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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
#include "mozilla/dom/ObservableArrayProxyHandler.h"
#include "jsapi.h"
#include "js/friend/ErrorMessages.h"
#include "js/Conversions.h"
#include "js/Object.h"
#include "mozilla/dom/JSSlots.h"
#include "mozilla/dom/ProxyHandlerUtils.h"
#include "mozilla/dom/ToJSValue.h"
#include "mozilla/ErrorResult.h"
#include "nsDebug.h"
#include "nsJSUtils.h"
namespace mozilla::dom {
const char ObservableArrayProxyHandler::family = 0;
bool ObservableArrayProxyHandler::defineProperty(
JSContext* aCx, JS::Handle<JSObject*> aProxy,
JS::Handle<JS::PropertyKey> aId, JS::Handle<JS::PropertyDescriptor> aDesc,
JS::ObjectOpResult& aResult) const {
if (aId.get() == s_length_id) {
if (aDesc.isAccessorDescriptor()) {
return aResult.failNotDataDescriptor();
}
if (aDesc.hasConfigurable() && aDesc.configurable()) {
return aResult.failInvalidDescriptor();
}
if (aDesc.hasEnumerable() && aDesc.enumerable()) {
return aResult.failInvalidDescriptor();
}
if (aDesc.hasWritable() && !aDesc.writable()) {
return aResult.failInvalidDescriptor();
}
if (aDesc.hasValue()) {
JS::Rooted<JSObject*> backingListObj(aCx);
if (!GetBackingListObject(aCx, aProxy, &backingListObj)) {
return false;
}
return SetLength(aCx, aProxy, backingListObj, aDesc.value(), aResult);
}
return aResult.succeed();
}
uint32_t index = GetArrayIndexFromId(aId);
if (IsArrayIndex(index)) {
if (aDesc.isAccessorDescriptor()) {
return aResult.failNotDataDescriptor();
}
if (aDesc.hasConfigurable() && !aDesc.configurable()) {
return aResult.failInvalidDescriptor();
}
if (aDesc.hasEnumerable() && !aDesc.enumerable()) {
return aResult.failInvalidDescriptor();
}
if (aDesc.hasWritable() && !aDesc.writable()) {
return aResult.failInvalidDescriptor();
}
if (aDesc.hasValue()) {
JS::Rooted<JSObject*> backingListObj(aCx);
if (!GetBackingListObject(aCx, aProxy, &backingListObj)) {
return false;
}
return SetIndexedValue(aCx, aProxy, backingListObj, index, aDesc.value(),
aResult);
}
return aResult.succeed();
}
return ForwardingProxyHandler::defineProperty(aCx, aProxy, aId, aDesc,
aResult);
}
bool ObservableArrayProxyHandler::delete_(JSContext* aCx,
JS::Handle<JSObject*> aProxy,
JS::Handle<JS::PropertyKey> aId,
JS::ObjectOpResult& aResult) const {
if (aId.get() == s_length_id) {
return aResult.failCantDelete();
}
uint32_t index = GetArrayIndexFromId(aId);
if (IsArrayIndex(index)) {
JS::Rooted<JSObject*> backingListObj(aCx);
if (!GetBackingListObject(aCx, aProxy, &backingListObj)) {
return false;
}
uint32_t oldLen = 0;
if (!JS::GetArrayLength(aCx, backingListObj, &oldLen)) {
return false;
}
// We do not follow the spec (step 3.3 in
// is because `oldLen - 1` could be `-1` if the backing list is empty, but
// `oldLen` is `uint32_t` in practice. See also
if (oldLen != index + 1) {
return aResult.failBadIndex();
}
JS::Rooted<JS::Value> value(aCx);
if (!JS_GetElement(aCx, backingListObj, index, &value)) {
return false;
}
if (!OnDeleteItem(aCx, aProxy, value, index)) {
return false;
}
if (!JS::SetArrayLength(aCx, backingListObj, index)) {
return false;
}
return aResult.succeed();
}
return ForwardingProxyHandler::delete_(aCx, aProxy, aId, aResult);
}
bool ObservableArrayProxyHandler::get(JSContext* aCx,
JS::Handle<JSObject*> aProxy,
JS::Handle<JS::Value> aReceiver,
JS::Handle<JS::PropertyKey> aId,
JS::MutableHandle<JS::Value> aVp) const {
JS::Rooted<JSObject*> backingListObj(aCx);
if (!GetBackingListObject(aCx, aProxy, &backingListObj)) {
return false;
}
uint32_t length = 0;
