zlib.c

嵌入式ARM的一些源代码

/*
 * This file is derived from various .h and .c files from the zlib-0.95
 * distribution by Jean-loup Gailly and Mark Adler, with some additions
 * by Paul Mackerras to aid in implementing Deflate compression and
 * decompression for PPP packets.  See zlib.h for conditions of
 * distribution and use.
 *
 * Changes that have been made include:
 * - changed functions not used outside this file to "local"
 * - added minCompression parameter to deflateInit2
 * - added Z_PACKET_FLUSH (see zlib.h for details)
 * - added inflateIncomp
 *
 * $Id: zlib.c,v 1.2 2000/10/25 11:26:00 wdenk Exp $
 */

/*+++++*/
/* zutil.h -- internal interface and configuration of the compression library
 * Copyright (C) 1995 Jean-loup Gailly.
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/* WARNING: this file should *not* be used by applications. It is
   part of the implementation of the compression library and is
   subject to change. Applications should only use zlib.h.
 */

/* From: zutil.h,v 1.9 1995/05/03 17:27:12 jloup Exp */

#define _Z_UTIL_H

#include "zlib.h"

#ifndef local
#  define local static
#endif
/* compile with -Dlocal if your debugger can't find static symbols */

#define FAR

typedef unsigned char  uch;
typedef uch FAR uchf;
typedef unsigned short ush;
typedef ush FAR ushf;
typedef unsigned long  ulg;

extern char *z_errmsg[]; /* indexed by 1-zlib_error */

#define ERR_RETURN(strm,err) return (strm->msg=z_errmsg[1-err], err)
/* To be used only when the state is known to be valid */

#ifndef NULL
#define NULL	((void *) 0)
#endif

        /* common constants */

#define DEFLATED   8

#ifndef DEF_WBITS
#  define DEF_WBITS MAX_WBITS
#endif
/* default windowBits for decompression. MAX_WBITS is for compression only */

#if MAX_MEM_LEVEL >= 8
#  define DEF_MEM_LEVEL 8
#else
#  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
#endif
/* default memLevel */

#define STORED_BLOCK 0
#define STATIC_TREES 1
#define DYN_TREES    2
/* The three kinds of block type */

#define MIN_MATCH  3
#define MAX_MATCH  258
/* The minimum and maximum match lengths */

         /* functions */

#include <linux/string.h>
#define zmemcpy memcpy
#define zmemzero(dest, len)	memset(dest, 0, len)

/* Diagnostic functions */
#ifdef DEBUG_ZLIB
#  include <stdio.h>
#  ifndef verbose
#    define verbose 0
#  endif
#  define Assert(cond,msg) {if(!(cond)) z_error(msg);}
#  define Trace(x) fprintf x
#  define Tracev(x) {if (verbose) fprintf x ;}
#  define Tracevv(x) {if (verbose>1) fprintf x ;}
#  define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
#  define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
#else
#  define Assert(cond,msg)
#  define Trace(x)
#  define Tracev(x)
#  define Tracevv(x)
#  define Tracec(c,x)
#  define Tracecv(c,x)
#endif


typedef uLong (*check_func) OF((uLong check, Bytef *buf, uInt len));

/* voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); */
/* void   zcfree  OF((voidpf opaque, voidpf ptr)); */

#define ZALLOC(strm, items, size) \
           (*((strm)->zalloc))((strm)->opaque, (items), (size))
#define ZFREE(strm, addr, size)	\
	   (*((strm)->zfree))((strm)->opaque, (voidpf)(addr), (size))
#define TRY_FREE(s, p, n) {if (p) ZFREE(s, p, n);}

/* deflate.h -- internal compression state
 * Copyright (C) 1995 Jean-loup Gailly
 * For conditions of distribution and use, see copyright notice in zlib.h 
 */

/* WARNING: this file should *not* be used by applications. It is
   part of the implementation of the compression library and is
   subject to change. Applications should only use zlib.h.
 */

