FATFileSystem.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2012 ARM Limited
00003  *
00004  * Permission is hereby granted, free of charge, to any person obtaining a copy
00005  * of this software and associated documentation files (the "Software"), to deal
00006  * in the Software without restriction, including without limitation the rights
00007  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00008  * copies of the Software, and to permit persons to whom the Software is
00009  * furnished to do so, subject to the following conditions:
00010  *
00011  * The above copyright notice and this permission notice shall be included in
00012  * all copies or substantial portions of the Software.
00013  *
00014  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00015  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00016  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00017  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00018  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00019  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
00020  * SOFTWARE.
00021  */
00022 #ifndef MBED_FATFILESYSTEM_H
00023 #define MBED_FATFILESYSTEM_H
00024 
00025 #include "FileSystem.h"
00026 #include "BlockDevice.h"
00027 #include "FileHandle.h"
00028 #include "ff.h"
00029 #include <stdint.h>
00030 #include "PlatformMutex.h"
00031 
00032 using namespace mbed;
00033 
00034 /**
00035  * FATFileSystem based on ChaN's Fat Filesystem library v0.8
00036  */
00037 class FATFileSystem : public FileSystem {
00038 public:
00039     /** Lifetime of the FATFileSystem
00040      *
00041      *  @param name     Name to add filesystem to tree as
00042      *  @param bd       BlockDevice to mount, may be passed instead to mount call
00043      */
00044     FATFileSystem(const char *name = NULL, BlockDevice *bd = NULL);
00045     virtual ~FATFileSystem();
00046     
00047     /** Formats a logical drive, FDISK partitioning rule.
00048      *
00049      *  The block device to format should be mounted when this function is called.
00050      *
00051      *  @param bd
00052      *    This is the block device that will be formated.
00053      *
00054      *  @param allocation_unit
00055      *    This is the number of bytes per cluster size. The valid value is N
00056      *    times the sector size. N is a power of 2 from 1 to 128 for FAT
00057      *    volume and upto 16MiB for exFAT volume. If zero is given,
00058      *    the default allocation unit size is selected by the underlying
00059      *    filesystem, which depends on the volume size.
00060      */
00061     static int format(BlockDevice *bd, int allocation_unit = 0);
00062 
00063     /** Mounts a filesystem to a block device
00064      *
00065      *  @param bd       BlockDevice to mount to
00066      *  @return         0 on success, negative error code on failure
00067      */
00068     virtual int mount(BlockDevice *bd);
00069 
00070     /** Mounts a filesystem to a block device
00071      *
00072      *  @param bd       BlockDevice to mount to
00073      *  @param force    Flag to force the underlying filesystem to force mounting the filesystem
00074      *  @return         0 on success, negative error code on failure
00075      */
00076     virtual int mount(BlockDevice *bd, bool force);
00077 
00078     /** Unmounts a filesystem from the underlying block device
00079      *
00080      *  @return         0 on success, negative error code on failure
00081      */
00082     virtual int unmount();
00083 
00084     /** Remove a file from the filesystem.
00085      *
00086      *  @param path     The name of the file to remove.
00087      *  @return         0 on success, negative error code on failure
00088      */
00089     virtual int remove(const char *path);
00090 
00091     /** Rename a file in the filesystem.
00092      *
00093      *  @param path     The name of the file to rename.
00094      *  @param newpath  The name to rename it to
00095      *  @return         0 on success, negative error code on failure
00096      */
00097     virtual int rename(const char *path, const char *newpath);
00098 
00099     /** Store information about the file in a stat structure
00100      *
00101      *  @param path     The name of the file to find information about
00102      *  @param st       The stat buffer to write to
00103      *  @return         0 on success, negative error code on failure
00104      */
00105     virtual int stat(const char *path, struct stat *st);
00106 
00107     /** Create a directory in the filesystem.
00108      *
00109      *  @param path     The name of the directory to create.
