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node_modules/mongodb/lib/cmap/connection_pool.js

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+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.ConnectionPool = exports.PoolState = void 0;
+const timers_1 = require("timers");
+const constants_1 = require("../constants");
+const error_1 = require("../error");
+const mongo_types_1 = require("../mongo_types");
+const utils_1 = require("../utils");
+const connect_1 = require("./connect");
+const connection_1 = require("./connection");
+const connection_pool_events_1 = require("./connection_pool_events");
+const errors_1 = require("./errors");
+const metrics_1 = require("./metrics");
+/** @internal */
+const kServer = Symbol('server');
+/** @internal */
+const kConnections = Symbol('connections');
+/** @internal */
+const kPending = Symbol('pending');
+/** @internal */
+const kCheckedOut = Symbol('checkedOut');
+/** @internal */
+const kMinPoolSizeTimer = Symbol('minPoolSizeTimer');
+/** @internal */
+const kGeneration = Symbol('generation');
+/** @internal */
+const kServiceGenerations = Symbol('serviceGenerations');
+/** @internal */
+const kConnectionCounter = Symbol('connectionCounter');
+/** @internal */
+const kCancellationToken = Symbol('cancellationToken');
+/** @internal */
+const kWaitQueue = Symbol('waitQueue');
+/** @internal */
+const kCancelled = Symbol('cancelled');
+/** @internal */
+const kMetrics = Symbol('metrics');
+/** @internal */
+const kProcessingWaitQueue = Symbol('processingWaitQueue');
+/** @internal */
+const kPoolState = Symbol('poolState');
+/** @internal */
+exports.PoolState = Object.freeze({
+    paused: 'paused',
+    ready: 'ready',
+    closed: 'closed'
+});
+/**
+ * A pool of connections which dynamically resizes, and emit events related to pool activity
+ * @internal
+ */
+class ConnectionPool extends mongo_types_1.TypedEventEmitter {
+    constructor(server, options) {
+        super();
+        this.options = Object.freeze({
+            ...options,
+            connectionType: connection_1.Connection,
+            maxPoolSize: options.maxPoolSize ?? 100,
+            minPoolSize: options.minPoolSize ?? 0,
+            maxConnecting: options.maxConnecting ?? 2,
+            maxIdleTimeMS: options.maxIdleTimeMS ?? 0,
+            waitQueueTimeoutMS: options.waitQueueTimeoutMS ?? 0,
+            minPoolSizeCheckFrequencyMS: options.minPoolSizeCheckFrequencyMS ?? 100,
+            autoEncrypter: options.autoEncrypter,
+            metadata: options.metadata
+        });
+        if (this.options.minPoolSize > this.options.maxPoolSize) {
+            throw new error_1.MongoInvalidArgumentError('Connection pool minimum size must not be greater than maximum pool size');
+        }
+        this[kPoolState] = exports.PoolState.paused;
+        this[kServer] = server;
+        this[kConnections] = new utils_1.List();
+        this[kPending] = 0;
+        this[kCheckedOut] = new Set();
+        this[kMinPoolSizeTimer] = undefined;
+        this[kGeneration] = 0;
+        this[kServiceGenerations] = new Map();
+        this[kConnectionCounter] = (0, utils_1.makeCounter)(1);
+        this[kCancellationToken] = new mongo_types_1.CancellationToken();
+        this[kCancellationToken].setMaxListeners(Infinity);
+        this[kWaitQueue] = new utils_1.List();
+        this[kMetrics] = new metrics_1.ConnectionPoolMetrics();
+        this[kProcessingWaitQueue] = false;
+        process.nextTick(() => {
+            this.emit(ConnectionPool.CONNECTION_POOL_CREATED, new connection_pool_events_1.ConnectionPoolCreatedEvent(this));
+        });
+    }
+    /** The address of the endpoint the pool is connected to */
+    get address() {
+        return this.options.hostAddress.toString();
+    }
+    /**
+     * Check if the pool has been closed
+     *
+     * TODO(NODE-3263): We can remove this property once shell no longer needs it
+     */
+    get closed() {
+        return this[kPoolState] === exports.PoolState.closed;
+    }
+    /** An integer representing the SDAM generation of the pool */
+    get generation() {
+        return this[kGeneration];
+    }
+    /** An integer expressing how many total connections (available + pending + in use) the pool currently has */
+    get totalConnectionCount() {
+        return (this.availableConnectionCount + this.pendingConnectionCount + this.currentCheckedOutCount);
+    }
+    /** An integer expressing how many connections are currently available in the pool. */
+    get availableConnectionCount() {
+        return this[kConnections].length;
+    }
+    get pendingConnectionCount() {
+        return this[kPending];
+    }
+    get currentCheckedOutCount() {
+        return this[kCheckedOut].size;
+    }
+    get waitQueueSize() {
+        return this[kWaitQueue].length;
+    }
+    get loadBalanced() {
+        return this.options.loadBalanced;
+    }
+    get serviceGenerations() {
+        return this[kServiceGenerations];
+    }
+    get serverError() {
+        return this[kServer].description.error;
+    }
+    /**
+     * This is exposed ONLY for use in mongosh, to enable
+     * killing all connections if a user quits the shell with
+     * operations in progress.
