refactor: Client.clients & Agent is a Client.

Refs: #616
nodejs · Mar 27, 2021 · ee1ccff · ee1ccff
1 parent 0c92094
commit ee1ccff
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Showing 13 changed files with 301 additions and 247 deletions.
diff --git a/index.js b/index.js
@@ -1,45 +1,63 @@
 'use strict'
 
-const Client = require('./lib/core/client')
+const Client = require('./lib/client')
 const errors = require('./lib/core/errors')
-const Pool = require('./lib/client-pool')
-const { Agent, getGlobalAgent, setGlobalAgent } = require('./lib/agent')
+const Pool = require('./lib/pool')
+const Agent = require('./lib/agent')
 const util = require('./lib/core/util')
 const { InvalidArgumentError } = require('./lib/core/errors')
 const api = require('./lib/api')
 
 Object.assign(Client.prototype, api)
 Object.assign(Pool.prototype, api)
+Object.assign(Agent.prototype, api)
 
 function undici (url, opts) {
   return new Pool(url, opts)
 }
-
 module.exports = undici
 
 module.exports.Pool = Pool
 module.exports.Client = Client
 module.exports.errors = errors
 
 module.exports.Agent = Agent
-module.exports.setGlobalAgent = setGlobalAgent
-module.exports.getGlobalAgent = getGlobalAgent
 
-function dispatchFromAgent (fn) {
-  return (url, { agent = getGlobalAgent(), method = 'GET', ...opts } = {}, ...additionalArgs) => {
+let globalClient = new Agent()
+
+function setGlobalClient (agent) {
+  if (!agent || typeof agent.dispatch !== 'function') {
+    throw new InvalidArgumentError('Argument agent must implement Agent')
+  }
+  globalClient = agent
+}
+
+function getGlobalClient () {
+  return globalClient
+}
+
+function makeDispatch (fn) {
+  return (url, { agent, client = getGlobalClient(), method = 'GET', ...opts } = {}, ...additionalArgs) => {
     if (opts.path != null) {
       throw new InvalidArgumentError('unsupported opts.path')
     }
 
+    if (agent) {
+      throw new InvalidArgumentError('unsupported opts.agent. Did you mean opts.client?')
+    }
+
     const { origin, pathname, search } = util.parseURL(url)
     const path = search ? `${pathname}${search}` : pathname
 
-    return fn.call(agent, { ...opts, origin, method, path }, ...additionalArgs)
+    return fn.call(client, { ...opts, origin, method, path }, ...additionalArgs)
   }
 }
 
-module.exports.request = dispatchFromAgent(api.request)
-module.exports.stream = dispatchFromAgent(api.stream)
-module.exports.pipeline = dispatchFromAgent(api.pipeline)
-module.exports.connect = dispatchFromAgent(api.connect)
-module.exports.upgrade = dispatchFromAgent(api.upgrade)
+module.exports.setGlobalClient = setGlobalClient
+module.exports.getGlobalClient = getGlobalClient
+
+module.exports.request = makeDispatch(api.request)
+module.exports.stream = makeDispatch(api.stream)
+module.exports.pipeline = makeDispatch(api.pipeline)
+module.exports.connect = makeDispatch(api.connect)
+module.exports.upgrade = makeDispatch(api.upgrade)
diff --git a/lib/agent/index.js → lib/agent.js b/lib/agent/index.js → lib/agent.js
@@ -1,17 +1,18 @@
 'use strict'
 
