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    Subject[RFC] LZO de/compression support - take 3
    Hi,

    This contains LZO1X-1 compressor and LZO1X decompressor (safe and
    standard version).
    This includes changes suggested by various people - Thanks to all who
    reviewed previous patches for this LZO port.

    Changelog vs original LZO 2.02 code:
    - Chopped down huge parts of original code that were irrelevant fot this port
    - Use of standard data types
    - Use memcpy() instead of COPY4 macros used in orig. code
    - Various macros -> static inline functions
    - Code matches general kernel style
    - Various other cleanups suggested in reviews

    For now, tested on x86 only.

    Signed-off-by: Nitin Gupta <nitingupta910@gmail.com>
    ---

    diff --git a/Makefile b/Makefile
    index 34210af..88053ba 100644
    --- a/Makefile
    +++ b/Makefile
    @@ -826,11 +826,18 @@ include/config/kernel.release:
    include/config/auto.conf FORCE
    # Listed in dependency order
    PHONY += prepare archprepare prepare0 prepare1 prepare2 prepare3

    +# prepare4 does module specific things prior to compilation
    +prepare4:
    +ifneq ($(CONFIG_LZO1X),n)
    + $(Q)ln -sf $(srctree)/lib/lzo1x/lzo1x_decompress.c \
    + $(srctree)/lib/lzo1x/lzo1x_decompress_safe.c
    +endif
    +
    # prepare3 is used to check if we are building in a separate output directory,
    # and if so do:
    # 1) Check that make has not been executed in the kernel src $(srctree)
    # 2) Create the include2 directory, used for the second asm symlink
    -prepare3: include/config/kernel.release
    +prepare3: prepare4 include/config/kernel.release
    ifneq ($(KBUILD_SRC),)
    @echo ' Using $(srctree) as source for kernel'
    $(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then \
    diff --git a/include/linux/lzo1x.h b/include/linux/lzo1x.h
    new file mode 100755
    index 0000000..7c2f633
    --- /dev/null
    +++ b/include/linux/lzo1x.h
    @@ -0,0 +1,80 @@
    +/* lzo1x.h -- public interface of the LZO1X compression algorithm
    +
    + This file is part of the LZO real-time data compression library.
    +
    + Copyright (C) 1996-2005 Markus Franz Xaver Johannes Oberhumer
    + All Rights Reserved.
    +
    + The LZO library is free software; you can redistribute it and/or
    + modify it under the terms of the GNU General Public License,
    + version 2, as published by the Free Software Foundation.
    +
    + The LZO library is distributed in the hope that it will be useful,
    + but WITHOUT ANY WARRANTY; without even the implied warranty of
    + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    + GNU General Public License for more details.
    +
    + You should have received a copy of the GNU General Public License
    + along with the LZO library; see the file COPYING.
    + If not, write to the Free Software Foundation, Inc.,
    + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
    +
    + Markus F.X.J. Oberhumer
    + <markus@oberhumer.com>
    + http://www.oberhumer.com/opensource/lzo/
    +
    +
    + This file is modified version of lzo1x.h found in original LZO 2.02
    + code. Some additional changes have also been made to make it work
    + in kernel space.
    +
    + Nitin Gupta
    + <nitingupta910@gmail.com>
    + */
    +
    +#ifndef __LZO1X_H
    +#define __LZO1X_H
    +
    +/* LZO return codes */
    +#define LZO_E_OK 0
    +#define LZO_E_ERROR (-1)
    +#define LZO_E_OUT_OF_MEMORY (-2) /* [not used right now] */
    +#define LZO_E_NOT_COMPRESSIBLE (-3) /* [not used right now] */
    +#define LZO_E_INPUT_OVERRUN (-4)
    +#define LZO_E_OUTPUT_OVERRUN (-5)
    +#define LZO_E_LOOKBEHIND_OVERRUN (-6)
    +#define LZO_E_EOF_NOT_FOUND (-7)
    +#define LZO_E_INPUT_NOT_CONSUMED (-8)
    +#define LZO_E_NOT_YET_IMPLEMENTED (-9) /* [not used right now] */
    +
    +/* Size of temp buffer (workmem) required by lzo1x_compress */
    +#define LZO1X_WORKMEM_SIZE ((size_t) (16384L * sizeof(unsigned char *)))
    +
    +/*
    + * This required 'workmem' of size LZO1X_WORKMEM_SIZE
    + */
    +int lzo1x_compress(const unsigned char *src, size_t src_len,
    + unsigned char *dst, size_t *dst_len,
    + void *workmem);
    +
    +
    +/*
    + * This decompressor expects valid compressed data.
