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After compression lib experiment

This commit is contained in:
Mark Qvist 2014-04-14 11:44:39 +02:00
parent bdbfda626a
commit 434cf6f2e6
8 changed files with 1108 additions and 3 deletions
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543
Modem/compression/fastlz.c Normal file
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/*
FastLZ - lightning-fast lossless compression library
Copyright (C) 2007 Ariya Hidayat (ariya@kde.org)
Copyright (C) 2006 Ariya Hidayat (ariya@kde.org)
Copyright (C) 2005 Ariya Hidayat (ariya@kde.org)
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
#if !defined(FASTLZ__COMPRESSOR) && !defined(FASTLZ_DECOMPRESSOR)
/*
* Always check for bound when decompressing.
* Generally it is best to leave it defined.
*/
#define FASTLZ_SAFE
/*
* Give hints to the compiler for branch prediction optimization.
*/
#if defined(__GNUC__) && (__GNUC__ > 2)
#define FASTLZ_EXPECT_CONDITIONAL(c) (__builtin_expect((c), 1))
#define FASTLZ_UNEXPECT_CONDITIONAL(c) (__builtin_expect((c), 0))
#else
#define FASTLZ_EXPECT_CONDITIONAL(c) (c)
#define FASTLZ_UNEXPECT_CONDITIONAL(c) (c)
#endif
/*
* Use inlined functions for supported systems.
*/
#if defined(__GNUC__) || defined(__DMC__) || defined(__POCC__) || defined(__WATCOMC__) || defined(__SUNPRO_C)
#define FASTLZ_INLINE inline
#elif defined(__BORLANDC__) || defined(_MSC_VER) || defined(__LCC__)
#define FASTLZ_INLINE __inline
#else
#define FASTLZ_INLINE
#endif
/*
* Prevent accessing more than 8-bit at once, except on x86 architectures.
*/
#if !defined(FASTLZ_STRICT_ALIGN)
#define FASTLZ_STRICT_ALIGN
#if defined(__i386__) || defined(__386) /* GNU C, Sun Studio */
#undef FASTLZ_STRICT_ALIGN
#elif defined(__i486__) || defined(__i586__) || defined(__i686__) /* GNU C */
#undef FASTLZ_STRICT_ALIGN
#elif defined(_M_IX86) /* Intel, MSVC */
#undef FASTLZ_STRICT_ALIGN
#elif defined(__386)
#undef FASTLZ_STRICT_ALIGN
#elif defined(_X86_) /* MinGW */
#undef FASTLZ_STRICT_ALIGN
#elif defined(__I86__) /* Digital Mars */
#undef FASTLZ_STRICT_ALIGN
#endif
#endif
/*
* FIXME: use preprocessor magic to set this on different platforms!
*/
typedef unsigned char flzuint8;
typedef unsigned short flzuint16;
typedef unsigned int flzuint32;
/* prototypes */
int fastlz_compress(const void* input, int length, void* output);
int fastlz_compress_level(int level, const void* input, int length, void* output);
int fastlz_decompress(const void* input, int length, void* output, int maxout);
#define MAX_COPY 32
#define MAX_LEN 264 /* 256 + 8 */
#define MAX_DISTANCE 8192
#if !defined(FASTLZ_STRICT_ALIGN)
#define FASTLZ_READU16(p) *((const flzuint16*)(p))
#else
#define FASTLZ_READU16(p) ((p)[0] | (p)[1]<<8)
#endif
#define HASH_LOG 13
#define HASH_SIZE (1<< HASH_LOG)
#define HASH_MASK (HASH_SIZE-1)
#define HASH_FUNCTION(v,p) { v = FASTLZ_READU16(p); v ^= FASTLZ_READU16(p+1)^(v>>(16-HASH_LOG));v &= HASH_MASK; }
#undef FASTLZ_LEVEL
#define FASTLZ_LEVEL 1
#undef FASTLZ_COMPRESSOR
