bzlib.c

高效率的一种通用压缩/解压程序

   if ( !abandon && !ferror ( bzf->handle ) ) {
      fflush ( bzf->handle );
      if (ferror(bzf->handle))
         { BZ_SETERR(BZ_IO_ERROR); return; };
   }

   if (nbytes_in != NULL) *nbytes_in = bzf->strm.total_in;
   if (nbytes_out != NULL) *nbytes_out = bzf->strm.total_out;

   BZ_SETERR(BZ_OK);
   bzCompressEnd ( &(bzf->strm) );
   free ( bzf );
}


/*---------------------------------------------------*/
BZFILE* BZ_API(bzReadOpen) 
                   ( int*  bzerror, 
                     FILE* f, 
                     int   verbosity,
                     int   small,
                     void* unused,
                     int   nUnused )
{
   bzFile* bzf = NULL;
   int     ret;

   BZ_SETERR(BZ_OK);

   if (f == NULL || 
       (small != 0 && small != 1) ||
       (verbosity < 0 || verbosity > 4) ||
       (unused == NULL && nUnused != 0) ||
       (unused != NULL && (nUnused < 0 || nUnused > BZ_MAX_UNUSED)))
      { BZ_SETERR(BZ_PARAM_ERROR); return NULL; };

   if (ferror(f))
      { BZ_SETERR(BZ_IO_ERROR); return NULL; };

   bzf = malloc ( sizeof(bzFile) );
   if (bzf == NULL) 
      { BZ_SETERR(BZ_MEM_ERROR); return NULL; };

   BZ_SETERR(BZ_OK);

   bzf->initialisedOk = False;
   bzf->handle        = f;
   bzf->bufN          = 0;
   bzf->writing       = False;
   bzf->strm.bzalloc  = NULL;
   bzf->strm.bzfree   = NULL;
   bzf->strm.opaque   = NULL;
   
   while (nUnused > 0) {
      bzf->buf[bzf->bufN] = *((UChar*)(unused)); bzf->bufN++;
      unused = ((void*)( 1 + ((UChar*)(unused))  ));
      nUnused--;
   }

   ret = bzDecompressInit ( &(bzf->strm), verbosity, small );
   if (ret != BZ_OK)
      { BZ_SETERR(ret); free(bzf); return NULL; };

   bzf->strm.avail_in = bzf->bufN;
   bzf->strm.next_in  = bzf->buf;

   bzf->initialisedOk = True;
   return bzf;   
}


/*---------------------------------------------------*/
void BZ_API(bzReadClose) ( int *bzerror, BZFILE *b )
{
   bzFile* bzf = (bzFile*)b;

   BZ_SETERR(BZ_OK);
   if (bzf == NULL)
      { BZ_SETERR(BZ_OK); return; };

   if (bzf->writing)
      { BZ_SETERR(BZ_SEQUENCE_ERROR); return; };

   if (bzf->initialisedOk)
      (void)bzDecompressEnd ( &(bzf->strm) );
   free ( bzf );
}


/*---------------------------------------------------*/
int BZ_API(bzRead) 
           ( int*    bzerror, 
             BZFILE* b, 
             void*   buf, 
             int     len )
{
   Int32   n, ret;
   bzFile* bzf = (bzFile*)b;

   BZ_SETERR(BZ_OK);

   if (bzf == NULL || buf == NULL || len < 0)
      { BZ_SETERR(BZ_PARAM_ERROR); return 0; };

   if (bzf->writing)
      { BZ_SETERR(BZ_SEQUENCE_ERROR); return 0; };

   if (len == 0)
      { BZ_SETERR(BZ_OK); return 0; };

   bzf->strm.avail_out = len;
   bzf->strm.next_out = buf;

   while (True) {

      if (ferror(bzf->handle)) 
         { BZ_SETERR(BZ_IO_ERROR); return 0; };

      if (bzf->strm.avail_in == 0 && !myfeof(bzf->handle)) {
         n = fread ( bzf->buf, sizeof(UChar), 
                     BZ_MAX_UNUSED, bzf->handle );
         if (ferror(bzf->handle))
            { BZ_SETERR(BZ_IO_ERROR); return 0; };
         bzf->bufN = n;
         bzf->strm.avail_in = bzf->bufN;
         bzf->strm.next_in = bzf->buf;
      }

      ret = bzDecompress ( &(bzf->strm) );

      if (ret != BZ_OK && ret != BZ_STREAM_END)
         { BZ_SETERR(ret); return 0; };

      if (ret == BZ_OK && myfeof(bzf->handle) && 
          bzf->strm.avail_in == 0 && bzf->strm.avail_out > 0)
         { BZ_SETERR(BZ_UNEXPECTED_EOF); return 0; };

      if (ret == BZ_STREAM_END)
         { BZ_SETERR(BZ_STREAM_END);
           return len - bzf->strm.avail_out; };
      if (bzf->strm.avail_out == 0)
         { BZ_SETERR(BZ_OK); return len; };
      