    + *
    + * If the compressed data gets corrupted somehow (e.g. transmission
    + * via an erroneous channel, disk errors, ...) it will probably crash
    + * your application because absolutely no additional checks are done.
    + */
    +int lzo1x_decompress(const unsigned char *src, size_t src_len,
    + unsigned char *dst, size_t *dst_len);
    +
    +
    +/*
    + * The `safe' decompressor. Somewhat slower.
    + *
    + * This decompressor will catch all compressed data violations and
    + * return an error code in this case.
    + */
    +int lzo1x_decompress_safe(const unsigned char *src, size_t src_len,
    + unsigned char *dst, size_t *dst_len);
    +#endif
    diff --git a/lib/Kconfig b/lib/Kconfig
    index 2e7ae6b..9d30b1f 100644
    --- a/lib/Kconfig
    +++ b/lib/Kconfig
    @@ -64,6 +64,12 @@ config ZLIB_INFLATE
    config ZLIB_DEFLATE
    tristate

    +config LZO1X
    + tristate "LZO1X Compression/Decompression"
    + help
    + Compression: LZO1X-1
    + Decompression: LZO1X
    +
    #
    # Generic allocator support is selected if needed
    #
    diff --git a/lib/Makefile b/lib/Makefile
    index c8c8e20..4dad99d 100644
    --- a/lib/Makefile
    +++ b/lib/Makefile
    @@ -49,6 +49,7 @@ obj-$(CONFIG_GENERIC_ALLOCATOR) += genalloc.o
    obj-$(CONFIG_ZLIB_INFLATE) += zlib_inflate/
    obj-$(CONFIG_ZLIB_DEFLATE) += zlib_deflate/
    obj-$(CONFIG_REED_SOLOMON) += reed_solomon/
    +obj-$(CONFIG_LZO1X) += lzo1x/

    obj-$(CONFIG_TEXTSEARCH) += textsearch.o
    obj-$(CONFIG_TEXTSEARCH_KMP) += ts_kmp.o
    diff --git a/lib/lzo1x/Makefile b/lib/lzo1x/Makefile
    new file mode 100644
    index 0000000..e036b42
    --- /dev/null
    +++ b/lib/lzo1x/Makefile
    @@ -0,0 +1,11 @@
    +#
    +# When compiling this module out of tree, do 'make prepare_lzo'
    +# before compiling as usual
    +#
    +obj-$(CONFIG_LZO1X) += lzo1x.o
    +CFLAGS_lzo1x_decompress_safe.o += -DLZO1X_DECOMPRESS_SAFE
    +lzo1x-objs := lzo1x_compress.o lzo1x_decompress.o lzo1x_decompress_safe.o
    +
    +prepare_lzo:
    + @ln -sf lzo1x_decompress.c lzo1x_decompress_safe.c
    +
    diff --git a/lib/lzo1x/lzo1x_compress.c b/lib/lzo1x/lzo1x_compress.c
    new file mode 100755
    index 0000000..690c082
    --- /dev/null
    +++ b/lib/lzo1x/lzo1x_compress.c
    @@ -0,0 +1,256 @@
    +/* lzo1x_compress.c -- LZO1X-1 compression
    +
    + This file is part of the LZO real-time data compression library.
    +
    + Copyright (C) 1996-2005 Markus Franz Xaver Johannes Oberhumer
    + All Rights Reserved.
    +
    + The LZO library is free software; you can redistribute it and/or
    + modify it under the terms of the GNU General Public License,
    + version 2, as published by the Free Software Foundation.
    +
    + The LZO library is distributed in the hope that it will be useful,
    + but WITHOUT ANY WARRANTY; without even the implied warranty of
    + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    + GNU General Public License for more details.