+     *
+     * This property may be removed as a part of NODE-3263.
+     */
+    get checkedOutConnections() {
+        return this[kCheckedOut];
+    }
+    /**
+     * Get the metrics information for the pool when a wait queue timeout occurs.
+     */
+    waitQueueErrorMetrics() {
+        return this[kMetrics].info(this.options.maxPoolSize);
+    }
+    /**
+     * Set the pool state to "ready"
+     */
+    ready() {
+        if (this[kPoolState] !== exports.PoolState.paused) {
+            return;
+        }
+        this[kPoolState] = exports.PoolState.ready;
+        this.emit(ConnectionPool.CONNECTION_POOL_READY, new connection_pool_events_1.ConnectionPoolReadyEvent(this));
+        (0, timers_1.clearTimeout)(this[kMinPoolSizeTimer]);
+        this.ensureMinPoolSize();
+    }
+    /**
+     * Check a connection out of this pool. The connection will continue to be tracked, but no reference to it
+     * will be held by the pool. This means that if a connection is checked out it MUST be checked back in or
+     * explicitly destroyed by the new owner.
+     */
+    checkOut(callback) {
+        this.emit(ConnectionPool.CONNECTION_CHECK_OUT_STARTED, new connection_pool_events_1.ConnectionCheckOutStartedEvent(this));
+        const waitQueueMember = { callback };
+        const waitQueueTimeoutMS = this.options.waitQueueTimeoutMS;
+        if (waitQueueTimeoutMS) {
+            waitQueueMember.timer = (0, timers_1.setTimeout)(() => {
+                waitQueueMember[kCancelled] = true;
+                waitQueueMember.timer = undefined;
+                this.emit(ConnectionPool.CONNECTION_CHECK_OUT_FAILED, new connection_pool_events_1.ConnectionCheckOutFailedEvent(this, 'timeout'));
+                waitQueueMember.callback(new errors_1.WaitQueueTimeoutError(this.loadBalanced
+                    ? this.waitQueueErrorMetrics()
+                    : 'Timed out while checking out a connection from connection pool', this.address));
+            }, waitQueueTimeoutMS);
+        }
+        this[kWaitQueue].push(waitQueueMember);
+        process.nextTick(() => this.processWaitQueue());
+    }
+    /**
+     * Check a connection into the pool.
+     *
+     * @param connection - The connection to check in
+     */
+    checkIn(connection) {
+        if (!this[kCheckedOut].has(connection)) {
+            return;
+        }
+        const poolClosed = this.closed;
+        const stale = this.connectionIsStale(connection);
+        const willDestroy = !!(poolClosed || stale || connection.closed);
+        if (!willDestroy) {
+            connection.markAvailable();
+            this[kConnections].unshift(connection);
+        }
+        this[kCheckedOut].delete(connection);
+        this.emit(ConnectionPool.CONNECTION_CHECKED_IN, new connection_pool_events_1.ConnectionCheckedInEvent(this, connection));
+        if (willDestroy) {
+            const reason = connection.closed ? 'error' : poolClosed ? 'poolClosed' : 'stale';
+            this.destroyConnection(connection, reason);
+        }
+        process.nextTick(() => this.processWaitQueue());
+    }
+    /**
+     * Clear the pool
+     *
+     * Pool reset is handled by incrementing the pool's generation count. Any existing connection of a
+     * previous generation will eventually be pruned during subsequent checkouts.
