imf.h

NUcleus plus 支持的文件系统。 是学习文件系统的很好参考资料。

/***************************************************************************                                                       
*    Copyright (c)  1993 - 2001 Accelerated Technology, Inc.               
*                                                                          
* PROPRIETARY RIGHTS of Accelerated Technology are involved in the subject 
* matter of this material.  All manufacturing, reproduction, use and sales 
* rights pertaining to this subject matter are governed by the license     
* agreement.  The recipient of this software implicity accepts the terms   
* of the license.                                                          
*                                                                          
****************************************************************************/
/****************************************************************************
*                                                                          
*  FILENAME                                                 VERSION        
*                                                                          
*      IMF.H                                                1.0      
*                                                                          
*  COMPONENT
*
*       File Abstraction Layer
*
*  DESCRIPTION                                                             
*                                                                          
*      This file contains the In-Memory File System function prototypes   
*      and miscellaneous defines.                                            
*
*   DATA STRUCTURES
*
*       mem_file        An In-Memory File System file.
*
*   FUNCTIONS
*
*       None
*
*   DEPENDENCIES
*
*       nucleus.h
*       target.h
*                                                                          
****************************************************************************/

#ifndef IMF_H
#define IMF_H

#include "plus/nucleus.h"
#include "net/target.h"

#ifdef          __cplusplus
extern  "C" {                               /* C declarations in C++     */
#endif /* _cplusplus */

extern INT p_errno;

#define MAX_FILES           2
#define MAX_FILE_SIZE       40000UL
#define NAME_LENGTH         12

#define PSEEK_SET           0           /* Offset from beginning of file. */
#define PSEEK_CUR           1           /* Offset from current file pointer. */
#define PSEEK_END           2           /* Offset from end of file. */

#define IMF_EOF             -1

/* File access flags */
#define IMF_RDONLY 0x0000               /* Open for read only*/
#define IMF_WRONLY 0x0001               /* Open for write only*/
#define IMF_RDWR   0x0002               /* Read/write access allowed.*/
#define IMF_APPEND 0x0008               /* Seek to eof on each write*/
#define IMF_CREAT  0x0100               /* Create the file if it does not exist.*/
#define IMF_TRUNC  0x0200               /* Truncate the file if it already exists*/
#define IMF_EXCL   0x0400               /* Fail if creating and already exists*/
#define IMF_NOSHAREANY   0x0004         /* Wants this open to fail if already
                                         * open.  Other opens will fail while
                                         * this open is active */
#define IMF_NOSHAREWRITE 0x0800         /* Wants this opens to fail if already
                                         * open for write. Other open for
                                         * write calls will fail while this
                                         * open is active. */

/* IMF has been allocated 2501-2750 for error codes */
#define IMF_NO_BUFFERS      -2501        /* No free buffers to open a new file */
#define IMF_FILE_OPEN       -2502        /* File is open */
#define IMF_FILE_CLOSED     -2503        /* File is closed */
#define IMF_NO_FILE         -2504        /* File does not exist */
#define IMF_INVAL_DESC      -2505        /* Invalid file descriptor */
#define IMF_END_FILE        -2506        /* Reached end of file */
#define IMF_FILE_EXISTS     -2507        /* File already exists */
#define IMF_INVAL_FLAG      -2508        /* Invalid flag was passed */
#define IMF_INVAL_BUFFER    -2509        /* Invalid buffer */
#define IMF_FILE_READONLY   -2510        /* The file cannot be written */
#define IMF_FILE_WRITEONLY  -2511        /* The file cannot be read */
#define IMF_BUFFER_FULL     -2512        /* No room to write to the buffer */

typedef struct mem_file {
    HUGE CHAR    *start;
    HUGE CHAR    *end;
    HUGE CHAR    *file_ptr;                 
    HUGE CHAR    *eof_ptr;                 
    UINT32       max_length;
    UINT32       length;
    UINT32       flag;
    CHAR         name[NAME_LENGTH + 1];
    INT16        used;                  /* Used to indicate that a file is in use.*/
    INT16        open;                  /* Used to indicate that a file is currently
                                           open. */
} MEM_FILE;

extern MEM_FILE    file_desc_ary[MAX_FILES];
extern NU_MEMORY_POOL  System_Memory;

INT     IMF_Open(CHAR *path, INT16 flag);   
INT     IMF_Find_File(CHAR *path, INT16 flag);
INT     IMF_Close(INT file);
INT32   IMF_Write(CHAR *buf, INT size, INT file);
INT32   IMF_Read(CHAR *buffer, INT buffersize, INT file_desc);
INT     IMF_Delete(CHAR *name);
INT32   IMF_Seek(INT file_desc, INT32 offset, INT16 origin);
INT     IMF_Store_Name(CHAR *name, MEM_FILE *r_file);
CHAR *  IMF_Fgets(CHAR *line, INT16 size, INT file);
INT     IMF_Rename(CHAR *rename_path, CHAR *curr_name);


#ifdef          __cplusplus
}
#endif /* _cplusplus */

#endif