v8/test/mjsunit/harmony/private.js
rossberg@chromium.org cec8383cff Provide private symbols through internal APIs
Adds a notion of private symbols, mainly intended for internal use, especially, self-hosting of built-in types that would otherwise require new C++ classes.

On the JS side (i.e., in built-ins), private properties can be created and accessed through a set of macros:

  NEW_PRIVATE(print_name)
  HAS_PRIVATE(obj, sym)
  GET_PRIVATE(obj, sym)
  SET_PRIVATE(obj, sym, val)
  DELETE_PRIVATE(obj, sym)

In the V8 API, they are accessible via a new class Private, and respective HasPrivate/Get/Private/SetPrivate/DeletePrivate methods on calss Object.

These APIs are designed and restricted such that their implementation can later be replaced by whatever ES7+ will officially provide.

R=yangguo@chromium.org
BUG=

Review URL: https://codereview.chromium.org/48923002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17683 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-11-13 10:34:06 +00:00

325 lines
9.1 KiB
JavaScript

// 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
// 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.
// Flags: --harmony-symbols --harmony-collections
// Flags: --expose-gc --allow-natives-syntax
var symbols = []
// Test different forms of constructor calls, all equivalent.
function TestNew() {
for (var i = 0; i < 2; ++i) {
for (var j = 0; j < 5; ++j) {
symbols.push(%CreatePrivateSymbol("66"))
symbols.push(Object(%CreatePrivateSymbol("66")).valueOf())
}
gc() // Promote existing symbols and then allocate some more.
}
}
TestNew()
function TestType() {
for (var i in symbols) {
assertEquals("symbol", typeof symbols[i])
assertTrue(typeof symbols[i] === "symbol")
assertTrue(%SymbolIsPrivate(symbols[i]))
assertEquals(null, %_ClassOf(symbols[i]))
assertEquals("Symbol", %_ClassOf(new Symbol(symbols[i])))
assertEquals("Symbol", %_ClassOf(Object(symbols[i])))
}
}
TestType()
function TestPrototype() {
for (var i in symbols) {
assertSame(Symbol.prototype, symbols[i].__proto__)
}
}
TestPrototype()
function TestConstructor() {
for (var i in symbols) {
assertSame(Symbol, symbols[i].__proto__.constructor)
}
}
TestConstructor()
function TestName() {
for (var i in symbols) {
var name = symbols[i].name
assertTrue(name === "66")
}
}
TestName()
function TestToString() {
for (var i in symbols) {
assertThrows(function() { String(symbols[i]) }, TypeError)
assertThrows(function() { symbols[i] + "" }, TypeError)
assertThrows(function() { symbols[i].toString() }, TypeError)
assertThrows(function() { (new Symbol(symbols[i])).toString() }, TypeError)
assertThrows(function() { Object(symbols[i]).toString() }, TypeError)
assertEquals("[object Symbol]", Object.prototype.toString.call(symbols[i]))
}
}
TestToString()
function TestToBoolean() {
for (var i in symbols) {
assertTrue(Boolean(symbols[i]).valueOf())
assertFalse(!symbols[i])
assertTrue(!!symbols[i])
assertTrue(symbols[i] && true)
assertFalse(!symbols[i] && false)
assertTrue(!symbols[i] || true)
assertEquals(1, symbols[i] ? 1 : 2)
assertEquals(2, !symbols[i] ? 1 : 2)
if (!symbols[i]) assertUnreachable();
if (symbols[i]) {} else assertUnreachable();
}
}
TestToBoolean()
function TestToNumber() {
for (var i in symbols) {
assertSame(NaN, Number(symbols[i]).valueOf())
assertSame(NaN, symbols[i] + 0)
}
}
TestToNumber()
function TestEquality() {
// Every symbol should equal itself, and non-strictly equal its wrapper.
for (var i in symbols) {
assertSame(symbols[i], symbols[i])
assertEquals(symbols[i], symbols[i])
assertTrue(Object.is(symbols[i], symbols[i]))
assertTrue(symbols[i] === symbols[i])
assertTrue(symbols[i] == symbols[i])
assertFalse(symbols[i] === new Symbol(symbols[i]))
assertFalse(new Symbol(symbols[i]) === symbols[i])
assertTrue(symbols[i] == new Symbol(symbols[i]))
assertTrue(new Symbol(symbols[i]) == symbols[i])
}
// All symbols should be distinct.
for (var i = 0; i < symbols.length; ++i) {
for (var j = i + 1; j < symbols.length; ++j) {
assertFalse(Object.is(symbols[i], symbols[j]))
assertFalse(symbols[i] === symbols[j])
assertFalse(symbols[i] == symbols[j])
