ip;
+
+ return 0;
+}
+
+static int lz4_compresshcctx(struct lz4hc_data *ctx,
+ const char *source,
+ char *dest,
+ int isize)
+{
+ const u8 *ip = (const u8 *)source;
+ const u8 *anchor = ip;
+ const u8 *const iend = ip + isize;
+ const u8 *const mflimit = iend - MFLIMIT;
+ const u8 *const matchlimit = (iend - LASTLITERALS);
+
+ u8 *op = (u8 *)dest;
+
+ int ml, ml2, ml3, ml0;
+ const u8 *ref = NULL;
+ const u8 *start2 = NULL;
+ const u8 *ref2 = NULL;
+ const u8 *start3 = NULL;
+ const u8 *ref3 = NULL;
+ const u8 *start0;
+ const u8 *ref0;
+ int lastrun;
+
+ ip++;
+
+ /* Main Loop */
+ while (ip < mflimit) {
+ ml = lz4hc_insertandfindbestmatch(ctx, ip, matchlimit, (&ref));
+ if (!ml) {
+ ip++;
+ continue;
+ }
+
+ /* saved, in case we would skip too much */
+ start0 = ip;
+ ref0 = ref;
+ ml0 = ml;
+_search2:
+ if (ip+ml < mflimit)
+ ml2 = lz4hc_insertandgetwidermatch(ctx, ip + ml - 2,
+ ip + 1, matchlimit, ml, &ref2, &start2);
+ else
+ ml2 = ml;
+ /* No better match */
+ if (ml2 == ml) {
+ lz4_encodesequence(&ip, &op, &anchor, ml, ref);
+ continue;
+ }
+
+ if (start0 < ip) {
+ /* empirical */
+ if (start2 < ip + ml0) {
+ ip = start0;
+ ref = ref0;
+ ml = ml0;
+ }
+ }
+ /*
+ * Here, start0==ip
+ * First Match too small : removed
+ */
+ if ((start2 - ip) < 3) {
+ ml = ml2;
+ ip = start2;
+ ref = ref2;
+ goto _search2;
+ }
+
+_search3:
+ /*
+ * Currently we have :
+ * ml2 > ml1, and
+ * ip1+3 <= ip2 (usually < ip1+ml1)
+ */
+ if ((start2 - ip) < OPTIMAL_ML) {
+ int correction;
+ int new_ml = ml;
+ if (new_ml > OPTIMAL_ML)
+ new_ml = OPTIMAL_ML;
+ if (ip + new_ml > start2 + ml2 - MINMATCH)
+ new_ml = (int)(start2 - ip) + ml2 - MINMATCH;
+ correction = new_ml - (int)(start2 - ip);
+ if (correction > 0) {
+ start2 += correction;
+ ref2 += correction;
+ ml2 -= correction;
+ }
+ }
+ /*
+ * Now, we have start2 = ip+new_ml,
+ * with new_ml=min(ml, OPTIMAL_ML=18)
+ */
+ if (start2 + ml2 < mflimit)
+ ml3 = lz4hc_insertandgetwidermatch(ctx,
+ start2 + ml2 - 3, start2, matchlimit,
+ ml2, &ref3, &start3);
+ else
+ ml3 = ml2;
+
+ /* No better match : 2 sequences to encode */
+ if (ml3 == ml2) {
+ /* ip & ref are known; Now for ml */
+ if (start2 < ip+ml)
+ ml = (int)(start2 - ip);
+
+ /* Now, encode 2 sequences */
+ lz4_encodesequence(&ip, &op, &anchor, ml, ref);
+ ip = start2;
+ lz4_encodesequence(&ip, &op, &anchor, ml2, ref2);
+ continue;
+ }
+
+ /* Not enough space for match 2 : remove it */
+ if (start3 < ip + ml + 3) {
+ /*
+ * can write Seq1 immediately ==> Seq2 is removed,
+ * so Seq3 becomes Seq1
+ */
+ if (start3 >= (ip + ml)) {
+ if (start2 < ip + ml) {
+ int correction =
+ (int)(ip + ml - start2);
+ start2 += correction;
+ ref2 += correction;
+ ml2 -= correction;
+ if (ml2 < MINMATCH) {
+ start2 = start3;
+ ref2 = ref3;
+ ml2 = ml3;
+ }
+ }
+
+ lz4_encodesequence(&ip, &op, &anchor, ml, ref);
+ ip = start3;
+ ref = ref3;
+ ml = ml3;
+
+ start0 = start2;
+ ref0 = ref2;
+ ml0 = ml2;
+ goto _search2;
+ }
+
+ start2 = start3;
+ ref2 = ref3;
+ ml2 = ml3;
+ goto _search3;
+ }
+
+ /*
+ * OK, now we have 3 ascending matches; let's write at least
+ * the first one ip & ref are known; Now for ml
+ */
+ if (start2 < ip + ml) {
+ if ((start2 - ip) < (int)ML_MASK) {
+ int correction;
+ if (ml > OPTIMAL_ML)
+ ml = OPTIMAL_ML;
+ if (ip + ml > start2 + ml2 - MINMATCH)
+ ml = (int)(start2 - ip) + ml2
+ - MINMATCH;
+ correction = ml - (int)(start2 - ip);
+ if (correction > 0) {
+ start2 += correction;
+ ref2 += correction;
+ ml2 -= correction;
+ }
+ } else
+ ml = (int)(start2 - ip);
+ }
+ lz4_encodesequence(&ip, &op, &anchor, ml, ref);
+
+ ip = start2;
+ ref = ref2;
+ ml = ml2;
+
+ start2 = start3;
+ ref2 = ref3;
+ ml2 = ml3;
+
+ goto _search3;
+ }
+
+ /* Encode Last Literals */
+ lastrun = (int)(iend - anchor);
+ if (lastrun >= (int)RUN_MASK) {
+ *op++ = (RUN_MASK << ML_BITS);
+ lastrun -= RUN_MASK;
+ for (; lastrun > 254 ; lastrun -= 255)
+ *op++ = 255;
+ *op++ = (u8) lastrun;
+ } else
+ *op++ = (lastrun << ML_BITS);
+ memcpy(op, anchor, iend - anchor);
+ op += iend - anchor;
+ /* End */
+ return (int) (((char *)op) - dest);
+}
+
+int lz4hc_compress(const unsigned char *src, size_t src_len,
+ unsigned char *dst, size_t *dst_len, void *wrkmem)
+{
+ int ret = -1;
+ int out_len = 0;
+
+ struct lz4hc_data *hc4 = (struct lz4hc_data *)wrkmem;
+ lz4hc_init(hc4, (const u8 *)src);
+ out_len = lz4_compresshcctx((struct lz4hc_data *)hc4, (const u8 *)src,
+ (char *)dst, (int)src_len);
+
+ if (out_len < 0)
+ goto exit;
+
+ *dst_len = out_len;
+ return 0;
+
+exit:
+ return ret;
+}
+EXPORT_SYMBOL_GPL(lz4hc_compress);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("LZ4HC compressor");
projects / users / hch / xfs.git / commitdiff