feat(pool): added acquireTimeout supports

Author: fenying

README.md

@@ -131,6 +131,7 @@ const pool = mysql.createPool({
   user: 'root',
   database: 'test',
   waitForConnections: true,
+  acquireTimeout: 10000,
   connectionLimit: 10,
   maxIdle: 10, // max idle connections, the default value is the same as `connectionLimit`
   idleTimeout: 60000, // idle connections timeout, in milliseconds, the default value 60000

documentation_zh-cn/README.md

@@ -131,6 +131,7 @@ const pool = mysql.createPool({
   user: 'root',
   database: 'test',
   waitForConnections: true,
+  acquireTimeout: 10000,
   connectionLimit: 10,
   queueLimit: 0
 });

lib/connection_config.js

@@ -64,7 +64,8 @@ const validOptions = {
   idleTimeout: 1,
   Promise: 1,
   queueLimit: 1,
-  waitForConnections: 1
+  waitForConnections: 1,
+  acquireTimeout: 1
 };
 
 class ConnectionConfig {

lib/pool.js

@@ -78,6 +78,25 @@ class Pool extends EventEmitter {
       return cb(new Error('Queue limit reached.'));
     }
     this.emit('enqueue');
+
+    if (this.config.acquireTimeout > 0) {
+
+      const timeout = setTimeout(() => {
+
+        spliceConnection(this._connectionQueue, cb);
+        cb(new Error('Timeout acquiring connection'));
+
+      }, this.config.acquireTimeout);
+
+      return this._connectionQueue.push((err, connection) => {
+
+        clearTimeout(timeout);
+
+        cb(err, connection);
+
+      }, this.config.acquireTimeout);
+    }
+
     return this._connectionQueue.push(cb);
   }
 

lib/pool_config.js

@@ -15,6 +15,9 @@ class PoolConfig {
     this.connectionLimit = isNaN(options.connectionLimit)
       ? 10
       : Number(options.connectionLimit);
+    this.acquireTimeout = Number.isInteger(options.acquireTimeout) && options.acquireTimeout >= 0
+      ? options.acquireTimeout
+      : 10000;
     this.maxIdle = isNaN(options.maxIdle)
       ? this.connectionLimit
       : Number(options.maxIdle);

test/integration/test-pool-acquire-timeout.js

@@ -0,0 +1,48 @@
+'use strict';
+
+const mysql = require('../..');
+const test = require('utest');
+const assert = require('assert');
+const common = require('../common');
+
+const poolConfig = common.getConfig();
+
+const ACQUITE_TIMEOUT = 500;
+const poolWithAcquireTimeout = new mysql.createPool({
+    ...poolConfig,
+    acquireTimeout: ACQUITE_TIMEOUT,
+    connectionLimit: 2
+});
+
+poolWithAcquireTimeout.getConnection(function (err, c1) {
+    assert.equal(!!c1, true);
+    assert.ifError(err);
+    poolWithAcquireTimeout.getConnection(function (err, c2) {
+        assert.ifError(err);
+        assert.equal(!!c2, true);
+        const C3_STARTED_AT = Date.now();
+        poolWithAcquireTimeout.getConnection(function (e3, c3) {
+            const C3_DONE_AT = Date.now();
+
+            poolWithAcquireTimeout.releaseConnection(c1);
+
+            poolWithAcquireTimeout.getConnection(function (e4, c4) {
+
+                test('Pool With Acquire Timeout', {
+                    'timeout of pool is full': () => {
+                        assert.equal(e3 !== null, true);
+                        assert.equal(!c3, true);
+                        assert.equal(C3_DONE_AT - C3_STARTED_AT >= ACQUITE_TIMEOUT, true);
+                        assert.equal(C3_DONE_AT - C3_STARTED_AT < ACQUITE_TIMEOUT * 2, true);
+                    },
+                    'ok if pool is not full': () => {
+                        assert.equal(e4 === null, true);
+                        assert.equal(!!c4, true);
+                    }
+                });
+    
+                poolWithAcquireTimeout.releaseConnection(c4);
+            });
+        });
+    });
+});