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/**
* @file
*
* @brief RTEMS File System Directory Support
*
* @ingroup rtems_rfs
*
* RTEMS File System Directory Support
*
* This file provides the directory support functions.
*/
/*
* COPYRIGHT (c) 2010 Chris Johns <chrisj@rtems.org>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#if !defined (_RTEMS_RFS_DIR_H_)
#define _RTEMS_RFS_DIR_H_
#include <dirent.h>
#include <rtems/libio_.h>
#include <rtems/rfs/rtems-rfs-data.h>
#include <rtems/rfs/rtems-rfs-file-system.h>
#include <rtems/rfs/rtems-rfs-inode.h>
/**
* Define the offsets of the fields of a directory entry.
*/
#define RTEMS_RFS_DIR_ENTRY_INO (0) /**< The ino offset in a directory
* entry. */
#define RTEMS_RFS_DIR_ENTRY_HASH (4) /**< The hash offset in a directory
* entry. The hash is 32bits. We need at
* least 16bits and given the length and
* ino field are 4 the extra 2 bytes is
* not a big overhead.*/
#define RTEMS_RFS_DIR_ENTRY_LEN (8) /**< The length offset in a directory
* entry. */
/**
* The length of the directory entry header.
*/
#define RTEMS_RFS_DIR_ENTRY_SIZE (4 + 4 + 2)
/**
* The length when the remainder of the directory block is empty.
*/
#define RTEMS_RFS_DIR_ENTRY_EMPTY (0xffff)
/**
* Return the hash of the entry.
*
* @param[in] _e is a pointer to the directory entry.
*
* @retval hash The uint32_t hash of the entry.
*/
#define rtems_rfs_dir_entry_hash(_e) \
rtems_rfs_read_u32 (_e + RTEMS_RFS_DIR_ENTRY_HASH)
/**
* Set the hash of the entry.
*
* @param[in] _e is a pointer to the directory entry.
*
* @param[in] _h is the hash of the entry.
*/
#define rtems_rfs_dir_set_entry_hash(_e, _h) \
rtems_rfs_write_u32 (_e + RTEMS_RFS_DIR_ENTRY_HASH, _h)
/**
* Return the ino of the entry.
*
* @param[in] _e is a pointer to the directory entry.
*
* @retval ino The ino of the entry.
*/
#define rtems_rfs_dir_entry_ino(_e) \
rtems_rfs_read_u32 (_e + RTEMS_RFS_DIR_ENTRY_INO)
/**
* Set the ino of the entry.
*
* @param[in] _e is a pointer to the directory entry.
*
* @param[in] _i is the ino of the entry.
*/
#define rtems_rfs_dir_set_entry_ino(_e, _i) \
rtems_rfs_write_u32 (_e + RTEMS_RFS_DIR_ENTRY_INO, _i)
/**
* Return the length of the entry.
*
* @param[in] _e Pointer to the directory entry.
*
* @retval length The length of the entry.
*/
#define rtems_rfs_dir_entry_length(_e) \
rtems_rfs_read_u16 (_e + RTEMS_RFS_DIR_ENTRY_LEN)
/**
* Set the length of the entry.
*
* @param[in] _e is a pointer to the directory entry.
* @param[in] _l is the length.
*/
#define rtems_rfs_dir_set_entry_length(_e, _l) \
rtems_rfs_write_u16 (_e + RTEMS_RFS_DIR_ENTRY_LEN, _l)
/**
* Look up a directory entry in the directory pointed to by the inode. The look
* up is local to this directory. No need to decend.
*
* @param[in] fs is the file system.
* @param[in] inode is a pointer to the inode of the directory to search.
* @param[in] name is a pointer to the name to look up. The name may not be
* nul terminated.
* @param[in] length is the length of the name.
* @param[out] ino will be filled in with the inode number
* if there is no error.
* @param[in] offset is the offset in the directory for the entry.
*
* @retval 0 Successful operation.
* @retval error_code An error occurred.
*/
int rtems_rfs_dir_lookup_ino (rtems_rfs_file_system* fs,
rtems_rfs_inode_handle* inode,
const char* name,
int length,
rtems_rfs_ino* ino,
uint32_t* offset);
/**
* Add an entry to the directory returing the inode number allocated to the
* entry.
*
* @param[in] fs is the file system data.
* @param[in] dir is a pointer to the directory inode the
* entry is to be added too.
* @param[in] name is a pointer to the name of the entry to be added.
* @param[in] length is the length of the name excluding a terminating 0.
* @param[in] ino is the ino of the entry.
*
* @retval 0 Successful operation.
* @retval error_code An error occurred.
*/
int rtems_rfs_dir_add_entry (rtems_rfs_file_system* fs,
rtems_rfs_inode_handle* dir,
const char* name,
size_t length,
rtems_rfs_ino ino);
/**
* Del an entry from the directory using an inode number as a key.
*
* @param[in] fs is the file system data.
* @param[in] dir is a pointer to the directory inode the
* entry is to be deleted from.
* @param[in] ino is the ino of the entry.
* @param[in] offset is the offset in the directory of the entry
* to delete. If 0 search from the start for the ino.
*
* @retval 0 Successful operation.
* @retval error_code An error occurred.
*/
int rtems_rfs_dir_del_entry (rtems_rfs_file_system* fs,
rtems_rfs_inode_handle* dir,
rtems_rfs_ino ino,
uint32_t offset);
/**
* Read the directory entry from offset into the directory entry buffer and
* return the length of space this entry uses in the directory table.
*
* @param[in] fs is the file system data.
* @param[in] dir is a pointer to the direct inode handler.
* @param[in] offset is the offset in the directory to read from.
* @param[in] dirent is a ointer to the dirent structure the entry
* is written into.
* @param[out] length will contain the length this entry
* takes in the directory.
*
* @retval 0 Successful operation.
* @retval error_code An error occurred.
*/
int rtems_rfs_dir_read (rtems_rfs_file_system* fs,
rtems_rfs_inode_handle* dir,
rtems_rfs_pos_rel offset,
struct dirent* dirent,
size_t* length);
/**
* Check if the directory is empty. The current and parent directory entries
* are ignored.
*
* @param[in] fs is the file system data
* @param[in] dir is a pointer to the directory inode to check.
*
* @retval 0 Successful operation.
* @retval error_code An error occurred.
*/
int rtems_rfs_dir_empty (rtems_rfs_file_system* fs,
rtems_rfs_inode_handle* dir);
#endif
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