#undef FASTLZ_DECOMPRESSOR
#define FASTLZ_COMPRESSOR fastlz1_compress
#define FASTLZ_DECOMPRESSOR fastlz1_decompress
static FASTLZ_INLINE int FASTLZ_COMPRESSOR(const void* input, int length, void* output);
static FASTLZ_INLINE int FASTLZ_DECOMPRESSOR(const void* input, int length, void* output, int maxout);
#include "fastlz.c"
#undef FASTLZ_LEVEL
#define FASTLZ_LEVEL 2
#undef MAX_DISTANCE
#define MAX_DISTANCE 8191
#define MAX_FARDISTANCE (65535+MAX_DISTANCE-1)
#undef FASTLZ_COMPRESSOR
#undef FASTLZ_DECOMPRESSOR
#define FASTLZ_COMPRESSOR fastlz2_compress
#define FASTLZ_DECOMPRESSOR fastlz2_decompress
static FASTLZ_INLINE int FASTLZ_COMPRESSOR(const void* input, int length, void* output);
static FASTLZ_INLINE int FASTLZ_DECOMPRESSOR(const void* input, int length, void* output, int maxout);
#include "fastlz.c"
int fastlz_compress(const void* input, int length, void* output)
{
return fastlz1_compress(input, length, output);
// Fastlz2 doesn't really matter for us
// because of small block sizes
// return fastlz2_compress(input, length, output);
}
int fastlz_decompress(const void* input, int length, void* output, int maxout)
{
/* magic identifier for compression level */
int level = ((*(const flzuint8*)input) >> 5) + 1;
if(level == 1)
return fastlz1_decompress(input, length, output, maxout);
if(level == 2)
return fastlz2_decompress(input, length, output, maxout);
/* unknown level, trigger error */
return 0;
}
int fastlz_compress_level(int level, const void* input, int length, void* output)
{
if(level == 1)
return fastlz1_compress(input, length, output);
if(level == 2)
return fastlz2_compress(input, length, output);
return 0;
}
#else /* !defined(FASTLZ_COMPRESSOR) && !defined(FASTLZ_DECOMPRESSOR) */
static FASTLZ_INLINE int FASTLZ_COMPRESSOR(const void* input, int length, void* output)
{
const flzuint8* ip = (const flzuint8*) input;
const flzuint8* ip_bound = ip + length - 2;
const flzuint8* ip_limit = ip + length - 12;
flzuint8* op = (flzuint8*) output;
const flzuint8* htab[HASH_SIZE];
const flzuint8** hslot;
flzuint32 hval;
flzuint32 copy;
/* sanity check */
if(FASTLZ_UNEXPECT_CONDITIONAL(length < 4))
{
if(length)
{
/* create literal copy only */
*op++ = length-1;
ip_bound++;
while(ip <= ip_bound)
*op++ = *ip++;
return length+1;
}
else
return 0;
}
/* initializes hash table */
for (hslot = htab; hslot < htab + HASH_SIZE; hslot++)
*hslot = ip;
/* we start with literal copy */
copy = 2;
*op++ = MAX_COPY-1;
*op++ = *ip++;
*op++ = *ip++;
/* main loop */
while(FASTLZ_EXPECT_CONDITIONAL(ip < ip_limit))
{
const flzuint8* ref;
flzuint32 distance;
/* minimum match length */
flzuint32 len = 3;
/* comparison starting-point */
const flzuint8* anchor = ip;
/* check for a run */
#if FASTLZ_LEVEL==2
if(ip[0] == ip[-1] && FASTLZ_READU16(ip-1)==FASTLZ_READU16(ip+1))
{
distance = 1;
ip += 3;
ref = anchor - 1 + 3;
goto match;
}
#endif
/* find potential match */
HASH_FUNCTION(hval,ip);
hslot = htab + hval;
ref = htab[hval];
/* calculate distance to the match */