-const { InvalidArgumentError } = require('../core/errors')
-const Pool = require('../client-pool')
-const Client = require('../core/client')
+const { InvalidArgumentError } = require('./core/errors')
+const Pool = require('./pool')
+const Client = require('./client')
 const EventEmitter = require('events')
-const util = require('../core/util')
+const util = require('./core/util')
 const assert = require('assert')
-const RedirectHandler = require('./redirect')
+const RedirectHandler = require('./handler/redirect')
 
 const kOnConnect = Symbol('onConnect')
 const kOnDisconnect = Symbol('onDisconnect')
 const kClients = Symbol('clients')
 const kMaxRedirections = Symbol('maxRedirections')
+const kOnDrain = Symbol('onDrain')
 const kFactory = Symbol('factory')
 
 function defaultFactory (origin, opts) {
@@ -38,36 +39,54 @@ class Agent extends EventEmitter {
 
     const agent = this
 
-    this[kOnConnect] = function onConnect (client) {
-      agent.emit('connect', client)
+    this[kOnConnect] = function onConnect (origin, clients) {
+      agent.emit('connect', origin, [...clients, agent])
     }
 
-    this[kOnDisconnect] = function onDestroy (client, err) {
+    this[kOnDrain] = function onDrain (origin) {
+      agent.emit('drain', origin)
+    }
+
+    this[kOnDisconnect] = function onDestroy (origin, clients, err) {
       if (this.connected === 0 && this.size === 0) {
         this.off('disconnect', agent[kOnDisconnect])
         agent[kClients].delete(this.origin)
       }
 
-      agent.emit('disconnect', client, err)
+      agent.emit('disconnect', origin, [...clients, agent], err)
     }
   }
 
-  get (origin) {
-    if (typeof origin !== 'string' || origin === '') {
-      throw new InvalidArgumentError('Origin must be a non-empty string.')
+  get connected () {
+    let ret = 0
+    for (const { connected } of this[kClients].values()) {
+      ret += connected
     }
+    return ret
+  }
 
-    let pool = this[kClients].get(origin)
-
-    if (!pool) {
-      pool = this[kFactory](origin)
-        .on('connect', this[kOnConnect])
-        .on('disconnect', this[kOnDisconnect])
+  get size () {
+    let ret = 0
+    for (const { size } of this[kClients].values()) {
+      ret += size
+    }
+    return ret
+  }
 
-      this[kClients].set(origin, pool)
+  get pending () {
+    let ret = 0
+    for (const { pending } of this[kClients].values()) {
+      ret += pending
     }
+    return ret
+  }
 
-    return pool
+  get running () {
+    let ret = 0
+    for (const { running } of this[kClients].values()) {
+      ret += running
+    }
+    return ret
   }
 
   dispatch (opts, handler) {
@@ -80,14 +99,26 @@ class Agent extends EventEmitter {
         throw new InvalidArgumentError('opts must be a object.')
       }
 
+      if (typeof opts.origin !== 'string' || opts.origin === '') {
+        throw new InvalidArgumentError('Origin must be a non-empty string.')
+      }
+
+      let client = this[kClients].get(opts.origin)
+
+      if (!client) {
+        client = this[kFactory](opts.origin)
+          .on('connect', this[kOnConnect])
+          .on('disconnect', this[kOnDisconnect])
+          .on('drain', this[kOnDrain])
+
+        this[kClients].set(opts.origin, client)
+      }
+
       const { maxRedirections = this[kMaxRedirections] } = opts
 
       if (!Number.isInteger(maxRedirections) || maxRedirections < 0) {
         throw new InvalidArgumentError('maxRedirections must be a positive number')
       }
-
-      const client = this.get(opts.origin)
-
       if (!maxRedirections) {
         return client.dispatch(opts, handler)
       }
@@ -107,7 +138,7 @@ class Agent extends EventEmitter {
           })
       }
 
-      client.dispatch(opts, new RedirectHandler(this, opts, handler))
+      return client.dispatch(opts, new RedirectHandler(this, opts, handler))
     } catch (err) {
       if (typeof handler.onError !== 'function') {
         throw new InvalidArgumentError('invalid onError method')
@@ -134,21 +165,4 @@ class Agent extends EventEmitter {
   }
 }
 