+     */
+    clear(options = {}) {
+        if (this.closed) {
+            return;
+        }
+        // handle load balanced case
+        if (this.loadBalanced) {
+            const { serviceId } = options;
+            if (!serviceId) {
+                throw new error_1.MongoRuntimeError('ConnectionPool.clear() called in load balanced mode with no serviceId.');
+            }
+            const sid = serviceId.toHexString();
+            const generation = this.serviceGenerations.get(sid);
+            // Only need to worry if the generation exists, since it should
+            // always be there but typescript needs the check.
+            if (generation == null) {
+                throw new error_1.MongoRuntimeError('Service generations are required in load balancer mode.');
+            }
+            else {
+                // Increment the generation for the service id.
+                this.serviceGenerations.set(sid, generation + 1);
+            }
+            this.emit(ConnectionPool.CONNECTION_POOL_CLEARED, new connection_pool_events_1.ConnectionPoolClearedEvent(this, { serviceId }));
+            return;
+        }
+        // handle non load-balanced case
+        const interruptInUseConnections = options.interruptInUseConnections ?? false;
+        const oldGeneration = this[kGeneration];
+        this[kGeneration] += 1;
+        const alreadyPaused = this[kPoolState] === exports.PoolState.paused;
+        this[kPoolState] = exports.PoolState.paused;
+        this.clearMinPoolSizeTimer();
+        if (!alreadyPaused) {
+            this.emit(ConnectionPool.CONNECTION_POOL_CLEARED, new connection_pool_events_1.ConnectionPoolClearedEvent(this, { interruptInUseConnections }));
+        }
+        if (interruptInUseConnections) {
+            process.nextTick(() => this.interruptInUseConnections(oldGeneration));
+        }
+        this.processWaitQueue();
+    }
+    /**
+     * Closes all stale in-use connections in the pool with a resumable PoolClearedOnNetworkError.
+     *
+     * Only connections where `connection.generation <= minGeneration` are killed.
+     */
+    interruptInUseConnections(minGeneration) {
+        for (const connection of this[kCheckedOut]) {
+            if (connection.generation <= minGeneration) {
+                this.checkIn(connection);
+                connection.onError(new errors_1.PoolClearedOnNetworkError(this));
+            }
+        }
+    }
+    close(_options, _cb) {
+        let options = _options;
+        const callback = (_cb ?? _options);
+        if (typeof options === 'function') {
+            options = {};
+        }
+        options = Object.assign({ force: false }, options);
+        if (this.closed) {
+            return callback();
+        }
+        // immediately cancel any in-flight connections
+        this[kCancellationToken].emit('cancel');
+        // end the connection counter
+        if (typeof this[kConnectionCounter].return === 'function') {
+            this[kConnectionCounter].return(undefined);
+        }
+        this[kPoolState] = exports.PoolState.closed;
+        this.clearMinPoolSizeTimer();
+        this.processWaitQueue();
+        (0, utils_1.eachAsync)(this[kConnections].toArray(), (conn, cb) => {
+            this.emit(ConnectionPool.CONNECTION_CLOSED, new connection_pool_events_1.ConnectionClosedEvent(this, conn, 'poolClosed'));
+            conn.destroy({ force: !!options.force }, cb);
+        }, err => {
+            this[kConnections].clear();
+            this.emit(ConnectionPool.CONNECTION_POOL_CLOSED, new connection_pool_events_1.ConnectionPoolClosedEvent(this));
+            callback(err);
+        });
+    }
+    /**
+     * Runs a lambda with an implicitly checked out connection, checking that connection back in when the lambda
+     * has completed by calling back.
+     *
+     * NOTE: please note the required signature of `fn`
+     *
+     * @remarks When in load balancer mode, connections can be pinned to cursors or transactions.
