lib: faster type checks for some types

TimothyGu · evanlucas · commit 67aed7972de5 · 2017-10-23T09:10:04.000-05:00
Backport-PR-URL: #16073 PR-URL: #15663 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de> Reviewed-By: Luigi Pinca <luigipinca@gmail.com> Reviewed-By: Benedikt Meurer <benedikt.meurer@gmail.com> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>
diff --git a/lib/assert.js b/lib/assert.js
@@ -23,6 +23,7 @@
 const { compare } = process.binding('buffer');
 const { isSet, isMap, isDate, isRegExp } = process.binding('util');
 const { objectToString } = require('internal/util');
+const { isArrayBufferView } = require('internal/util/types');
 const errors = require('internal/errors');
 
 // The assert module provides functions that throw
@@ -198,7 +199,7 @@ function strictDeepEqual(actual, expected) {
     if (actual.message !== expected.message) {
       return false;
     }
-  } else if (!isFloatTypedArrayTag(actualTag) && ArrayBuffer.isView(actual)) {
+  } else if (!isFloatTypedArrayTag(actualTag) && isArrayBufferView(actual)) {
     if (!areSimilarTypedArrays(actual, expected)) {
       return false;
     }
@@ -254,7 +255,7 @@ function looseDeepEqual(actual, expected) {
   const expectedTag = objectToString(expected);
   if (actualTag === expectedTag) {
     if (!isObjectOrArrayTag(actualTag) && !isFloatTypedArrayTag(actualTag) &&
-      ArrayBuffer.isView(actual)) {
+        isArrayBufferView(actual)) {
       return areSimilarTypedArrays(actual, expected);
     }
   // Ensure reflexivity of deepEqual with `arguments` objects.
diff --git a/lib/buffer.js b/lib/buffer.js
@@ -24,7 +24,11 @@
 const binding = process.binding('buffer');
 const config = process.binding('config');
 const { compare: compare_, compareOffset } = binding;
-const { isAnyArrayBuffer, isUint8Array } = process.binding('util');
+const { isAnyArrayBuffer } = process.binding('util');
+const {
+  isArrayBufferView,
+  isUint8Array
+} = require('internal/util/types');
 const bindingObj = {};
 const internalUtil = require('internal/util');
 const pendingDeprecation = !!config.pendingDeprecation;
@@ -468,7 +472,7 @@ function base64ByteLength(str, bytes) {
 
 function byteLength(string, encoding) {
   if (typeof string !== 'string') {
-    if (ArrayBuffer.isView(string) || isAnyArrayBuffer(string)) {
+    if (isArrayBufferView(string) || isAnyArrayBuffer(string)) {
       return string.byteLength;
     }
 
diff --git a/lib/child_process.js b/lib/child_process.js
@@ -23,6 +23,7 @@
 
 const util = require('util');
 const { deprecate, convertToValidSignal } = require('internal/util');
+const { isUint8Array } = require('internal/util/types');
 const { createPromise,
         promiseResolve, promiseReject } = process.binding('util');
 const debug = util.debuglog('child_process');
@@ -31,7 +32,6 @@ const uv = process.binding('uv');
 const spawn_sync = process.binding('spawn_sync');
 const Buffer = require('buffer').Buffer;
 const Pipe = process.binding('pipe_wrap').Pipe;
-const { isUint8Array } = process.binding('util');
 const child_process = require('internal/child_process');
 
 const errnoException = util._errnoException;
diff --git a/lib/crypto.js b/lib/crypto.js
@@ -43,7 +43,10 @@ const Buffer = require('buffer').Buffer;
 const kBufferMaxLength = require('buffer').kMaxLength;
 const stream = require('stream');
 const util = require('util');
-const { isUint8Array } = process.binding('util');
+const {
+  isArrayBufferView,
+  isUint8Array
+} = require('internal/util/types');
 const LazyTransform = require('internal/streams/lazy_transform');
 
 const DH_GENERATOR = 2;
@@ -416,7 +419,7 @@ function DiffieHellman(sizeOrKey, keyEncoding, generator, genEncoding) {
 
