Revision: 3859
Author: [email protected]
Date: Mon Feb 15 05:25:06 2010
Log: Introduce builtin for Array.unshift function.
Review URL: http://codereview.chromium.org/600124
http://code.google.com/p/v8/source/detail?r=3859
Added:
/branches/bleeding_edge/test/mjsunit/array-unshift.js
Modified:
/branches/bleeding_edge/src/bootstrapper.cc
/branches/bleeding_edge/src/builtins.cc
/branches/bleeding_edge/src/builtins.h
=======================================
--- /dev/null
+++ /branches/bleeding_edge/test/mjsunit/array-unshift.js Mon Feb 15
05:25:06 2010
@@ -0,0 +1,116 @@
+// Copyright 2010 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
+// with the distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived
+// from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Check that unshifting array of holes keeps the original array
+// as array of holes
+(function() {
+ var array = new Array(10);
+ assertEquals(13, array.unshift('1st', '2ns', '3rd'));
+ assertTrue(0 in array);
+ assertTrue(1 in array);
+ assertTrue(2 in array);
+ assertFalse(3 in array);
+})();
+
+
+// Check that unshif with no args has a side-effect of
+// feeling the holes with elements from the prototype
+// (if present, of course)
+(function() {
+ var len = 3;
+ var array = new Array(len);
+
+ var at0 = '@0';
+ var at2 = '@2';
+
+ Array.prototype[0] = at0;
+ Array.prototype[2] = at2;
+
+ // array owns nothing...
+ assertFalse(array.hasOwnProperty(0));
+ assertFalse(array.hasOwnProperty(1));
+ assertFalse(array.hasOwnProperty(2));
+
+ // ... but sees values from Array.prototype
+ assertEquals(array[0], at0);
+ assertEquals(array[1], undefined);
+ assertEquals(array[2], at2);
+
+ assertEquals(len, array.unshift());
+
+ assertTrue(delete Array.prototype[0]);
+ assertTrue(delete Array.prototype[2]);
+
+ // unshift makes array own 0 and 2...
+ assertTrue(array.hasOwnProperty(0));
+ assertFalse(array.hasOwnProperty(1));
+ assertTrue(array.hasOwnProperty(2));
+
+ // ... so they are not affected be delete.
+ assertEquals(array[0], at0);
+ assertEquals(array[1], undefined);
+ assertEquals(array[2], at2);
+})();
+
+
+// Now check the case with array of holes and some elements on prototype.
+(function() {
+ var len = 9;
+ var array = new Array(len);
+ Array.prototype[3] = "@3";
+ Array.prototype[7] = "@7";
+
+ assertEquals(len, array.length);
+ for (var i = 0; i < array.length; i++) {
+ assertEquals(array[i], Array.prototype[i]);
+ }
+
+ assertEquals(len + 1, array.unshift('head'));
+
+ assertEquals(len + 1, array.length);
+ // Note that unshift copies values from prototype into the array.
+ assertEquals(array[4], Array.prototype[3]);
+ assertTrue(array.hasOwnProperty(4));
+
+ assertEquals(array[8], Array.prototype[7]);
+ assertTrue(array.hasOwnProperty(8));
+
+ // ... but keeps the rest as holes:
+ Array.prototype[5] = "@5";
+ assertEquals(array[5], Array.prototype[5]);
+ assertFalse(array.hasOwnProperty(5));
+
+ assertEquals(array[3], Array.prototype[3]);
+ assertFalse(array.hasOwnProperty(3));
+
+ assertEquals(array[7], Array.prototype[7]);
+ assertFalse(array.hasOwnProperty(7));
+
+ assertTrue(delete Array.prototype[3]);
+ assertTrue(delete Array.prototype[5]);
+ assertTrue(delete Array.prototype[7]);
+})();
=======================================
--- /branches/bleeding_edge/src/bootstrapper.cc Mon Feb 15 01:17:38 2010
+++ /branches/bleeding_edge/src/bootstrapper.cc Mon Feb 15 05:25:06 2010
@@ -1494,6 +1494,8 @@
Handle<Code>(Builtins::builtin(Builtins::ArrayPush)));
AddSpecialFunction(special_prototype, "shift",
Handle<Code>(Builtins::builtin(Builtins::ArrayShift)));
+ AddSpecialFunction(special_prototype, "unshift",
+
Handle<Code>(Builtins::builtin(Builtins::ArrayUnshift)));
}
=======================================
--- /branches/bleeding_edge/src/builtins.cc Mon Feb 15 01:17:38 2010
+++ /branches/bleeding_edge/src/builtins.cc Mon Feb 15 05:25:06 2010
@@ -246,19 +246,16 @@
JSArray* array = JSArray::cast(*args.receiver());
ASSERT(array->HasFastElements());
- // Make sure we have space for the elements.
int len = Smi::cast(array->length())->value();
-
- // Set new length.
- int new_length = len + args.length() - 1;
+ int to_add = args.length() - 1;
+ if (to_add == 0) {
+ return Smi::FromInt(len);
+ }
+
+ int new_length = len + to_add;
FixedArray* elms = FixedArray::cast(array->elements());
- if (new_length <= elms->length()) {
- // Backing storage has extra space for the provided values.
