Files
elasticsearch-js/lib/Transport.js
2018-10-18 17:27:31 +02:00

127 lines
3.5 KiB
JavaScript

'use strict'
const debug = require('debug')('elasticsearch')
const once = require('once')
const {
ConnectionError,
TimeoutError,
NoLivingConnectionsError,
ResponseError
} = require('./errors')
const noop = () => {}
const kRemainingAttempts = Symbol('elasticsearch-remaining-attempts')
class Transport {
constructor (opts = {}) {
this.connectionPool = opts.connectionPool
this.serializer = opts.serializer
this.maxRetries = opts.maxRetries
this.requestTimeout = opts.requestTimeout
this.sniffInterval = opts.sniffInterval
this._sniffEnabled = typeof this.sniffInterval === 'number'
this._nextSniff = this._sniffEnabled ? (Date.now() + this.sniffInterval) : 0
this._isSniffing = false
if (opts.sniffOnStart === true) {
this.sniff()
}
}
request (params, callback) {
callback = once(callback)
const attempts = params[kRemainingAttempts] || params.maxRetries || this.maxRetries
const connection = this.getConnection()
if (connection === null) {
return callback(new NoLivingConnectionsError('There are not living connections'))
}
if (params.body !== null) {
try {
params.body = this.serializer.serialize(params.body)
} catch (err) {
return callback(err)
}
params.headers = params.headers || {}
params.headers['Content-Type'] = 'application/json'
params.headers['Content-Length'] = '' + Buffer.byteLength(params.body)
}
const request = connection.request(params, (err, response) => {
if (err != null) {
this.connectionPool.markDead(connection)
if (attempts > 0) {
debug(`Retrying request, there are still ${attempts} attempts`, params)
params[kRemainingAttempts] = attempts - 1
return this.request(params, callback)
}
if (err.message === 'Request timed out') {
return callback(new TimeoutError(err.message))
} else {
return callback(new ConnectionError(err.message))
}
}
var json = ''
response.setEncoding('utf8')
response.on('data', chunk => { json += chunk })
response.on('error', err => callback(err))
response.on('end', () => {
this.connectionPool.markAlive(connection)
try {
var payload = this.serializer.deserialize(json)
} catch (err) {
return callback(err)
}
const { statusCode } = response
if (statusCode >= 400) {
callback(new ResponseError(payload))
} else {
callback(null, payload)
}
})
})
return function requestAborter () {
request.abort()
debug('Request aborted', params)
}
}
getConnection () {
const now = Date.now()
if (this._sniffEnabled === true && now > this._nextSniff) {
this.sniff(now)
}
this.connectionPool.resurrect(now)
return this.connectionPool.getConnection()
}
sniff (now = Date.now(), callback = noop) {
if (this._isSniffing === true) return
debug('Started sniffing request')
this.request({
method: 'GET',
path: '_nodes/_all/http'
}, (err, body) => {
if (this._sniffEnabled === true) {
this._nextSniff = now + this.sniffInterval
}
if (err) {
debug('Siffing errored', err)
return callback(err)
}
debug('Siffing ended successfully', body)
const hosts = this.connectionPool.nodesToHost(body.nodes)
this.connectionPool
.empty()
.addConnection(hosts)
callback()
})
}
}
module.exports = Transport