distance = anchor - ref;
/* update hash table */
*hslot = anchor;
/* is this a match? check the first 3 bytes */
if(distance==0 || (distance >= MAX_DISTANCE) || *ref++ != *ip++ || *ref++!=*ip++ || *ref++!=*ip++) goto literal;
#if FASTLZ_LEVEL==2
/* far, needs at least 5-byte match */
if(distance >= MAX_DISTANCE)
{
if(*ip++ != *ref++ || *ip++!= *ref++)
goto literal;
len += 2;
}
match:
#endif
/* last matched byte */
ip = anchor + len;
/* distance is biased */
distance--;
if(!distance)
{
/* zero distance means a run */
flzuint8 x = ip[-1];
while(ip < ip_bound)
if(*ref++ != x) break; else ip++;
}
else
for(;;)
{
/* safe because the outer check against ip limit */
if(*ref++ != *ip++) break;
if(*ref++ != *ip++) break;
if(*ref++ != *ip++) break;
if(*ref++ != *ip++) break;
if(*ref++ != *ip++) break;
if(*ref++ != *ip++) break;
if(*ref++ != *ip++) break;
if(*ref++ != *ip++) break;
while(ip < ip_bound)
if(*ref++ != *ip++) break;
break;
}
/* if we have copied something, adjust the copy count */
if(copy)
/* copy is biased, '0' means 1 byte copy */
*(op-copy-1) = copy-1;
else
/* back, to overwrite the copy count */
op--;
/* reset literal counter */
copy = 0;
/* length is biased, '1' means a match of 3 bytes */
ip -= 3;
len = ip - anchor;
/* encode the match */
#if FASTLZ_LEVEL==2
if(distance < MAX_DISTANCE)
{
if(len < 7)
{
*op++ = (len << 5) + (distance >> 8);
*op++ = (distance & 255);
}
else
{
*op++ = (7 << 5) + (distance >> 8);
for(len-=7; len >= 255; len-= 255)
*op++ = 255;
*op++ = len;
*op++ = (distance & 255);
}
}
else
{
/* far away, but not yet in the another galaxy... */
if(len < 7)
{
distance -= MAX_DISTANCE;
*op++ = (len << 5) + 31;
*op++ = 255;
*op++ = distance >> 8;
*op++ = distance & 255;
}
else
{
distance -= MAX_DISTANCE;
*op++ = (7 << 5) + 31;
for(len-=7; len >= 255; len-= 255)
*op++ = 255;
*op++ = len;
*op++ = 255;
*op++ = distance >> 8;
*op++ = distance & 255;
}
}
#else
if(FASTLZ_UNEXPECT_CONDITIONAL(len > MAX_LEN-2))
while(len > MAX_LEN-2)
{
*op++ = (7 << 5) + (distance >> 8);
*op++ = MAX_LEN - 2 - 7 -2;
*op++ = (distance & 255);
len -= MAX_LEN-2;
}
if(len < 7)
{
*op++ = (len << 5) + (distance >> 8);
*op++ = (distance & 255);
}
else
{
*op++ = (7 << 5) + (distance >> 8);
*op++ = len - 7;
*op++ = (distance & 255);
}
#endif
/* update the hash at match boundary */
HASH_FUNCTION(hval,ip);
htab[hval] = ip++;
HASH_FUNCTION(hval,ip);
htab[hval] = ip++;
/* assuming literal copy */
*op++ = MAX_COPY-1;
continue;
literal:
*op++ = *anchor++;
ip = anchor;
copy++;
if(FASTLZ_UNEXPECT_CONDITIONAL(copy == MAX_COPY))
{
copy = 0;
*op++ = MAX_COPY-1;
}
}
/* left-over as literal copy */
ip_bound++;
while(ip <= ip_bound)
{
*op++ = *ip++;
copy++;
if(copy == MAX_COPY)
{
copy = 0;
*op++ = MAX_COPY-1;
}
}
/* if we have copied something, adjust the copy length */
if(copy)
*(op-copy-1) = copy-1;
else
op--;
#if FASTLZ_LEVEL==2
/* marker for fastlz2 */
*(flzuint8*)output |= (1 << 5);
#endif
return op - (flzuint8*)output;
}
