openreplay/frontend/app/player/MessageDistributor/MessageGenerator.js
2021-05-01 15:12:01 +05:30

82 lines
No EOL
1.8 KiB
JavaScript

import type { TimedMessage } from './Timed';
import logger from 'App/logger';
import readMessage from './messages';
function needSkipMessage(data: Uint8Array, p: number, pLast: number): boolean {
for (let i = 7; i >= 0; i--) {
if (data[ p + i ] !== data[ pLast + i ]) {
return data[ p + i ] - data[ pLast + i ] < 0
}
}
return true
}
export default class MessageGenerator {
#data: Uint8Array;
#p: number = 0;
#pLastMessageID: number = 0;
#startTime: number;
#currentTime: ?number;
#error: boolean = false;
constructor(data: Uint8Array, startTime: number) {
this.#startTime = startTime;
this.#data = data;
}
_needSkipMessage():boolean {
if (this.#p === 0) return false;
for (let i = 7; i >= 0; i--) {
if (this.#data[ this.#p + i ] !== this.#data[ this.#pLastMessageID + i ]) {
return this.#data[ this.#p + i ] - this.#data[ this.#pLastMessageID + i ] < 0;
}
}
return true;
}
_readMessage(): ?Message {
this.#p += 8;
try {
let msg
[ msg, this.#p ] = readMessage(this.#data, this.#p);
return msg;
} catch (e) {
this.#error = true;
logger.error("Read message error:", e);
return null;
}
}
hasNext():boolean {
return !this.#error && this.#data.length > this.#p;
}
next(): ?[ TimedMessage, number] {
if (!this.hasNext()) {
return null;
}
while (this._needSkipMessage()) {
this._readMessage();
}
this.#pLastMessageID = this.#p;
const msg = this._readMessage();
if (!msg) {
return null;
}
if (msg.tp === "timestamp") {
// if (this.#startTime == null) {
// this.#startTime = msg.timestamp
// }
this.#currentTime = msg.timestamp - this.#startTime;
} else {
msg.time = this.#currentTime;
msg._index = this.#pLastMessageID;
return [msg, this.#pLastMessageID];
}
}
}