bitfile.h

LZSS 压缩/解压算法 算法简单

/***************************************************************************
*                            Bit Stream File Header
*
*   File    : bitfile.h
*   Purpose : Providea definitions and prototypes for a simple library of
*             I/O functions for files that contain data in sizes that aren't
*             integral bytes.
*             An attempt was made to make the functions in this library
*             analogous to functions provided to manipulate byte streams.
*             The functions contained in this library were created with
*             compression algorithms in mind, but may be suited to other
*             applications.
*   Author  : Michael Dipperstein
*   Date    : January 9, 2004
*
****************************************************************************
*   UPDATES
*
*   $Id: bitfile.h,v 1.4 2005/12/06 15:06:37 michael Exp $
*   $Log: bitfile.h,v $
*   Revision 1.4  2005/12/06 15:06:37  michael
*   Added BitFileGetBitsInt and BitFilePutBitsInt for integer types.
*
*   Revision 1.3  2004/11/09 14:16:58  michael
*   Added functions to convert open bit_file_t to FILE and to
*   align open bit_file_t to the next byte.
*
*   Revision 1.2  2004/06/15 13:16:10  michael
*   Use incomplete type to hide definition of bitfile structure
*
*   Revision 1.1.1.1  2004/02/09 05:31:42  michael
*   Initial release
*
*
****************************************************************************
*
* Bitfile: Bit stream File I/O Routines
* Copyright (C) 2004-2005 by Michael Dipperstein ([e-mail])
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*
***************************************************************************/

#ifndef _BITFILE_H_
#define _BITFILE_H_

/***************************************************************************
*                             INCLUDED FILES
***************************************************************************/
#include <stdio.h>

/***************************************************************************
*                            TYPE DEFINITIONS
***************************************************************************/
typedef enum
{
    BF_READ = 0,
    BF_WRITE = 1,
    BF_APPEND= 2,
    BF_NO_MODE
} BF_MODES;

/* incomplete type to hide implementation */
struct bit_file_t;
typedef struct bit_file_t bit_file_t;

/***************************************************************************
*                               PROTOTYPES
***************************************************************************/

/* open/close file */
bit_file_t *BitFileOpen(const char *fileName, const BF_MODES mode);
bit_file_t *MakeBitFile(FILE *stream, const BF_MODES mode);
int BitFileClose(bit_file_t *stream);
FILE *BitFileToFILE(bit_file_t *stream);

/* toss spare bits and byte align file */
int BitFileByteAlign(bit_file_t *stream);

/* get/put character */
int BitFileGetChar(bit_file_t *stream);
int BitFilePutChar(const int c, bit_file_t *stream);

/* get/put single bit */
int BitFileGetBit(bit_file_t *stream);
int BitFilePutBit(const int c, bit_file_t *stream);

/* get/put number of bits (most significant bit to least significat bit) */
int BitFileGetBits(bit_file_t *stream, void *bits, const unsigned int count);
int BitFilePutBits(bit_file_t *stream, void *bits, const unsigned int count);

/***************************************************************************
* get/put number of bits from integer types (short, int, long, ...)
* machine endiness is accounted for.
* size is the size of the data structure pointer to by bits.
***************************************************************************/
int BitFileGetBitsInt(bit_file_t *stream, void *bits, const unsigned int count,
    const size_t size);
int BitFilePutBitsInt(bit_file_t *stream, void *bits, const unsigned int count,
    const size_t size);

#endif /* _BITFILE_H_ */