static FASTLZ_INLINE int FASTLZ_DECOMPRESSOR(const void* input, int length, void* output, int maxout)
{
const flzuint8* ip = (const flzuint8*) input;
const flzuint8* ip_limit = ip + length;
flzuint8* op = (flzuint8*) output;
flzuint8* op_limit = op + maxout;
flzuint32 ctrl = (*ip++) & 31;
int loop = 1;
do
{
const flzuint8* ref = op;
flzuint32 len = ctrl >> 5;
flzuint32 ofs = (ctrl & 31) << 8;
if(ctrl >= 32)
{
#if FASTLZ_LEVEL==2
flzuint8 code;
#endif
len--;
ref -= ofs;
if (len == 7-1)
#if FASTLZ_LEVEL==1
len += *ip++;
ref -= *ip++;
#else
do
{
code = *ip++;
len += code;
} while (code==255);
code = *ip++;
ref -= code;
/* match from 16-bit distance */
if(FASTLZ_UNEXPECT_CONDITIONAL(code==255))
if(FASTLZ_EXPECT_CONDITIONAL(ofs==(31 << 8)))
{
ofs = (*ip++) << 8;
ofs += *ip++;
ref = op - ofs - MAX_DISTANCE;
}
#endif
#ifdef FASTLZ_SAFE
if (FASTLZ_UNEXPECT_CONDITIONAL(op + len + 3 > op_limit))
return 0;
if (FASTLZ_UNEXPECT_CONDITIONAL(ref-1 < (flzuint8 *)output))
return 0;
#endif
if(FASTLZ_EXPECT_CONDITIONAL(ip < ip_limit))
ctrl = *ip++;
else
loop = 0;
if(ref == op)
{
/* optimize copy for a run */
flzuint8 b = ref[-1];
*op++ = b;
*op++ = b;
*op++ = b;
for(; len; --len)
*op++ = b;
}
else
{
#if !defined(FASTLZ_STRICT_ALIGN)
const flzuint16* p;
flzuint16* q;
#endif
/* copy from reference */
ref--;
*op++ = *ref++;
*op++ = *ref++;
*op++ = *ref++;
#if !defined(FASTLZ_STRICT_ALIGN)
/* copy a byte, so that now it's word aligned */
if(len & 1)
{
*op++ = *ref++;
len--;
}
/* copy 16-bit at once */
q = (flzuint16*) op;
op += len;
p = (const flzuint16*) ref;
for(len>>=1; len > 4; len-=4)
{
*q++ = *p++;
*q++ = *p++;
*q++ = *p++;
*q++ = *p++;
}
for(; len; --len)
*q++ = *p++;
#else
for(; len; --len)
*op++ = *ref++;
#endif
}
}
else
{
ctrl++;
#ifdef FASTLZ_SAFE
if (FASTLZ_UNEXPECT_CONDITIONAL(op + ctrl > op_limit))
return 0;
if (FASTLZ_UNEXPECT_CONDITIONAL(ip + ctrl > ip_limit))
return 0;
#endif
*op++ = *ip++;
for(--ctrl; ctrl; ctrl--)
*op++ = *ip++;
loop = FASTLZ_EXPECT_CONDITIONAL(ip < ip_limit);
if(loop)
ctrl = *ip++;
}
}
while(FASTLZ_EXPECT_CONDITIONAL(loop));
return op - (flzuint8*)output;
}
#endif /* !defined(FASTLZ_COMPRESSOR) && !defined(FASTLZ_DECOMPRESSOR) */

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/*
FastLZ - lightning-fast lossless compression library
Copyright (C) 2007 Ariya Hidayat (ariya@kde.org)
Copyright (C) 2006 Ariya Hidayat (ariya@kde.org)
Copyright (C) 2005 Ariya Hidayat (ariya@kde.org)
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
#ifndef FASTLZ_H
#define FASTLZ_H
#define FASTLZ_VERSION 0x000100
#define FASTLZ_VERSION_MAJOR 0
#define FASTLZ_VERSION_MINOR 0
#define FASTLZ_VERSION_REVISION 0
#define FASTLZ_VERSION_STRING "0.1.0"
#if defined (__cplusplus)
extern "C" {
#endif
/**
Compress a block of data in the input buffer and returns the size of
compressed block. The size of input buffer is specified by length. The
minimum input buffer size is 16.
The output buffer must be at least 5% larger than the input buffer
and can not be smaller than 66 bytes.
