Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 | 400x 400x 400x 400x 400x 400x 400x 400x 400x 400x 400x 400x 400x 400x 400x 400x 12170433x 400x 400x 3031021x 3031021x 3031021x 3031021x 3031021x 3031021x 3031021x 3031021x 3031021x 3031021x 3031021x 3031021x 3031021x 3031021x 3031021x 3031021x 3031021x 3031021x 71116x 3031021x 3010050x 1x 3010049x 3010049x 3010049x 2763900x 2325812x 438088x 196498x 196498x 164011x 32487x 32487x 32487x 32487x 32487x 32487x 3011217x 1172x 3010045x 3010045x 3010045x 3010045x 3213867x 3213865x 138457x 3213883x 3042532x 3042532x 3042532x 3042532x 3042532x 3042532x 3042532x 3042532x 3042532x 9597506x 5524226x 5524226x 5404813x 5402315x 5399111x 3307827x 3307827x 3307827x 162483x 162483x 162483x 162483x 162483x 162483x 1506x 162483x 162483x 201603x 19033x 201603x 201603x 201603x 201603x 74134x 74134x 127469x 127469x 127469x 3307827x 3307827x 266460x 266460x 266460x 266460x 266460x 266460x 138457x 266460x 266460x 138758x 138758x 212892x 74134x 127702x 127702x 127702x 3041367x 3041367x 3022961x 3022961x 3022961x 3022961x 3017875x 5086x 5086x 3017875x 5595x 5595x 3012280x 3012280x 3012280x 3012280x 3012280x 23492x 23492x 23492x 3042536x 3307827x 3307827x 3302232x 3142899x 3302232x 3307827x 3302232x 162483x 24833x 3277399x 2642611x 2642611x 2588855x 3277399x 138758x 400x 138457x 138457x 138457x 138457x 138457x 138457x 138457x 138457x 138457x 138457x 138457x 66869x 44x 44x 66825x 6631x 66825x 66825x 60734x 68028x 68028x 68028x 68028x 7294x 6675x 619x 7294x 60734x 60734x 60194x 540x 540x 540x 400x 3042596x 3042596x 3042596x 3042596x 3042596x 3042596x 3042596x 3042596x 3042596x 3010053x 32543x 3027003x 3027003x 3027003x 8x 3026995x 65x 3026930x 346301x 2680629x 2658206x 2658206x 2658206x 22423x 3042604x 3042604x 3015375x 3015375x 3042604x 3042604x 5993073x 5833215x 2817840x 5833215x 3042596x 3307923x 3307923x 297870x 3307923x 3307923x 3307923x 3302324x 3302324x 3302324x 400x 3031069x 3031069x 3031069x 3214279x 3214279x 3087132x 3214279x 3213881x 202386x 202386x 1328052x 202386x 3213871x 3213871x 3213871x 4541923x 3213871x 138469x 138465x 3042536x 3042536x | import { clearTimeout, setTimeout } from 'timers';
import { type Document, Long } from '../bson';
import { connect, makeConnection, makeSocket, performInitialHandshake } from '../cmap/connect';
import type { Connection, ConnectionOptions } from '../cmap/connection';
import { getFAASEnv } from '../cmap/handshake/client_metadata';
import { LEGACY_HELLO_COMMAND } from '../constants';
import { MongoError, MongoErrorLabel, MongoNetworkTimeoutError } from '../error';
import { MongoLoggableComponent } from '../mongo_logger';
import { CancellationToken, TypedEventEmitter } from '../mongo_types';
import {
calculateDurationInMs,
type Callback,
type EventEmitterWithState,
makeStateMachine,
noop,
now,
ns
} from '../utils';
import { ServerType, STATE_CLOSED, STATE_CLOSING } from './common';
import {
ServerHeartbeatFailedEvent,
ServerHeartbeatStartedEvent,
ServerHeartbeatSucceededEvent
} from './events';
import { Server } from './server';
import type { TopologyVersion } from './server_description';
const STATE_IDLE = 'idle';
const STATE_MONITORING = 'monitoring';
const stateTransition = makeStateMachine({
[STATE_CLOSING]: [STATE_CLOSING, STATE_IDLE, STATE_CLOSED],
[STATE_CLOSED]: [STATE_CLOSED, STATE_MONITORING],
[STATE_IDLE]: [STATE_IDLE, STATE_MONITORING, STATE_CLOSING],
[STATE_MONITORING]: [STATE_MONITORING, STATE_IDLE, STATE_CLOSING]