    +
    + You should have received a copy of the GNU General Public License
    + along with the LZO library; see the file COPYING.
    + If not, write to the Free Software Foundation, Inc.,
    + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
    +
    + Markus F.X.J. Oberhumer
    + <markus@oberhumer.com>
    + http://www.oberhumer.com/opensource/lzo/
    +
    +
    + This file is derived from lzo1x_1.c and lzo1x_c.ch found in original
    + LZO 2.02 code. Some additional changes have also been made to make
    + it work in kernel space.
    +
    + Nitin Gupta
    + <nitingupta910@gmail.com>
    + */
    +
    +#include <linux/kernel.h>
    +#include <linux/module.h>
    +#include <linux/compiler.h>
    +
    +#include "lzo1x_int.h"
    +
    +MODULE_LICENSE("GPL");
    +MODULE_DESCRIPTION("LZO1X Compression");
    +
    +/* compress a block of data. */
    +static unsigned int
    +lzo1x_compress_worker(const unsigned char *in, size_t in_len,
    + unsigned char *out, size_t *out_len,
    + void *workmem)
    +{
    + const unsigned char *ip;
    + unsigned char *op;
    + const unsigned char * const in_end = in + in_len;
    + const unsigned char * const ip_end = in + in_len - M2_MAX_LEN - 5;
    + const unsigned char *ii;
    + const unsigned char ** const dict = (const unsigned char **)workmem;
    +
    + op = out;
    + ip = in;
    + ii = ip;
    +
    + ip += 4;
    + for (;;) {
    + const unsigned char *m_pos;
    + size_t m_off;
    + size_t m_len;
    + size_t dindex;
    +
    + dindex = DINDEX1(ip);
    + m_pos = dict[dindex];
    +
    + if ((m_pos < in) || (m_off = (size_t)(ip - m_pos)) <= 0
    + || m_off > M4_MAX_OFFSET)
    + goto literal;
    +
    + if (m_off <= M2_MAX_OFFSET || m_pos[3] == ip[3])
    + goto try_match;
    +
    + dindex = DINDEX2(dindex);
    + m_pos = dict[dindex];
    +
    + if ((m_pos < in) || (m_off = (size_t)(ip - m_pos)) <= 0
    + || m_off > M4_MAX_OFFSET)
    + goto literal;
    +
    + if (m_off <= M2_MAX_OFFSET || m_pos[3] == ip[3])
    + goto try_match;
    +
    + goto literal;
    +
    +try_match:
    + if (*(const unsigned short *)m_pos ==
    + *(const unsigned short *)ip) {
    + if (likely(m_pos[2] == ip[2]))
    + goto match;
    + }
    +
    + /* a literal */
    +literal:
    + dict[dindex] = ip;
    + ++ip;
    + if (unlikely(ip >= ip_end))
    + break;
    + continue;
    +
    + /* a match */
    +match:
    + dict[dindex] = ip;
    + /* store current literal run */
    + if ((size_t)(ip - ii) > 0) {
    + size_t t = (size_t)(ip - ii);
    + if (t <= 3)
    + op[-2] |= (unsigned char)(t);
    + else if (t <= 18)
    + *op++ = (unsigned char)(t - 3);
    + else {
    + size_t tt = t - 18;
    + *op++ = 0;
    + while (tt > 255) {
    + tt -= 255;
    + *op++ = 0;
    + }
    + *op++ = (unsigned char)tt;
    + }
    + do *op++ = *ii++; while (--t > 0);
    + }
    +
    + /* code the match */
    + ip += 3;
    + if (m_pos[3] != *ip++ || m_pos[4] != *ip++ ||
    + m_pos[5] != *ip++ || m_pos[6] != *ip++ ||
    + m_pos[7] != *ip++ || m_pos[8] != *ip++) {
    + --ip;
    + m_len = (size_t)(ip - ii);
    +
    + if (m_off <= M2_MAX_OFFSET) {
