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    SubjectRe: Suspend 2 merge: 46/51: LZF support.
    On Thu, Nov 25, 2004 at 01:38:44PM +1100, Nigel Cunningham wrote:
    > Hi.
    >
    > On Thu, 2004-11-25 at 10:01, Bartlomiej Zolnierkiewicz wrote:
    > > Hi Nigel!
    > >
    > > Shouldn't LZF code go to lib/ ?
    >
    > I suppose it could. Will do.
    >
    > Regards,

    === include/linux/lzf.h
    ==================================================================
    --- include/linux/lzf.h (revision 24482)
    +++ include/linux/lzf.h (revision 24483)
    @@ -0,0 +1,7 @@
    +#ifndef _LZF_H_
    +#define _LZF_H_
    +
    +unsigned int lzf_decompress (const void *const in_data, unsigned int in_len, void *out_data, unsigned int out_len);
    +unsigned int lzf_compress (const void *const in_data, unsigned int in_len, void *out_data, unsigned int out_len, void *hbuf);
    +
    +#endif
    === lib/lzf_d.c
    ==================================================================
    --- lib/lzf_d.c (revision 24482)
    +++ lib/lzf_d.c (revision 24483)
    @@ -0,0 +1,98 @@
    +/*
    + * Copyright (c) 2000-2002 Marc Alexander Lehmann <pcg@goof.com>
    + *
    + * Redistribution and use in source and binary forms, with or without modifica-
    + * tion, are permitted provided that the following conditions are met:
    + *
    + * 1. Redistributions of source code must retain the above copyright notice,
    + * this list of conditions and the following disclaimer.
    + *
    + * 2. 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.
    + *
    + * 3. The name of the author may not be used to endorse or promote products
    + * derived from this software without specific prior written permission.
    + *
    + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
    + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
    + * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
    + * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
    + * CIAL, 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 OTH-
    + * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
    + * OF THE POSSIBILITY OF SUCH DAMAGE.
    + *
    + * Alternatively, the contents of this file may be used under the terms of
    + * the GNU General Public License version 2 (the "GPL"), in which case the
    + * provisions of the GPL are applicable instead of the above. If you wish to
    + * allow the use of your version of this file only under the terms of the
    + * GPL and not to allow others to use your version of this file under the
    + * BSD license, indicate your decision by deleting the provisions above and
    + * replace them with the notice and other provisions required by the GPL. If
    + * you do not delete the provisions above, a recipient may use your version
    + * of this file under either the BSD or the GPL.
    + */
    +
    +unsigned int
    +lzf_decompress (const void *const in_data, unsigned int in_len,
    + void *out_data, unsigned int out_len)
    +{
    + u8 const *ip = in_data;
    + u8 *op = out_data;
    + u8 const *const in_end = ip + in_len;
    + u8 *const out_end = op + out_len;
    +
    + do
    + {
    + unsigned int ctrl = *ip++;
    +
    + if (ctrl < (1 << 5)) /* literal run */
    + {
    + ctrl++;
    +
    + if (op + ctrl > out_end)
    + return 0;
    +
    +#if USE_MEMCPY
    + memcpy (op, ip, ctrl);
    + op += ctrl;
    + ip += ctrl;
    +#else
    + do
    + *op++ = *ip++;
    + while (--ctrl);
    +#endif
    + }
    + else /* back reference */
    + {
    + unsigned int len = ctrl >> 5;
    +
    + u8 *ref = op - ((ctrl & 0x1f) << 8) - 1;
    +
    + if (len == 7)
    + len += *ip++;
    +
    + ref -= *ip++;
    +
    + if (op + len + 2 > out_end)
    + return 0;
    +
    + if (ref < (u8 *)out_data)
    + return 0;
    +
    + *op++ = *ref++;
    + *op++ = *ref++;
    +
    + do
    + *op++ = *ref++;
    + while (--len);
    + }
    + }
    + while (op < out_end && ip < in_end);
    +
    + return op - (u8 *)out_data;
    +}
    +
    === lib/Kconfig
    ==================================================================
    --- lib/Kconfig (revision 24482)
    +++ lib/Kconfig (revision 24483)
    @@ -30,6 +30,9 @@
    require M here. See Castagnoli93.
    Module will be libcrc32c.