if (!JS::GetArrayLength(aCx, backingListObj, &length)) {
return false;
}
if (aId.get() == s_length_id) {
return ToJSValue(aCx, length, aVp);
}
uint32_t index = GetArrayIndexFromId(aId);
if (IsArrayIndex(index)) {
if (index >= length) {
aVp.setUndefined();
return true;
}
return JS_GetElement(aCx, backingListObj, index, aVp);
}
return ForwardingProxyHandler::get(aCx, aProxy, aReceiver, aId, aVp);
}
bool ObservableArrayProxyHandler::getOwnPropertyDescriptor(
JSContext* aCx, JS::Handle<JSObject*> aProxy,
JS::Handle<JS::PropertyKey> aId,
JS::MutableHandle<Maybe<JS::PropertyDescriptor>> aDesc) const {
JS::Rooted<JSObject*> backingListObj(aCx);
if (!GetBackingListObject(aCx, aProxy, &backingListObj)) {
return false;
}
uint32_t length = 0;
if (!JS::GetArrayLength(aCx, backingListObj, &length)) {
return false;
}
if (aId.get() == s_length_id) {
JS::Rooted<JS::Value> value(aCx, JS::NumberValue(length));
aDesc.set(Some(JS::PropertyDescriptor::Data(
value, {JS::PropertyAttribute::Writable})));
return true;
}
uint32_t index = GetArrayIndexFromId(aId);
if (IsArrayIndex(index)) {
if (index >= length) {
return true;
}
JS::Rooted<JS::Value> value(aCx);
if (!JS_GetElement(aCx, backingListObj, index, &value)) {
return false;
}
aDesc.set(Some(JS::PropertyDescriptor::Data(
value,
{JS::PropertyAttribute::Configurable, JS::PropertyAttribute::Writable,
JS::PropertyAttribute::Enumerable})));
return true;
}
return ForwardingProxyHandler::getOwnPropertyDescriptor(aCx, aProxy, aId,
aDesc);
}
bool ObservableArrayProxyHandler::has(JSContext* aCx,
JS::Handle<JSObject*> aProxy,
JS::Handle<JS::PropertyKey> aId,
bool* aBp) const {
if (aId.get() == s_length_id) {
*aBp = true;
return true;
}
uint32_t index = GetArrayIndexFromId(aId);
if (IsArrayIndex(index)) {
uint32_t length = 0;
if (!GetBackingListLength(aCx, aProxy, &length)) {
return false;
}
*aBp = (index < length);
return true;
}
return ForwardingProxyHandler::has(aCx, aProxy, aId, aBp);
}
bool ObservableArrayProxyHandler::ownPropertyKeys(
JSContext* aCx, JS::Handle<JSObject*> aProxy,
JS::MutableHandleVector<jsid> aProps) const {
uint32_t length = 0;
if (!GetBackingListLength(aCx, aProxy, &length)) {
return false;
}
for (int32_t i = 0; i < int32_t(length); i++) {
if (!aProps.append(JS::PropertyKey::Int(i))) {
return false;
}
}
return ForwardingProxyHandler::ownPropertyKeys(aCx, aProxy, aProps);
}
bool ObservableArrayProxyHandler::preventExtensions(
JSContext* aCx, JS::Handle<JSObject*> aProxy,
JS::ObjectOpResult& aResult) const {
return aResult.failCantPreventExtensions();
}
bool ObservableArrayProxyHandler::set(JSContext* aCx,
JS::Handle<JSObject*> aProxy,
JS::Handle<JS::PropertyKey> aId,
JS::Handle<JS::Value> aV,
JS::Handle<JS::Value> aReceiver,
JS::ObjectOpResult& aResult) const {
if (aId.get() == s_length_id) {
JS::Rooted<JSObject*> backingListObj(aCx);
if (!GetBackingListObject(aCx, aProxy, &backingListObj)) {
return false;
}
return SetLength(aCx, aProxy, backingListObj, aV, aResult);
}
uint32_t index = GetArrayIndexFromId(aId);
if (IsArrayIndex(index)) {
JS::Rooted<JSObject*> backingListObj(aCx);
if (!GetBackingListObject(aCx, aProxy, &backingListObj)) {
return false;
}
return SetIndexedValue(aCx, aProxy, backingListObj, index, aV, aResult);
}
return ForwardingProxyHandler::set(aCx, aProxy, aId, aV, aReceiver, aResult);
}
bool ObservableArrayProxyHandler::GetBackingListObject(
JSContext* aCx, JS::Handle<JSObject*> aProxy,
JS::MutableHandle<JSObject*> aBackingListObject) const {
// Retrieve the backing list object from the reserved slot on the proxy
// object. If it doesn't exist yet, create it.