   if (typeof sizeOrKey !== 'number' &&
       typeof sizeOrKey !== 'string' &&
-      !ArrayBuffer.isView(sizeOrKey)) {
+      !isArrayBufferView(sizeOrKey)) {
     throw new TypeError('First argument should be number, string, ' +
                         'Buffer, TypedArray, or DataView');
   }
diff --git a/lib/dgram.js b/lib/dgram.js
@@ -26,6 +26,7 @@ const errors = require('internal/errors');
 const Buffer = require('buffer').Buffer;
 const dns = require('dns');
 const util = require('util');
+const { isUint8Array } = require('internal/util/types');
 const EventEmitter = require('events');
 const setInitTriggerId = require('async_hooks').setInitTriggerId;
 const UV_UDP_REUSEADDR = process.binding('constants').os.UV_UDP_REUSEADDR;
@@ -34,7 +35,6 @@ const nextTick = require('internal/process/next_tick').nextTick;
 
 const UDP = process.binding('udp_wrap').UDP;
 const SendWrap = process.binding('udp_wrap').SendWrap;
-const { isUint8Array } = process.binding('util');
 
 const BIND_STATE_UNBOUND = 0;
 const BIND_STATE_BINDING = 1;
diff --git a/lib/fs.js b/lib/fs.js
@@ -28,7 +28,8 @@ const constants = process.binding('constants').fs;
 const { S_IFIFO, S_IFLNK, S_IFMT, S_IFREG, S_IFSOCK } = constants;
 const util = require('util');
 const pathModule = require('path');
-const { isUint8Array, createPromise, promiseResolve } = process.binding('util');
+const { isUint8Array } = require('internal/util/types');
+const { createPromise, promiseResolve } = process.binding('util');
 
 const binding = process.binding('fs');
 const fs = exports;
diff --git a/lib/internal/buffer.js b/lib/internal/buffer.js
@@ -8,7 +8,7 @@ const normalizeEncoding = require('internal/util').normalizeEncoding;
 const Buffer = require('buffer').Buffer;
 
 const icu = process.binding('icu');
-const { isUint8Array } = process.binding('util');
+const { isUint8Array } = require('internal/util/types');
 
 // Transcodes the Buffer from one encoding to another, returning a new
 // Buffer instance.
diff --git a/lib/internal/child_process.js b/lib/internal/child_process.js
@@ -16,8 +16,8 @@ const TTY = process.binding('tty_wrap').TTY;
 const TCP = process.binding('tcp_wrap').TCP;
 const UDP = process.binding('udp_wrap').UDP;
 const SocketList = require('internal/socket_list');
-const { isUint8Array } = process.binding('util');
 const { convertToValidSignal } = require('internal/util');
+const { isUint8Array } = require('internal/util/types');
 
 const errnoException = util._errnoException;
 const SocketListSend = SocketList.SocketListSend;
diff --git a/lib/internal/encoding.js b/lib/internal/encoding.js
@@ -20,6 +20,8 @@ const {
   customInspectSymbol: inspect
 } = require('internal/util');
 
+const { isArrayBufferView } = require('internal/util/types');
+
 const {
   isArrayBuffer
 } = process.binding('util');
@@ -386,7 +388,7 @@ function makeTextDecoderICU() {
         throw new errors.TypeError('ERR_INVALID_THIS', 'TextDecoder');
       if (isArrayBuffer(input)) {
         input = lazyBuffer().from(input);
-      } else if (!ArrayBuffer.isView(input)) {
+      } else if (!isArrayBufferView(input)) {
         throw new errors.TypeError('ERR_INVALID_ARG_TYPE', 'input',
                                    ['ArrayBuffer', 'ArrayBufferView']);
       }
@@ -462,7 +464,7 @@ function makeTextDecoderJS() {
         throw new errors.TypeError('ERR_INVALID_THIS', 'TextDecoder');
       if (isArrayBuffer(input)) {
         input = lazyBuffer().from(input);
-      } else if (ArrayBuffer.isView(input)) {
+      } else if (isArrayBufferView(input)) {
         input = lazyBuffer().from(input.buffer, input.byteOffset,
                                   input.byteLength);
       } else {
diff --git a/lib/internal/http2/core.js b/lib/internal/http2/core.js
@@ -21,8 +21,9 @@ const { onServerStream,
 } = require('internal/http2/compat');
 const { utcDate } = require('internal/http');
 const { promisify } = require('internal/util');
+const { isUint8Array } = require('internal/util/types');
 const { _connectionListener: httpConnectionListener } = require('http');
-const { isUint8Array, createPromise, promiseResolve } = process.binding('util');
+const { createPromise, promiseResolve } = process.binding('util');
 const debug = util.debuglog('http2');
 
