Add configurable query timeout (#1760)

* Add read_timeout to connection settings

* Fix uncaught error issue

* Fix lint

* Fix "queryCallback is not a function"

* Added test and fixed error returning

* Added query timeout to native client

* Added test for timeout not reached

* Ensure error is the correct one
Correct test name

* Removed dubious check

* Added new test

* Improved test

Author: edevil

lib/client.js

@@ -399,15 +399,20 @@ Client.prototype.query = function (config, values, callback) {
   // can take in strings, config object or query object
   var query
   var result
+  var readTimeout
+  var readTimeoutTimer
+  var queryCallback
 
   if (config === null || config === undefined) {
     throw new TypeError('Client was passed a null or undefined query')
   } else if (typeof config.submit === 'function') {
+    readTimeout = config.query_timeout || this.connectionParameters.query_timeout
     result = query = config
     if (typeof values === 'function') {
       query.callback = query.callback || values
     }
   } else {
+    readTimeout = this.connectionParameters.query_timeout
     query = new Query(config, values, callback)
     if (!query.callback) {
       result = new this._Promise((resolve, reject) => {
@@ -416,6 +421,37 @@ Client.prototype.query = function (config, values, callback) {
     }
   }
 
+  if (readTimeout) {
+    queryCallback = query.callback
+
+    readTimeoutTimer = setTimeout(() => {
+      var error = new Error('Query read timeout')
+
+      process.nextTick(() => {
+        query.handleError(error, this.connection)
+      })
+
+      queryCallback(error)
+
+      // we already returned an error,
+      // just do nothing if query completes
+      query.callback = () => {}
+
+      // Remove from queue
+      var index = this.queryQueue.indexOf(query)
+      if (index > -1) {
+        this.queryQueue.splice(index, 1)
+      }
+
+      this._pulseQueryQueue()
+    }, readTimeout)
+
+    query.callback = (err, res) => {
+      clearTimeout(readTimeoutTimer)
+      queryCallback(err, res)
+    }
+  }
+
   if (this.binary && !query.binary) {
     query.binary = true
   }

lib/connection-parameters.js

@@ -65,6 +65,7 @@ var ConnectionParameters = function (config) {
   this.application_name = val('application_name', config, 'PGAPPNAME')
   this.fallback_application_name = val('fallback_application_name', config, false)
   this.statement_timeout = val('statement_timeout', config, false)
+  this.query_timeout = val('query_timeout', config, false)
 }
 
 // Convert arg to a string, surround in single quotes, and escape single quotes and backslashes

lib/defaults.js

@@ -55,7 +55,10 @@ module.exports = {
   parseInputDatesAsUTC: false,
 
   // max milliseconds any query using this connection will execute for before timing out in error. false=unlimited
-  statement_timeout: false
+  statement_timeout: false,
+
+  // max miliseconds to wait for query to complete (client side)
+  query_timeout: false
 }
 
 var pgTypes = require('pg-types')

lib/native/client.js

@@ -146,14 +146,21 @@ Client.prototype.connect = function (callback) {
 Client.prototype.query = function (config, values, callback) {
   var query
   var result
-
-  if (typeof config.submit === 'function') {
+  var readTimeout
+  var readTimeoutTimer
+  var queryCallback
+
+  if (config === null || config === undefined) {
+    throw new TypeError('Client was passed a null or undefined query')
+  } else if (typeof config.submit === 'function') {
+    readTimeout = config.query_timeout || this.connectionParameters.query_timeout
     result = query = config
     // accept query(new Query(...), (err, res) => { }) style
     if (typeof values === 'function') {
       config.callback = values
     }
   } else {
+    readTimeout = this.connectionParameters.query_timeout
     query = new NativeQuery(config, values, callback)
     if (!query.callback) {
       let resolveOut, rejectOut
@@ -165,6 +172,37 @@ Client.prototype.query = function (config, values, callback) {
     }
   }
 
+  if (readTimeout) {
+    queryCallback = query.callback
+
+    readTimeoutTimer = setTimeout(() => {
+      var error = new Error('Query read timeout')
+
+      process.nextTick(() => {
+        query.handleError(error, this.connection)
+      })
+
+      queryCallback(error)
+
+      // we already returned an error,
+      // just do nothing if query completes
+      query.callback = () => {}
+
+      // Remove from queue
+      var index = this._queryQueue.indexOf(query)
+      if (index > -1) {
+        this._queryQueue.splice(index, 1)
+      }
+
+      this._pulseQueryQueue()
+    }, readTimeout)
+
+    query.callback = (err, res) => {
+      clearTimeout(readTimeoutTimer)
+      queryCallback(err, res)
+    }
+  }
+
   if (!this._queryable) {
     query.native = this.native
     process.nextTick(() => {

test/integration/client/api-tests.js

@@ -15,6 +15,47 @@ suite.test('pool callback behavior', done => {
   })
 })
 
+suite.test('query timeout', (cb) => {
+  const pool = new pg.Pool({query_timeout: 1000})
+  pool.connect().then((client) => {
+    client.query('SELECT pg_sleep(2)', assert.calls(function (err, result) {
+      assert(err)
+      assert(err.message === 'Query read timeout')
+      client.release()
+      pool.end(cb)
+    }))
+  })
+})
+
+suite.test('query recover from timeout', (cb) => {
+  const pool = new pg.Pool({query_timeout: 1000})
+  pool.connect().then((client) => {
+    client.query('SELECT pg_sleep(20)', assert.calls(function (err, result) {
+      assert(err)
+      assert(err.message === 'Query read timeout')
+      client.release(err)
+      pool.connect().then((client) => {
+        client.query('SELECT 1', assert.calls(function (err, result) {
+          assert(!err)
+          client.release(err)
+          pool.end(cb)
+        }))
+      })
+    }))
+  })
+})
+
+suite.test('query no timeout', (cb) => {
+  const pool = new pg.Pool({query_timeout: 10000})
+  pool.connect().then((client) => {
+    client.query('SELECT pg_sleep(1)', assert.calls(function (err, result) {
+      assert(!err)
+      client.release()
+      pool.end(cb)
+    }))
+  })
+})
+
 suite.test('callback API', done => {
   const client = new helper.Client()
   client.query('CREATE TEMP TABLE peep(name text)')