File content as of revision 1:f5ac63519541:

/* mbed Microcontroller Library - MemFileSystem
 * Copyright (c) 2008, sford
 */


#ifndef MBED_MEMFILESYSTEM_H
#define MBED_MEMFILESYSTEM_H

#include "FATFileSystem.h"

namespace mbed {

class MemFileSystem : public FATFileSystem {
public:

    // 2000 sectors, each 512 bytes (malloced as required)
    char *sectors[2000];

    MemFileSystem(const char* name) : FATFileSystem(name) {
        memset(sectors, 0, sizeof(sectors));
    }

    virtual ~MemFileSystem() {
        for(int i = 0; i < 2000; i++) {
            if(sectors[i]) {
                free(sectors[i]);
            }
        }
    }

    // read a sector in to the buffer, return 0 if ok
    virtual int disk_read(char *buffer, int sector) {
        if(sectors[sector] == 0) {
            // nothing allocated means sector is empty
            memset(buffer, 0, 512);
        } else {
            memcpy(buffer, sectors[sector], 512);
        }
        return 0;
    }

    // write a sector from the buffer, return 0 if ok
    virtual int disk_write(const char *buffer, int sector) {
        // if buffer is zero deallocate sector
        char zero[512];
        memset(zero, 0, 512);
        if(memcmp(zero, buffer, 512)==0) {
            if(sectors[sector] != 0) {
                free(sectors[sector]);
                sectors[sector] = 0;
            }
            return 0;
        }
        // else allocate a sector if needed, and write
        if(sectors[sector] == 0) {
            char *sec = (char*)malloc(512);
            if(sec==0) {
                return 1; // out of memory
            }
            sectors[sector] = sec;
        }
        memcpy(sectors[sector], buffer, 512);
        return 0;
    }
        
    // return the number of sectors
    virtual int disk_sectors() {
        return sizeof(sectors)/sizeof(sectors[0]);
    }

};
    
}

#endif