+     *   In these cases we pass the connection in to this method to ensure it is used and a new
+     *   connection is not checked out.
+     *
+     * @param conn - A pinned connection for use in load balancing mode.
+     * @param fn - A function which operates on a managed connection
+     * @param callback - The original callback
+     */
+    withConnection(conn, fn, callback) {
+        if (conn) {
+            // use the provided connection, and do _not_ check it in after execution
+            fn(undefined, conn, (fnErr, result) => {
+                if (typeof callback === 'function') {
+                    if (fnErr) {
+                        callback(fnErr);
+                    }
+                    else {
+                        callback(undefined, result);
+                    }
+                }
+            });
+            return;
+        }
+        this.checkOut((err, conn) => {
+            // don't callback with `err` here, we might want to act upon it inside `fn`
+            fn(err, conn, (fnErr, result) => {
+                if (typeof callback === 'function') {
+                    if (fnErr) {
+                        callback(fnErr);
+                    }
+                    else {
+                        callback(undefined, result);
+                    }
+                }
+                if (conn) {
+                    this.checkIn(conn);
+                }
+            });
+        });
+    }
+    /** Clear the min pool size timer */
+    clearMinPoolSizeTimer() {
+        const minPoolSizeTimer = this[kMinPoolSizeTimer];
+        if (minPoolSizeTimer) {
+            (0, timers_1.clearTimeout)(minPoolSizeTimer);
+        }
+    }
+    destroyConnection(connection, reason) {
+        this.emit(ConnectionPool.CONNECTION_CLOSED, new connection_pool_events_1.ConnectionClosedEvent(this, connection, reason));
+        // destroy the connection
+        process.nextTick(() => connection.destroy({ force: false }));
+    }
+    connectionIsStale(connection) {
+        const serviceId = connection.serviceId;
+        if (this.loadBalanced && serviceId) {
+            const sid = serviceId.toHexString();
+            const generation = this.serviceGenerations.get(sid);
+            return connection.generation !== generation;
+        }
+        return connection.generation !== this[kGeneration];
+    }
+    connectionIsIdle(connection) {
+        return !!(this.options.maxIdleTimeMS && connection.idleTime > this.options.maxIdleTimeMS);
+    }
+    /**
+     * Destroys a connection if the connection is perished.
+     *
+     * @returns `true` if the connection was destroyed, `false` otherwise.
+     */
+    destroyConnectionIfPerished(connection) {
+        const isStale = this.connectionIsStale(connection);
+        const isIdle = this.connectionIsIdle(connection);
+        if (!isStale && !isIdle && !connection.closed) {
+            return false;
+        }
+        const reason = connection.closed ? 'error' : isStale ? 'stale' : 'idle';
+        this.destroyConnection(connection, reason);
+        return true;
+    }
+    createConnection(callback) {
+        const connectOptions = {
+            ...this.options,
+            id: this[kConnectionCounter].next().value,
+            generation: this[kGeneration],
+            cancellationToken: this[kCancellationToken]
+        };
+        this[kPending]++;
+        // This is our version of a "virtual" no-I/O connection as the spec requires
+        this.emit(ConnectionPool.CONNECTION_CREATED, new connection_pool_events_1.ConnectionCreatedEvent(this, { id: connectOptions.id }));
+        (0, connect_1.connect)(connectOptions, (err, connection) => {
+            if (err || !connection) {
+                this[kPending]--;
+                this.emit(ConnectionPool.CONNECTION_CLOSED, new connection_pool_events_1.ConnectionClosedEvent(this, { id: connectOptions.id, serviceId: undefined }, 'error'));
+                if (err instanceof error_1.MongoNetworkError || err instanceof error_1.MongoServerError) {
+                    err.connectionGeneration = connectOptions.generation;
+                }
+                callback(err ?? new error_1.MongoRuntimeError('Connection creation failed without error'));
+                return;
+            }
