streams: optimize creation

Refs: nodejs/performance#79

PR-URL: #50337

Author: ronag

lib/internal/streams/duplex.js

@@ -35,9 +35,12 @@ const {
 
 module.exports = Duplex;
 
+const Stream = require('internal/streams/legacy').Stream;
 const Readable = require('internal/streams/readable');
 const Writable = require('internal/streams/writable');
 
+const { kOnConstructed } = require('internal/streams/utils');
+
 ObjectSetPrototypeOf(Duplex.prototype, Readable.prototype);
 ObjectSetPrototypeOf(Duplex, Readable);
 
@@ -55,8 +58,8 @@ function Duplex(options) {
   if (!(this instanceof Duplex))
     return new Duplex(options);
 
-  Readable.call(this, options);
-  Writable.call(this, options);
+  this._readableState = new Readable.ReadableState(options, this, true);
+  this._writableState = new Writable.WritableState(options, this, true);
 
   if (options) {
     this.allowHalfOpen = options.allowHalfOpen !== false;
@@ -73,9 +76,39 @@ function Duplex(options) {
       this._writableState.ended = true;
       this._writableState.finished = true;
     }
+
+    if (typeof options.read === 'function')
+      this._read = options.read;
+
+    if (typeof options.write === 'function')
+      this._write = options.write;
+
+    if (typeof options.writev === 'function')
+      this._writev = options.writev;
+
+    if (typeof options.destroy === 'function')
+      this._destroy = options.destroy;
+
+    if (typeof options.final === 'function')
+      this._final = options.final;
+
+    if (typeof options.construct === 'function')
+      this._construct = options.construct;
+
+    if (options.signal)
+      addAbortSignal(options.signal, this);
   } else {
     this.allowHalfOpen = true;
   }
+
+  Stream.call(this, options);
+
+  if (this._construct != null) {
+    destroyImpl.construct(this, () => {
+      this._readableState[kOnConstructed](this);
+      this._writableState[kOnConstructed](this);
+    });
+  }
 }
 
 ObjectDefineProperties(Duplex.prototype, {

lib/internal/streams/readable.js

@@ -71,6 +71,7 @@ const {
   AbortError,
 } = require('internal/errors');
 const { validateObject } = require('internal/validators');
+const { kOnConstructed } = require('internal/streams/utils');
 
 const kState = Symbol('kState');
 
@@ -251,14 +252,6 @@ ObjectDefineProperties(ReadableState.prototype, {
 
 
 function ReadableState(options, stream, isDuplex) {
-  // Duplex streams are both readable and writable, but share
-  // the same options object.
-  // However, some cases require setting options to different
-  // values for the readable and the writable sides of the duplex stream.
-  // These options can be provided separately as readableXXX and writableXXX.
-  if (typeof isDuplex !== 'boolean')
-    isDuplex = stream instanceof Stream.Duplex;
-
   // Bit map field to store ReadableState more effciently with 1 bit per field
   // instead of a V8 slot per field.
   this[kState] = kEmitClose | kAutoDestroy | kConstructed | kSync;
@@ -310,16 +303,17 @@ function ReadableState(options, stream, isDuplex) {
   }
 }
 
+ReadableState.prototype[kOnConstructed] = function onConstructed (stream) {
+  if ((this.state & kNeedReadable) !== 0) {
+    maybeReadMore(stream, this);
+  }
+}
 
 function Readable(options) {
   if (!(this instanceof Readable))
     return new Readable(options);
 
-  // Checking for a Stream.Duplex instance is faster here instead of inside
-  // the ReadableState constructor, at least with V8 6.5.
-  const isDuplex = this instanceof Stream.Duplex;
-
-  this._readableState = new ReadableState(options, this, isDuplex);
+  this._readableState = new ReadableState(options, this, false);
 
   if (options) {
     if (typeof options.read === 'function')
@@ -331,17 +325,17 @@ function Readable(options) {
     if (typeof options.construct === 'function')
       this._construct = options.construct;
 
-    if (options.signal && !isDuplex)
+    if (options.signal)
       addAbortSignal(options.signal, this);
   }
 
   Stream.call(this, options);
 