If the input is not compressible, the return value might be larger than
length (input buffer size).
The input buffer and the output buffer can not overlap.
*/
int fastlz_compress(const void* input, int length, void* output);
/**
Decompress a block of compressed data and returns the size of the
decompressed block. If error occurs, e.g. the compressed data is
corrupted or the output buffer is not large enough, then 0 (zero)
will be returned instead.
The input buffer and the output buffer can not overlap.
Decompression is memory safe and guaranteed not to write the output buffer
more than what is specified in maxout.
*/
int fastlz_decompress(const void* input, int length, void* output, int maxout);
/**
Compress a block of data in the input buffer and returns the size of
compressed block. The size of input buffer is specified by length. The
minimum input buffer size is 16.
The output buffer must be at least 5% larger than the input buffer
and can not be smaller than 66 bytes.
If the input is not compressible, the return value might be larger than
length (input buffer size).
The input buffer and the output buffer can not overlap.
Compression level can be specified in parameter level. At the moment,
only level 1 and level 2 are supported.
Level 1 is the fastest compression and generally useful for short data.
Level 2 is slightly slower but it gives better compression ratio.
Note that the compressed data, regardless of the level, can always be
decompressed using the function fastlz_decompress above.
*/
int fastlz_compress_level(int level, const void* input, int length, void* output);
#if defined (__cplusplus)
}
#endif
#endif /* FASTLZ_H */

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/*
* Copyright (c) 2009 Andrew Collette <andrew.collette at gmail.com>
* http://lzfx.googlecode.com
*
* Implements an LZF-compatible compressor/decompressor based on the liblzf
* codebase written by Marc Lehmann. This code is released under the BSD
* license. License and original copyright statement follow.
*
*
* Copyright (c) 2000-2008 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.
*/
#include "lzfx.h"
#define LZFX_HSIZE (1 << (LZFX_HLOG))
/* We need this for memset */
# include <string.h>
// #if __GNUC__ >= 3 && !DISABLE_EXPECT
// # define fx_expect_false(expr) __builtin_expect((expr) != 0, 0)
// # define fx_expect_true(expr) __builtin_expect((expr) != 0, 1)
// #else
# define fx_expect_false(expr) (expr)
# define fx_expect_true(expr) (expr)
//#endif
typedef unsigned char u8;
typedef const u8 *LZSTATE[LZFX_HSIZE];
/* Define the hash function */
#define LZFX_FRST(p) (((p[0]) << 8) | p[1])
#define LZFX_NEXT(v,p) (((v) << 8) | p[2])
#define LZFX_IDX(h) ((( h >> (3*8 - LZFX_HLOG)) - h ) & (LZFX_HSIZE - 1))
/* These cannot be changed, as they are related to the compressed format. */
#define LZFX_MAX_LIT (1 << 5)
#define LZFX_MAX_OFF (1 << 13)
#define LZFX_MAX_REF ((1 << 8) + (1 << 3))
static
int lzfx_getsize(const void* ibuf, unsigned int ilen, unsigned int *olen);
/* Compressed format
There are two kinds of structures in LZF/LZFX: literal runs and back
references. The length of a literal run is encoded as L - 1, as it must
contain at least one byte. Literals are encoded as follows:
000LLLLL <L+1 bytes>
Back references are encoded as follows. The smallest possible encoded
length value is 1, as otherwise the control byte would be recognized as
