bzlib.c

p2p技术C源代码.rar

/*-------------------------------------------------------------*/
/*--- Library top-level functions.                          ---*/
/*---                                               bzlib.c ---*/
/*-------------------------------------------------------------*/

/*--
  This file is a part of bzip2 and/or libbzip2, a program and
  library for lossless, block-sorting data compression.

  Copyright (C) 1996-2002 Julian R Seward.  All rights reserved.

  Redistribution and use in source and binary forms, with or without
  modification, 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. The origin of this software must not be misrepresented; you must 
     not claim that you wrote the original software.  If you use this 
     software in a product, an acknowledgment in the product 
     documentation would be appreciated but is not required.

  3. Altered source versions must be plainly marked as such, and must
     not be misrepresented as being the original software.

  4. 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 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 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 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

  Julian Seward, Cambridge, UK.
  [e-mail]
  bzip2/libbzip2 version 1.0 of 21 March 2000

  This program is based on (at least) the work of:
     Mike Burrows
     David Wheeler
     Peter Fenwick
     Alistair Moffat
     Radford Neal
     Ian H. Witten
     Robert Sedgewick
     Jon L. Bentley

  For more information on these sources, see the manual.
--*/

/*--
   CHANGES
   ~~~~~~~
   0.9.0 -- original version.

   0.9.0a/b -- no changes in this file.

   0.9.0c
      * made zero-length BZ_FLUSH work correctly in bzCompress().
      * fixed bzWrite/bzRead to ignore zero-length requests.
      * fixed bzread to correctly handle read requests after EOF.
      * wrong parameter order in call to bzDecompressInit in
        bzBuffToBuffDecompress.  Fixed.
--*/

#include "bzlib_private.h"


/*---------------------------------------------------*/
/*--- Compression stuff                           ---*/
/*---------------------------------------------------*/


/*---------------------------------------------------*/
#ifndef BZ_NO_STDIO
void BZ2_bz__AssertH__fail ( int errcode )
{
   fprintf(stderr, 
      "\n\nbzip2/libbzip2: internal error number %d.\n"
      "This is a bug in bzip2/libbzip2, %s.\n"
      "Please report it to me at: [e-mail].  If this happened\n"
      "when you were using some program which uses libbzip2 as a\n"
      "component, you should also report this bug to the author(s)\n"
      "of that program.  Please make an effort to report this bug;\n"
      "timely and accurate bug reports eventually lead to higher\n"
      "quality software.  Thanks.  Julian Seward, 30 December 2001.\n\n",
      errcode,
      BZ2_bzlibVersion()
   );

   if (errcode == 1007) {
   fprintf(stderr,
      "\n*** A special note about internal error number 1007 ***\n"
      "\n"
      "Experience suggests that a common cause of i.e. 1007\n"
      "is unreliable memory or other hardware.  The 1007 assertion\n"
      "just happens to cross-check the results of huge numbers of\n"
      "memory reads/writes, and so acts (unintendedly) as a stress\n"
      "test of your memory system.\n"
      "\n"
      "I suggest the following: try compressing the file again,\n"
      "possibly monitoring progress in detail with the -vv flag.\n"
      "\n"
      "* If the error cannot be reproduced, and/or happens at different\n"
      "  points in compression, you may have a flaky memory system.\n"
      "  Try a memory-test program.  I have used Memtest86\n"
      "  (www.memtest86.com).  At the time of writing it is free (GPLd).\n"
      "  Memtest86 tests memory much more thorougly than your BIOSs\n"
      "  power-on test, and may find failures that the BIOS doesn't.\n"
      "\n"
