playcanvas
Version:
PlayCanvas WebGL game engine
71 lines (69 loc) • 1.53 kB
JavaScript
class ReadStream {
constructor(arraybuffer){
this.offset = 0;
this.arraybuffer = arraybuffer;
this.dataView = new DataView(arraybuffer);
}
get remainingBytes() {
return this.dataView.byteLength - this.offset;
}
reset(offset = 0) {
this.offset = offset;
}
skip(bytes) {
this.offset += bytes;
}
align(bytes) {
this.offset = this.offset + bytes - 1 & ~(bytes - 1);
}
_inc(amount) {
this.offset += amount;
return this.offset - amount;
}
readChar() {
return String.fromCharCode(this.dataView.getUint8(this.offset++));
}
readChars(numChars) {
let result = '';
for(let i = 0; i < numChars; ++i){
result += this.readChar();
}
return result;
}
readU8() {
return this.dataView.getUint8(this.offset++);
}
readU16() {
return this.dataView.getUint16(this._inc(2), true);
}
readU32() {
return this.dataView.getUint32(this._inc(4), true);
}
readU64() {
return this.readU32() + 2 ** 32 * this.readU32();
}
readU32be() {
return this.dataView.getUint32(this._inc(4), false);
}
readArray(result) {
for(let i = 0; i < result.length; ++i){
result[i] = this.readU8();
}
}
readLine() {
const view = this.dataView;
let result = '';
while(true){
if (this.offset >= view.byteLength) {
break;
}
const c = String.fromCharCode(this.readU8());
if (c === '\n') {
break;
}
result += c;
}
return result;
}
}
export { ReadStream };