});
const INVALID_REQUEST_CHECK_STATES = new Set([STATE_CLOSING, STATE_CLOSED, STATE_MONITORING]);
function isInCloseState(monitor: Monitor) {
return monitor.s.state === STATE_CLOSED || monitor.s.state === STATE_CLOSING;
}
/** @public */
export const ServerMonitoringMode = Object.freeze({
auto: 'auto',
poll: 'poll',
stream: 'stream'
} as const);
/** @public */
export type ServerMonitoringMode = (typeof ServerMonitoringMode)[keyof typeof ServerMonitoringMode];
/** @internal */
export interface MonitorPrivate {
state: string;
}
/** @public */
export interface MonitorOptions
extends Omit<ConnectionOptions, 'id' | 'generation' | 'hostAddress'> {
connectTimeoutMS: number;
heartbeatFrequencyMS: number;
minHeartbeatFrequencyMS: number;
serverMonitoringMode: ServerMonitoringMode;
}
/** @public */
export type MonitorEvents = {
serverHeartbeatStarted(event: ServerHeartbeatStartedEvent): void;
serverHeartbeatSucceeded(event: ServerHeartbeatSucceededEvent): void;
serverHeartbeatFailed(event: ServerHeartbeatFailedEvent): void;
resetServer(error?: MongoError): void;
resetConnectionPool(): void;
close(): void;
} & EventEmitterWithState;
/** @internal */
export class Monitor extends TypedEventEmitter<MonitorEvents> {
/** @internal */
s: MonitorPrivate;
address: string;
options: Readonly<
Pick<
MonitorOptions,
| 'connectTimeoutMS'
| 'heartbeatFrequencyMS'
| 'minHeartbeatFrequencyMS'
| 'serverMonitoringMode'
>
>;
connectOptions: ConnectionOptions;
isRunningInFaasEnv: boolean;
server: Server;
connection: Connection | null;
cancellationToken: CancellationToken;
/** @internal */
monitorId?: MonitorInterval;
rttPinger?: RTTPinger;
/** @internal */
override component = MongoLoggableComponent.TOPOLOGY;
/** @internal */
private rttSampler: RTTSampler;
constructor(server: Server, options: MonitorOptions) {
super();
this.on('error', noop);
this.server = server;
this.connection = null;
this.cancellationToken = new CancellationToken();
this.cancellationToken.setMaxListeners(Infinity);
this.monitorId = undefined;
this.s = {
state: STATE_CLOSED
};
this.address = server.description.address;
this.options = Object.freeze({
connectTimeoutMS: options.connectTimeoutMS ?? 10000,
heartbeatFrequencyMS: options.heartbeatFrequencyMS ?? 10000,
minHeartbeatFrequencyMS: options.minHeartbeatFrequencyMS ?? 500,
serverMonitoringMode: options.serverMonitoringMode
});
this.isRunningInFaasEnv = getFAASEnv() != null;
this.mongoLogger = this.server.topology.client?.mongoLogger;
this.rttSampler = new RTTSampler(10);
const cancellationToken = this.cancellationToken;
// TODO: refactor this to pull it directly from the pool, requires new ConnectionPool integration
const connectOptions = {
id: '<monitor>' as const,
generation: server.pool.generation,
cancellationToken,
hostAddress: server.description.hostAddress,
...options,
// force BSON serialization options
raw: false,
useBigInt64: false,
promoteLongs: true,
promoteValues: true,
promoteBuffers: true
};
// ensure no authentication is used for monitoring
delete connectOptions.credentials;
if (connectOptions.autoEncrypter) {
delete connectOptions.autoEncrypter;
}
this.connectOptions = Object.freeze(connectOptions);
}
connect(): void {
if (this.s.state !== STATE_CLOSED) {
return;
}
// start
const heartbeatFrequencyMS = this.options.heartbeatFrequencyMS;
const minHeartbeatFrequencyMS = this.options.minHeartbeatFrequencyMS;
this.monitorId = new MonitorInterval(monitorServer(this), {