a literal run. Since at least three bytes must match for a back reference
to be inserted, the length is encoded as L - 2 instead of L - 1. The
offset (distance to the desired data in the output buffer) is encoded as
o - 1, as all offsets are at least 1. The binary format is:
LLLooooo oooooooo for backrefs of real length < 9 (1 <= L < 7)
111ooooo LLLLLLLL oooooooo for backrefs of real length >= 9 (L > 7)
*/
#include <stdio.h>
int lzfx_compress(const void *const ibuf, const unsigned int ilen,
void *obuf, unsigned int *const olen){
/* Hash table; an array of u8*'s which point
to various locations in the input buffer */
const u8 *htab[LZFX_HSIZE];
const u8 **hslot; /* Pointer to entry in hash table */
unsigned int hval; /* Hash value generated by macros above */
const u8 *ref; /* Pointer to candidate match location in input */
const u8 *ip = (const u8 *)ibuf;
const u8 *const in_end = ip + ilen;
u8 *op = (u8 *)obuf;
const u8 *const out_end = (olen == NULL ? NULL : op + *olen);
int lit; /* # of bytes in current literal run */
#if defined (WIN32) && defined (_M_X64)
unsigned _int64 off; /* workaround for missing POSIX compliance */
#else
unsigned long off;
#endif
if(olen == NULL) return LZFX_EARGS;
if(ibuf == NULL){
if(ilen != 0) return LZFX_EARGS;
*olen = 0;
return 0;
}
if(obuf == NULL){
if(olen != 0) return LZFX_EARGS;
return lzfx_getsize(ibuf, ilen, olen);
}
memset(htab, 0, sizeof(htab));
/* Start a literal run. Whenever we do this the output pointer is
advanced because the current byte will hold the encoded length. */
lit = 0; op++;
hval = LZFX_FRST(ip);
while(ip + 2 < in_end){ /* The NEXT macro reads 2 bytes ahead */
hval = LZFX_NEXT(hval, ip);
hslot = htab + LZFX_IDX(hval);
ref = *hslot; *hslot = ip;
if( ref < ip
&& (off = ip - ref - 1) < LZFX_MAX_OFF
&& ip + 4 < in_end /* Backref takes up to 3 bytes, so don't bother */
&& ref > (u8 *)ibuf
&& ref[0] == ip[0]
&& ref[1] == ip[1]
&& ref[2] == ip[2] ) {
unsigned int len = 3; /* We already know 3 bytes match */
const unsigned int maxlen = in_end - ip - 2 > LZFX_MAX_REF ?
LZFX_MAX_REF : in_end - ip - 2;
/* lit == 0: op + 3 must be < out_end (because we undo the run)
lit != 0: op + 3 + 1 must be < out_end */
if(fx_expect_false(op - !lit + 3 + 1 >= out_end))
return LZFX_ESIZE;
op [- lit - 1] = lit - 1; /* Terminate literal run */
op -= !lit; /* Undo run if length is zero */
/* Start checking at the fourth byte */
while (len < maxlen && ref[len] == ip[len])
len++;
len -= 2; /* We encode the length as #octets - 2 */
/* Format 1: [LLLooooo oooooooo] */
if (len < 7) {
*op++ = (off >> 8) + (len << 5);
*op++ = off;
/* Format 2: [111ooooo LLLLLLLL oooooooo] */
} else {
*op++ = (off >> 8) + (7 << 5);
*op++ = len - 7;
*op++ = off;
}
lit = 0; op++;
ip += len + 1; /* ip = initial ip + #octets -1 */
if (fx_expect_false (ip + 3 >= in_end)){
ip++; /* Code following expects exit at bottom of loop */
break;
}
hval = LZFX_FRST (ip);
hval = LZFX_NEXT (hval, ip);
htab[LZFX_IDX (hval)] = ip;
ip++; /* ip = initial ip + #octets */
} else {
/* Keep copying literal bytes */
if (fx_expect_false (op >= out_end)) return LZFX_ESIZE;
lit++; *op++ = *ip++;
if (fx_expect_false (lit == LZFX_MAX_LIT)) {
op [- lit - 1] = lit - 1; /* stop run */
lit = 0; op++; /* start run */
}
} /* if() found match in htab */
} /* while(ip < ilen -2) */
/* At most 3 bytes remain in input. We therefore need 4 bytes available
in the output buffer to store them (3 data + ctrl byte).*/