/*+++++*/
/* infblock.h -- header to use infblock.c
 * Copyright (C) 1995 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h 
 */

/* WARNING: this file should *not* be used by applications. It is
   part of the implementation of the compression library and is
   subject to change. Applications should only use zlib.h.
 */

struct inflate_blocks_state;
typedef struct inflate_blocks_state FAR inflate_blocks_statef;

local inflate_blocks_statef * inflate_blocks_new OF((
    z_stream *z,
    check_func c,               /* check function */
    uInt w));                   /* window size */

local int inflate_blocks OF((
    inflate_blocks_statef *,
    z_stream *,
    int));                      /* initial return code */

local void inflate_blocks_reset OF((
    inflate_blocks_statef *,
    z_stream *,
    uLongf *));                  /* check value on output */

local int inflate_blocks_free OF((
    inflate_blocks_statef *,
    z_stream *,
    uLongf *));                  /* check value on output */

local int inflate_addhistory OF((
    inflate_blocks_statef *,
    z_stream *));

local int inflate_packet_flush OF((
    inflate_blocks_statef *));

/*+++++*/
/* inftrees.h -- header to use inftrees.c
 * Copyright (C) 1995 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h 
 */

/* WARNING: this file should *not* be used by applications. It is
   part of the implementation of the compression library and is
   subject to change. Applications should only use zlib.h.
 */

/* Huffman code lookup table entry--this entry is four bytes for machines
   that have 16-bit pointers (e.g. PC's in the small or medium model). */

typedef struct inflate_huft_s FAR inflate_huft;

struct inflate_huft_s {
  union {
    struct {
      Byte Exop;        /* number of extra bits or operation */
      Byte Bits;        /* number of bits in this code or subcode */
    } what;
    uInt Nalloc;	/* number of these allocated here */
    Bytef *pad;         /* pad structure to a power of 2 (4 bytes for */
  } word;               /*  16-bit, 8 bytes for 32-bit machines) */
  union {
    uInt Base;          /* literal, length base, or distance base */
    inflate_huft *Next; /* pointer to next level of table */
  } more;
};

#ifdef DEBUG_ZLIB
  local uInt inflate_hufts;
#endif

local int inflate_trees_bits OF((
    uIntf *,                    /* 19 code lengths */
    uIntf *,                    /* bits tree desired/actual depth */
    inflate_huft * FAR *,       /* bits tree result */
    z_stream *));               /* for zalloc, zfree functions */

local int inflate_trees_dynamic OF((
    uInt,                       /* number of literal/length codes */
    uInt,                       /* number of distance codes */
    uIntf *,                    /* that many (total) code lengths */
    uIntf *,                    /* literal desired/actual bit depth */
    uIntf *,                    /* distance desired/actual bit depth */
    inflate_huft * FAR *,       /* literal/length tree result */
    inflate_huft * FAR *,       /* distance tree result */
    z_stream *));               /* for zalloc, zfree functions */

local int inflate_trees_fixed OF((
    uIntf *,                    /* literal desired/actual bit depth */
    uIntf *,                    /* distance desired/actual bit depth */
    inflate_huft * FAR *,       /* literal/length tree result */
    inflate_huft * FAR *));     /* distance tree result */

local int inflate_trees_free OF((
    inflate_huft *,             /* tables to free */
    z_stream *));               /* for zfree function */


/*+++++*/
/* infcodes.h -- header to use infcodes.c
 * Copyright (C) 1995 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h 
 */

/* WARNING: this file should *not* be used by applications. It is
   part of the implementation of the compression library and is
   subject to change. Applications should only use zlib.h.
 */

struct inflate_codes_state;
typedef struct inflate_codes_state FAR inflate_codes_statef;

local inflate_codes_statef *inflate_codes_new OF((
    uInt, uInt,
    inflate_huft *, inflate_huft *,
    z_stream *));

local int inflate_codes OF((
    inflate_blocks_statef *,
    z_stream *,
    int));

local void inflate_codes_free OF((
    inflate_codes_statef *,
    z_stream *));