 
diff --git a/lib/internal/util/types.js b/lib/internal/util/types.js
@@ -0,0 +1,36 @@
+'use strict';
+
+const ReflectApply = Reflect.apply;
+
+// This function is borrowed from the function with the same name on V8 Extras'
+// `utils` object. V8 implements Reflect.apply very efficiently in conjunction
+// with the spread syntax, such that no additional special case is needed for
+// function calls w/o arguments.
+// Refs: https://github.com/v8/v8/blob/d6ead37d265d7215cf9c5f768f279e21bd170212/src/js/prologue.js#L152-L156
+function uncurryThis(func) {
+  return (thisArg, ...args) => ReflectApply(func, thisArg, args);
+}
+
+const TypedArrayPrototype = Object.getPrototypeOf(Uint8Array.prototype);
+
+const TypedArrayProto_toStringTag =
+    uncurryThis(
+      Object.getOwnPropertyDescriptor(TypedArrayPrototype,
+                                      Symbol.toStringTag).get);
+
+// Cached to make sure no userland code can tamper with it.
+const isArrayBufferView = ArrayBuffer.isView;
+
+function isTypedArray(value) {
+  return TypedArrayProto_toStringTag(value) !== undefined;
+}
+
+function isUint8Array(value) {
+  return TypedArrayProto_toStringTag(value) === 'Uint8Array';
+}
+
+module.exports = {
+  isArrayBufferView,
+  isTypedArray,
+  isUint8Array
+};
diff --git a/lib/repl.js b/lib/repl.js
@@ -44,6 +44,7 @@
 
 const internalModule = require('internal/module');
 const internalUtil = require('internal/util');
+const { isTypedArray } = require('internal/util/types');
 const util = require('util');
 const utilBinding = process.binding('util');
 const inherits = util.inherits;
@@ -700,7 +701,7 @@ const ARRAY_LENGTH_THRESHOLD = 1e6;
 function mayBeLargeObject(obj) {
   if (Array.isArray(obj)) {
     return obj.length > ARRAY_LENGTH_THRESHOLD ? ['length'] : null;
-  } else if (utilBinding.isTypedArray(obj)) {
+  } else if (isTypedArray(obj)) {
     return obj.length > ARRAY_LENGTH_THRESHOLD ? [] : null;
   }
 
diff --git a/lib/stream.js b/lib/stream.js
@@ -38,10 +38,16 @@ Stream.Stream = Stream;
 
 // Internal utilities
 try {
-  Stream._isUint8Array = process.binding('util').isUint8Array;
+  Stream._isUint8Array = require('internal/util/types').isUint8Array;
 } catch (e) {
-  // This throws for Node < 4.2.0 because there’s no util binding and
-  // returns undefined for Node < 7.4.0.
+  // Throws for code outside of Node.js core.
+
+  try {
+    Stream._isUint8Array = process.binding('util').isUint8Array;
+  } catch (e) {
+    // This throws for Node < 4.2.0 because there’s no util binding and
+    // returns undefined for Node < 7.4.0.
+  }
 }
 
 if (!Stream._isUint8Array) {
diff --git a/lib/tls.js b/lib/tls.js
@@ -23,12 +23,12 @@
 
 const internalUtil = require('internal/util');
 internalUtil.assertCrypto();
+const { isUint8Array } = require('internal/util/types');
 
 const net = require('net');
 const url = require('url');
 const binding = process.binding('crypto');
 const Buffer = require('buffer').Buffer;
-const { isUint8Array } = process.binding('util');
 
 // Allow {CLIENT_RENEG_LIMIT} client-initiated session renegotiations
 // every {CLIENT_RENEG_WINDOW} seconds. An error event is emitted if more
diff --git a/lib/util.js b/lib/util.js
@@ -38,13 +38,16 @@ const {
   isPromise,
   isSet,
   isSetIterator,
-  isTypedArray,
   isRegExp,
   isDate,
   kPending,
   kRejected,
 } = process.binding('util');
 
+const {
+  isTypedArray
+} = require('internal/util/types');
+
 const {
   customInspectSymbol,
   deprecate,
diff --git a/lib/zlib.js b/lib/zlib.js
@@ -31,6 +31,7 @@ const kRangeErrorMessage = 'Cannot create final Buffer. It would be larger ' +
 
 const constants = process.binding('constants').zlib;
 const { inherits } = require('util');
+const { isArrayBufferView } = require('internal/util/types');
 
