Re: Suspend 2 merge: 46/51: LZF support.

[hugang]

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@xxxxxxxx>
+ * 
+ * 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@xxxxxxxx>
+ * Copyright (C) 2003,2004 Nigel Cunningham <ncunningham@xxxxxxxxxxxxx>
+ *
+ * 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@xxxxxxxx>
+ * 
+ * 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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