heartbeatFrequencyMS: heartbeatFrequencyMS,
minHeartbeatFrequencyMS: minHeartbeatFrequencyMS,
immediate: true
});
}
requestCheck(): void {
if (INVALID_REQUEST_CHECK_STATES.has(this.s.state)) {
return;
}
this.monitorId?.wake();
}
reset(): void {
const topologyVersion = this.server.description.topologyVersion;
if (isInCloseState(this) || topologyVersion == null) {
return;
}
stateTransition(this, STATE_CLOSING);
resetMonitorState(this);
// restart monitor
stateTransition(this, STATE_IDLE);
// restart monitoring
const heartbeatFrequencyMS = this.options.heartbeatFrequencyMS;
const minHeartbeatFrequencyMS = this.options.minHeartbeatFrequencyMS;
this.monitorId = new MonitorInterval(monitorServer(this), {
heartbeatFrequencyMS: heartbeatFrequencyMS,
minHeartbeatFrequencyMS: minHeartbeatFrequencyMS
});
}
close(): void {
if (isInCloseState(this)) {
return;
}
stateTransition(this, STATE_CLOSING);
resetMonitorState(this);
// close monitor
this.emit('close');
stateTransition(this, STATE_CLOSED);
}
get roundTripTime(): number {
return this.rttSampler.average();
}
get minRoundTripTime(): number {
return this.rttSampler.min();
}
get latestRtt(): number | null {
return this.rttSampler.last;
}
addRttSample(rtt: number) {
this.rttSampler.addSample(rtt);
}
clearRttSamples() {
this.rttSampler.clear();
}
}
function resetMonitorState(monitor: Monitor) {
monitor.monitorId?.stop();
monitor.monitorId = undefined;
monitor.rttPinger?.close();
monitor.rttPinger = undefined;
monitor.cancellationToken.emit('cancel');
monitor.connection?.destroy();
monitor.connection = null;
monitor.clearRttSamples();
}
function useStreamingProtocol(monitor: Monitor, topologyVersion: TopologyVersion | null): boolean {
// If we have no topology version we always poll no matter
// what the user provided, since the server does not support
// the streaming protocol.
if (topologyVersion == null) return false;
const serverMonitoringMode = monitor.options.serverMonitoringMode;
if (serverMonitoringMode === ServerMonitoringMode.poll) return false;
if (serverMonitoringMode === ServerMonitoringMode.stream) return true;
// If we are in auto mode, we need to figure out if we're in a FaaS
// environment or not and choose the appropriate mode.
if (monitor.isRunningInFaasEnv) return false;
return true;
}
function checkServer(monitor: Monitor, callback: Callback<Document | null>) {
let start: number;
let awaited: boolean;
const topologyVersion = monitor.server.description.topologyVersion;
const isAwaitable = useStreamingProtocol(monitor, topologyVersion);
monitor.emitAndLogHeartbeat(
Server.SERVER_HEARTBEAT_STARTED,
monitor.server.topology.s.id,
undefined,
new ServerHeartbeatStartedEvent(monitor.address, isAwaitable)
);
function onHeartbeatFailed(err: Error) {
monitor.connection?.destroy();
monitor.connection = null;
monitor.emitAndLogHeartbeat(
Server.SERVER_HEARTBEAT_FAILED,
monitor.server.topology.s.id,
undefined,
new ServerHeartbeatFailedEvent(monitor.address, calculateDurationInMs(start), err, awaited)
);
const error = !(err instanceof MongoError)
? new MongoError(MongoError.buildErrorMessage(err), { cause: err })
: err;
error.addErrorLabel(MongoErrorLabel.ResetPool);
if (error instanceof MongoNetworkTimeoutError) {
error.addErrorLabel(MongoErrorLabel.InterruptInUseConnections);
}
monitor.emit('resetServer', error);
callback(err);
}
function onHeartbeatSucceeded(hello: Document) {
if (!('isWritablePrimary' in hello)) {
// Provide hello-style response document.