JS::Rooted<JS::Value> slotValue(aCx);
slotValue = js::GetProxyReservedSlot(
aProxy, OBSERVABLE_ARRAY_BACKING_LIST_OBJECT_SLOT);
if (slotValue.isUndefined()) {
JS::Rooted<JSObject*> newBackingListObj(aCx);
newBackingListObj.set(JS::NewArrayObject(aCx, 0));
if (NS_WARN_IF(!newBackingListObj)) {
return false;
}
slotValue = JS::ObjectValue(*newBackingListObj);
js::SetProxyReservedSlot(aProxy, OBSERVABLE_ARRAY_BACKING_LIST_OBJECT_SLOT,
slotValue);
}
aBackingListObject.set(&slotValue.toObject());
return true;
}
bool ObservableArrayProxyHandler::GetBackingListLength(
JSContext* aCx, JS::Handle<JSObject*> aProxy, uint32_t* aLength) const {
JS::Rooted<JSObject*> backingListObj(aCx);
if (!GetBackingListObject(aCx, aProxy, &backingListObj)) {
return false;
}
return JS::GetArrayLength(aCx, backingListObj, aLength);
}
bool ObservableArrayProxyHandler::SetLength(JSContext* aCx,
JS::Handle<JSObject*> aProxy,
uint32_t aLength) const {
JS::Rooted<JSObject*> backingListObj(aCx);
if (!GetBackingListObject(aCx, aProxy, &backingListObj)) {
return false;
}
JS::ObjectOpResult result;
if (!SetLength(aCx, aProxy, backingListObj, aLength, result)) {
return false;
}
return result ? true : result.reportError(aCx, aProxy);
}
bool ObservableArrayProxyHandler::SetLength(JSContext* aCx,
JS::Handle<JSObject*> aProxy,
JS::Handle<JSObject*> aBackingList,
uint32_t aLength,
JS::ObjectOpResult& aResult) const {
uint32_t oldLen;
if (!JS::GetArrayLength(aCx, aBackingList, &oldLen)) {
return false;
}
if (aLength > oldLen) {
return aResult.failBadArrayLength();
}
bool ok = true;
uint32_t len = oldLen;
for (; len > aLength; len--) {
uint32_t indexToDelete = len - 1;
JS::Rooted<JS::Value> value(aCx);
if (!JS_GetElement(aCx, aBackingList, indexToDelete, &value)) {
ok = false;
break;
}
if (!OnDeleteItem(aCx, aProxy, value, indexToDelete)) {
ok = false;
break;
}
}
return JS::SetArrayLength(aCx, aBackingList, len) && ok ? aResult.succeed()
: false;
}
bool ObservableArrayProxyHandler::SetLength(JSContext* aCx,
JS::Handle<JSObject*> aProxy,
JS::Handle<JSObject*> aBackingList,
JS::Handle<JS::Value> aValue,
JS::ObjectOpResult& aResult) const {
uint32_t uint32Len;
if (!ToUint32(aCx, aValue, &uint32Len)) {
return false;
}
double numberLen;
if (!ToNumber(aCx, aValue, &numberLen)) {
return false;
}
if (uint32Len != numberLen) {
JS_ReportErrorNumberASCII(aCx, js::GetErrorMessage, nullptr,
JSMSG_BAD_INDEX);
return false;
}
return SetLength(aCx, aProxy, aBackingList, uint32Len, aResult);
}
} // namespace mozilla::dom