Writing and Reading 'persistent' data using FlashEEPROM (journaling) module

Unionized arrays anyone?

//ArrayTrick1.js
//30 Aug 2016
//https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer

var f = new (require("FlashEEPROM"))();

var buff = new ArrayBuffer(16);
var view   = new Int32Array(buff);

for(var i=0;i<4;i++)view[i]=i*256*256*256+i*100;

//buff and view are unionized
console.log("buff= ",buff);
console.log("view= ",view);

buff[0]=5;
console.log("buff= ",buff);
console.log("view= ",view);

console.log("write to ROM");
f.write(21,JSON.stringify(btoa(buff)));

console.log("read from ROM");
var H=new Int32Array(E.toArrayBuffer(atob(JSON.parse(E.toString(f.read(21))))));

console.log("H= ",H);

The output:

ent>echo(0);
buff=  new ArrayBuffer([0, 0, 0, 0, 100, 0, 0, 1, 200, 0, 0, 2, 44, 1, 0, 3])
view=  new Int32Array([0, 16777316, 33554632, 50331948])
buff=  new ArrayBuffer([5, 0, 0, 0, 100, 0, 0, 1, 200, 0, 0, 2, 44, 1, 0, 3])
view=  new Int32Array([5, 16777316, 33554632, 50331948])
write to ROM
read from ROM
H=  new Int32Array([5, 16777316, 33554632, 50331948])er code here

1 Attachment

• arraytrick1.js