/*+++++*/
/* inflate.c -- zlib interface to inflate modules
 * Copyright (C) 1995 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h 
 */

/* inflate private state */
struct internal_state {

  /* mode */
  enum {
      METHOD,   /* waiting for method byte */
      FLAG,     /* waiting for flag byte */
      BLOCKS,   /* decompressing blocks */
      CHECK4,   /* four check bytes to go */
      CHECK3,   /* three check bytes to go */
      CHECK2,   /* two check bytes to go */
      CHECK1,   /* one check byte to go */
      DONE,     /* finished check, done */
      BAD}      /* got an error--stay here */
    mode;               /* current inflate mode */

  /* mode dependent information */
  union {
    uInt method;        /* if FLAGS, method byte */
    struct {
      uLong was;                /* computed check value */
      uLong need;               /* stream check value */
    } check;            /* if CHECK, check values to compare */
    uInt marker;        /* if BAD, inflateSync's marker bytes count */
  } sub;        /* submode */

  /* mode independent information */
  int  nowrap;          /* flag for no wrapper */
  uInt wbits;           /* log2(window size)  (8..15, defaults to 15) */
  inflate_blocks_statef 
    *blocks;            /* current inflate_blocks state */

};


int inflateReset(z)
z_stream *z;
{
  uLong c;

  if (z == Z_NULL || z->state == Z_NULL)
    return Z_STREAM_ERROR;
  z->total_in = z->total_out = 0;
  z->msg = Z_NULL;
  z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
  inflate_blocks_reset(z->state->blocks, z, &c);
  Trace((stderr, "inflate: reset\n"));
  return Z_OK;
}


int inflateEnd(z)
z_stream *z;
{
  uLong c;

  if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
    return Z_STREAM_ERROR;
  if (z->state->blocks != Z_NULL)
    inflate_blocks_free(z->state->blocks, z, &c);
  ZFREE(z, z->state, sizeof(struct internal_state));
  z->state = Z_NULL;
  Trace((stderr, "inflate: end\n"));
  return Z_OK;
}


int inflateInit2(z, w)
z_stream *z;
int w;
{
  /* initialize state */
  if (z == Z_NULL)
    return Z_STREAM_ERROR;
/*  if (z->zalloc == Z_NULL) z->zalloc = zcalloc; */
/*  if (z->zfree == Z_NULL) z->zfree = zcfree; */
  if ((z->state = (struct internal_state FAR *)
       ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
    return Z_MEM_ERROR;
  z->state->blocks = Z_NULL;

  /* handle undocumented nowrap option (no zlib header or check) */
  z->state->nowrap = 0;
  if (w < 0)
  {
    w = - w;
    z->state->nowrap = 1;
  }

  /* set window size */
  if (w < 8 || w > 15)
  {
    inflateEnd(z);
    return Z_STREAM_ERROR;
  }
  z->state->wbits = (uInt)w;

  /* create inflate_blocks state */
  if ((z->state->blocks =
       inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, 1 << w))
      == Z_NULL)
  {
    inflateEnd(z);
    return Z_MEM_ERROR;
  }
  Trace((stderr, "inflate: allocated\n"));

  /* reset state */
  inflateReset(z);
  return Z_OK;
}


int inflateInit(z)
z_stream *z;
{
  return inflateInit2(z, DEF_WBITS);
}


#define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
#define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)

int inflate(z, f)
z_stream *z;
int f;
{
  int r;
  uInt b;

  if (z == Z_NULL || z->next_in == Z_NULL)
    return Z_STREAM_ERROR;
  r = Z_BUF_ERROR;
  while (1) switch (z->state->mode)
  {
    case METHOD:
      NEEDBYTE
      if (((z->state->sub.method = NEXTBYTE) & 0xf) != DEFLATED)
      {
        z->state->mode = BAD;
        z->msg = "unknown compression method";
        z->state->sub.marker = 5;       /* can't try inflateSync */