'use strict'
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/**
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* Copyright (c) 2010-2017 Brian Carlson (brian.m.carlson@gmail.com)
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* All rights reserved.
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*
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* This source code is licensed under the MIT license found in the
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* README.md file in the root directory of this source tree.
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*/
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// eslint-disable-next-line
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var Native = require('pg-native')
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var TypeOverrides = require('../type-overrides')
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var semver = require('semver')
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var pkg = require('../../package.json')
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var assert = require('assert')
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var EventEmitter = require('events').EventEmitter
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var util = require('util')
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var ConnectionParameters = require('../connection-parameters')
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var msg = 'Version >= ' + pkg.minNativeVersion + ' of pg-native required.'
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assert(semver.gte(Native.version, pkg.minNativeVersion), msg)
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var NativeQuery = require('./query')
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var Client = module.exports = function (config) {
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EventEmitter.call(this)
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config = config || {}
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this._Promise = config.Promise || global.Promise
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this._types = new TypeOverrides(config.types)
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this.native = new Native({
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types: this._types
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})
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this._queryQueue = []
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this._ending = false
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this._connecting = false
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this._connected = false
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this._queryable = true
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// keep these on the object for legacy reasons
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// for the time being. TODO: deprecate all this jazz
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var cp = this.connectionParameters = new ConnectionParameters(config)
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this.user = cp.user
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this.password = cp.password
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this.database = cp.database
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this.host = cp.host
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this.port = cp.port
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// a hash to hold named queries
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this.namedQueries = {}
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}
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Client.Query = NativeQuery
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util.inherits(Client, EventEmitter)
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Client.prototype._errorAllQueries = function (err) {
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const enqueueError = (query) => {
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process.nextTick(() => {
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query.native = this.native
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query.handleError(err)
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})
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}
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if (this._hasActiveQuery()) {
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enqueueError(this._activeQuery)
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this._activeQuery = null
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}
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this._queryQueue.forEach(enqueueError)
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this._queryQueue.length = 0
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}
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// connect to the backend
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// pass an optional callback to be called once connected
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// or with an error if there was a connection error
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Client.prototype._connect = function (cb) {
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var self = this
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if (this._connecting) {
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process.nextTick(() => cb(new Error('Client has already been connected. You cannot reuse a client.')))
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return
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}
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this._connecting = true
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this.connectionParameters.getLibpqConnectionString(function (err, conString) {
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if (err) return cb(err)
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self.native.connect(conString, function (err) {
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if (err) return cb(err)
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// set internal states to connected
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self._connected = true
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// handle connection errors from the native layer
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self.native.on('error', function (err) {
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self._queryable = false
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self._errorAllQueries(err)
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self.emit('error', err)
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})
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self.native.on('notification', function (msg) {
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self.emit('notification', {
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channel: msg.relname,
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payload: msg.extra
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})
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})
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// signal we are connected now
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self.emit('connect')
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self._pulseQueryQueue(true)
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cb()
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})
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})
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}
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Client.prototype.connect = function (callback) {
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if (callback) {
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this._connect(callback)
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return
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}
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return new this._Promise((resolve, reject) => {
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this._connect((error) => {
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if (error) {
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reject(error)
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} else {
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resolve()
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}
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})
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})
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}
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// send a query to the server
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// this method is highly overloaded to take
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// 1) string query, optional array of parameters, optional function callback
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// 2) object query with {
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// string query
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// optional array values,
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// optional function callback instead of as a separate parameter
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// optional string name to name & cache the query plan
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// optional string rowMode = 'array' for an array of results
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// }
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Client.prototype.query = function (config, values, callback) {
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var query
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var result
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var readTimeout
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var readTimeoutTimer
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var queryCallback
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if (config === null || config === undefined) {
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throw new TypeError('Client was passed a null or undefined query')
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} else if (typeof config.submit === 'function') {
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readTimeout = config.query_timeout || this.connectionParameters.query_timeout
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result = query = config
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// accept query(new Query(...), (err, res) => { }) style
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if (typeof values === 'function') {
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config.callback = values
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}
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} else {
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readTimeout = this.connectionParameters.query_timeout
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query = new NativeQuery(config, values, callback)
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if (!query.callback) {
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let resolveOut, rejectOut
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result = new this._Promise((resolve, reject) => {
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resolveOut = resolve
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rejectOut = reject
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})
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query.callback = (err, res) => err ? rejectOut(err) : resolveOut(res)
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}
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}
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if (readTimeout) {
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queryCallback = query.callback
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readTimeoutTimer = setTimeout(() => {
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var error = new Error('Query read timeout')
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process.nextTick(() => {
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query.handleError(error, this.connection)
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})
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queryCallback(error)
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// we already returned an error,
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// just do nothing if query completes
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query.callback = () => {}
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// Remove from queue
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var index = this._queryQueue.indexOf(query)
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if (index > -1) {
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this._queryQueue.splice(index, 1)
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}
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this._pulseQueryQueue()
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}, readTimeout)
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query.callback = (err, res) => {
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clearTimeout(readTimeoutTimer)
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queryCallback(err, res)
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}
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}
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if (!this._queryable) {
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query.native = this.native
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process.nextTick(() => {
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query.handleError(new Error('Client has encountered a connection error and is not queryable'))
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})
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return result
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}
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if (this._ending) {
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query.native = this.native
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process.nextTick(() => {
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query.handleError(new Error('Client was closed and is not queryable'))
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})
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return result
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}
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this._queryQueue.push(query)
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this._pulseQueryQueue()
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return result
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}
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// disconnect from the backend server
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Client.prototype.end = function (cb) {
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var self = this
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this._ending = true
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if (!this._connected) {
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this.once('connect', this.end.bind(this, cb))
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}
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var result
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if (!cb) {
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result = new this._Promise(function (resolve, reject) {
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cb = (err) => err ? reject(err) : resolve()
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})
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}
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this.native.end(function () {
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self._errorAllQueries(new Error('Connection terminated'))
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process.nextTick(() => {
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self.emit('end')
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if (cb) cb()
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})
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})
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return result
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}
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Client.prototype._hasActiveQuery = function () {
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return this._activeQuery && this._activeQuery.state !== 'error' && this._activeQuery.state !== 'end'
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}
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Client.prototype._pulseQueryQueue = function (initialConnection) {
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if (!this._connected) {
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return
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}
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if (this._hasActiveQuery()) {
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return
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}
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var query = this._queryQueue.shift()
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if (!query) {
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if (!initialConnection) {
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this.emit('drain')
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}
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return
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}
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this._activeQuery = query
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query.submit(this)
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var self = this
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query.once('_done', function () {
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self._pulseQueryQueue()
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})
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}
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// attempt to cancel an in-progress query
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Client.prototype.cancel = function (query) {
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if (this._activeQuery === query) {
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this.native.cancel(function () {})
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} else if (this._queryQueue.indexOf(query) !== -1) {
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this._queryQueue.splice(this._queryQueue.indexOf(query), 1)
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}
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}
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Client.prototype.setTypeParser = function (oid, format, parseFn) {
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return this._types.setTypeParser(oid, format, parseFn)
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}
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Client.prototype.getTypeParser = function (oid, format) {
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return this._types.getTypeParser(oid, format)
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}
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