if (op + 3 > out_end) return LZFX_ESIZE;
while (ip < in_end) {
lit++; *op++ = *ip++;
if (fx_expect_false (lit == LZFX_MAX_LIT)){
op [- lit - 1] = lit - 1;
lit = 0; op++;
}
}
op [- lit - 1] = lit - 1;
op -= !lit;
*olen = op - (u8 *)obuf;
return 0;
}
/* Decompressor */
int lzfx_decompress(const void* ibuf, unsigned int ilen,
void* obuf, unsigned int *olen){
u8 const *ip = (const u8 *)ibuf;
u8 const *const in_end = ip + ilen;
u8 *op = (u8 *)obuf;
u8 const *const out_end = (olen == NULL ? NULL : op + *olen);
unsigned int remain_len = 0;
int rc;
if(olen == NULL) return LZFX_EARGS;
if(ibuf == NULL){
if(ilen != 0) return LZFX_EARGS;
*olen = 0;
return 0;
}
if(obuf == NULL){
if(olen != 0) return LZFX_EARGS;
return lzfx_getsize(ibuf, ilen, olen);
}
do {
unsigned int ctrl = *ip++;
/* Format 000LLLLL: a literal byte string follows, of length L+1 */
if(ctrl < (1 << 5)) {
ctrl++;
if(fx_expect_false(op + ctrl > out_end)){
--ip; /* Rewind to control byte */
goto guess;
}
if(fx_expect_false(ip + ctrl > in_end)) return LZFX_ECORRUPT;
do
*op++ = *ip++;
while(--ctrl);
/* Format #1 [LLLooooo oooooooo]: backref of length L+1+2
^^^^^ ^^^^^^^^
A B
#2 [111ooooo LLLLLLLL oooooooo] backref of length L+7+2
^^^^^ ^^^^^^^^
A B
In both cases the location of the backref is computed from the
remaining part of the data as follows:
location = op - A*256 - B - 1
*/
} else {
unsigned int len = (ctrl >> 5);
u8 *ref = op - ((ctrl & 0x1f) << 8) -1;
if(len==7) len += *ip++; /* i.e. format #2 */
len += 2; /* len is now #octets */
if(fx_expect_false(op + len > out_end)){
ip -= (len >= 9) ? 2 : 1; /* Rewind to control byte */
goto guess;
}
if(fx_expect_false(ip >= in_end)) return LZFX_ECORRUPT;
ref -= *ip++;
if(fx_expect_false(ref < (u8*)obuf)) return LZFX_ECORRUPT;
do
*op++ = *ref++;
while (--len);
}
} while (ip < in_end);
*olen = op - (u8 *)obuf;
return 0;
guess:
rc = lzfx_getsize(ip, ilen - (ip-(u8*)ibuf), &remain_len);
if(rc>=0) *olen = remain_len + (op - (u8*)obuf);
return rc;
}
/* Guess len. No parameters may be NULL; this is not checked. */
static
int lzfx_getsize(const void* ibuf, unsigned int ilen, unsigned int *olen){
u8 const *ip = (const u8 *)ibuf;
u8 const *const in_end = ip + ilen;
int tot_len = 0;
while (ip < in_end) {
unsigned int ctrl = *ip++;
if(ctrl < (1 << 5)) {
ctrl++;
if(ip + ctrl > in_end)
return LZFX_ECORRUPT;
tot_len += ctrl;
ip += ctrl;
} else {
unsigned int len = (ctrl >> 5);
if(len==7){ /* i.e. format #2 */
len += *ip++;
}
len += 2; /* len is now #octets */
if(ip >= in_end) return LZFX_ECORRUPT;
ip++; /* skip the ref byte */
tot_len += len;
}
}
*olen = tot_len;
return 0;
}

90
Modem/compression/lzfx.h Normal file
View File

@ -0,0 +1,90 @@
/*
* Copyright (c) 2009 Andrew Collette <andrew.collette at gmail.com>
* http://lzfx.googlecode.com
*
* Implements an LZF-compatible compressor/decompressor based on the liblzf
* codebase written by Marc Lehmann. This code is released under the BSD
* license. License and original copyright statement follow.
*
*
* Copyright (c) 2000-2008 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.
*/
#ifndef LZFX_H
#define LZFX_H
/* Documented behavior, including function signatures and error codes,
is guaranteed to remain unchanged for releases with the same major
version number. Releases of the same major version are also able
to read each other's output, although the output itself is not
guaranteed to be byte-for-byte identical.
