Files
collabvm-1.2.ts/qemu/src/QmpClient.ts
2024-07-11 02:29:26 -04:00

166 lines
3.6 KiB
TypeScript

import { EventEmitter } from 'node:events';
enum QmpClientState {
Handshaking,
Connected
}
function qmpStringify(obj: any) {
return JSON.stringify(obj) + '\r\n';
}
// this writer interface is used to poll back to a higher level
// I/O layer that we want to write some data.
export interface IQmpClientWriter {
writeSome(data: Buffer): void;
}
export type QmpClientCallback = (err: Error | null, res: any | null) => void;
type QmpClientCallbackEntry = {
id: number;
callback: QmpClientCallback | null;
};
export enum QmpEvent {
BlockIOError = 'BLOCK_IO_ERROR',
Reset = 'RESET',
Resume = 'RESUME',
RtcChange = 'RTC_CHANGE',
Shutdown = 'SHUTDOWN',
Stop = 'STOP',
VncConnected = 'VNC_CONNECTED',
VncDisconnected = 'VNC_DISCONNECTED',
VncInitalized = 'VNC_INITALIZED',
Watchdog = 'WATCHDOG'
}
class LineStream extends EventEmitter {
// The given line seperator for the stream
lineSeperator = '\r\n';
buffer = '';
constructor() {
super();
}
push(data: Buffer) {
this.buffer += data.toString('utf-8');
let lines = this.buffer.split(this.lineSeperator);
if (lines.length > 1) {
this.buffer = lines.pop()!;
lines = lines.filter((l) => !!l);
//console.log(lines)
lines.forEach(l => this.emit('line', l));
}
return [];
}
reset() {
this.buffer = '';
}
}
// A QMP client
export class QmpClient extends EventEmitter {
private state = QmpClientState.Handshaking;
private writer: IQmpClientWriter | null = null;
private lastID = 0;
private callbacks = new Array<QmpClientCallbackEntry>();
private lineStream = new LineStream();
constructor() {
super();
let self = this;
this.lineStream.on('line', (line: string) => {
self.handleQmpLine(line);
});
}
setWriter(writer: IQmpClientWriter) {
this.writer = writer;
}
feed(data: Buffer): void {
// Forward to the line stream. It will generate 'line' events
// as it is able to split out lines automatically.
this.lineStream.push(data);
}
private handleQmpLine(line: string) {
let obj = JSON.parse(line);
switch (this.state) {
case QmpClientState.Handshaking:
if (obj['return'] != undefined) {
this.state = QmpClientState.Connected;
this.emit('connected');
return;
}
let capabilities = qmpStringify({
execute: 'qmp_capabilities'
});
this.writer?.writeSome(Buffer.from(capabilities, 'utf8'));
break;
case QmpClientState.Connected:
if (obj['return'] != undefined || obj['error'] != undefined) {
if (obj['id'] == null) return;
let cb = this.callbacks.find((v) => v.id == obj['id']);
if (cb == undefined) return;
let error: Error | null = obj.error ? new Error(obj.error.desc) : null;
if (cb.callback) cb.callback(error, obj.return);
this.callbacks.slice(this.callbacks.indexOf(cb));
} else if (obj['event']) {
this.emit(obj.event, {
timestamp: obj.timestamp,
data: obj.data
});
}
break;
}
}
executeSync(command: string, args: any | undefined, callback: QmpClientCallback | null) {
let entry = {
callback: callback,
id: ++this.lastID
};
let qmpOut: any = {
execute: command,
id: entry.id
};
if (args !== undefined) qmpOut['arguments'] = args;
this.callbacks.push(entry);
this.writer?.writeSome(Buffer.from(qmpStringify(qmpOut), 'utf8'));
}
async execute(command: string, args: any | undefined = undefined): Promise<any> {
return new Promise((res, rej) => {
this.executeSync(command, args, (err, result) => {
if (err) rej(err);
res(result);
});
});
}
reset() {
this.lineStream.reset();
this.state = QmpClientState.Handshaking;
}
}