    +config LZF
    + tristate "LZF Compress/Decompress Support"
    +
    #
    # compression support is select'ed if needed
    #
    === lib/lzf.c
    ==================================================================
    --- lib/lzf.c (revision 24482)
    +++ lib/lzf.c (revision 24483)
    @@ -0,0 +1,46 @@
    +/*
    + * lib/lzf.c
    + *
    + * Copyright (C) 2003 Marc Lehmann <pcg@goof.com>
    + * Copyright (C) 2003,2004 Nigel Cunningham <ncunningham@linuxmail.org>
    + *
    + * This file is released under the GPLv2.
    + *
    + * This file contains LZH data compression and decompress for kernel.
    + */
    +
    +#include <linux/suspend.h>
    +#include <linux/module.h>
    +
    +/*
    + * size of hashtable is (1 << HLOG) * sizeof (char *)
    + * decompression is independent of the hash table size
    + * the difference between 15 and 14 is very small
    + * for small blocks (and 14 is also faster).
    + * For a low-memory configuration, use HLOG == 13;
    + * For best compression, use 15 or 16.
    + */
    +#ifndef HLOG
    +# define HLOG 14
    +#endif
    +
    +/*
    + * sacrifice some compression quality in favour of compression speed.
    + * (roughly 1-2% worse compression for large blocks and
    + * 9-10% for small, redundant, blocks and >>20% better speed in both cases)
    + * In short: enable this for binary data, disable this for text data.
    + */
    +#ifndef ULTRA_FAST
    +# define ULTRA_FAST 1
    +#endif
    +
    +#define STRICT_ALIGN 0
    +#define USE_MEMCPY 1
    +#define INIT_HTAB 0
    +
    +#include "lzf_c.c"
    +#include "lzf_d.c"
    +
    +EXPORT_SYMBOL_GPL(lzf_compress);
    +EXPORT_SYMBOL_GPL(lzf_decompress);
    +
    === lib/Makefile
    ==================================================================
    --- lib/Makefile (revision 24482)
    +++ lib/Makefile (revision 24483)
    @@ -15,6 +15,7 @@
    lib-y += dec_and_lock.o
    endif

    +
    obj-$(CONFIG_CRC_CCITT) += crc-ccitt.o
    obj-$(CONFIG_CRC32) += crc32.o
    obj-$(CONFIG_LIBCRC32C) += libcrc32c.o
    @@ -23,6 +24,8 @@
    obj-$(CONFIG_ZLIB_INFLATE) += zlib_inflate/
    obj-$(CONFIG_ZLIB_DEFLATE) += zlib_deflate/

    +obj-$(CONFIG_LZF) += lzf.o
    +
    hostprogs-y := gen_crc32table
    clean-files := crc32table.h