}
}
// Symbols should not be equal to any other value (and the test terminates).
var values = [347, 1.275, NaN, "string", null, undefined, {}, function() {}]
for (var i in symbols) {
for (var j in values) {
assertFalse(symbols[i] === values[j])
assertFalse(values[j] === symbols[i])
assertFalse(symbols[i] == values[j])
assertFalse(values[j] == symbols[i])
}
}
}
TestEquality()
function TestGet() {
for (var i in symbols) {
assertThrows(function() { symbols[i].toString() }, TypeError)
assertEquals(symbols[i], symbols[i].valueOf())
assertEquals(undefined, symbols[i].a)
assertEquals(undefined, symbols[i]["a" + "b"])
assertEquals(undefined, symbols[i]["" + "1"])
assertEquals(undefined, symbols[i][62])
}
}
TestGet()
function TestSet() {
for (var i in symbols) {
symbols[i].toString = 0
assertThrows(function() { symbols[i].toString() }, TypeError)
symbols[i].valueOf = 0
assertEquals(symbols[i], symbols[i].valueOf())
symbols[i].a = 0
assertEquals(undefined, symbols[i].a)
symbols[i]["a" + "b"] = 0
assertEquals(undefined, symbols[i]["a" + "b"])
symbols[i][62] = 0
assertEquals(undefined, symbols[i][62])
}
}
TestSet()
function TestCollections() {
var set = new Set
var map = new Map
var weakmap = new WeakMap
for (var i in symbols) {
set.add(symbols[i])
map.set(symbols[i], i)
weakmap.set(symbols[i], i)
}
assertEquals(symbols.length, set.size)
assertEquals(symbols.length, map.size)
for (var i in symbols) {
assertTrue(set.has(symbols[i]))
assertTrue(map.has(symbols[i]))
assertTrue(weakmap.has(symbols[i]))
assertEquals(i, map.get(symbols[i]))
assertEquals(i, weakmap.get(symbols[i]))
}
for (var i in symbols) {
assertTrue(set.delete(symbols[i]))
assertTrue(map.delete(symbols[i]))
assertTrue(weakmap.delete(symbols[i]))
}
assertEquals(0, set.size)
assertEquals(0, map.size)
}
TestCollections()
function TestKeySet(obj) {
assertTrue(%HasFastProperties(obj))
// Set the even symbols via assignment.
for (var i = 0; i < symbols.length; i += 2) {
obj[symbols[i]] = i
// Object should remain in fast mode until too many properties were added.
assertTrue(%HasFastProperties(obj) || i >= 30)
}
}
function TestKeyDefine(obj) {
// Set the odd symbols via defineProperty (as non-enumerable).
for (var i = 1; i < symbols.length; i += 2) {
Object.defineProperty(obj, symbols[i], {value: i, configurable: true})
}
}
function TestKeyGet(obj) {
var obj2 = Object.create(obj)
for (var i in symbols) {
assertEquals(i|0, obj[symbols[i]])
assertEquals(i|0, obj2[symbols[i]])
}
}
function TestKeyHas() {
for (var i in symbols) {
assertTrue(symbols[i] in obj)
assertTrue(Object.hasOwnProperty.call(obj, symbols[i]))
}
}
function TestKeyEnum(obj) {
for (var name in obj) {
assertEquals("string", typeof name)
}
}
function TestKeyNames(obj) {
assertEquals(0, Object.keys(obj).length)
var names = Object.getOwnPropertyNames(obj)
for (var i in names) {
assertEquals("string", typeof names[i])
}
}
function TestKeyDescriptor(obj) {
for (var i in symbols) {
var desc = Object.getOwnPropertyDescriptor(obj, symbols[i]);
assertEquals(i|0, desc.value)
assertTrue(desc.configurable)
assertEquals(i % 2 == 0, desc.writable)
assertEquals(i % 2 == 0, desc.enumerable)
assertEquals(i % 2 == 0,
Object.prototype.propertyIsEnumerable.call(obj, symbols[i]))
}
}
function TestKeyDelete(obj) {
for (var i in symbols) {
delete obj[symbols[i]]
}
for (var i in symbols) {
assertEquals(undefined, Object.getOwnPropertyDescriptor(obj, symbols[i]))
}
}
var objs = [{}, [], Object.create(null), Object(1), new Map, function(){}]
for (var i in objs) {
var obj = objs[i]
TestKeySet(obj)
TestKeyDefine(obj)
TestKeyGet(obj)
TestKeyHas(obj)
TestKeyEnum(obj)
TestKeyNames(obj)
TestKeyDescriptor(obj)
TestKeyDelete(obj)
}
function TestCachedKeyAfterScavenge() {
gc();
// Keyed property lookup are cached. Hereby we assume that the keys are
// tenured, so that we only have to clear the cache between mark compacts,
// but not between scavenges. This must also apply for symbol keys.
var key = Symbol("key");
var a = {};
a[key] = "abc";
for (var i = 0; i < 1000000; i++) {
a[key] += "a"; // Allocations cause a scavenge.
}
}
TestCachedKeyAfterScavenge();