*/
#define LZFX_VERSION_MAJOR 0
#define LZFX_VERSION_MINOR 1
#define LZFX_VERSION_STRING "0.1"
/* Hashtable size (2**LZFX_HLOG entries) */
#ifndef LZFX_HLOG
# define LZFX_HLOG 8
#endif
/* Predefined errors. */
#define LZFX_ESIZE -1 /* Output buffer too small */
#define LZFX_ECORRUPT -2 /* Invalid data for decompression */
#define LZFX_EARGS -3 /* Arguments invalid (NULL) */
/* Buffer-to buffer compression.
Supply pre-allocated input and output buffers via ibuf and obuf, and
their size in bytes via ilen and olen. Buffers may not overlap.
On success, the function returns a non-negative value and the argument
olen contains the compressed size in bytes. On failure, a negative
value is returned and olen is not modified.
*/
int lzfx_compress(const void* ibuf, unsigned int ilen,
void* obuf, unsigned int *olen);
/* Buffer-to-buffer decompression.
Supply pre-allocated input and output buffers via ibuf and obuf, and
their size in bytes via ilen and olen. Buffers may not overlap.
On success, the function returns a non-negative value and the argument
olen contains the uncompressed size in bytes. On failure, a negative
value is returned.
If the failure code is LZFX_ESIZE, olen contains the minimum buffer size
required to hold the decompressed data. Otherwise, olen is not modified.
Supplying a zero *olen is a valid and supported strategy to determine the
required buffer size. This does not require decompression of the entire
stream and is consequently very fast. Argument obuf may be NULL in
this case only.
*/
int lzfx_decompress(const void* ibuf, unsigned int ilen,
void* obuf, unsigned int *olen);
#endif

8
Modem/main.c
View File

@ -15,6 +15,7 @@
#include "afsk.h" // Header for AFSK modem #include "afsk.h" // Header for AFSK modem
#include "protocol/mp1.h" // Header for MP.1 protocol #include "protocol/mp1.h" // Header for MP.1 protocol
////////////////////////////////////////////////////// //////////////////////////////////////////////////////
// A few definitions // // A few definitions //
////////////////////////////////////////////////////// //////////////////////////////////////////////////////
@ -51,6 +52,12 @@ static void mp1Callback(struct MP1Packet *packet) {
//kprintf("%.*s\n", packet->dataLength, packet->data); //kprintf("%.*s\n", packet->dataLength, packet->data);
} }
// static int freeRam () {
// extern int __heap_start, *__brkval;
// int v;
// return (int) &v - (__brkval == 0 ? (int) &__heap_start : (int) __brkval);
// }
// Simple initialization function. // Simple initialization function.
static void init(void) static void init(void)
{ {
@ -119,6 +126,7 @@ int main(void)
// If we should, pass the buffer to the protocol's // If we should, pass the buffer to the protocol's
// send function. // send function.
mp1Send(&mp1, serialBuffer, serialLen); mp1Send(&mp1, serialBuffer, serialLen);
// Reset the transmission flag and length counter // Reset the transmission flag and length counter
sertx = false; sertx = false;
serialLen = 0; serialLen = 0;

4
Modem/protocol/mp1.h
View File

@ -4,9 +4,11 @@
#include <cfg/compiler.h> #include <cfg/compiler.h>
#include <io/kfile.h> #include <io/kfile.h>
#include "compression/lzfx.h"
// Frame sizing & checksum // Frame sizing & checksum
#define MP1_MIN_FRAME_LENGTH 3 #define MP1_MIN_FRAME_LENGTH 3
#define MP1_MAX_FRAME_LENGTH 300 #define MP1_MAX_FRAME_LENGTH 200
#define MP1_CHECKSUM_INIT 0xAA #define MP1_CHECKSUM_INIT 0xAA
// We need to know some basic HDLC flag bytes // We need to know some basic HDLC flag bytes

2
buildrev.h
View File

@ -1,2 +1,2 @@
#define VERS_BUILD 835 #define VERS_BUILD 930
#define VERS_HOST "vixen" #define VERS_HOST "vixen"