 // translation table for return codes.
 const codes = {
@@ -86,7 +87,7 @@ function responseData(engine, buffer) {
 function zlibBuffer(engine, buffer, callback) {
   // Streams do not support non-Buffer ArrayBufferViews yet. Convert it to a
   // Buffer without copying.
-  if (ArrayBuffer.isView(buffer) &&
+  if (isArrayBufferView(buffer) &&
       Object.getPrototypeOf(buffer) !== Buffer.prototype) {
     buffer = Buffer.from(buffer.buffer, buffer.byteOffset, buffer.byteLength);
   }
@@ -134,7 +135,7 @@ function zlibBuffer(engine, buffer, callback) {
 function zlibBufferSync(engine, buffer) {
   if (typeof buffer === 'string')
     buffer = Buffer.from(buffer);
-  else if (!ArrayBuffer.isView(buffer))
+  else if (!isArrayBufferView(buffer))
     throw new TypeError('"buffer" argument must be a string, Buffer, ' +
                         'TypedArray, or DataView');
 
@@ -221,7 +222,7 @@ function Zlib(opts, mode) {
     throw new TypeError('Invalid strategy: ' + opts.strategy);
 
   if (opts.dictionary !== undefined) {
-    if (!ArrayBuffer.isView(opts.dictionary)) {
+    if (!isArrayBufferView(opts.dictionary)) {
       throw new TypeError(
         'Invalid dictionary: it should be a Buffer, TypedArray, or DataView');
     }
@@ -362,7 +363,7 @@ Zlib.prototype._transform = function _transform(chunk, encoding, cb) {
   var ending = ws.ending || ws.ended;
   var last = ending && (!chunk || ws.length === chunk.byteLength);
 
-  if (chunk !== null && !ArrayBuffer.isView(chunk))
+  if (chunk !== null && !isArrayBufferView(chunk))
     return cb(new TypeError('invalid input'));
 
   if (!this._handle)
diff --git a/node.gyp b/node.gyp
@@ -114,6 +114,7 @@
       'lib/internal/test/unicode.js',
       'lib/internal/url.js',
       'lib/internal/util.js',
+      'lib/internal/util/types.js',
       'lib/internal/http2/core.js',
       'lib/internal/http2/compat.js',
       'lib/internal/http2/util.js',
diff --git a/test/parallel/test-types.js b/test/parallel/test-types.js
@@ -0,0 +1,57 @@
+'use strict';
+
+// Flags: --expose-internals
+
+require('../common');
+const assert = require('assert');
+const types = require('internal/util/types');
+
+const primitive = true;
+const arrayBuffer = new ArrayBuffer();
+const dataView = new DataView(arrayBuffer);
+const int32Array = new Int32Array(arrayBuffer);
+const uint8Array = new Uint8Array(arrayBuffer);
+const buffer = Buffer.from(arrayBuffer);
+
+const fakeDataView = Object.create(DataView.prototype);
+const fakeInt32Array = Object.create(Int32Array.prototype);
+const fakeUint8Array = Object.create(Uint8Array.prototype);
+const fakeBuffer = Object.create(Buffer.prototype);
+
+const stealthyDataView =
+    Object.setPrototypeOf(new DataView(arrayBuffer), Uint8Array.prototype);
+const stealthyInt32Array =
+    Object.setPrototypeOf(new Int32Array(arrayBuffer), uint8Array);
+const stealthyUint8Array =
+    Object.setPrototypeOf(new Uint8Array(arrayBuffer), ArrayBuffer.prototype);
+
+const all = [
+  primitive, arrayBuffer, dataView, int32Array, uint8Array, buffer,
+  fakeDataView, fakeInt32Array, fakeUint8Array, fakeBuffer,
+  stealthyDataView, stealthyInt32Array, stealthyUint8Array
+];
+
+const expected = {
+  isArrayBufferView: [
+    dataView, int32Array, uint8Array, buffer,
+    stealthyDataView, stealthyInt32Array, stealthyUint8Array
+  ],
+  isTypedArray: [
+    int32Array, uint8Array, buffer, stealthyInt32Array, stealthyUint8Array
+  ],
+  isUint8Array: [
+    uint8Array, buffer, stealthyUint8Array
+  ]
+};
+
+for (const testedFunc of Object.keys(expected)) {
+  const func = types[testedFunc];
+  const yup = [];
+  for (const value of all) {
+    if (func(value)) {
+      yup.push(value);
+    }
+  }
+  console.log('Testing', testedFunc);
+  assert.deepStrictEqual(yup, expected[testedFunc]);
+}
