RBlob Sample usage var b = new RBlob(new Blob([new Uint8Array([0,1,2,3,4,5,6,7,8])])); b.read(0,3).then(arr => console.log(arr)); // [0,1,2] b.read().then(arr => console.log(arr)); // [0,1,2,3,4,5,6,7,8]