      "* If the error can be repeatably reproduced, this is a bug in\n"
      "  bzip2, and I would very much like to hear about it.  Please\n"
      "  let me know, and, ideally, save a copy of the file causing the\n"
      "  problem -- without which I will be unable to investigate it.\n"
      "\n"
   );
   }

   exit(3);
}
#endif


void bz_internal_error ( int errcode ) { errcode; };
/*---------------------------------------------------*/
static
int bz_config_ok ( void )
{
   if (sizeof(int)   != 4) return 0;
   if (sizeof(short) != 2) return 0;
   if (sizeof(char)  != 1) return 0;
   return 1;
}


/*---------------------------------------------------*/
static
void* default_bzalloc ( void* opaque, Int32 items, Int32 size )
{
   void* v = malloc ( items * size );
   return v;
}

static
void default_bzfree ( void* opaque, void* addr )
{
   if (addr != NULL) free ( addr );
}


/*---------------------------------------------------*/
static
void prepare_new_block ( EState* s )
{
   Int32 i;
   s->nblock = 0;
   s->numZ = 0;
   s->state_out_pos = 0;
   BZ_INITIALISE_CRC ( s->blockCRC );
   for (i = 0; i < 256; i++) s->inUse[i] = False;
   s->blockNo++;
}


/*---------------------------------------------------*/
static
void init_RL ( EState* s )
{
   s->state_in_ch  = 256;
   s->state_in_len = 0;
}


static
Bool isempty_RL ( EState* s )
{
   if (s->state_in_ch < 256 && s->state_in_len > 0)
      return False; else
      return True;
}


/*---------------------------------------------------*/
int BZ_API(BZ2_bzCompressInit) 
                    ( bz_stream* strm, 
                     int        blockSize100k,
                     int        verbosity,
                     int        workFactor )
{
   Int32   n;
   EState* s;

   if (!bz_config_ok()) return BZ_CONFIG_ERROR;

   if (strm == NULL || 
       blockSize100k < 1 || blockSize100k > 9 ||
       workFactor < 0 || workFactor > 250)
     return BZ_PARAM_ERROR;

   if (workFactor == 0) workFactor = 30;
   if (strm->bzalloc == NULL) strm->bzalloc = default_bzalloc;
   if (strm->bzfree == NULL) strm->bzfree = default_bzfree;

   s = BZALLOC( sizeof(EState) );
   if (s == NULL) return BZ_MEM_ERROR;
   s->strm = strm;

   s->arr1 = NULL;
   s->arr2 = NULL;
   s->ftab = NULL;

   n       = 100000 * blockSize100k;
   s->arr1 = BZALLOC( n                  * sizeof(UInt32) );
   s->arr2 = BZALLOC( (n+BZ_N_OVERSHOOT) * sizeof(UInt32) );
   s->ftab = BZALLOC( 65537              * sizeof(UInt32) );

   if (s->arr1 == NULL || s->arr2 == NULL || s->ftab == NULL) {
      if (s->arr1 != NULL) BZFREE(s->arr1);
      if (s->arr2 != NULL) BZFREE(s->arr2);
      if (s->ftab != NULL) BZFREE(s->ftab);
      if (s       != NULL) BZFREE(s);
      return BZ_MEM_ERROR;
   }

   s->blockNo           = 0;
   s->state             = BZ_S_INPUT;
   s->mode              = BZ_M_RUNNING;
   s->combinedCRC       = 0;
   s->blockSize100k     = blockSize100k;
   s->nblockMAX         = 100000 * blockSize100k - 19;
   s->verbosity         = verbosity;
   s->workFactor        = workFactor;

   s->block             = (UChar*)s->arr2;
   s->mtfv              = (UInt16*)s->arr1;
   s->zbits             = NULL;
   s->ptr               = (UInt32*)s->arr1;

   strm->state          = s;
   strm->total_in_lo32  = 0;
   strm->total_in_hi32  = 0;
   strm->total_out_lo32 = 0;
   strm->total_out_hi32 = 0;
   init_RL ( s );
   prepare_new_block ( s );
   return BZ_OK;
}


/*---------------------------------------------------*/
static
void add_pair_to_block ( EState* s )
{
   Int32 i;
   UChar ch = (UChar)(s->state_in_ch);
   for (i = 0; i < s->state_in_len; i++) {
      BZ_UPDATE_CRC( s->blockCRC, ch );
   }
   s->inUse[s->state_in_ch] = True;
   switch (s->state_in_len) {
      case 1:
         s->block[s->nblock] = (UChar)ch; s->nblock++;
         break;
      case 2:
         s->block[s->nblock] = (UChar)ch; s->nblock++;
         s->block[s->nblock] = (UChar)ch; s->nblock++;
         break;