    + m_off -= 1;
    + *op++ = (unsigned char)(((m_len - 1) << 5) |
    + ((m_off & 7) << 2));
    + *op++ = (unsigned char)(m_off >> 3);
    + }
    + else if (m_off <= M3_MAX_OFFSET) {
    + m_off -= 1;
    + *op++ = (unsigned char)(M3_MARKER |
    + (m_len - 2));
    + goto m3_m4_offset;
    + } else {
    + m_off -= 0x4000;
    + *op++ = (unsigned char)(M4_MARKER |
    + ((m_off & 0x4000) >> 11) |
    + (m_len - 2));
    + goto m3_m4_offset;
    + }
    + } else {
    + const unsigned char *end = in_end;
    + const unsigned char *m = m_pos + M2_MAX_LEN + 1;
    + while (ip < end && *m == *ip)
    + m++, ip++;
    + m_len = (size_t)(ip - ii);
    +
    + if (m_off <= M3_MAX_OFFSET) {
    + m_off -= 1;
    + if (m_len <= 33)
    + *op++ = (unsigned char)(M3_MARKER |
    + (m_len - 2));
    + else {
    + m_len -= 33;
    + *op++ = M3_MARKER | 0;
    + goto m3_m4_len;
    + }
    + } else {
    + m_off -= 0x4000;
    + if (m_len <= M4_MAX_LEN)
    + *op++ = (unsigned char)(M4_MARKER |
    + ((m_off & 0x4000) >> 11) |
    + (m_len - 2));
    + else {
    + m_len -= M4_MAX_LEN;
    + *op++ = (unsigned char)(M4_MARKER |
    + ((m_off & 0x4000) >> 11));
    +m3_m4_len:
    + while (m_len > 255) {
    + m_len -= 255;
    + *op++ = 0;
    + }
    + *op++ = (unsigned char)(m_len);
    + }
    + }
    +
    +m3_m4_offset:
    + *op++ = (unsigned char)((m_off & 63) << 2);
    + *op++ = (unsigned char)(m_off >> 6);
    + }
    +
    + ii = ip;
    + if (unlikely(ip >= ip_end))
    + break;
    + }
    +
    + *out_len = (size_t)(op - out);
    + return (size_t)(in_end - ii);
    +}
    +
    +
    +/*
    + * This requires buffer (workmem) of size LZO1X_WORKMEM_SIZE
    + * (exported by lzo1x.h).
    + */
    +int
    +lzo1x_compress(const unsigned char *in, size_t in_len,
    + unsigned char *out, size_t *out_len,
    + void *workmem)
    +{
    + unsigned char *op = out;
    + size_t t;
    +
    + if (!workmem)
    + return -EINVAL;
    +
    + if (unlikely(in_len <= M2_MAX_LEN + 5))
    + t = in_len;
    + else {
    + t = lzo1x_compress_worker(in, in_len, op, out_len, workmem);
    + op += *out_len;
    + }
    +
    + if (t > 0) {
    + const unsigned char *ii = in + in_len - t;
    +
    + if (op == out && t <= 238)
    + *op++ = (unsigned char)(17 + t);
    + else if (t <= 3)
    + op[-2] |= (unsigned char)(t);
    + else if (t <= 18)
    + *op++ = (unsigned char)(t - 3);
    + else {
    + size_t tt = t - 18;
    + *op++ = 0;
    + while (tt > 255) {
    + tt -= 255;
    + *op++ = 0;
    + }
    + *op++ = (unsigned char)tt;
    + }
    + memcpy(op, ii, t);
    + op += t;
    + ii += t;
    + }
    + *op++ = M4_MARKER | 1;
    + *op++ = 0;
    + *op++ = 0;
    +
    + *out_len = (size_t)(op - out);
    + return 0;
    +}
    +
    +EXPORT_SYMBOL(lzo1x_compress);
    diff --git a/lib/lzo1x/lzo1x_decompress.c b/lib/lzo1x/lzo1x_decompress.c
    new file mode 100755
    index 0000000..09fa1ca
    --- /dev/null
    +++ b/lib/lzo1x/lzo1x_decompress.c
    @@ -0,0 +1,224 @@
    +/* lzo1x_decompress.c -- LZO1X decompression
    +
    + This file is part of the LZO real-time data compression library.
