Jordan Beason / FATDirHandle1

Final

MemFileSystem.h@0:e126ae11d20b, 2019-11-06 (annotated)

Committer:
jbeason3
Date:
Wed Nov 06 04:53:44 2019 +0000
Revision:
0:e126ae11d20b
Final

Who changed what in which revision?

UserRevisionLine numberNew contents of line
jbeason3 0:e126ae11d20b 1 /* mbed Microcontroller Library - MemFileSystem
jbeason3 0:e126ae11d20b 2 * Copyright (c) 2008, sford
jbeason3 0:e126ae11d20b 3 */
jbeason3 0:e126ae11d20b 4
jbeason3 0:e126ae11d20b 5
jbeason3 0:e126ae11d20b 6 #ifndef MBED_MEMFILESYSTEM_H
jbeason3 0:e126ae11d20b 7 #define MBED_MEMFILESYSTEM_H
jbeason3 0:e126ae11d20b 8
jbeason3 0:e126ae11d20b 9 #include "FATFileSystem.h"
jbeason3 0:e126ae11d20b 10
jbeason3 0:e126ae11d20b 11 namespace mbed
jbeason3 0:e126ae11d20b 12 {
jbeason3 0:e126ae11d20b 13
jbeason3 0:e126ae11d20b 14 class MemFileSystem : public FATFileSystem
jbeason3 0:e126ae11d20b 15 {
jbeason3 0:e126ae11d20b 16 public:
jbeason3 0:e126ae11d20b 17
jbeason3 0:e126ae11d20b 18 // 2000 sectors, each 512 bytes (malloced as required)
jbeason3 0:e126ae11d20b 19 char *sectors[2000];
jbeason3 0:e126ae11d20b 20
jbeason3 0:e126ae11d20b 21 MemFileSystem(const char* name) : FATFileSystem(name) {
jbeason3 0:e126ae11d20b 22 memset(sectors, 0, sizeof(sectors));
jbeason3 0:e126ae11d20b 23 }
jbeason3 0:e126ae11d20b 24
jbeason3 0:e126ae11d20b 25 virtual ~MemFileSystem() {
jbeason3 0:e126ae11d20b 26 for(int i = 0; i < 2000; i++) {
jbeason3 0:e126ae11d20b 27 if(sectors[i]) {
jbeason3 0:e126ae11d20b 28 free(sectors[i]);
jbeason3 0:e126ae11d20b 29 }
jbeason3 0:e126ae11d20b 30 }
jbeason3 0:e126ae11d20b 31 }
jbeason3 0:e126ae11d20b 32
jbeason3 0:e126ae11d20b 33 // read a sector in to the buffer, return 0 if ok
jbeason3 0:e126ae11d20b 34 virtual int disk_read(char *buffer, int sector) {
jbeason3 0:e126ae11d20b 35 if(sectors[sector] == 0) {
jbeason3 0:e126ae11d20b 36 // nothing allocated means sector is empty
jbeason3 0:e126ae11d20b 37 memset(buffer, 0, 512);
jbeason3 0:e126ae11d20b 38 } else {
jbeason3 0:e126ae11d20b 39 memcpy(buffer, sectors[sector], 512);
jbeason3 0:e126ae11d20b 40 }
jbeason3 0:e126ae11d20b 41 return 0;
jbeason3 0:e126ae11d20b 42 }
jbeason3 0:e126ae11d20b 43
jbeason3 0:e126ae11d20b 44 // write a sector from the buffer, return 0 if ok
jbeason3 0:e126ae11d20b 45 virtual int disk_write(const char *buffer, int sector) {
jbeason3 0:e126ae11d20b 46 // if buffer is zero deallocate sector
jbeason3 0:e126ae11d20b 47 char zero[512];
jbeason3 0:e126ae11d20b 48 memset(zero, 0, 512);
jbeason3 0:e126ae11d20b 49 if(memcmp(zero, buffer, 512)==0) {
jbeason3 0:e126ae11d20b 50 if(sectors[sector] != 0) {
jbeason3 0:e126ae11d20b 51 free(sectors[sector]);
jbeason3 0:e126ae11d20b 52 sectors[sector] = 0;
jbeason3 0:e126ae11d20b 53 }
jbeason3 0:e126ae11d20b 54 return 0;
jbeason3 0:e126ae11d20b 55 }
jbeason3 0:e126ae11d20b 56 // else allocate a sector if needed, and write
jbeason3 0:e126ae11d20b 57 if(sectors[sector] == 0) {
jbeason3 0:e126ae11d20b 58 char *sec = (char*)malloc(512);
jbeason3 0:e126ae11d20b 59 if(sec==0) {
jbeason3 0:e126ae11d20b 60 return 1; // out of memory
jbeason3 0:e126ae11d20b 61 }
jbeason3 0:e126ae11d20b 62 sectors[sector] = sec;
jbeason3 0:e126ae11d20b 63 }
jbeason3 0:e126ae11d20b 64 memcpy(sectors[sector], buffer, 512);
jbeason3 0:e126ae11d20b 65 return 0;
jbeason3 0:e126ae11d20b 66 }
jbeason3 0:e126ae11d20b 67
jbeason3 0:e126ae11d20b 68 // return the number of sectors
jbeason3 0:e126ae11d20b 69 virtual int disk_sectors() {
jbeason3 0:e126ae11d20b 70 return sizeof(sectors)/sizeof(sectors[0]);
jbeason3 0:e126ae11d20b 71 }
jbeason3 0:e126ae11d20b 72
jbeason3 0:e126ae11d20b 73 };
jbeason3 0:e126ae11d20b 74
jbeason3 0:e126ae11d20b 75 }
jbeason3 0:e126ae11d20b 76
jbeason3 0:e126ae11d20b 77 #endif