hello.isWritablePrimary = hello[LEGACY_HELLO_COMMAND];
}
// NOTE: here we use the latestRtt as this measurement corresponds with the value
// obtained for this successful heartbeat, if there is no latestRtt, then we calculate the
// duration
const duration =
isAwaitable && monitor.rttPinger
? (monitor.rttPinger.latestRtt ?? calculateDurationInMs(start))
: calculateDurationInMs(start);
monitor.addRttSample(duration);
monitor.emitAndLogHeartbeat(
Server.SERVER_HEARTBEAT_SUCCEEDED,
monitor.server.topology.s.id,
hello.connectionId,
new ServerHeartbeatSucceededEvent(monitor.address, duration, hello, isAwaitable)
);
if (isAwaitable) {
// If we are using the streaming protocol then we immediately issue another 'started'
// event, otherwise the "check" is complete and return to the main monitor loop
monitor.emitAndLogHeartbeat(
Server.SERVER_HEARTBEAT_STARTED,
monitor.server.topology.s.id,
undefined,
new ServerHeartbeatStartedEvent(monitor.address, true)
);
// We have not actually sent an outgoing handshake, but when we get the next response we
// want the duration to reflect the time since we last heard from the server
start = now();
} else {
monitor.rttPinger?.close();
monitor.rttPinger = undefined;
callback(undefined, hello);
}
}
const { connection } = monitor;
if (connection && !connection.closed) {
const { serverApi, helloOk } = connection;
const connectTimeoutMS = monitor.options.connectTimeoutMS;
const maxAwaitTimeMS = monitor.options.heartbeatFrequencyMS;
const cmd = {
[serverApi?.version || helloOk ? 'hello' : LEGACY_HELLO_COMMAND]: 1,
...(isAwaitable && topologyVersion
? { maxAwaitTimeMS, topologyVersion: makeTopologyVersion(topologyVersion) }
: {})
};
const options = isAwaitable
? {
socketTimeoutMS: connectTimeoutMS ? connectTimeoutMS + maxAwaitTimeMS : 0,
exhaustAllowed: true
}
: { socketTimeoutMS: connectTimeoutMS };
if (isAwaitable && monitor.rttPinger == null) {
monitor.rttPinger = new RTTPinger(monitor);
}
// Record new start time before sending handshake
start = now();
if (isAwaitable) {
awaited = true;
return connection.exhaustCommand(ns('admin.$cmd'), cmd, options, (error, hello) => {
if (error) return onHeartbeatFailed(error);
return onHeartbeatSucceeded(hello);
});
}
awaited = false;
connection
.command(ns('admin.$cmd'), cmd, options)
.then(onHeartbeatSucceeded, onHeartbeatFailed);
return;
}
// connecting does an implicit `hello`
(async () => {
const socket = await makeSocket(monitor.connectOptions);
const connection = makeConnection(monitor.connectOptions, socket);
// The start time is after socket creation but before the handshake
start = now();
try {
await performInitialHandshake(connection, monitor.connectOptions);
return connection;
} catch (error) {
connection.destroy();
throw error;
}
})().then(
connection => {
if (isInCloseState(monitor)) {
connection.destroy();
return;
}
const duration = calculateDurationInMs(start);
monitor.addRttSample(duration);
monitor.connection = connection;
monitor.emitAndLogHeartbeat(
Server.SERVER_HEARTBEAT_SUCCEEDED,
monitor.server.topology.s.id,
connection.hello?.connectionId,
new ServerHeartbeatSucceededEvent(
monitor.address,
duration,
connection.hello,
useStreamingProtocol(monitor, connection.hello?.topologyVersion)
)
);
callback(undefined, connection.hello);
},
error => {
monitor.connection = null;
awaited = false;
onHeartbeatFailed(error);
}
);
}
function monitorServer(monitor: Monitor) {
return (callback: Callback) => {
Iif (monitor.s.state === STATE_MONITORING) {
process.nextTick(callback);
return;
}
stateTransition(monitor, STATE_MONITORING);
function done() {
if (!isInCloseState(monitor)) {
stateTransition(monitor, STATE_IDLE);
}
callback();
}
checkServer(monitor, (err, hello) => {
if (err) {
// otherwise an error occurred on initial discovery, also bail