    +
    + Copyright (C) 1996-2005 Markus Franz Xaver Johannes Oberhumer
    + All Rights Reserved.
    +
    + The LZO library is free software; you can redistribute it and/or
    + modify it under the terms of the GNU General Public License,
    + version 2, as published by the Free Software Foundation.
    +
    + The LZO library is distributed in the hope that it will be useful,
    + but WITHOUT ANY WARRANTY; without even the implied warranty of
    + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    + GNU General Public License for more details.
    +
    + You should have received a copy of the GNU General Public License
    + along with the LZO library; see the file COPYING.
    + If not, write to the Free Software Foundation, Inc.,
    + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
    +
    + Markus F.X.J. Oberhumer
    + <markus@oberhumer.com>
    + http://www.oberhumer.com/opensource/lzo/
    +
    +
    + This file is derived from lzo1x_d1.c and lzo1x_d.ch found in original
    + LZO 2.02 code. Some additional changes have also been made to make
    + it work in kernel space.
    +
    + Nitin Gupta
    + <nitingupta910@gmail.com>
    + */
    +
    +#include <linux/kernel.h>
    +#include <linux/module.h>
    +#include <asm/byteorder.h>
    +#include <linux/lzo1x.h>
    +
    +#include "lzo1x_int.h"
    +
    +MODULE_LICENSE("GPL");
    +MODULE_DESCRIPTION("LZO1X Decompression");
    +
    +int
    +lzo1x_decompress(const unsigned char *in, size_t in_len,
    + unsigned char *out, size_t *out_len)
    +{
    + size_t t;
    + unsigned char *op = out;
    + const unsigned char *ip = in, *m_pos;
    + const unsigned char * const ip_end = in + in_len;
    +#if defined(HAVE_ANY_OP)
    + unsigned char * const op_end = out + *out_len;
    +#endif
    + *out_len = 0;
    +
    + if (*ip > 17) {
    + t = *ip++ - 17;
    + if (t < 4)
    + goto match_next;
    + NEED_OP(t);
    + NEED_IP(t + 1);
    + memcpy(op, ip, t);
    + op += t;
    + ip += t;
    + goto first_literal_run;
    + }
    +
    + while (TEST_IP) {
    + t = *ip++;
    + if (t >= 16)
    + goto match;
    + /* a literal run */
    + if (t == 0) {
    + NEED_IP(1);
    + while (*ip == 0) {
    + t += 255;
    + ip++;
    + NEED_IP(1);
    + }
    + t += 15 + *ip++;
    + }
    + /* copy literals */
    + NEED_OP(t + 3);
    + NEED_IP(t + 4);
    + memcpy(op, ip, t + 3);
    + op += t + 3;
    + ip += t + 3;
    +
    +first_literal_run:
    + t = *ip++;
    + if (t >= 16)
    + goto match;
    + m_pos = op - (1 + M2_MAX_OFFSET);
    + m_pos -= t >> 2;
    + m_pos -= *ip++ << 2;
    + TEST_LB(m_pos);
    + NEED_OP(3);
    + *op++ = *m_pos++;
    + *op++ = *m_pos++;
    + *op++ = *m_pos;
    + goto match_done;
    +
    + /* handle matches */
    + do {
    +match:
    + if (t >= 64) { /* a M2 match */
    + m_pos = op - 1;
    + m_pos -= (t >> 2) & 7;
    + m_pos -= *ip++ << 3;
    + t = (t >> 5) - 1;
    + TEST_LB(m_pos);
    + NEED_OP(t + 3 - 1);
    + goto copy_match;
    + } else if (t >= 32) { /* a M3 match */
    + t &= 31;
    + if (t == 0) {
    + NEED_IP(1);
    + while (*ip == 0) {
    + t += 255;
    + ip++;
    + NEED_IP(1);
    + }
    + t += 31 + *ip++;
    + }
    + m_pos = op - 1 - (cpu_to_le16(
    + *(const unsigned short *)ip) >> 2);
    + ip += 2;
    + } else if (t >= 16) { /* a M4 match */
    + m_pos = op;
    + m_pos -= (t & 8) << 11;
    + t &= 7;