   }

   return 0; /*not reached*/
}


/*---------------------------------------------------*/
void BZ_API(bzReadGetUnused) 
                     ( int*    bzerror, 
                       BZFILE* b, 
                       void**  unused, 
                       int*    nUnused )
{
   bzFile* bzf = (bzFile*)b;
   if (bzf == NULL)
      { BZ_SETERR(BZ_PARAM_ERROR); return; };
   if (bzf->lastErr != BZ_STREAM_END)
      { BZ_SETERR(BZ_SEQUENCE_ERROR); return; };
   if (unused == NULL || nUnused == NULL)
      { BZ_SETERR(BZ_PARAM_ERROR); return; };

   BZ_SETERR(BZ_OK);
   *nUnused = bzf->strm.avail_in;
   *unused = bzf->strm.next_in;
}
#endif


/*---------------------------------------------------*/
/*--- Misc convenience stuff                      ---*/
/*---------------------------------------------------*/

/*---------------------------------------------------*/
int BZ_API(bzBuffToBuffCompress) 
                         ( char*         dest, 
                           unsigned int* destLen,
                           char*         source, 
                           unsigned int  sourceLen,
                           int           blockSize100k, 
                           int           verbosity, 
                           int           workFactor )
{
   bz_stream strm;
   int ret;

   if (dest == NULL || destLen == NULL || 
       source == NULL ||
       blockSize100k < 1 || blockSize100k > 9 ||
       verbosity < 0 || verbosity > 4 ||
       workFactor < 0 || workFactor > 250) 
      return BZ_PARAM_ERROR;

   if (workFactor == 0) workFactor = 30;
   strm.bzalloc = NULL;
   strm.bzfree = NULL;
   strm.opaque = NULL;
   ret = bzCompressInit ( &strm, blockSize100k, 
                          verbosity, workFactor );
   if (ret != BZ_OK) return ret;

   strm.next_in = source;
   strm.next_out = dest;
   strm.avail_in = sourceLen;
   strm.avail_out = *destLen;

   ret = bzCompress ( &strm, BZ_FINISH );
   if (ret == BZ_FINISH_OK) goto output_overflow;
   if (ret != BZ_STREAM_END) goto errhandler;

   /* normal termination */
   *destLen -= strm.avail_out;   
   bzCompressEnd ( &strm );
   return BZ_OK;

   output_overflow:
   bzCompressEnd ( &strm );
   return BZ_OUTBUFF_FULL;

   errhandler:
   bzCompressEnd ( &strm );
   return ret;
}


/*---------------------------------------------------*/
int BZ_API(bzBuffToBuffDecompress) 
                           ( char*         dest, 
                             unsigned int* destLen,
                             char*         source, 
                             unsigned int  sourceLen,
                             int           small,
                             int           verbosity )
{
   bz_stream strm;
   int ret;

   if (dest == NULL || destLen == NULL || 
       source == NULL ||
       (small != 0 && small != 1) ||
       verbosity < 0 || verbosity > 4) 
          return BZ_PARAM_ERROR;

   strm.bzalloc = NULL;
   strm.bzfree = NULL;
   strm.opaque = NULL;
   ret = bzDecompressInit ( &strm, verbosity, small );
   if (ret != BZ_OK) return ret;

   strm.next_in = source;
   strm.next_out = dest;
   strm.avail_in = sourceLen;
   strm.avail_out = *destLen;

   ret = bzDecompress ( &strm );
   if (ret == BZ_OK) goto output_overflow_or_eof;
   if (ret != BZ_STREAM_END) goto errhandler;

   /* normal termination */
   *destLen -= strm.avail_out;
   bzDecompressEnd ( &strm );
   return BZ_OK;

   output_overflow_or_eof:
   if (strm.avail_out > 0) {
      bzDecompressEnd ( &strm );
      return BZ_UNEXPECTED_EOF;
   } else {
      bzDecompressEnd ( &strm );
      return BZ_OUTBUFF_FULL;
   };      

   errhandler:
   bzDecompressEnd ( &strm );
   return BZ_SEQUENCE_ERROR;
}


/*---------------------------------------------------*/
/*--
   Code contributed by Yoshioka Tsuneo
   ([e-mail]/[e-mail]),
   to support better zlib compatibility.
   This code is not _officially_ part of libbzip2 (yet);
   I haven't tested it, documented it, or considered the
   threading-safeness of it.
   If this code breaks, please contact both Yoshioka and me.
--*/
/*---------------------------------------------------*/

/*---------------------------------------------------*/
/*--
   return version like "0.9.0c".
--*/
const char * BZ_API(bzlibVersion)(void)
{
   return BZ_VERSION;
}