if (monitor.server.description.type === ServerType.Unknown) {
return done();
}
}
// if the check indicates streaming is supported, immediately reschedule monitoring
if (useStreamingProtocol(monitor, hello?.topologyVersion)) {
setTimeout(() => {
if (!isInCloseState(monitor)) {
monitor.monitorId?.wake();
}
}, 0);
}
done();
});
};
}
function makeTopologyVersion(tv: TopologyVersion) {
return {
processId: tv.processId,
// tests mock counter as just number, but in a real situation counter should always be a Long
// TODO(NODE-2674): Preserve int64 sent from MongoDB
counter: Long.isLong(tv.counter) ? tv.counter : Long.fromNumber(tv.counter)
};
}
/** @internal */
export interface RTTPingerOptions extends ConnectionOptions {
heartbeatFrequencyMS: number;
}
/** @internal */
export class RTTPinger {
connection?: Connection;
/** @internal */
cancellationToken: CancellationToken;
/** @internal */
monitorId: NodeJS.Timeout;
/** @internal */
monitor: Monitor;
closed: boolean;
/** @internal */
latestRtt?: number;
constructor(monitor: Monitor) {
this.connection = undefined;
this.cancellationToken = monitor.cancellationToken;
this.closed = false;
this.monitor = monitor;
this.latestRtt = monitor.latestRtt ?? undefined;
const heartbeatFrequencyMS = monitor.options.heartbeatFrequencyMS;
this.monitorId = setTimeout(() => this.measureRoundTripTime(), heartbeatFrequencyMS);
}
get roundTripTime(): number {
return this.monitor.roundTripTime;
}
get minRoundTripTime(): number {
return this.monitor.minRoundTripTime;
}
close(): void {
this.closed = true;
clearTimeout(this.monitorId);
this.connection?.destroy();
this.connection = undefined;
}
private measureAndReschedule(start: number, conn?: Connection) {
if (this.closed) {
conn?.destroy();
return;
}
if (this.connection == null) {
this.connection = conn;
}
this.latestRtt = calculateDurationInMs(start);
this.monitorId = setTimeout(
() => this.measureRoundTripTime(),
this.monitor.options.heartbeatFrequencyMS
);
}
private measureRoundTripTime() {
const start = now();
Iif (this.closed) {
return;
}
const connection = this.connection;
if (connection == null) {
connect(this.monitor.connectOptions).then(
connection => {
this.measureAndReschedule(start, connection);
},
() => {
this.connection = undefined;
}
);
return;
}
const commandName =
connection.serverApi?.version || connection.helloOk ? 'hello' : LEGACY_HELLO_COMMAND;
connection.command(ns('admin.$cmd'), { [commandName]: 1 }, undefined).then(
() => this.measureAndReschedule(start),
() => {
this.connection?.destroy();
this.connection = undefined;
return;
}
);
}
}
/**
* @internal
*/
export interface MonitorIntervalOptions {
/** The interval to execute a method on */
heartbeatFrequencyMS: number;
/** A minimum interval that must elapse before the method is called */
minHeartbeatFrequencyMS: number;
/** Whether the method should be called immediately when the interval is started */
immediate: boolean;
}
/**
* @internal
*/
export class MonitorInterval {
fn: (callback: Callback) => void;
timerId: NodeJS.Timeout | undefined;
lastExecutionEnded: number;
isExpeditedCallToFnScheduled = false;
stopped = false;
isExecutionInProgress = false;
hasExecutedOnce = false;
heartbeatFrequencyMS: number;
minHeartbeatFrequencyMS: number;
constructor(fn: (callback: Callback) => void, options: Partial<MonitorIntervalOptions> = {}) {
this.fn = fn;
this.lastExecutionEnded = -Infinity;
this.heartbeatFrequencyMS = options.heartbeatFrequencyMS ?? 1000;
this.minHeartbeatFrequencyMS = options.minHeartbeatFrequencyMS ?? 500;
if (options.immediate) {
this._executeAndReschedule();
} else {
this._reschedule(undefined);
}
}
wake() {
const currentTime = now();
const timeSinceLastCall = currentTime - this.lastExecutionEnded;
// TODO(NODE-4674): Add error handling and logging to the monitor