    + if (t == 0) {
    + NEED_IP(1);
    + while (*ip == 0) {
    + t += 255;
    + ip++;
    + NEED_IP(1);
    + }
    + t += 7 + *ip++;
    + }
    + m_pos -= cpu_to_le16(
    + *(const unsigned short *)ip) >> 2;
    + ip += 2;
    + if (m_pos == op)
    + goto eof_found;
    + m_pos -= 0x4000;
    + } else { /* a M1 match */
    + m_pos = op - 1;
    + m_pos -= t >> 2;
    + m_pos -= *ip++ << 2;
    + TEST_LB(m_pos);
    + NEED_OP(2);
    + *op++ = *m_pos++;
    + *op++ = *m_pos;
    + goto match_done;
    + }
    +
    + /* copy match */
    + TEST_LB(m_pos);
    + NEED_OP(t + 3 - 1);
    +
    +copy_match:
    + if (op - m_pos >= BITS_PER_LONG / BITS_PER_BYTE) {
    + memcpy(op, m_pos, t + 2);
    + op += t + 2;
    + m_pos += t + 2;
    + } else {
    + *op = *m_pos;
    + *++op = *++m_pos;
    + do
    + *++op = *++m_pos;
    + while (--t > 0);
    + op++;
    + m_pos++;
    + }
    +
    +match_done:
    + t = ip[-2] & 3;
    + if (t == 0)
    + break;
    +
    + /* copy literals */
    +match_next:
    + NEED_OP(t);
    + NEED_IP(t+1);
    + *op++ = *ip++;
    + if (t > 1) {
    + *op++ = *ip++;
    + if (t > 2)
    + *op++ = *ip++;
    + }
    + t = *ip++;
    + } while (TEST_IP);
    + }
    +
    +#if defined(HAVE_TEST_IP)
    + /* no EOF code was found */
    + *out_len = (size_t)(op - out);
    + return LZO_E_EOF_NOT_FOUND;
    +#endif
    +
    +eof_found:
    + *out_len = (size_t)(op - out);
    + return (ip == ip_end ? LZO_E_OK :
    + (ip < ip_end ? LZO_E_INPUT_NOT_CONSUMED : LZO_E_INPUT_OVERRUN));
    +
    +#if defined(LZO1X_DECOMPRESS_SAFE)
    +input_overrun:
    + *out_len = (size_t)(op - out);
    + return LZO_E_INPUT_OVERRUN;
    +
    +output_overrun:
    + *out_len = (size_t)(op - out);
    + return LZO_E_OUTPUT_OVERRUN;
    +
    +lookbehind_overrun:
    + *out_len = (size_t)(op - out);
    + return LZO_E_LOOKBEHIND_OVERRUN;
    +#endif
    +}
    +
    +EXPORT_SYMBOL(lzo1x_decompress);
    diff --git a/lib/lzo1x/lzo1x_int.h b/lib/lzo1x/lzo1x_int.h
    new file mode 100755
    index 0000000..69e6d9b
    --- /dev/null
    +++ b/lib/lzo1x/lzo1x_int.h
    @@ -0,0 +1,122 @@
    +/* lzo1x_int.h -- to be used internally by LZO de/compression algorithms
    +
    + This file is part of the LZO real-time data compression library.
    +
    + Copyright (C) 1996-2005 Markus Franz Xaver Johannes Oberhumer
    + All Rights Reserved.
    +
    + The LZO library is free software; you can redistribute it and/or
    + modify it under the terms of the GNU General Public License,
    + version 2, as published by the Free Software Foundation.
    +
    + The LZO library is distributed in the hope that it will be useful,
    + but WITHOUT ANY WARRANTY; without even the implied warranty of
    + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    + GNU General Public License for more details.
    +
    + You should have received a copy of the GNU General Public License
    + along with the LZO library; see the file COPYING.
    + If not, write to the Free Software Foundation, Inc.,
    + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
    +
    + Markus F.X.J. Oberhumer
    + <markus@oberhumer.com>
    + http://www.oberhumer.com/opensource/lzo/
    +
    +
    + This file was derived from several header files found in original
    + LZO 2.02 code. Some additional changes have also been made to make
    + it work in kernel space.