-let globalAgent = new Agent({ connections: null })
-
-function setGlobalAgent (agent) {
-  if (!agent || typeof agent.get !== 'function') {
-    throw new InvalidArgumentError('Argument agent must implement Agent')
-  }
-  globalAgent = agent
-}
-
-function getGlobalAgent () {
-  return globalAgent
-}
-
-module.exports = {
-  setGlobalAgent,
-  getGlobalAgent,
-  Agent
-}
+module.exports = Agent
diff --git a/lib/client.js b/lib/client.js
@@ -0,0 +1 @@
+module.exports = require('./core/client')
diff --git a/lib/core/client.js b/lib/core/client.js
@@ -183,14 +183,17 @@ class Client extends EventEmitter {
     this[kPendingIdx] = 0
   }
 
+  // TODO: Make private?
   get url () {
     return this[kUrl]
   }
 
+  // TODO: Make private?
   get pipelining () {
     return this[kPipelining]
   }
 
+  // TODO: Make private?
   set pipelining (value) {
     this[kPipelining] = value
     resume(this, true)
@@ -220,13 +223,9 @@ class Client extends EventEmitter {
     return this[kQueue].length - this[kRunningIdx]
   }
 
+  // TODO: Make private?
   get busy () {
-    const socket = this[kSocket]
-    return (
-      (socket && (socket[kReset] || socket[kWriting])) ||
-      (this.size >= (this[kPipelining] || 1)) ||
-      this.pending > 0
-    )
+    return this[kNeedDrain] > 1
   }
 
   get destroyed () {
@@ -277,13 +276,19 @@ class Client extends EventEmitter {
       } else {
         resume(this, true)
       }
+
+      if (this[kResuming] && this[kNeedDrain] !== 2 && isBusy(this)) {
+        this[kNeedDrain] = 2
+      }
     } catch (err) {
       if (typeof handler.onError !== 'function') {
         throw new InvalidArgumentError('invalid onError method')
       }
 
       handler.onError(err)
     }
+
+    return this[kNeedDrain] < 2
   }
 
   close (callback) {
@@ -473,7 +478,7 @@ class Parser extends HTTPParser {
     detachSocket(socket)
     client[kSocket] = null
     client[kQueue][client[kRunningIdx]++] = null
-    client.emit('disconnect', client, new InformationalError('upgrade'))
+    client.emit('disconnect', client[kUrl], [client], new InformationalError('upgrade'))
 
     try {
       request.onUpgrade(statusCode, headers, socket)
@@ -756,7 +761,7 @@ function onSocketConnect () {
   clearTimeout(this[kConnectTimeout])
   this[kConnectTimeout] = null
 
-  client.emit('connect', client)
+  client.emit('connect', client[kUrl], [client])
   resume(client)
 }
 
@@ -844,7 +849,7 @@ function onSocketClose () {
     // Retry remaining requests.
     client[kPendingIdx] = client[kRunningIdx]
 
-    client.emit('disconnect', client, err)
+    client.emit('disconnect', client[kUrl], [client], err)
   }
 
   resume(client)
@@ -919,7 +924,16 @@ function connect (client) {
 
 function emitDrain (client) {
   client[kNeedDrain] = 0
-  client.emit('drain')
+  client.emit('drain', client[kUrl].origin)
+}
+
+function isBusy (client) {
+  const socket = client[kSocket]
+  return (
+    (socket && (socket[kReset] || socket[kWriting])) ||
+    (client.size >= (client[kPipelining] || 1)) ||
+    client.pending > 0
+  )
 }
 
 function resume (client, sync) {
@@ -974,7 +988,7 @@ function _resume (client, sync) {
       }
     }
 
-    if (client.busy) {
+    if (isBusy(client)) {
       client[kNeedDrain] = 2
     } else if (client[kNeedDrain] === 2) {
       if (sync) {

diff --git a/lib/agent/redirect.js → lib/handler/redirect.js b/lib/agent/redirect.js → lib/handler/redirect.js