初始化

node_modules/undici/lib/dispatcher/agent.js

@@ -0,0 +1,156 @@
+'use strict'
+
+const { InvalidArgumentError, MaxOriginsReachedError } = require('../core/errors')
+const { kClients, kRunning, kClose, kDestroy, kDispatch, kUrl } = require('../core/symbols')
+const DispatcherBase = require('./dispatcher-base')
+const Pool = require('./pool')
+const Client = require('./client')
+const util = require('../core/util')
+
+const kOnConnect = Symbol('onConnect')
+const kOnDisconnect = Symbol('onDisconnect')
+const kOnConnectionError = Symbol('onConnectionError')
+const kOnDrain = Symbol('onDrain')
+const kFactory = Symbol('factory')
+const kOptions = Symbol('options')
+const kOrigins = Symbol('origins')
+
+function defaultFactory (origin, opts) {
+  return opts && opts.connections === 1
+    ? new Client(origin, opts)
+    : new Pool(origin, opts)
+}
+
+class Agent extends DispatcherBase {
+  constructor ({ factory = defaultFactory, maxOrigins = Infinity, connect, ...options } = {}) {
+    if (typeof factory !== 'function') {
+      throw new InvalidArgumentError('factory must be a function.')
+    }
+
+    if (connect != null && typeof connect !== 'function' && typeof connect !== 'object') {
+      throw new InvalidArgumentError('connect must be a function or an object')
+    }
+
+    if (typeof maxOrigins !== 'number' || Number.isNaN(maxOrigins) || maxOrigins <= 0) {
+      throw new InvalidArgumentError('maxOrigins must be a number greater than 0')
+    }
+
+    super()
+
+    if (connect && typeof connect !== 'function') {
+      connect = { ...connect }
+    }
+
+    this[kOptions] = { ...util.deepClone(options), maxOrigins, connect }
+    this[kFactory] = factory
+    this[kClients] = new Map()
+    this[kOrigins] = new Set()
+
+    this[kOnDrain] = (origin, targets) => {
+      this.emit('drain', origin, [this, ...targets])
+    }
+
+    this[kOnConnect] = (origin, targets) => {
+      this.emit('connect', origin, [this, ...targets])
+    }
+
+    this[kOnDisconnect] = (origin, targets, err) => {
+      this.emit('disconnect', origin, [this, ...targets], err)
+    }
+
+    this[kOnConnectionError] = (origin, targets, err) => {
+      this.emit('connectionError', origin, [this, ...targets], err)
+    }
+  }
+
+  get [kRunning] () {
+    let ret = 0
+    for (const { dispatcher } of this[kClients].values()) {
+      ret += dispatcher[kRunning]
+    }
+    return ret
+  }
+
+  [kDispatch] (opts, handler) {
+    let key
+    if (opts.origin && (typeof opts.origin === 'string' || opts.origin instanceof URL)) {
+      key = String(opts.origin)
+    } else {
+      throw new InvalidArgumentError('opts.origin must be a non-empty string or URL.')
+    }
+
+    if (this[kOrigins].size >= this[kOptions].maxOrigins && !this[kOrigins].has(key)) {
+      throw new MaxOriginsReachedError()
+    }
+
+    const result = this[kClients].get(key)
+    let dispatcher = result && result.dispatcher
+    if (!dispatcher) {
+      const closeClientIfUnused = (connected) => {
+        const result = this[kClients].get(key)
+        if (result) {
+          if (connected) result.count -= 1
+          if (result.count <= 0) {
+            this[kClients].delete(key)
+            result.dispatcher.close()
+          }
+          this[kOrigins].delete(key)
+        }
+      }
+      dispatcher = this[kFactory](opts.origin, this[kOptions])
+        .on('drain', this[kOnDrain])
+        .on('connect', (origin, targets) => {
+          const result = this[kClients].get(key)
+          if (result) {
+            result.count += 1
+          }
+          this[kOnConnect](origin, targets)
+        })
+        .on('disconnect', (origin, targets, err) => {
+          closeClientIfUnused(true)
+          this[kOnDisconnect](origin, targets, err)
+        })
+        .on('connectionError', (origin, targets, err) => {
+          closeClientIfUnused(false)
+          this[kOnConnectionError](origin, targets, err)
+        })
+
+      this[kClients].set(key, { count: 0, dispatcher })
+      this[kOrigins].add(key)
+    }
+
+    return dispatcher.dispatch(opts, handler)
+  }
+
+  [kClose] () {
+    const closePromises = []
+    for (const { dispatcher } of this[kClients].values()) {
+      closePromises.push(dispatcher.close())
+    }
+    this[kClients].clear()
+
+    return Promise.all(closePromises)
+  }
+
+  [kDestroy] (err) {
+    const destroyPromises = []
+    for (const { dispatcher } of this[kClients].values()) {
+      destroyPromises.push(dispatcher.destroy(err))
+    }
+    this[kClients].clear()
+
+    return Promise.all(destroyPromises)
+  }
+
+  get stats () {
+    const allClientStats = {}
+    for (const { dispatcher } of this[kClients].values()) {
+      if (dispatcher.stats) {
+        allClientStats[dispatcher[kUrl].origin] = dispatcher.stats
+      }
+    }
+    return allClientStats
+  }
+}
+
+module.exports = Agent