fix: tryDispatch

lib/core/symbols.js

@@ -2,6 +2,7 @@ module.exports = {
   kClose: Symbol('close'),
   kDestroy: Symbol('destroy'),
   kDispatch: Symbol('dispatch'),
+  kTryDispatch: Symbol('tryDispatch'),
   kUrl: Symbol('url'),
   kWriting: Symbol('writing'),
   kResuming: Symbol('resuming'),

lib/dispatcher/agent.js

@@ -1,7 +1,7 @@
 'use strict'
 
 const { InvalidArgumentError } = require('../core/errors')
-const { kClients, kRunning, kClose, kDestroy, kDispatch, kInterceptors } = require('../core/symbols')
+const { kClients, kRunning, kClose, kDestroy, kDispatch, kTryDispatch, kInterceptors } = require('../core/symbols')
 const DispatcherBase = require('./dispatcher-base')
 const Pool = require('./pool')
 const Client = require('./client')
@@ -79,7 +79,7 @@ class Agent extends DispatcherBase {
     return ret
   }
 
-  [kDispatch] (opts, handler) {
+  #getDispatcher (opts) {
     let key
     if (opts.origin && (typeof opts.origin === 'string' || opts.origin instanceof URL)) {
       key = String(opts.origin)
@@ -102,7 +102,15 @@ class Agent extends DispatcherBase {
       this[kClients].set(key, dispatcher)
     }
 
-    return dispatcher.dispatch(opts, handler)
+    return dispatcher
+  }
+
+  [kDispatch] (opts, handler) {
+    return this.#getDispatcher(opts).dispatch(opts, handler)
+  }
+
+  [kTryDispatch] (opts, handler) {
+    return this.#getDispatcher(opts).tryDispatch?.(opts, handler) ?? false
   }
 
   async [kClose] () {

lib/dispatcher/client.js

@@ -49,6 +49,7 @@ const {
   kClose,
   kDestroy,
   kDispatch,
+  kTryDispatch,
   kInterceptors,
   kLocalAddress,
   kMaxResponseSize,
@@ -299,6 +300,16 @@ class Client extends DispatcherBase {
     this.once('connect', cb)
   }
 
+  [kTryDispatch] (opts, handler) {
+    if (this[kBusy]) {
+      return false
+    }
+
+    this[kDispatch](opts, handler)
+
+    return true
+  }
+
   [kDispatch] (opts, handler) {
     const origin = opts.origin || this[kUrl].origin
     const request = new Request(origin, opts, handler)

lib/dispatcher/dispatcher-base.js

@@ -6,7 +6,7 @@ const {
   ClientClosedError,
   InvalidArgumentError
 } = require('../core/errors')
-const { kDestroy, kClose, kClosed, kDestroyed, kDispatch, kInterceptors } = require('../core/symbols')
+const { kDestroy, kClose, kClosed, kDestroyed, kDispatch, kTryDispatch, kInterceptors } = require('../core/symbols')
 
 const kOnDestroyed = Symbol('onDestroyed')
 const kOnClosed = Symbol('onClosed')
@@ -185,6 +185,36 @@ class DispatcherBase extends Dispatcher {
       return false
     }
   }
+
+  tryDispatch (opts, handler) {
+    if (!handler || typeof handler !== 'object') {
+      throw new InvalidArgumentError('handler must be an object')
+    }
+
+    try {
+      if (!opts || typeof opts !== 'object') {
+        throw new InvalidArgumentError('opts must be an object.')
+      }
+
+      if (this[kDestroyed] || this[kOnDestroyed]) {
+        throw new ClientDestroyedError()
+      }
+
+      if (this[kClosed]) {
+        throw new ClientClosedError()
+      }
+
+      return this[kTryDispatch]?.(opts, handler) ?? false
+    } catch (err) {
+      if (typeof handler.onError !== 'function') {
+        throw new InvalidArgumentError('invalid onError method')
+      }
+
+      handler.onError(err)
+
+      return false
+    }
+  }
 }
 
 module.exports = DispatcherBase

lib/dispatcher/pool-base.js

@@ -2,7 +2,7 @@
 
 const DispatcherBase = require('./dispatcher-base')
 const FixedQueue = require('./fixed-queue')
-const { kConnected, kSize, kRunning, kPending, kQueued, kBusy, kFree, kUrl, kClose, kDestroy, kDispatch } = require('../core/symbols')
+const { kConnected, kSize, kRunning, kPending, kQueued, kBusy, kFree, kUrl, kClose, kDestroy, kDispatch, kTryDispatch } = require('../core/symbols')
 const PoolStats = require('./pool-stats')
 
 const kClients = Symbol('clients')
@@ -14,6 +14,7 @@ const kOnConnect = Symbol('onConnect')
 const kOnDisconnect = Symbol('onDisconnect')
 const kOnConnectionError = Symbol('onConnectionError')
 const kGetDispatcher = Symbol('get dispatcher')
+const kGetDispatchers = Symbol('get dispatchers')
 const kAddClient = Symbol('add client')
 const kRemoveClient = Symbol('remove client')
 const kStats = Symbol('stats')
@@ -134,6 +135,14 @@ class PoolBase extends DispatcherBase {
   }
 
   [kDispatch] (opts, handler) {
+    if (this[kGetDispatchers]) {
+      for (const dispatcher of this[kGetDispatchers]()) {
+        if (dispatcher.tryDispatch?.(opts, handler)) {
+          return true
+        }
+      }
+    }
+
     const dispatcher = this[kGetDispatcher]()
 
     if (!dispatcher) {
@@ -148,6 +157,17 @@ class PoolBase extends DispatcherBase {
     return !this[kNeedDrain]
   }
 
+  [kTryDispatch] (opts, handler) {
+    if (this[kGetDispatchers]) {
+      for (const dispatcher of this[kGetDispatchers]()) {
+        if (dispatcher[kTryDispatch]?.(opts, handler)) {
+          return true
+        }
+      }
+    }
+    return false
+  }
+
   [kAddClient] (client) {
     client
       .on('drain', this[kOnDrain])
@@ -190,5 +210,6 @@ module.exports = {
   kNeedDrain,
   kAddClient,
   kRemoveClient,
-  kGetDispatcher
+  kGetDispatcher,
+  kGetDispatchers
 }

lib/dispatcher/pool.js

@@ -5,7 +5,8 @@ const {
   kClients,
   kNeedDrain,
   kAddClient,
-  kGetDispatcher
+  kGetDispatcher,
+  kGetDispatchers
 } = require('./pool-base')
 const Client = require('./client')
 const {
@@ -88,6 +89,16 @@ class Pool extends PoolBase {
       return dispatcher
     }
   }
+
+  * [kGetDispatchers] () {
+    yield * this[kClients]
+
+    if (!this[kConnections] || this[kClients].length < this[kConnections]) {
+      const dispatcher = this[kFactory](this[kUrl], this[kOptions])
+      this[kAddClient](dispatcher)
+      yield dispatcher
+    }
+  }
 }
 
 module.exports = Pool