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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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