#ifndef BZ_NO_STDIO
/*---------------------------------------------------*/

#if defined(_WIN32) || defined(OS2) || defined(MSDOS)
#   include <fcntl.h>
#   include <io.h>
#   define SET_BINARY_MODE(file) setmode(fileno(file),O_BINARY)
#else
#   define SET_BINARY_MODE(file)
#endif
static
BZFILE * bzopen_or_bzdopen
               ( const char *path,   /* no use when bzdopen */
                 int fd,             /* no use when bzdopen */
                 const char *mode,
                 int open_mode)      /* bzopen: 0, bzdopen:1 */
{
   int    bzerr;
   char   unused[BZ_MAX_UNUSED];
   int    blockSize100k = 9;
   int    writing       = 0;
   char   mode2[10]     = "";
   FILE   *fp           = NULL;
   BZFILE *bzfp         = NULL;
   int    verbosity     = 0;
   int    workFactor    = 30;
   int    smallMode     = 0;
   int    nUnused       = 0; 

   if(mode==NULL){return NULL;}
   while(*mode){
      switch(*mode){
      case 'r':
         writing = 0;break;
      case 'w':
         writing = 1;break;
      case 's':
         smallMode = 1;break;
      default:
         if(isdigit(*mode)){
            blockSize100k = 0;
            while(isdigit(*mode)){
               blockSize100k = blockSize100k*10 + *mode-'0';
               mode++;
            }
         }else{
            /* ignore */
         }
      }
      mode++;
   }
   strcat(mode2, writing ? "w" : "r" );
   strcat(mode2,"b");   /* binary mode */

   if(open_mode==0){
      if(path==NULL || strcmp(path,"")==0){
        fp = (writing ? stdout : stdin);
        SET_BINARY_MODE(fp);
      }else{
        fp = fopen(path,mode2);
      }
   }else{
#ifdef BZ_STRICT_ANSI
      fp = NULL;
#else
      fp = fdopen(fd,mode2);
#endif
   }
   if(fp==NULL){return NULL;}

   if(writing){
      bzfp = bzWriteOpen(&bzerr,fp,blockSize100k,verbosity,workFactor);
   }else{
      bzfp = bzReadOpen(&bzerr,fp,verbosity,smallMode,unused,nUnused);
   }
   if(bzfp==NULL){
      if(fp!=stdin && fp!=stdout) fclose(fp);
      return NULL;
   }
   return bzfp;
}


/*---------------------------------------------------*/
/*--
   open file for read or write.
      ex) bzopen("file","w9")
      case path="" or NULL => use stdin or stdout.
--*/
BZFILE * BZ_API(bzopen)
               ( const char *path,
                 const char *mode )
{
   return bzopen_or_bzdopen(path,-1,mode,/*bzopen*/0);
}


/*---------------------------------------------------*/
BZFILE * BZ_API(bzdopen)
               ( int fd,
                 const char *mode )
{
   return bzopen_or_bzdopen(NULL,fd,mode,/*bzdopen*/1);
}


/*---------------------------------------------------*/
int BZ_API(bzread) (BZFILE* b, void* buf, int len )
{
   int bzerr, nread;
   if (((bzFile*)b)->lastErr == BZ_STREAM_END) return 0;
   nread = bzRead(&bzerr,b,buf,len);
   if (bzerr == BZ_OK || bzerr == BZ_STREAM_END) {
      return nread;
   } else {
      return -1;
   }
}


/*---------------------------------------------------*/
int BZ_API(bzwrite) (BZFILE* b, void* buf, int len )
{
   int bzerr;

   bzWrite(&bzerr,b,buf,len);
   if(bzerr == BZ_OK){
      return len;
   }else{
      return -1;
   }
}


/*---------------------------------------------------*/
int BZ_API(bzflush) (BZFILE *b)
{
   /* do nothing now... */
   return 0;
}


/*---------------------------------------------------*/
void BZ_API(bzclose) (BZFILE* b)
{
   int bzerr;
   FILE *fp = ((bzFile *)b)->handle;
   
   if(b==NULL){return;}
   if(((bzFile*)b)->writing){
      bzWriteClose(&bzerr,b,0,NULL,NULL);
      if(bzerr != BZ_OK){
         bzWriteClose(NULL,b,1,NULL,NULL);
      }
   }else{
      bzReadClose(&bzerr,b);
   }
   if(fp!=stdin && fp!=stdout){
      fclose(fp);
   }
}


/*---------------------------------------------------*/
/*--
   return last error code 
--*/
static char *bzerrorstrings[] = {
       "OK"
      ,"SEQUENCE_ERROR"
      ,"PARAM_ERROR"
      ,"MEM_ERROR"
      ,"DATA_ERROR"
      ,"DATA_ERROR_MAGIC"
      ,"IO_ERROR"
      ,"UNEXPECTED_EOF"
      ,"OUTBUFF_FULL"
      ,"???"   /* for future */
      ,"???"   /* for future */
      ,"???"   /* for future */
      ,"???"   /* for future */
      ,"???"   /* for future */
      ,"???"   /* for future */
};


const char * BZ_API(bzerror) (BZFILE *b, int *errnum)
{
   int err = ((bzFile *)b)->lastErr;

   if(err>0) err = 0;
   *errnum = err;
   return bzerrorstrings[err*-1];
}
#endif


/*-------------------------------------------------------------*/
/*--- end                                           bzlib.c ---*/
/*-------------------------------------------------------------*/