Mark Schwarzer / SDFileSystem_A8

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FATFileSystem/MemFileSystem.h@0:a9d72fcb5d03, 2020-11-17 (annotated)

Committer:
markschwarzer
Date:
Tue Nov 17 20:28:59 2020 +0000
Revision:
0:a9d72fcb5d03
logs gps data to SD card

Who changed what in which revision?

UserRevisionLine numberNew contents of line
markschwarzer 0:a9d72fcb5d03 1 /* mbed Microcontroller Library - MemFileSystem
markschwarzer 0:a9d72fcb5d03 2 * Copyright (c) 2008, sford
markschwarzer 0:a9d72fcb5d03 3 */
markschwarzer 0:a9d72fcb5d03 4
markschwarzer 0:a9d72fcb5d03 5
markschwarzer 0:a9d72fcb5d03 6 #ifndef MBED_MEMFILESYSTEM_H
markschwarzer 0:a9d72fcb5d03 7 #define MBED_MEMFILESYSTEM_H
markschwarzer 0:a9d72fcb5d03 8
markschwarzer 0:a9d72fcb5d03 9 #include "FATFileSystem.h"
markschwarzer 0:a9d72fcb5d03 10
markschwarzer 0:a9d72fcb5d03 11 namespace mbed
markschwarzer 0:a9d72fcb5d03 12 {
markschwarzer 0:a9d72fcb5d03 13
markschwarzer 0:a9d72fcb5d03 14 class MemFileSystem : public FATFileSystem
markschwarzer 0:a9d72fcb5d03 15 {
markschwarzer 0:a9d72fcb5d03 16 public:
markschwarzer 0:a9d72fcb5d03 17
markschwarzer 0:a9d72fcb5d03 18 // 2000 sectors, each 512 bytes (malloced as required)
markschwarzer 0:a9d72fcb5d03 19 char *sectors[2000];
markschwarzer 0:a9d72fcb5d03 20
markschwarzer 0:a9d72fcb5d03 21 MemFileSystem(const char* name) : FATFileSystem(name) {
markschwarzer 0:a9d72fcb5d03 22 memset(sectors, 0, sizeof(sectors));
markschwarzer 0:a9d72fcb5d03 23 }
markschwarzer 0:a9d72fcb5d03 24
markschwarzer 0:a9d72fcb5d03 25 virtual ~MemFileSystem() {
markschwarzer 0:a9d72fcb5d03 26 for(int i = 0; i < 2000; i++) {
markschwarzer 0:a9d72fcb5d03 27 if(sectors[i]) {
markschwarzer 0:a9d72fcb5d03 28 free(sectors[i]);
markschwarzer 0:a9d72fcb5d03 29 }
markschwarzer 0:a9d72fcb5d03 30 }
markschwarzer 0:a9d72fcb5d03 31 }
markschwarzer 0:a9d72fcb5d03 32
markschwarzer 0:a9d72fcb5d03 33 // read a sector in to the buffer, return 0 if ok
markschwarzer 0:a9d72fcb5d03 34 virtual int disk_read(char *buffer, int sector) {
markschwarzer 0:a9d72fcb5d03 35 if(sectors[sector] == 0) {
markschwarzer 0:a9d72fcb5d03 36 // nothing allocated means sector is empty
markschwarzer 0:a9d72fcb5d03 37 memset(buffer, 0, 512);
markschwarzer 0:a9d72fcb5d03 38 } else {
markschwarzer 0:a9d72fcb5d03 39 memcpy(buffer, sectors[sector], 512);
markschwarzer 0:a9d72fcb5d03 40 }
markschwarzer 0:a9d72fcb5d03 41 return 0;
markschwarzer 0:a9d72fcb5d03 42 }
markschwarzer 0:a9d72fcb5d03 43
markschwarzer 0:a9d72fcb5d03 44 // write a sector from the buffer, return 0 if ok
markschwarzer 0:a9d72fcb5d03 45 virtual int disk_write(const char *buffer, int sector) {
markschwarzer 0:a9d72fcb5d03 46 // if buffer is zero deallocate sector
markschwarzer 0:a9d72fcb5d03 47 char zero[512];
markschwarzer 0:a9d72fcb5d03 48 memset(zero, 0, 512);
markschwarzer 0:a9d72fcb5d03 49 if(memcmp(zero, buffer, 512)==0) {
markschwarzer 0:a9d72fcb5d03 50 if(sectors[sector] != 0) {
markschwarzer 0:a9d72fcb5d03 51 free(sectors[sector]);
markschwarzer 0:a9d72fcb5d03 52 sectors[sector] = 0;
markschwarzer 0:a9d72fcb5d03 53 }
markschwarzer 0:a9d72fcb5d03 54 return 0;
markschwarzer 0:a9d72fcb5d03 55 }
markschwarzer 0:a9d72fcb5d03 56 // else allocate a sector if needed, and write
markschwarzer 0:a9d72fcb5d03 57 if(sectors[sector] == 0) {
markschwarzer 0:a9d72fcb5d03 58 char *sec = (char*)malloc(512);
markschwarzer 0:a9d72fcb5d03 59 if(sec==0) {
markschwarzer 0:a9d72fcb5d03 60 return 1; // out of memory
markschwarzer 0:a9d72fcb5d03 61 }
markschwarzer 0:a9d72fcb5d03 62 sectors[sector] = sec;
markschwarzer 0:a9d72fcb5d03 63 }
markschwarzer 0:a9d72fcb5d03 64 memcpy(sectors[sector], buffer, 512);
markschwarzer 0:a9d72fcb5d03 65 return 0;
markschwarzer 0:a9d72fcb5d03 66 }
markschwarzer 0:a9d72fcb5d03 67
markschwarzer 0:a9d72fcb5d03 68 // return the number of sectors
markschwarzer 0:a9d72fcb5d03 69 virtual int disk_sectors() {
markschwarzer 0:a9d72fcb5d03 70 return sizeof(sectors)/sizeof(sectors[0]);
markschwarzer 0:a9d72fcb5d03 71 }
markschwarzer 0:a9d72fcb5d03 72
markschwarzer 0:a9d72fcb5d03 73 };
markschwarzer 0:a9d72fcb5d03 74
markschwarzer 0:a9d72fcb5d03 75 }
markschwarzer 0:a9d72fcb5d03 76
markschwarzer 0:a9d72fcb5d03 77 #endif