if (timeSinceLastCall < 0) {
return this._executeAndReschedule();
}
if (this.isExecutionInProgress) {
return;
}
// debounce multiple calls to wake within the `minInterval`
if (this.isExpeditedCallToFnScheduled) {
return;
}
// reschedule a call as soon as possible, ensuring the call never happens
// faster than the `minInterval`
if (timeSinceLastCall < this.minHeartbeatFrequencyMS) {
this.isExpeditedCallToFnScheduled = true;
this._reschedule(this.minHeartbeatFrequencyMS - timeSinceLastCall);
return;
}
this._executeAndReschedule();
}
stop() {
this.stopped = true;
if (this.timerId) {
clearTimeout(this.timerId);
this.timerId = undefined;
}
this.lastExecutionEnded = -Infinity;
this.isExpeditedCallToFnScheduled = false;
}
toString() {
return JSON.stringify(this);
}
toJSON() {
const currentTime = now();
const timeSinceLastCall = currentTime - this.lastExecutionEnded;
return {
timerId: this.timerId != null ? 'set' : 'cleared',
lastCallTime: this.lastExecutionEnded,
isExpeditedCheckScheduled: this.isExpeditedCallToFnScheduled,
stopped: this.stopped,
heartbeatFrequencyMS: this.heartbeatFrequencyMS,
minHeartbeatFrequencyMS: this.minHeartbeatFrequencyMS,
currentTime,
timeSinceLastCall
};
}
private _reschedule(ms?: number) {
if (this.stopped) return;
if (this.timerId) {
clearTimeout(this.timerId);
}
this.timerId = setTimeout(this._executeAndReschedule, ms || this.heartbeatFrequencyMS);
}
private _executeAndReschedule = () => {
Iif (this.stopped) return;
if (this.timerId) {
clearTimeout(this.timerId);
}
this.isExpeditedCallToFnScheduled = false;
this.isExecutionInProgress = true;
this.fn(() => {
this.lastExecutionEnded = now();
this.isExecutionInProgress = false;
this._reschedule(this.heartbeatFrequencyMS);
});
};
}
/** @internal
* This class implements the RTT sampling logic specified for [CSOT](https://github.com/mongodb/specifications/blob/bbb335e60cd7ea1e0f7cd9a9443cb95fc9d3b64d/source/client-side-operations-timeout/client-side-operations-timeout.md#drivers-use-minimum-rtt-to-short-circuit-operations)
*
* This is implemented as a [circular buffer](https://en.wikipedia.org/wiki/Circular_buffer) keeping
* the most recent `windowSize` samples
* */
export class RTTSampler {
/** Index of the next slot to be overwritten */
private writeIndex: number;
private length: number;
private rttSamples: Float64Array;
constructor(windowSize = 10) {
this.rttSamples = new Float64Array(windowSize);
this.length = 0;
this.writeIndex = 0;
}
/**
* Adds an rtt sample to the end of the circular buffer
* When `windowSize` samples have been collected, `addSample` overwrites the least recently added
* sample
*/
addSample(sample: number) {
this.rttSamples[this.writeIndex++] = sample;
if (this.length < this.rttSamples.length) {
this.length++;
}
this.writeIndex %= this.rttSamples.length;
}
/**
* When \< 2 samples have been collected, returns 0
* Otherwise computes the minimum value samples contained in the buffer
*/
min(): number {
if (this.length < 2) return 0;
let min = this.rttSamples[0];
for (let i = 1; i < this.length; i++) {
if (this.rttSamples[i] < min) min = this.rttSamples[i];
}
return min;
}
/**
* Returns mean of samples contained in the buffer
*/
average(): number {
Iif (this.length === 0) return 0;
let sum = 0;
for (let i = 0; i < this.length; i++) {
sum += this.rttSamples[i];
}
return sum / this.length;
}
/**
* Returns most recently inserted element in the buffer
* Returns null if the buffer is empty
* */
get last(): number | null {
if (this.length === 0) return null;
return this.rttSamples[this.writeIndex === 0 ? this.length - 1 : this.writeIndex - 1];
}
/**
* Clear the buffer
* NOTE: this does not overwrite the data held in the internal array, just the pointers into
* this array
*/
clear() {
this.length = 0;
this.writeIndex = 0;
}
}
|