-  destroyImpl.construct(this, () => {
-    if (this._readableState.needReadable) {
-      maybeReadMore(this, this._readableState);
-    }
-  });
+  if (this._construct != null) {
+    destroyImpl.construct(this, () => {
+      this._readableState[kOnConstructed](this);
+    });
+  }
 }
 
 Readable.prototype.destroy = destroyImpl.destroy;

lib/internal/streams/utils.js

@@ -16,6 +16,8 @@ const kIsReadable = SymbolFor('nodejs.stream.readable');
 const kIsWritable = SymbolFor('nodejs.stream.writable');
 const kIsDisturbed = SymbolFor('nodejs.stream.disturbed');
 
+const kOnConstructed = Symbol('kOnConstructed')
+
 const kIsClosedPromise = SymbolFor('nodejs.webstream.isClosedPromise');
 const kControllerErrorFunction = SymbolFor('nodejs.webstream.controllerErrorFunction');
 
@@ -303,6 +305,7 @@ function isErrored(stream) {
 }
 
 module.exports = {
+  kOnConstructed,
   isDestroyed,
   kIsDestroyed,
   isDisturbed,

lib/internal/streams/writable.js

@@ -44,6 +44,7 @@ const EE = require('events');
 const Stream = require('internal/streams/legacy').Stream;
 const { Buffer } = require('buffer');
 const destroyImpl = require('internal/streams/destroy');
+const { kOnConstructed } = require('internal/streams/utils');
 
 const {
   addAbortSignal,
@@ -290,14 +291,6 @@ ObjectDefineProperties(WritableState.prototype, {
 });
 
 function WritableState(options, stream, isDuplex) {
-  // Duplex streams are both readable and writable, but share
-  // the same options object.
-  // However, some cases require setting options to different
-  // values for the readable and the writable sides of the duplex stream,
-  // e.g. options.readableObjectMode vs. options.writableObjectMode, etc.
-  if (typeof isDuplex !== 'boolean')
-    isDuplex = stream instanceof Stream.Duplex;
-
   // Bit map field to store WritableState more effciently with 1 bit per field
   // instead of a V8 slot per field.
   this[kState] = kSync | kConstructed | kEmitClose | kAutoDestroy;
@@ -372,23 +365,21 @@ ObjectDefineProperty(WritableState.prototype, 'bufferedRequestCount', {
   },
 });
 
-function Writable(options) {
-  // Writable ctor is applied to Duplexes, too.
-  // `realHasInstance` is necessary because using plain `instanceof`
-  // would return false, as no `_writableState` property is attached.
-
-  // Trying to use the custom `instanceof` for Writable here will also break the
-  // Node.js LazyTransform implementation, which has a non-trivial getter for
-  // `_writableState` that would lead to infinite recursion.
+WritableState.prototype[kOnConstructed] = function onConstructed(stream) {
+  if ((this[kState] & kWriting) === 0) {
+    clearBuffer(stream, this);
+  }
 
-  // Checking for a Stream.Duplex instance is faster here instead of inside
-  // the WritableState constructor, at least with V8 6.5.
-  const isDuplex = (this instanceof Stream.Duplex);
+  if ((this[kState] & kEnding) !== 0) {
+    finishMaybe(stream, this);
+  }
+}
 
-  if (!isDuplex && !FunctionPrototypeSymbolHasInstance(Writable, this))
+function Writable(options) {
+  if (!(this instanceof Writable))
     return new Writable(options);
 
-  this._writableState = new WritableState(options, this, isDuplex);
+  this._writableState = new WritableState(options, this, false);
 
   if (options) {
     if (typeof options.write === 'function')
@@ -412,17 +403,11 @@ function Writable(options) {
 
   Stream.call(this, options);
 
-  destroyImpl.construct(this, () => {
-    const state = this._writableState;
-
-    if ((state[kState] & kWriting) === 0) {
-      clearBuffer(this, state);
-    }
-
-    if ((state[kState] & kEnding) !== 0) {
-      finishMaybe(this, state);
-    }
-  });
+  if (this._construct != null) {
+    destroyImpl.construct(this, () => {
+      this._writableState[kOnConstructed](this);
+    });
+  }
 }
 
 ObjectDefineProperty(Writable, SymbolHasInstance, {