    === lib/lzf_c.c
    ==================================================================
    --- lib/lzf_c.c (revision 24482)
    +++ lib/lzf_c.c (revision 24483)
    @@ -0,0 +1,220 @@
    +/*
    + * Copyright (c) 2000-2003 Marc Alexander Lehmann <pcg@goof.com>
    + *
    + * Redistribution and use in source and binary forms, with or without modifica-
    + * tion, are permitted provided that the following conditions are met:
    + *
    + * 1. Redistributions of source code must retain the above copyright notice,
    + * this list of conditions and the following disclaimer.
    + *
    + * 2. 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.
    + *
    + * 3. The name of the author may not be used to endorse or promote products
    + * derived from this software without specific prior written permission.
    + *
    + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
    + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
    + * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
    + * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
    + * CIAL, 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 OTH-
    + * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
    + * OF THE POSSIBILITY OF SUCH DAMAGE.
    + *
    + * Alternatively, the contents of this file may be used under the terms of
    + * the GNU General Public License version 2 (the "GPL"), in which case the
    + * provisions of the GPL are applicable instead of the above. If you wish to
    + * allow the use of your version of this file only under the terms of the
    + * GPL and not to allow others to use your version of this file under the
    + * BSD license, indicate your decision by deleting the provisions above and
    + * replace them with the notice and other provisions required by the GPL. If
    + * you do not delete the provisions above, a recipient may use your version
    + * of this file under either the BSD or the GPL.
    + */
    +
    +#define HSIZE (1 << (HLOG))
    +
    +/*
    + * don't play with this unless you benchmark!
    + * decompression is not dependent on the hash function
    + * the hashing function might seem strange, just believe me
    + * it works ;)
    + */
    +#define FRST(p) (((p[0]) << 8) + p[1])
    +#define NEXT(v,p) (((v) << 8) + p[2])
    +#define IDX(h) ((((h ^ (h << 5)) >> (3*8 - HLOG)) + h*3) & (HSIZE - 1))
    +/*
    + * IDX works because it is very similar to a multiplicative hash, e.g.
    + * (h * 57321 >> (3*8 - HLOG))
    + * the next one is also quite good, albeit slow ;)
    + * (int)(cos(h & 0xffffff) * 1e6)
    + */
    +
    +#if 0
    +/* original lzv-like hash function */
    +# define FRST(p) (p[0] << 5) ^ p[1]
    +# define NEXT(v,p) ((v) << 5) ^ p[2]
    +# define IDX(h) ((h) & (HSIZE - 1))
    +#endif
    +
    +#define MAX_LIT (1 << 5)
    +#define MAX_OFF (1 << 13)
    +#define MAX_REF ((1 << 8) + (1 << 3))
    +
    +/*
    + * compressed format
    + *
    + * 000LLLLL <L+1> ; literal
    + * LLLOOOOO oooooooo ; backref L
    + * 111OOOOO LLLLLLLL oooooooo ; backref L+7
    + *
    + */
    +
    +unsigned int
    +lzf_compress (const void *const in_data, unsigned int in_len,
    + void *out_data, unsigned int out_len, void *hbuf)
    +{
    + const u8 **htab = hbuf;
    + const u8 **hslot;
    + const u8 *ip = (const u8 *)in_data;
    + u8 *op = (u8 *)out_data;
    + const u8 *in_end = ip + in_len;
    + u8 *out_end = op + out_len;
    + const u8 *ref;
    +
    + unsigned int hval = FRST (ip);
    + unsigned long off;
    + int lit = 0;
    +
    +#if INIT_HTAB
    +# if USE_MEMCPY
    + memset (htab, 0, sizeof (htab));
    +# else
    + for (hslot = htab; hslot < htab + HSIZE; hslot++)
    + *hslot++ = ip;
    +# endif
    +#endif
    +
    + for (;;)
    + {
    + if (ip < in_end - 2)
    + {
    + hval = NEXT (hval, ip);
    + hslot = htab + IDX (hval);
    + ref = *hslot; *hslot = ip;
    +
    + if (1
    +#if INIT_HTAB && !USE_MEMCPY
    + && ref < ip /* the next test will actually take care of this, but this is faster */
    +#endif
    + && (off = ip - ref - 1) < MAX_OFF
    + && ip + 4 < in_end
    + && ref > (u8 *)in_data
    +#if STRICT_ALIGN
    + && ref[0] == ip[0]
    + && ref[1] == ip[1]
    + && ref[2] == ip[2]
    +#else
    + && *(u16 *)ref == *(u16 *)ip
    + && ref[2] == ip[2]
    +#endif
    + )
    + {
    + /* match found at *ref++ */
    + unsigned int len = 2;
    + unsigned int maxlen = in_end - ip - len;
    + maxlen = maxlen > MAX_REF ? MAX_REF : maxlen;
    +
    + do
    + len++;
    + while (len < maxlen && ref[len] == ip[len]);
    +
    + if (op + lit + 1 + 3 >= out_end)
    + return 0;
    +
    + if (lit)
    + {
    + *op++ = lit - 1;
    + lit = -lit;
    + do
    + *op++ = ip[lit];
    + while (++lit);
    + }
    +
    + len -= 2;
    + ip++;
    +
    + if (len < 7)
    + {
    + *op++ = (off >> 8) + (len << 5);
    + }
    + else
    + {
    + *op++ = (off >> 8) + ( 7 << 5);
    + *op++ = len - 7;
    + }
    +
    + *op++ = off;
    +
    +#if ULTRA_FAST
    + ip += len;
    + hval = FRST (ip);
    + hval = NEXT (hval, ip);
    + htab[IDX (hval)] = ip;
    + ip++;
    +#else
    + do
    + {
    + hval = NEXT (hval, ip);
    + htab[IDX (hval)] = ip;
    + ip++;
    + }
    + while (len--);
    +#endif
    + continue;
    + }
    + }
    + else if (ip == in_end)
    + break;
    +
    + /* one more literal byte we must copy */
    + lit++;
    + ip++;
    +
    + if (lit == MAX_LIT)
    + {
    + if (op + 1 + MAX_LIT >= out_end)
    + return 0;
    +
    + *op++ = MAX_LIT - 1;
    +#if USE_MEMCPY
    + memcpy (op, ip - MAX_LIT, MAX_LIT);
    + op += MAX_LIT;
    + lit = 0;
    +#else
    + lit = -lit;
    + do
    + *op++ = ip[lit];
    + while (++lit);
    +#endif
    + }
    + }
    +
    + if (lit)
    + {
    + if (op + lit + 1 >= out_end)
    + return 0;
    +
    + *op++ = lit - 1;
    + lit = -lit;
    + do
    + *op++ = ip[lit];
    + while (++lit);
    + }
    +
    + return op - (u8 *) out_data;
    +}
    --
    --
    Hu Gang / Steve
    Linux Registered User 204016
    GPG Public Key: http://soulinfo.com/~hugang/hugang.asc
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