zu_file.h

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/**********************************************************************
zyGrib: meteorological GRIB file viewer
Copyright (C) 2008 - Jacques Zaninetti - http://www.zygrib.org
 
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
 
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
 
You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
***********************************************************************/
 
#ifndef ZU_FILE_H
#define ZU_FILE_H
 
#define ZU_COMPRESS_AUTO (-1)
#define ZU_COMPRESS_NONE 0
#define ZU_COMPRESS_GZIP 1
#define ZU_COMPRESS_BZIP 2
 
#define ZU_BUFREADSIZE 256000
 
#ifdef __cplusplus
extern "C" {
#endif
 
// zuFile : uniform interface for READING uncompressed, gziped and bziped files
// (with fseek ftell not so bugged as in ... library)
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
 
#include <zlib.h>
#include <bzlib.h>
 
typedef struct {
  int type;
  int ok;
  char *fname;
  long pos;
 
  void *zfile;  // exact file type depends of compress type
 
  FILE *faux;  // auxiliary file for bzip
} ZUFILE;
 
ZUFILE *zu_open(const char *fname, const char *mode,
                int type = ZU_COMPRESS_AUTO);
int zu_close(ZUFILE *f);
 
int zu_can_read_file(const char *fname);
 
int zu_read(ZUFILE *f, void *buf, long len);
 
long zu_tell(ZUFILE *f);
 
int zu_seek(ZUFILE *f, long offset, int whence);  // TODO: whence=SEEK_END
 
void zu_rewind(ZUFILE *f);
 
long zu_filesize(ZUFILE *f);
 
// for internal use :
int zu_bzSeekForward(ZUFILE *f, unsigned long nbytes);
 
#ifdef __cplusplus
}
#endif
 
#endif