Kotachi Liu / SDFileSystem

SD card data log

Dependents:   riset_Datalogger

FATFileSystem/MemFileSystem.h@0:18d80d7403d3, 2019-11-03 (annotated)

Committer:
kotachi
Date:
Sun Nov 03 07:28:09 2019 +0000
Revision:
0:18d80d7403d3
SD card logging system

Who changed what in which revision?

UserRevisionLine numberNew contents of line
kotachi 0:18d80d7403d3 1 /* mbed Microcontroller Library - MemFileSystem
kotachi 0:18d80d7403d3 2 * Copyright (c) 2008, sford
kotachi 0:18d80d7403d3 3 */
kotachi 0:18d80d7403d3 4
kotachi 0:18d80d7403d3 5
kotachi 0:18d80d7403d3 6 #ifndef MBED_MEMFILESYSTEM_H
kotachi 0:18d80d7403d3 7 #define MBED_MEMFILESYSTEM_H
kotachi 0:18d80d7403d3 8
kotachi 0:18d80d7403d3 9 #include "FATFileSystem.h"
kotachi 0:18d80d7403d3 10
kotachi 0:18d80d7403d3 11 namespace mbed
kotachi 0:18d80d7403d3 12 {
kotachi 0:18d80d7403d3 13
kotachi 0:18d80d7403d3 14 class MemFileSystem : public FATFileSystem
kotachi 0:18d80d7403d3 15 {
kotachi 0:18d80d7403d3 16 public:
kotachi 0:18d80d7403d3 17
kotachi 0:18d80d7403d3 18 // 2000 sectors, each 512 bytes (malloced as required)
kotachi 0:18d80d7403d3 19 char *sectors[2000];
kotachi 0:18d80d7403d3 20
kotachi 0:18d80d7403d3 21 MemFileSystem(const char* name) : FATFileSystem(name) {
kotachi 0:18d80d7403d3 22 memset(sectors, 0, sizeof(sectors));
kotachi 0:18d80d7403d3 23 }
kotachi 0:18d80d7403d3 24
kotachi 0:18d80d7403d3 25 virtual ~MemFileSystem() {
kotachi 0:18d80d7403d3 26 for(int i = 0; i < 2000; i++) {
kotachi 0:18d80d7403d3 27 if(sectors[i]) {
kotachi 0:18d80d7403d3 28 free(sectors[i]);
kotachi 0:18d80d7403d3 29 }
kotachi 0:18d80d7403d3 30 }
kotachi 0:18d80d7403d3 31 }
kotachi 0:18d80d7403d3 32
kotachi 0:18d80d7403d3 33 // read a sector in to the buffer, return 0 if ok
kotachi 0:18d80d7403d3 34 virtual int disk_read(char *buffer, int sector) {
kotachi 0:18d80d7403d3 35 if(sectors[sector] == 0) {
kotachi 0:18d80d7403d3 36 // nothing allocated means sector is empty
kotachi 0:18d80d7403d3 37 memset(buffer, 0, 512);
kotachi 0:18d80d7403d3 38 } else {
kotachi 0:18d80d7403d3 39 memcpy(buffer, sectors[sector], 512);
kotachi 0:18d80d7403d3 40 }
kotachi 0:18d80d7403d3 41 return 0;
kotachi 0:18d80d7403d3 42 }
kotachi 0:18d80d7403d3 43
kotachi 0:18d80d7403d3 44 // write a sector from the buffer, return 0 if ok
kotachi 0:18d80d7403d3 45 virtual int disk_write(const char *buffer, int sector) {
kotachi 0:18d80d7403d3 46 // if buffer is zero deallocate sector
kotachi 0:18d80d7403d3 47 char zero[512];
kotachi 0:18d80d7403d3 48 memset(zero, 0, 512);
kotachi 0:18d80d7403d3 49 if(memcmp(zero, buffer, 512)==0) {
kotachi 0:18d80d7403d3 50 if(sectors[sector] != 0) {
kotachi 0:18d80d7403d3 51 free(sectors[sector]);
kotachi 0:18d80d7403d3 52 sectors[sector] = 0;
kotachi 0:18d80d7403d3 53 }
kotachi 0:18d80d7403d3 54 return 0;
kotachi 0:18d80d7403d3 55 }
kotachi 0:18d80d7403d3 56 // else allocate a sector if needed, and write
kotachi 0:18d80d7403d3 57 if(sectors[sector] == 0) {
kotachi 0:18d80d7403d3 58 char *sec = (char*)malloc(512);
kotachi 0:18d80d7403d3 59 if(sec==0) {
kotachi 0:18d80d7403d3 60 return 1; // out of memory
kotachi 0:18d80d7403d3 61 }
kotachi 0:18d80d7403d3 62 sectors[sector] = sec;
kotachi 0:18d80d7403d3 63 }
kotachi 0:18d80d7403d3 64 memcpy(sectors[sector], buffer, 512);
kotachi 0:18d80d7403d3 65 return 0;
kotachi 0:18d80d7403d3 66 }
kotachi 0:18d80d7403d3 67
kotachi 0:18d80d7403d3 68 // return the number of sectors
kotachi 0:18d80d7403d3 69 virtual int disk_sectors() {
kotachi 0:18d80d7403d3 70 return sizeof(sectors)/sizeof(sectors[0]);
kotachi 0:18d80d7403d3 71 }
kotachi 0:18d80d7403d3 72
kotachi 0:18d80d7403d3 73 };
kotachi 0:18d80d7403d3 74
kotachi 0:18d80d7403d3 75 }
kotachi 0:18d80d7403d3 76
kotachi 0:18d80d7403d3 77 #endif