00110      *  @param mode     The permissions with which to create the directory
00111      *  @return         0 on success, negative error code on failure
00112      */
00113     virtual int mkdir(const char *path, mode_t mode);
00114 
00115 protected:
00116     /** Open a file on the filesystem
00117      *
00118      *  @param file     Destination for the handle to a newly created file
00119      *  @param path     The name of the file to open
00120      *  @param flags    The flags to open the file in, one of O_RDONLY, O_WRONLY, O_RDWR,
00121      *                  bitwise or'd with one of O_CREAT, O_TRUNC, O_APPEND
00122      *  @return         0 on success, negative error code on failure
00123      */
00124     virtual int file_open(fs_file_t *file, const char *path, int flags);
00125 
00126     /** Close a file
00127      *
00128      *  @param file     File handle
00129      *  return          0 on success, negative error code on failure
00130      */
00131     virtual int file_close(fs_file_t file);
00132 
00133     /** Read the contents of a file into a buffer
00134      *
00135      *  @param file     File handle
00136      *  @param buffer   The buffer to read in to
00137      *  @param size     The number of bytes to read
00138      *  @return         The number of bytes read, 0 at end of file, negative error on failure
00139      */
00140     virtual ssize_t file_read(fs_file_t file, void *buffer, size_t len);
00141 
00142     /** Write the contents of a buffer to a file
00143      *
00144      *  @param file     File handle
00145      *  @param buffer   The buffer to write from
00146      *  @param size     The number of bytes to write 
00147      *  @return         The number of bytes written, negative error on failure
00148      */
00149     virtual ssize_t file_write(fs_file_t file, const void *buffer, size_t len);
00150 
00151     /** Flush any buffers associated with the file
00152      *
00153      *  @param file     File handle
00154      *  @return         0 on success, negative error code on failure
00155      */
00156     virtual int file_sync(fs_file_t file);
00157 
00158     /** Move the file position to a given offset from from a given location
00159      *
00160      *  @param file     File handle
00161      *  @param offset   The offset from whence to move to
00162      *  @param whence   The start of where to seek
00163      *      SEEK_SET to start from beginning of file,
00164      *      SEEK_CUR to start from current position in file,
00165      *      SEEK_END to start from end of file
00166      *  @return         The new offset of the file
00167      */
00168     virtual off_t file_seek(fs_file_t file, off_t offset, int whence);
00169 
00170     /** Get the file position of the file
00171      *
00172      *  @param file     File handle
00173      *  @return         The current offset in the file
00174      */
00175     virtual off_t file_tell(fs_file_t file);
00176 
00177     /** Get the size of the file
00178      *
00179      *  @param file     File handle
00180      *  @return         Size of the file in bytes
00181      */
00182     virtual size_t file_size(fs_file_t file);
00183 
00184     /** Open a directory on the filesystem
00185      *
00186      *  @param dir      Destination for the handle to the directory
00187      *  @param path     Name of the directory to open
00188      *  @return         0 on success, negative error code on failure
00189      */
00190     virtual int dir_open(fs_dir_t *dir, const char *path);
00191 
00192     /** Close a directory
00193      *
00194      *  @param dir      Dir handle
00195      *  return          0 on success, negative error code on failure
00196      */
00197     virtual int dir_close(fs_dir_t dir);
00198 
00199     /** Read the next directory entry
00200      *
00201      *  @param dir      Dir handle
00202      *  @param ent      The directory entry to fill out
00203      *  @return         1 on reading a filename, 0 at end of directory, negative error on failure
00204      */
00205     virtual ssize_t dir_read(fs_dir_t dir, struct dirent *ent);
00206 
00207     /** Set the current position of the directory
00208      *
00209      *  @param dir      Dir handle
00210      *  @param offset   Offset of the location to seek to,
00211      *                  must be a value returned from dir_tell
00212      */
00213     virtual void dir_seek(fs_dir_t dir, off_t offset);
00214 
00215     /** Get the current position of the directory
00216      *
00217      *  @param dir      Dir handle
00218      *  @return         Position of the directory that can be passed to dir_rewind
00219      */
00220     virtual off_t dir_tell(fs_dir_t dir);
00221 
00222     /** Rewind the current position to the beginning of the directory
00223      *
00224      *  @param dir      Dir handle
00225      */
00226     virtual void dir_rewind(fs_dir_t dir);
00227     
00228 private:
00229     FATFS _fs; // Work area (file system object) for logical drive
00230     char _fsid[2];
00231     int _id;
00232 
00233 protected:
00234     virtual void lock();
00235     virtual void unlock();
00236 };
00237 
00238 #endif