LocalFileSystem.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2013 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 #ifndef MBED_LOCALFILESYSTEM_H
00017 #define MBED_LOCALFILESYSTEM_H
00018 
00019 #include "platform.h"
00020 
00021 #if DEVICE_LOCALFILESYSTEM
00022 
00023 #include "FileSystemLike.h"
00024 #include "PlatformMutex.h"
00025 
00026 namespace mbed {
00027 
00028 FILEHANDLE local_file_open(const char* name, int flags);
00029 
00030 class LocalFileHandle : public FileHandle {
00031 
00032 public:
00033     LocalFileHandle(FILEHANDLE fh);
00034 
00035     virtual int close();
00036 
00037     virtual ssize_t write(const void *buffer, size_t length);
00038 
00039     virtual ssize_t read(void *buffer, size_t length);
00040 
00041     virtual int isatty();
00042 
00043     virtual off_t lseek(off_t position, int whence);
00044 
00045     virtual int fsync();
00046 
00047     virtual off_t flen();
00048 
00049 protected:
00050     virtual void lock();
00051     virtual void unlock();
00052     FILEHANDLE _fh;
00053     int pos;
00054     PlatformMutex _mutex;
00055 };
00056 
00057 /** A filesystem for accessing the local mbed Microcontroller USB disk drive
00058  *
00059  *  This allows programs to read and write files on the same disk drive that is used to program the
00060  *  mbed Microcontroller. Once created, the standard C file access functions are used to open,
00061  *  read and write files.
00062  *
00063  * @Note Synchronization level: Thread safe
00064  *
00065  * Example:
00066  * @code
00067  * #include "mbed.h"
00068  *
00069  * LocalFileSystem local("local");               // Create the local filesystem under the name "local"
00070  *
00071  * int main() {
00072  *     FILE *fp = fopen("/local/out.txt", "w");  // Open "out.txt" on the local file system for writing
00073  *     fprintf(fp, "Hello World!");
00074  *     fclose(fp);
00075  *     remove("/local/out.txt");                 // Removes the file "out.txt" from the local file system
00076  *
00077  *     DIR *d = opendir("/local");               // Opens the root directory of the local file system
00078  *     struct dirent *p;
00079  *     while((p = readdir(d)) != NULL) {         // Print the names of the files in the local file system
00080  *       printf("%s\n", p->d_name);              // to stdout.
00081  *     }
00082  *     closedir(d);
00083  * }
00084  * @endcode
00085  *
00086  * @note
00087  *  If the microcontroller program makes an access to the local drive, it will be marked as "removed"
00088  *  on the Host computer. This means it is no longer accessible from the Host Computer.
00089  *
00090  *  The drive will only re-appear when the microcontroller program exists. Note that if the program does
00091  *  not exit, you will need to hold down reset on the mbed Microcontroller to be able to see the drive again!
00092  */
00093 class LocalFileSystem : public FileSystemLike {
00094     // No modifiable state
00095 
00096 public:
00097     LocalFileSystem(const char* n) : FileSystemLike(n) {
00098 
00099     }
00100 
00101     virtual FileHandle *open(const char* name, int flags);
00102     virtual int remove(const char *filename);
00103     virtual DirHandle *opendir(const char *name);
00104 };
00105 
00106 } // namespace mbed
00107 
00108 #endif
00109 
00110 #endif