TypedArray(length) constructor

src/typedarray.js

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 67 matching lines @@
   // TODO(dslomov): implement inheritance
   var result = new $ArrayBuffer(newLen);
 
   %ArrayBufferSliceImpl(this, result, first);
   return result;
 }
 
 // --------------- Typed Arrays ---------------------
 
 function CreateTypedArrayConstructor(name, elementSize, arrayId, constructor) {
-  return function (buffer, byteOffset, length) {
+  function ConstructByArrayBuffer(obj, buffer, byteOffset, length) {
+    var offset = IS_UNDEFINED(byteOffset)
+      ? 0 : offset = TO_POSITIVE_INTEGER(byteOffset);
+
+    if (offset % elementSize !== 0) {
+      throw MakeRangeError("invalid_typed_array_alignment",
+          "start offset", name, elementSize);
+    }
+    var bufferByteLength = %ArrayBufferGetByteLength(buffer);
+    if (offset >= bufferByteLength) {
+      throw MakeRangeError("invalid_typed_array_offset");
+    }
+
+    var newByteLength;
+    var newLength;
+    if (IS_UNDEFINED(length)) {
+      if (bufferByteLength % elementSize !== 0) {
+        throw MakeRangeError("invalid_typed_array_alignment",
+          "byte length", name, elementSize);
+      }
+      newByteLength = bufferByteLength - offset;
+      newLength = newByteLength / elementSize;
+    } else {
+      var newLength = TO_POSITIVE_INTEGER(length);
+      newByteLength = newLength * elementSize;
+    }
+    if (newByteLength > bufferByteLength) {
+      throw MakeRangeError("invalid_typed_array_length");
+    }
+    %TypedArrayInitialize(obj, arrayId, buffer, offset, newByteLength);
+  }
+
+  function ConstructByLength(obj, length) {
+    var l = IS_UNDEFINED(length) ? 0 : TO_POSITIVE_INTEGER(length);
+    var byteLength = l * elementSize;
+    var buffer = new $ArrayBuffer(byteLength);
+    %TypedArrayInitialize(obj, arrayId, buffer, 0, byteLength);
+  }
+
+  return function (arg1, arg2, arg3) {
     if (%_IsConstructCall()) {
-      if (!IS_ARRAYBUFFER(buffer)) {
-        throw MakeTypeError("Type error!");
+      if (IS_ARRAYBUFFER(arg1)) {
+        ConstructByArrayBuffer(this, arg1, arg2, arg3);
+      } else {
+        ConstructByLength(this, arg1);
       }
-      var offset = IS_UNDEFINED(byteOffset)
-        ? 0 : offset = TO_POSITIVE_INTEGER(byteOffset);
-
-      if (offset % elementSize !== 0) {
-        throw MakeRangeError("invalid_typed_array_alignment",
-            "start offset", name, elementSize);
-      }
-      var bufferByteLength = %ArrayBufferGetByteLength(buffer);
-      if (offset >= bufferByteLength) {
-        throw MakeRangeError("invalid_typed_array_offset");
-      }
-
-      var newByteLength;
-      var newLength;
-      if (IS_UNDEFINED(length)) {
-        if (bufferByteLength % elementSize !== 0) {
-          throw MakeRangeError("invalid_typed_array_alignment",
-            "byte length", name, elementSize);
-        }
-        newByteLength = bufferByteLength - offset;
-        newLength = newByteLength / elementSize;
-      } else {
-        var newLength = TO_POSITIVE_INTEGER(length);
-        newByteLength = newLength * elementSize;
-      }
-      if (newByteLength > bufferByteLength) {
-        throw MakeRangeError("invalid_typed_array_length");
-      }
-      %TypedArrayInitialize(this, arrayId, buffer, offset, newByteLength);
     } else {
-      return new constructor(buffer, byteOffset, length);
+      return new constructor(arg1, arg2, arg3);
     }
   }
 }
 
 function TypedArrayGetBuffer() {
   return %TypedArrayGetBuffer(this);
 }
 
 function TypedArrayGetByteLength() {
   return %TypedArrayGetByteLength(this);
@@ skipping 23 matching lines @@
   InstallGetter($ArrayBuffer.prototype, "byteLength", ArrayBufferGetByteLength);
 
   InstallFunctions($ArrayBuffer.prototype, DONT_ENUM, $Array(
       "slice", ArrayBufferSlice
   ));
 }
 
 SetUpArrayBuffer();
 
 function SetupTypedArray(arrayId, name, constructor, elementSize) {
-  var f = CreateTypedArrayConstructor(name, elementSize,
-                                      arrayId, constructor);
-  %SetCode(constructor, f);
+  %CheckIsBootstrapping();
+  var fun = CreateTypedArrayConstructor(name, elementSize,
+                                        arrayId, constructor);
+  %SetCode(constructor, fun);
   %FunctionSetPrototype(constructor, new $Object());
 
   %SetProperty(constructor.prototype,
                "constructor", constructor, DONT_ENUM);
   %SetProperty(constructor.prototype,
                "BYTES_PER_ELEMENT", elementSize,
                READ_ONLY | DONT_ENUM | DONT_DELETE);
   InstallGetter(constructor.prototype, "buffer", TypedArrayGetBuffer);
   InstallGetter(constructor.prototype, "byteOffset", TypedArrayGetByteOffset);
   InstallGetter(constructor.prototype, "byteLength", TypedArrayGetByteLength);
   InstallGetter(constructor.prototype, "length", TypedArrayGetLength);
 }
 
 // arrayIds below should be synchronized with Runtime_TypedArrayInitialize.
 SetupTypedArray(1, "Uint8Array", global.Uint8Array, 1);
 SetupTypedArray(2, "Int8Array", global.Int8Array, 1);
 SetupTypedArray(3, "Uint16Array", global.Uint16Array, 2);
 SetupTypedArray(4, "Int16Array", global.Int16Array, 2);
 SetupTypedArray(5, "Uint32Array", global.Uint32Array, 4);
 SetupTypedArray(6, "Int32Array", global.Int32Array, 4);
 SetupTypedArray(7, "Float32Array", global.Float32Array, 4);
 SetupTypedArray(8, "Float64Array", global.Float64Array, 8);