dir.h

来自「ST5518机顶盒系统文件系统源代码！绝对超值！」· C头文件 代码 · 共 95 行

/******************************************************************************

File Name : dir.h

Description: Directory management.

******************************************************************************/

#ifndef  DIR_H
#define  DIR_H

    /* Includes ------------------------------------------------------------ */

#include "avdevice.h"

    /* Exported Constants -------------------------------------------------- */

#define MAX_FILE_NAME_LEN         (59) /* max # chars in file name (without terminating 0) */

#define FILE_FLAG_ENTRY_UNUSED    (0X00000000)
#define FILE_FLAG_ENTRY_USED      (0X00000001)

#define FILE_FLAG_DIRECTORY       (0X00000100)
#define FILE_FLAG_STREAM_MODE     (0X00000200)
#define FILE_FLAG_BOOT_FILE       (0X00000400)
#define FILE_FLAG_CYCLIC_FILE     (0X00000800)

#define FILE_FLAG_BEING_DELETED   (0X00000010)
#define FILE_FLAG_OPEN_FOR_WRITE  (0X00000020)

#define RESERVED_FILE_CHAR        "/\\;:"
#define THIS_DIRECTORY            "."
#define PARENT_DIRECTORY          ".."

    /* Exported Types ------------------------------------------------------ */

typedef struct
{
    U32 LoopCount;      /* The number of time the file has looped */
    U32 TopOffset;      /* The offset to the top of file          */
}
stavfs_CyclicSize_t;

/*
 * The stavfs_DirEntry_t is made an exact fraction of a sector so that when it fits
 * into a Cluster the entries don't cross a sector boundary. Then writing to disk
 * any given sector will be written correctly (on some disks). So by not spanning
 * sectors no single entry will be corrupted.
 * We need to make 'holes' in the structure to make room for the fields added
 * to the cluster by back up on write.
 */

typedef struct
{
    U64 DummyLBA;       /* Provides space for the Backup on write LBA Value */

    U64 StartLBA;       /* LBA of first allocated Cluster */
    U64 EndLBA;         /* LBA of last  allocated Cluster */
    U64 AllocSize;      /* Allocated Size in Clusters */
    
    union
    {
        U64                  File; 
        stavfs_CyclicSize_t  Cyclic;
    }   Size;           /* Amount of data in the file     */
        
    U32 Flags;
    U32 Unused;
    U64 MetaData[2];
    U8  Name[MAX_FILE_NAME_LEN+1];
    
    U32 DummyCRC;       /* Provides space for the Backup on write CRC Value */
}
stavfs_DirEntry_t;

    /* Exported Variables -------------------------------------------------- */

    /* Exported Macros ----------------------------------------------------- */

    /* Exported Function Prototypes ---------------------------------------- */

ST_ErrorCode_t stavfs_InitRootDir      (stavfs_Device_t *Device_p);  /* Open and format the root directory */
ST_ErrorCode_t stavfs_OpenRootDir      (stavfs_Device_t *Device_p);  /* Open the root directory */
ST_ErrorCode_t stavfs_CloseRootDir     (stavfs_Device_t *Device_p);
ST_ErrorCode_t stavfs_FormatRootDir    (stavfs_Device_t *Device_p);
ST_ErrorCode_t stavfs_FlushDir         (stavfs_Device_t *Device_p, stavfs_DirEntry_t *Dir_p);
ST_ErrorCode_t stavfs_ModifyDirEntry   (stavfs_Device_t *Device_p, stavfs_DirEntry_t *DirEntry_p);
ST_ErrorCode_t stavfs_FindFileEntry    (stavfs_Device_t *Device_p, stavfs_DirEntry_t *Dir_p, char *Name, stavfs_DirEntry_t **Entry_p);
ST_ErrorCode_t stavfs_FindFreeEntry    (stavfs_Device_t *Device_p, stavfs_DirEntry_t *Dir_p, stavfs_DirEntry_t **Entry_p);
ST_ErrorCode_t stavfs_NextEntry        (stavfs_Device_t *Device_p, stavfs_DirEntry_t *Dir_p, stavfs_DirEntry_t **Entry_p);
ST_ErrorCode_t stavfs_ReleaseFileEntry (stavfs_Device_t *Device_p, stavfs_DirEntry_t *Entry_p);


#endif