Files
collabvm-1.2.ts/qemu/src/QmpClient.ts
2024-04-24 03:50:17 -04:00

136 lines
3.7 KiB
TypeScript

// This was originally based off the contents of the node-qemu-qmp package,
// but I've modified it possibly to the point where it could be treated as my own creation.
import split from 'split';
import { Socket } from 'net';
export type QmpCallback = (err: Error | null, res: any | null) => void;
type QmpCommandEntry = {
callback: QmpCallback | null;
id: number;
};
// TODO: Instead of the client "Is-A"ing a Socket, this should instead contain/store a Socket,
// (preferrably) passed by the user, to use for QMP communications.
// The client shouldn't have to know or care about the protocol, and it effectively hackily uses the fact
// Socket extends EventEmitter.
export default class QmpClient extends Socket {
public qmpHandshakeData: any;
private commandEntries: QmpCommandEntry[] = [];
private lastID = 0;
private ExecuteSync(command: string, args: any | null, callback: QmpCallback | null) {
let cmd: QmpCommandEntry = {
callback: callback,
id: ++this.lastID
};
let qmpOut: any = {
execute: command,
id: cmd.id
};
if (args) qmpOut['arguments'] = args;
// Add stuff
this.commandEntries.push(cmd);
this.write(JSON.stringify(qmpOut));
}
// TODO: Make this function a bit more ergonomic?
async Execute(command: string, args: any | null = null): Promise<any> {
return new Promise((res, rej) => {
this.ExecuteSync(command, args, (err, result) => {
if (err) rej(err);
res(result);
});
});
}
private Handshake(callback: () => void) {
this.write(
JSON.stringify({
execute: 'qmp_capabilities'
})
);
this.once('data', (data) => {
// Once QEMU replies to us, the handshake is done.
// We do not negotiate anything special.
callback();
});
}
// this can probably be made async
private ConnectImpl() {
let self = this;
this.once('connect', () => {
this.removeAllListeners('error');
});
this.once('error', (err) => {
// just rethrow lol
//throw err;
console.log('you have pants: rules,', err);
});
this.once('data', (data) => {
// Handshake QMP with the server.
self.qmpHandshakeData = JSON.parse(data.toString('utf8')).QMP;
self.Handshake(() => {
// Now ready to parse QMP responses/events.
self.pipe(split(JSON.parse))
.on('data', (json: any) => {
if (json == null) return self.end();
if (json.return || json.error) {
// Our handshake has a spurious return because we never assign it an ID,
// and it is gathered by this pipe for some reason I'm not quite sure about.
// So, just for safety's sake, don't process any return objects which don't have an ID attached to them.
if (json.id == null) return;
let callbackEntry = this.commandEntries.find((entry) => entry.id === json.id);
let error: Error | null = json.error ? new Error(json.error.desc) : null;
// we somehow didn't find a callback entry for this response.
// I don't know how. Techinically not an error..., but I guess you're not getting a reponse to whatever causes this to happen
if (callbackEntry == null) return;
if (callbackEntry?.callback) callbackEntry.callback(error, json.return);
// Remove the completed callback entry.
this.commandEntries.slice(this.commandEntries.indexOf(callbackEntry));
} else if (json.event) {
this.emit('event', json);
}
})
.on('error', () => {
// Give up.
return self.end();
});
this.emit('qmp-ready');
});
});
this.once('close', () => {
this.end();
this.removeAllListeners('data'); // wow. good job bud. cool memory leak
});
}
Connect(host: string, port: number) {
super.connect(port, host);
this.ConnectImpl();
}
ConnectUNIX(path: string) {
super.connect(path);
this.ConnectImpl();
}
}