Chris LU
123
Fork of
FATFileSystem
by 
mbed official
MemFileSystem.h@3:e960e2b81a3c, 2014-03-17 (annotated)
- Committer:
- screamer
- Date:
- Mon Mar 17 14:09:00 2014 +0000
- Revision:
- 3:e960e2b81a3c
Added code documentation and fixed compile warning
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| screamer | 3:e960e2b81a3c | 1 | /* mbed Microcontroller Library - MemFileSystem |
| screamer | 3:e960e2b81a3c | 2 | * Copyright (c) 2008, sford |
| screamer | 3:e960e2b81a3c | 3 | */ |
| screamer | 3:e960e2b81a3c | 4 | |
| screamer | 3:e960e2b81a3c | 5 | |
| screamer | 3:e960e2b81a3c | 6 | #ifndef MBED_MEMFILESYSTEM_H |
| screamer | 3:e960e2b81a3c | 7 | #define MBED_MEMFILESYSTEM_H |
| screamer | 3:e960e2b81a3c | 8 | |
| screamer | 3:e960e2b81a3c | 9 | #include "FATFileSystem.h" |
| screamer | 3:e960e2b81a3c | 10 | |
| screamer | 3:e960e2b81a3c | 11 | namespace mbed |
| screamer | 3:e960e2b81a3c | 12 | { |
| screamer | 3:e960e2b81a3c | 13 | |
| screamer | 3:e960e2b81a3c | 14 | class MemFileSystem : public FATFileSystem |
| screamer | 3:e960e2b81a3c | 15 | { |
| screamer | 3:e960e2b81a3c | 16 | public: |
| screamer | 3:e960e2b81a3c | 17 | |
| screamer | 3:e960e2b81a3c | 18 | // 2000 sectors, each 512 bytes (malloced as required) |
| screamer | 3:e960e2b81a3c | 19 | char *sectors[2000]; |
| screamer | 3:e960e2b81a3c | 20 | |
| screamer | 3:e960e2b81a3c | 21 | MemFileSystem(const char* name) : FATFileSystem(name) { |
| screamer | 3:e960e2b81a3c | 22 | memset(sectors, 0, sizeof(sectors)); |
| screamer | 3:e960e2b81a3c | 23 | } |
| screamer | 3:e960e2b81a3c | 24 | |
| screamer | 3:e960e2b81a3c | 25 | virtual ~MemFileSystem() { |
| screamer | 3:e960e2b81a3c | 26 | for(int i = 0; i < 2000; i++) { |
| screamer | 3:e960e2b81a3c | 27 | if(sectors[i]) { |
| screamer | 3:e960e2b81a3c | 28 | free(sectors[i]); |
| screamer | 3:e960e2b81a3c | 29 | } |
| screamer | 3:e960e2b81a3c | 30 | } |
| screamer | 3:e960e2b81a3c | 31 | } |
| screamer | 3:e960e2b81a3c | 32 | |
| screamer | 3:e960e2b81a3c | 33 | // read a sector in to the buffer, return 0 if ok |
| screamer | 3:e960e2b81a3c | 34 | virtual int disk_read(char *buffer, int sector) { |
| screamer | 3:e960e2b81a3c | 35 | if(sectors[sector] == 0) { |
| screamer | 3:e960e2b81a3c | 36 | // nothing allocated means sector is empty |
| screamer | 3:e960e2b81a3c | 37 | memset(buffer, 0, 512); |
| screamer | 3:e960e2b81a3c | 38 | } else { |
| screamer | 3:e960e2b81a3c | 39 | memcpy(buffer, sectors[sector], 512); |
| screamer | 3:e960e2b81a3c | 40 | } |
| screamer | 3:e960e2b81a3c | 41 | return 0; |
| screamer | 3:e960e2b81a3c | 42 | } |
| screamer | 3:e960e2b81a3c | 43 | |
| screamer | 3:e960e2b81a3c | 44 | // write a sector from the buffer, return 0 if ok |
| screamer | 3:e960e2b81a3c | 45 | virtual int disk_write(const char *buffer, int sector) { |
| screamer | 3:e960e2b81a3c | 46 | // if buffer is zero deallocate sector |
| screamer | 3:e960e2b81a3c | 47 | char zero[512]; |
| screamer | 3:e960e2b81a3c | 48 | memset(zero, 0, 512); |
| screamer | 3:e960e2b81a3c | 49 | if(memcmp(zero, buffer, 512)==0) { |
| screamer | 3:e960e2b81a3c | 50 | if(sectors[sector] != 0) { |
| screamer | 3:e960e2b81a3c | 51 | free(sectors[sector]); |
| screamer | 3:e960e2b81a3c | 52 | sectors[sector] = 0; |
| screamer | 3:e960e2b81a3c | 53 | } |
| screamer | 3:e960e2b81a3c | 54 | return 0; |
| screamer | 3:e960e2b81a3c | 55 | } |
| screamer | 3:e960e2b81a3c | 56 | // else allocate a sector if needed, and write |
| screamer | 3:e960e2b81a3c | 57 | if(sectors[sector] == 0) { |
| screamer | 3:e960e2b81a3c | 58 | char *sec = (char*)malloc(512); |
| screamer | 3:e960e2b81a3c | 59 | if(sec==0) { |
| screamer | 3:e960e2b81a3c | 60 | return 1; // out of memory |
| screamer | 3:e960e2b81a3c | 61 | } |
| screamer | 3:e960e2b81a3c | 62 | sectors[sector] = sec; |
| screamer | 3:e960e2b81a3c | 63 | } |
| screamer | 3:e960e2b81a3c | 64 | memcpy(sectors[sector], buffer, 512); |
| screamer | 3:e960e2b81a3c | 65 | return 0; |
| screamer | 3:e960e2b81a3c | 66 | } |
| screamer | 3:e960e2b81a3c | 67 | |
| screamer | 3:e960e2b81a3c | 68 | // return the number of sectors |
| screamer | 3:e960e2b81a3c | 69 | virtual int disk_sectors() { |
| screamer | 3:e960e2b81a3c | 70 | return sizeof(sectors)/sizeof(sectors[0]); |
| screamer | 3:e960e2b81a3c | 71 | } |
| screamer | 3:e960e2b81a3c | 72 | |
| screamer | 3:e960e2b81a3c | 73 | }; |
| screamer | 3:e960e2b81a3c | 74 | |
| screamer | 3:e960e2b81a3c | 75 | } |
| screamer | 3:e960e2b81a3c | 76 | |
| screamer | 3:e960e2b81a3c | 77 | #endif |