    +
    + Nitin Gupta
    + <nitingupta910@gmail.com>
    + */
    +
    +#ifndef __LZO1X_INT_H
    +#define __LZO1X_INT_H
    +
    +#include <linux/types.h>
    +
    +#define D_BITS 14
    +#define D_SIZE (1u << D_BITS)
    +#define D_MASK (D_SIZE - 1)
    +#define D_HIGH ((D_MASK >> 1) + 1)
    +
    +static inline size_t DX2(const unsigned char *p, size_t s1, size_t s2)
    +{
    + return (((((size_t)(p[2]) << s2) ^ p[1]) << s1) ^ p[0]);
    +}
    +
    +static inline size_t DX3(const unsigned char *p, size_t s1, size_t
    s2, size_t s3)
    +{
    + return (DX2(p + 1, s2, s3) << s1) ^ p[0];
    +}
    +
    +static inline size_t DINDEX1(const unsigned char *p)
    +{
    + return ((size_t)(0x21 * DX3(p, 5, 5, 6)) >> 5) & D_MASK;
    +}
    +
    +static inline size_t DINDEX2(size_t d)
    +{
    + return (d & (D_MASK & 0x7ff)) ^ (D_HIGH | 0x1f);
    +}
    +
    +/* LZO1X Specific constants */
    +#define M1_MAX_OFFSET 0x0400
    +#define M2_MAX_OFFSET 0x0800
    +#define M3_MAX_OFFSET 0x4000
    +#define M4_MAX_OFFSET 0xbfff
    +
    +#define M1_MIN_LEN 2
    +#define M1_MAX_LEN 2
    +#define M2_MIN_LEN 3
    +#define M2_MAX_LEN 8
    +#define M3_MIN_LEN 3
    +#define M3_MAX_LEN 33
    +#define M4_MIN_LEN 3
    +#define M4_MAX_LEN 9
    +
    +#define M1_MARKER 0
    +#define M2_MARKER 64
    +#define M3_MARKER 32
    +#define M4_MARKER 16
    +
    +/* LZO return codes */
    +#define LZO_E_OK 0
    +#define LZO_E_ERROR (-1)
    +#define LZO_E_OUT_OF_MEMORY (-2) /* [not used right now] */
    +#define LZO_E_NOT_COMPRESSIBLE (-3) /* [not used right now] */
    +#define LZO_E_INPUT_OVERRUN (-4)
    +#define LZO_E_OUTPUT_OVERRUN (-5)
    +#define LZO_E_LOOKBEHIND_OVERRUN (-6)
    +#define LZO_E_EOF_NOT_FOUND (-7)
    +#define LZO_E_INPUT_NOT_CONSUMED (-8)
    +#define LZO_E_NOT_YET_IMPLEMENTED (-9) /* [not used right now] */
    +
    +/* Macros for 'safe' decompression */
    +#ifdef LZO1X_DECOMPRESS_SAFE
    +
    +#define lzo1x_decompress lzo1x_decompress_safe
    +#define TEST_IP (ip < ip_end)
    +#define NEED_IP(x) \
    + if ((size_t)(ip_end - ip) < (size_t)(x)) goto input_overrun
    +#define NEED_OP(x) \
    + if ((size_t)(op_end - op) < (size_t)(x)) goto output_overrun
    +#define TEST_LB(m_pos) \
    + if (m_pos < out || m_pos >= op) goto lookbehind_overrun
    +#define HAVE_TEST_IP
    +#define HAVE_ANY_OP
    +
    +#else /* !LZO1X_DECOMPRESS_SAFE */
    +
    +#define TEST_IP 1
    +#define TEST_LB(x) ((void) 0)
    +#define NEED_IP(x) ((void) 0)
    +#define NEED_OP(x) ((void) 0)
    +#undef HAVE_TEST_IP
    +#undef HAVE_ANY_OP
    +
    +#endif /* LZO1X_DECOMPRESS_SAFE */
    +
    +#endif[unhandled content-type:application/x-bzip2]
    \
     
     \ /
      Last update: 2007-05-23 10:31    [W:0.062 / U:30.264 seconds]
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