+            // The pool might have closed since we started trying to create a connection
+            if (this[kPoolState] !== exports.PoolState.ready) {
+                this[kPending]--;
+                connection.destroy({ force: true });
+                callback(this.closed ? new errors_1.PoolClosedError(this) : new errors_1.PoolClearedError(this));
+                return;
+            }
+            // forward all events from the connection to the pool
+            for (const event of [...constants_1.APM_EVENTS, connection_1.Connection.CLUSTER_TIME_RECEIVED]) {
+                connection.on(event, (e) => this.emit(event, e));
+            }
+            if (this.loadBalanced) {
+                connection.on(connection_1.Connection.PINNED, pinType => this[kMetrics].markPinned(pinType));
+                connection.on(connection_1.Connection.UNPINNED, pinType => this[kMetrics].markUnpinned(pinType));
+                const serviceId = connection.serviceId;
+                if (serviceId) {
+                    let generation;
+                    const sid = serviceId.toHexString();
+                    if ((generation = this.serviceGenerations.get(sid))) {
+                        connection.generation = generation;
+                    }
+                    else {
+                        this.serviceGenerations.set(sid, 0);
+                        connection.generation = 0;
+                    }
+                }
+            }
+            connection.markAvailable();
+            this.emit(ConnectionPool.CONNECTION_READY, new connection_pool_events_1.ConnectionReadyEvent(this, connection));
+            this[kPending]--;
+            callback(undefined, connection);
+            return;
+        });
+    }
+    ensureMinPoolSize() {
+        const minPoolSize = this.options.minPoolSize;
+        if (this[kPoolState] !== exports.PoolState.ready || minPoolSize === 0) {
+            return;
+        }
+        this[kConnections].prune(connection => this.destroyConnectionIfPerished(connection));
+        if (this.totalConnectionCount < minPoolSize &&
+            this.pendingConnectionCount < this.options.maxConnecting) {
+            // NOTE: ensureMinPoolSize should not try to get all the pending
+            // connection permits because that potentially delays the availability of
+            // the connection to a checkout request
+            this.createConnection((err, connection) => {
+                if (err) {
+                    this[kServer].handleError(err);
+                }
+                if (!err && connection) {
+                    this[kConnections].push(connection);
+                    process.nextTick(() => this.processWaitQueue());
+                }
+                if (this[kPoolState] === exports.PoolState.ready) {
+                    (0, timers_1.clearTimeout)(this[kMinPoolSizeTimer]);
+                    this[kMinPoolSizeTimer] = (0, timers_1.setTimeout)(() => this.ensureMinPoolSize(), this.options.minPoolSizeCheckFrequencyMS);
+                }
+            });
+        }
+        else {
+            (0, timers_1.clearTimeout)(this[kMinPoolSizeTimer]);
+            this[kMinPoolSizeTimer] = (0, timers_1.setTimeout)(() => this.ensureMinPoolSize(), this.options.minPoolSizeCheckFrequencyMS);
+        }
+    }
+    processWaitQueue() {
+        if (this[kProcessingWaitQueue]) {
+            return;
+        }
+        this[kProcessingWaitQueue] = true;
+        while (this.waitQueueSize) {
+            const waitQueueMember = this[kWaitQueue].first();
+            if (!waitQueueMember) {
+                this[kWaitQueue].shift();
+                continue;
+            }
+            if (waitQueueMember[kCancelled]) {
+                this[kWaitQueue].shift();
+                continue;
+            }
+            if (this[kPoolState] !== exports.PoolState.ready) {
+                const reason = this.closed ? 'poolClosed' : 'connectionError';
+                const error = this.closed ? new errors_1.PoolClosedError(this) : new errors_1.PoolClearedError(this);
+                this.emit(ConnectionPool.CONNECTION_CHECK_OUT_FAILED, new connection_pool_events_1.ConnectionCheckOutFailedEvent(this, reason));
+                if (waitQueueMember.timer) {
+                    (0, timers_1.clearTimeout)(waitQueueMember.timer);