      case 3:
         s->block[s->nblock] = (UChar)ch; s->nblock++;
         s->block[s->nblock] = (UChar)ch; s->nblock++;
         s->block[s->nblock] = (UChar)ch; s->nblock++;
         break;
      default:
         s->inUse[s->state_in_len-4] = True;
         s->block[s->nblock] = (UChar)ch; s->nblock++;
         s->block[s->nblock] = (UChar)ch; s->nblock++;
         s->block[s->nblock] = (UChar)ch; s->nblock++;
         s->block[s->nblock] = (UChar)ch; s->nblock++;
         s->block[s->nblock] = ((UChar)(s->state_in_len-4));
         s->nblock++;
         break;
   }
}


/*---------------------------------------------------*/
static
void flush_RL ( EState* s )
{
   if (s->state_in_ch < 256) add_pair_to_block ( s );
   init_RL ( s );
}


/*---------------------------------------------------*/
#define ADD_CHAR_TO_BLOCK(zs,zchh0)               \
{                                                 \
   UInt32 zchh = (UInt32)(zchh0);                 \
   /*-- fast track the common case --*/           \
   if (zchh != zs->state_in_ch &&                 \
       zs->state_in_len == 1) {                   \
      UChar ch = (UChar)(zs->state_in_ch);        \
      BZ_UPDATE_CRC( zs->blockCRC, ch );          \
      zs->inUse[zs->state_in_ch] = True;          \
      zs->block[zs->nblock] = (UChar)ch;          \
      zs->nblock++;                               \
      zs->state_in_ch = zchh;                     \
   }                                              \
   else                                           \
   /*-- general, uncommon cases --*/              \
   if (zchh != zs->state_in_ch ||                 \
      zs->state_in_len == 255) {                  \
      if (zs->state_in_ch < 256)                  \
         add_pair_to_block ( zs );                \
      zs->state_in_ch = zchh;                     \
      zs->state_in_len = 1;                       \
   } else {                                       \
      zs->state_in_len++;                         \
   }                                              \
}


/*---------------------------------------------------*/
static
Bool copy_input_until_stop ( EState* s )
{
   Bool progress_in = False;

   if (s->mode == BZ_M_RUNNING) {

      /*-- fast track the common case --*/
      while (True) {
         /*-- block full? --*/
         if (s->nblock >= s->nblockMAX) break;
         /*-- no input? --*/
         if (s->strm->avail_in == 0) break;
         progress_in = True;
         ADD_CHAR_TO_BLOCK ( s, (UInt32)(*((UChar*)(s->strm->next_in))) ); 
         s->strm->next_in++;
         s->strm->avail_in--;
         s->strm->total_in_lo32++;
         if (s->strm->total_in_lo32 == 0) s->strm->total_in_hi32++;
      }

   } else {

      /*-- general, uncommon case --*/
      while (True) {
         /*-- block full? --*/
         if (s->nblock >= s->nblockMAX) break;
         /*-- no input? --*/
         if (s->strm->avail_in == 0) break;
         /*-- flush/finish end? --*/
         if (s->avail_in_expect == 0) break;
         progress_in = True;
         ADD_CHAR_TO_BLOCK ( s, (UInt32)(*((UChar*)(s->strm->next_in))) ); 
         s->strm->next_in++;
         s->strm->avail_in--;
         s->strm->total_in_lo32++;
         if (s->strm->total_in_lo32 == 0) s->strm->total_in_hi32++;
         s->avail_in_expect--;
      }
   }
   return progress_in;
}


/*---------------------------------------------------*/
static
Bool copy_output_until_stop ( EState* s )
{
   Bool progress_out = False;

   while (True) {

      /*-- no output space? --*/
      if (s->strm->avail_out == 0) break;

      /*-- block done? --*/
      if (s->state_out_pos >= s->numZ) break;

      progress_out = True;
      *(s->strm->next_out) = s->zbits[s->state_out_pos];
      s->state_out_pos++;
      s->strm->avail_out--;
      s->strm->next_out++;
      s->strm->total_out_lo32++;
      if (s->strm->total_out_lo32 == 0) s->strm->total_out_hi32++;
   }