Initial commit of liblzf
Unmodified liblzf 3.6 release from http://dist.schmorp.de/liblzf/liblzf-3.6.tar.gz
Website at http://oldhome.schmorp.de/marc/liblzf.html
Licence is BSD-type, and optionally GPLv2
Change-Id: I7d27f2d86c81589e7f5e719084373a7045063e84
Signed-off-by: David Li <davidxli@google.com>
diff --git a/lzf_c.c b/lzf_c.c
new file mode 100644
index 0000000..bc07084
--- /dev/null
+++ b/lzf_c.c
@@ -0,0 +1,291 @@
+/*
+ * Copyright (c) 2000-2010 Marc Alexander Lehmann <schmorp@schmorp.de>
+ *
+ * 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.
+ *
+ * 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 ("GPL") version 2 or any later version,
+ * 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.
+ */
+
+#include "lzfP.h"
+
+#define HSIZE (1 << (HLOG))
+
+/*
+ * don't play with this unless you benchmark!
+ * the data format is not dependent on the hash function.
+ * the hash function might seem strange, just believe me,
+ * it works ;)
+ */
+#ifndef FRST
+# define FRST(p) (((p[0]) << 8) | p[1])
+# define NEXT(v,p) (((v) << 8) | p[2])
+# if ULTRA_FAST
+# define IDX(h) ((( h >> (3*8 - HLOG)) - h ) & (HSIZE - 1))
+# elif VERY_FAST
+# define IDX(h) ((( h >> (3*8 - HLOG)) - h*5) & (HSIZE - 1))
+# else
+# define IDX(h) ((((h ^ (h << 5)) >> (3*8 - HLOG)) - h*5) & (HSIZE - 1))
+# endif
+#endif
+/*
+ * IDX works because it is very similar to a multiplicative hash, e.g.
+ * ((h * 57321 >> (3*8 - HLOG)) & (HSIZE - 1))
+ * the latter is also quite fast on newer CPUs, and compresses similarly.
+ *
+ * the next one is also quite good, albeit slow ;)
+ * (int)(cos(h & 0xffffff) * 1e6)
+ */
+
+#if 0
+/* original lzv-like hash function, much worse and thus slower */
+# 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))
+
+#if __GNUC__ >= 3
+# define expect(expr,value) __builtin_expect ((expr),(value))
+# define inline inline
+#else
+# define expect(expr,value) (expr)
+# define inline static
+#endif
+
+#define expect_false(expr) expect ((expr) != 0, 0)
+#define expect_true(expr) expect ((expr) != 0, 1)
+
+/*
+ * compressed format
+ *
+ * 000LLLLL <L+1> ; literal, L+1=1..33 octets
+ * LLLooooo oooooooo ; backref L+1=1..7 octets, o+1=1..4096 offset
+ * 111ooooo LLLLLLLL oooooooo ; backref L+8 octets, o+1=1..4096 offset
+ *
+ */
+
+unsigned int
+lzf_compress (const void *const in_data, unsigned int in_len,
+ void *out_data, unsigned int out_len
+#if LZF_STATE_ARG
+ , LZF_STATE htab
+#endif
+ )
+{
+#if !LZF_STATE_ARG
+ LZF_STATE htab;
+#endif
+ 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;
+
+ /* off requires a type wide enough to hold a general pointer difference.
+ * ISO C doesn't have that (size_t might not be enough and ptrdiff_t only
+ * works for differences within a single object). We also assume that no
+ * no bit pattern traps. Since the only platform that is both non-POSIX
+ * and fails to support both assumptions is windows 64 bit, we make a
+ * special workaround for it.