+                }
+                this[kWaitQueue].shift();
+                waitQueueMember.callback(error);
+                continue;
+            }
+            if (!this.availableConnectionCount) {
+                break;
+            }
+            const connection = this[kConnections].shift();
+            if (!connection) {
+                break;
+            }
+            if (!this.destroyConnectionIfPerished(connection)) {
+                this[kCheckedOut].add(connection);
+                this.emit(ConnectionPool.CONNECTION_CHECKED_OUT, new connection_pool_events_1.ConnectionCheckedOutEvent(this, connection));
+                if (waitQueueMember.timer) {
+                    (0, timers_1.clearTimeout)(waitQueueMember.timer);
+                }
+                this[kWaitQueue].shift();
+                waitQueueMember.callback(undefined, connection);
+            }
+        }
+        const { maxPoolSize, maxConnecting } = this.options;
+        while (this.waitQueueSize > 0 &&
+            this.pendingConnectionCount < maxConnecting &&
+            (maxPoolSize === 0 || this.totalConnectionCount < maxPoolSize)) {
+            const waitQueueMember = this[kWaitQueue].shift();
+            if (!waitQueueMember || waitQueueMember[kCancelled]) {
+                continue;
+            }
+            this.createConnection((err, connection) => {
+                if (waitQueueMember[kCancelled]) {
+                    if (!err && connection) {
+                        this[kConnections].push(connection);
+                    }
+                }
+                else {
+                    if (err) {
+                        this.emit(ConnectionPool.CONNECTION_CHECK_OUT_FAILED, new connection_pool_events_1.ConnectionCheckOutFailedEvent(this, 'connectionError'));
+                    }
+                    else if (connection) {
+                        this[kCheckedOut].add(connection);
+                        this.emit(ConnectionPool.CONNECTION_CHECKED_OUT, new connection_pool_events_1.ConnectionCheckedOutEvent(this, connection));
+                    }
+                    if (waitQueueMember.timer) {
+                        (0, timers_1.clearTimeout)(waitQueueMember.timer);
+                    }
+                    waitQueueMember.callback(err, connection);
+                }
+                process.nextTick(() => this.processWaitQueue());
+            });
+        }
+        this[kProcessingWaitQueue] = false;
+    }
+}
+exports.ConnectionPool = ConnectionPool;
+/**
+ * Emitted when the connection pool is created.
+ * @event
+ */
+ConnectionPool.CONNECTION_POOL_CREATED = constants_1.CONNECTION_POOL_CREATED;
+/**
+ * Emitted once when the connection pool is closed
+ * @event
+ */
+ConnectionPool.CONNECTION_POOL_CLOSED = constants_1.CONNECTION_POOL_CLOSED;
+/**
+ * Emitted each time the connection pool is cleared and it's generation incremented
+ * @event
+ */
+ConnectionPool.CONNECTION_POOL_CLEARED = constants_1.CONNECTION_POOL_CLEARED;
+/**
+ * Emitted each time the connection pool is marked ready
+ * @event
+ */
+ConnectionPool.CONNECTION_POOL_READY = constants_1.CONNECTION_POOL_READY;
+/**
+ * Emitted when a connection is created.
+ * @event
+ */
+ConnectionPool.CONNECTION_CREATED = constants_1.CONNECTION_CREATED;
+/**
+ * Emitted when a connection becomes established, and is ready to use
+ * @event
+ */
+ConnectionPool.CONNECTION_READY = constants_1.CONNECTION_READY;
+/**
+ * Emitted when a connection is closed
+ * @event
+ */
+ConnectionPool.CONNECTION_CLOSED = constants_1.CONNECTION_CLOSED;
+/**
+ * Emitted when an attempt to check out a connection begins
+ * @event
+ */
+ConnectionPool.CONNECTION_CHECK_OUT_STARTED = constants_1.CONNECTION_CHECK_OUT_STARTED;
+/**
+ * Emitted when an attempt to check out a connection fails
+ * @event
+ */
+ConnectionPool.CONNECTION_CHECK_OUT_FAILED = constants_1.CONNECTION_CHECK_OUT_FAILED;
+/**
+ * Emitted each time a connection is successfully checked out of the connection pool
+ * @event
+ */
+ConnectionPool.CONNECTION_CHECKED_OUT = constants_1.CONNECTION_CHECKED_OUT;
+/**
+ * Emitted each time a connection is successfully checked into the connection pool
+ * @event
+ */
+ConnectionPool.CONNECTION_CHECKED_IN = constants_1.CONNECTION_CHECKED_IN;
+//# sourceMappingURL=connection_pool.js.map