- for (int index = 0; index < args.length() - 1; index++) {
- elms->set(index + len, args[index+1]);
- }
- } else {
+ if (new_length > elms->length()) {
// New backing storage is needed.
int capacity = new_length + (new_length >> 1) + 16;
Object* obj = Heap::AllocateFixedArrayWithHoles(capacity);
@@ -269,16 +266,21 @@
WriteBarrierMode mode = new_elms->GetWriteBarrierMode(no_gc);
// Fill out the new array with old elements.
for (int i = 0; i < len; i++) new_elms->set(i, elms->get(i), mode);
- // Add the provided values.
- for (int index = 0; index < args.length() - 1; index++) {
- new_elms->set(index + len, args[index+1], mode);
- }
- // Set the new backing storage.
- array->set_elements(new_elms);
- }
+ elms = new_elms;
+ array->set_elements(elms);
+ }
+
+ AssertNoAllocation no_gc;
+ WriteBarrierMode mode = elms->GetWriteBarrierMode(no_gc);
+
+ // Add the provided values.
+ for (int index = 0; index < to_add; index++) {
+ elms->set(index + len, args[index + 1], mode);
+ }
+
// Set the length.
array->set_length(Smi::FromInt(new_length));
- return array->length();
+ return Smi::FromInt(new_length);
}
@@ -311,6 +313,17 @@
return top;
}
+
+
+static Object* GetElementToMove(uint32_t index,
+ FixedArray* elms,
+ JSObject* prototype) {
+ Object* e = elms->get(index);
+ if (e->IsTheHole() && prototype->HasElement(index)) {
+ e = prototype->GetElement(index);
+ }
+ return e;
+}
BUILTIN(ArrayShift) {
@@ -325,21 +338,17 @@
Top::context()->global_context()->array_function();
JSObject* prototype = JSObject::cast(array_function->prototype());
- // Get first element
FixedArray* elms = FixedArray::cast(array->elements());
- Object* first = elms->get(0);
-
+
+ // Get first element
+ Object* first = elms->get(0);
if (first->IsTheHole()) {
first = prototype->GetElement(0);
}
// Shift the elements.
for (int i = 0; i < len - 1; i++) {
- Object* e = elms->get(i + 1);
- if (e->IsTheHole() && prototype->HasElement(i + 1)) {
- e = prototype->GetElement(i + 1);
- }
- elms->set(i, e);
+ elms->set(i, GetElementToMove(i + 1, elms, prototype));
}
elms->set(len - 1, Heap::the_hole_value());
@@ -348,6 +357,66 @@
return first;
}
+
+
+BUILTIN(ArrayUnshift) {
+ JSArray* array = JSArray::cast(*args.receiver());
+ ASSERT(array->HasFastElements());
+
+ int len = Smi::cast(array->length())->value();
+ int to_add = args.length() - 1;
+ // Note that we cannot quit early if to_add == 0 as
+ // values should be lifted from prototype into
+ // the array.
+
+ int new_length = len + to_add;
+ FixedArray* elms = FixedArray::cast(array->elements());
+
+ // Fetch the prototype.
+ JSFunction* array_function =
+ Top::context()->global_context()->array_function();
+ JSObject* prototype = JSObject::cast(array_function->prototype());
+
+ if (new_length > elms->length()) {
+ // New backing storage is needed.
+ int capacity = new_length + (new_length >> 1) + 16;
+ Object* obj = Heap::AllocateFixedArrayWithHoles(capacity);
+ if (obj->IsFailure()) return obj;
+
+ AssertNoAllocation no_gc;
+ FixedArray* new_elms = FixedArray::cast(obj);
+ WriteBarrierMode mode = new_elms->GetWriteBarrierMode(no_gc);
+ // Fill out the new array with old elements.
+ for (int i = 0; i < len; i++)
+ new_elms->set(to_add + i,
+ GetElementToMove(i, elms, prototype),
+ mode);
+
+ elms = new_elms;
+ array->set_elements(elms);
+ } else {
+ AssertNoAllocation no_gc;
+ WriteBarrierMode mode = elms->GetWriteBarrierMode(no_gc);
+
+ // Move elements to the right
+ for (int i = 0; i < len; i++) {
+ elms->set(new_length - i - 1,
+ GetElementToMove(len - i - 1, elms, prototype),
+ mode);
+ }
+ }
+
+ // Add the provided values.
+ AssertNoAllocation no_gc;
+ WriteBarrierMode mode = elms->GetWriteBarrierMode(no_gc);
+ for (int i = 0; i < to_add; i++) {
+ elms->set(i, args[i + 1], mode);
+ }
+
+ // Set the length.
+ array->set_length(Smi::FromInt(new_length));
+ return Smi::FromInt(new_length);
+}
//
-----------------------------------------------------------------------------
=======================================
--- /branches/bleeding_edge/src/builtins.h Mon Feb 15 01:17:38 2010
+++ /branches/bleeding_edge/src/builtins.h Mon Feb 15 05:25:06 2010
@@ -49,6 +49,7 @@
V(ArrayPush, NO_EXTRA_ARGUMENTS) \
V(ArrayPop, NO_EXTRA_ARGUMENTS) \
V(ArrayShift, NO_EXTRA_ARGUMENTS) \
+ V(ArrayUnshift, NO_EXTRA_ARGUMENTS) \
\
V(HandleApiCall, NEEDS_CALLED_FUNCTION) \
V(FastHandleApiCall, NO_EXTRA_ARGUMENTS) \
--
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