+ */
+#if defined (WIN32) && defined (_M_X64)
+ unsigned _int64 off; /* workaround for missing POSIX compliance */
+#else
+ unsigned long off;
+#endif
+ unsigned int hval;
+ int lit;
+
+ if (!in_len || !out_len)
+ return 0;
+
+#if INIT_HTAB
+ memset (htab, 0, sizeof (htab));
+#endif
+
+ lit = 0; op++; /* start run */
+
+ hval = FRST (ip);
+ while (ip < in_end - 2)
+ {
+ LZF_HSLOT *hslot;
+
+ hval = NEXT (hval, ip);
+ hslot = htab + IDX (hval);
+ ref = *hslot + LZF_HSLOT_BIAS; *hslot = ip - LZF_HSLOT_BIAS;
+
+ if (1
+#if INIT_HTAB
+ && ref < ip /* the next test will actually take care of this, but this is faster */
+#endif
+ && (off = ip - ref - 1) < MAX_OFF
+ && ref > (u8 *)in_data
+ && ref[2] == ip[2]
+#if STRICT_ALIGN
+ && ((ref[1] << 8) | ref[0]) == ((ip[1] << 8) | ip[0])
+#else
+ && *(u16 *)ref == *(u16 *)ip
+#endif
+ )
+ {
+ /* match found at *ref++ */
+ unsigned int len = 2;
+ unsigned int maxlen = in_end - ip - len;
+ maxlen = maxlen > MAX_REF ? MAX_REF : maxlen;
+
+ if (expect_false (op + 3 + 1 >= out_end)) /* first a faster conservative test */
+ if (op - !lit + 3 + 1 >= out_end) /* second the exact but rare test */
+ return 0;
+
+ op [- lit - 1] = lit - 1; /* stop run */
+ op -= !lit; /* undo run if length is zero */
+
+ for (;;)
+ {
+ if (expect_true (maxlen > 16))
+ {
+ len++; if (ref [len] != ip [len]) break;
+ len++; if (ref [len] != ip [len]) break;
+ len++; if (ref [len] != ip [len]) break;
+ len++; if (ref [len] != ip [len]) break;
+
+ len++; if (ref [len] != ip [len]) break;
+ len++; if (ref [len] != ip [len]) break;
+ len++; if (ref [len] != ip [len]) break;
+ len++; if (ref [len] != ip [len]) break;
+
+ len++; if (ref [len] != ip [len]) break;
+ len++; if (ref [len] != ip [len]) break;
+ len++; if (ref [len] != ip [len]) break;
+ len++; if (ref [len] != ip [len]) break;
+
+ len++; if (ref [len] != ip [len]) break;
+ len++; if (ref [len] != ip [len]) break;
+ len++; if (ref [len] != ip [len]) break;
+ len++; if (ref [len] != ip [len]) break;
+ }
+
+ do
+ len++;
+ while (len < maxlen && ref[len] == ip[len]);
+
+ break;
+ }
+
+ len -= 2; /* len is now #octets - 1 */
+ ip++;
+
+ if (len < 7)
+ {
+ *op++ = (off >> 8) + (len << 5);
+ }
+ else
+ {
+ *op++ = (off >> 8) + ( 7 << 5);
+ *op++ = len - 7;
+ }
+
+ *op++ = off;
+
+ lit = 0; op++; /* start run */
+
+ ip += len + 1;
+
+ if (expect_false (ip >= in_end - 2))
+ break;
+
+#if ULTRA_FAST || VERY_FAST
+ --ip;
+# if VERY_FAST && !ULTRA_FAST
+ --ip;
+# endif
+ hval = FRST (ip);
+
+ hval = NEXT (hval, ip);
+ htab[IDX (hval)] = ip - LZF_HSLOT_BIAS;
+ ip++;
+
+# if VERY_FAST && !ULTRA_FAST
+ hval = NEXT (hval, ip);
+ htab[IDX (hval)] = ip - LZF_HSLOT_BIAS;
+ ip++;
+# endif
+#else
+ ip -= len + 1;
+
+ do
+ {
+ hval = NEXT (hval, ip);
+ htab[IDX (hval)] = ip - LZF_HSLOT_BIAS;
+ ip++;
+ }
+ while (len--);
+#endif
+ }
+ else
+ {
+ /* one more literal byte we must copy */
+ if (expect_false (op >= out_end))
+ return 0;
+
+ lit++; *op++ = *ip++;
+
+ if (expect_false (lit == MAX_LIT))
+ {
+ op [- lit - 1] = lit - 1; /* stop run */
+ lit = 0; op++; /* start run */
+ }
+ }
+ }
+
+ if (op + 3 > out_end) /* at most 3 bytes can be missing here */
+ return 0;
+
+ while (ip < in_end)
+ {
+ lit++; *op++ = *ip++;
+
+ if (expect_false (lit == MAX_LIT))
+ {
+ op [- lit - 1] = lit - 1; /* stop run */
+ lit = 0; op++; /* start run */
+ }
+ }
+
+ op [- lit - 1] = lit - 1; /* end run */
+ op -= !lit; /* undo run if length is zero */
+
+ return op - (u8 *)out_data;
+}
+