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      1 /*
      2  * Copyright (C) 2009 Google Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions are
      6  * met:
      7  *
      8  *     * Redistributions of source code must retain the above copyright
      9  * notice, this list of conditions and the following disclaimer.
     10  *     * Redistributions in binary form must reproduce the above
     11  * copyright notice, this list of conditions and the following disclaimer
     12  * in the documentation and/or other materials provided with the
     13  * distribution.
     14  *     * Neither the name of Google Inc. nor the names of its
     15  * contributors may be used to endorse or promote products derived from
     16  * this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #include "config.h"
     32 #include "bindings/v8/V8DOMWrapper.h"
     33 
     34 #include "V8HTMLCollection.h"
     35 #include "V8HTMLDocument.h"
     36 #include "V8Window.h"
     37 #include "bindings/v8/V8Binding.h"
     38 #include "bindings/v8/V8HiddenPropertyName.h"
     39 #include "bindings/v8/V8ObjectConstructor.h"
     40 #include "bindings/v8/V8PerContextData.h"
     41 #include "bindings/v8/V8ScriptRunner.h"
     42 
     43 namespace WebCore {
     44 
     45 class V8WrapperInstantiationScope {
     46 public:
     47     explicit V8WrapperInstantiationScope(v8::Handle<v8::Object> creationContext)
     48         : m_didEnterContext(false)
     49         , m_context(v8::Context::GetCurrent())
     50     {
     51         // FIXME: Remove all empty creationContexts from caller sites.
     52         // If a creationContext is empty, we will end up creating a new object
     53         // in the context currently entered. This is wrong.
     54         if (creationContext.IsEmpty())
     55             return;
     56         v8::Handle<v8::Context> contextForWrapper = creationContext->CreationContext();
     57         // For performance, we enter the context only if the currently running context
     58         // is different from the context that we are about to enter.
     59         if (contextForWrapper == m_context)
     60             return;
     61         m_context = v8::Local<v8::Context>::New(contextForWrapper);
     62         m_didEnterContext = true;
     63         m_context->Enter();
     64     }
     65 
     66     ~V8WrapperInstantiationScope()
     67     {
     68         if (!m_didEnterContext)
     69             return;
     70         m_context->Exit();
     71     }
     72 
     73     v8::Handle<v8::Context> context() const { return m_context; }
     74 
     75 private:
     76     bool m_didEnterContext;
     77     v8::Handle<v8::Context> m_context;
     78 };
     79 
     80 static v8::Local<v8::Object> wrapInShadowTemplate(v8::Local<v8::Object> wrapper, Node* impl, v8::Isolate* isolate)
     81 {
     82     // This is only for getting a unique pointer which we can pass to privateTemplate.
     83     static const char* shadowTemplateUniqueKey = "wrapInShadowTemplate";
     84     WrapperWorldType currentWorldType = worldType(isolate);
     85     V8PerIsolateData* data = V8PerIsolateData::from(isolate);
     86     v8::Handle<v8::FunctionTemplate> shadowTemplate = data->privateTemplateIfExists(currentWorldType, &shadowTemplateUniqueKey);
     87     if (shadowTemplate.IsEmpty()) {
     88         shadowTemplate = v8::FunctionTemplate::New();
     89         if (shadowTemplate.IsEmpty())
     90             return v8::Local<v8::Object>();
     91         shadowTemplate->SetClassName(v8::String::NewSymbol("HTMLDocument"));
     92         shadowTemplate->Inherit(V8HTMLDocument::GetTemplate(isolate, currentWorldType));
     93         shadowTemplate->InstanceTemplate()->SetInternalFieldCount(V8HTMLDocument::internalFieldCount);
     94         data->setPrivateTemplate(currentWorldType, &shadowTemplateUniqueKey, shadowTemplate);
     95     }
     96 
     97     v8::Local<v8::Function> shadowConstructor = shadowTemplate->GetFunction();
     98     if (shadowConstructor.IsEmpty())
     99         return v8::Local<v8::Object>();
    100 
    101     v8::Local<v8::Object> shadow = V8ScriptRunner::instantiateObject(shadowConstructor);
    102     if (shadow.IsEmpty())
    103         return v8::Local<v8::Object>();
    104     shadow->SetPrototype(wrapper);
    105     V8DOMWrapper::setNativeInfo(wrapper, &V8HTMLDocument::info, impl);
    106     return shadow;
    107 }
    108 
    109 v8::Local<v8::Object> V8DOMWrapper::createWrapper(v8::Handle<v8::Object> creationContext, WrapperTypeInfo* type, void* impl, v8::Isolate* isolate)
    110 {
    111     V8WrapperInstantiationScope scope(creationContext);
    112 
    113     V8PerContextData* perContextData = V8PerContextData::from(scope.context());
    114     v8::Local<v8::Object> wrapper = perContextData ? perContextData->createWrapperFromCache(type) : V8ObjectConstructor::newInstance(type->getTemplate(isolate, worldTypeInMainThread(isolate))->GetFunction());
    115 
    116     if (type == &V8HTMLDocument::info && !wrapper.IsEmpty())
    117         wrapper = wrapInShadowTemplate(wrapper, static_cast<Node*>(impl), isolate);
    118 
    119     return wrapper;
    120 }
    121 
    122 static bool hasInternalField(v8::Handle<v8::Value> value)
    123 {
    124     if (value.IsEmpty() || !value->IsObject())
    125         return false;
    126     return v8::Handle<v8::Object>::Cast(value)->InternalFieldCount();
    127 }
    128 
    129 #ifndef NDEBUG
    130 bool V8DOMWrapper::maybeDOMWrapper(v8::Handle<v8::Value> value)
    131 {
    132     if (!hasInternalField(value))
    133         return false;
    134 
    135     v8::Handle<v8::Object> object = v8::Handle<v8::Object>::Cast(value);
    136     ASSERT(object->InternalFieldCount() >= v8DefaultWrapperInternalFieldCount);
    137 
    138     v8::HandleScope scope;
    139     ASSERT(object->GetAlignedPointerFromInternalField(v8DOMWrapperObjectIndex));
    140 
    141     return true;
    142 }
    143 #endif
    144 
    145 bool V8DOMWrapper::isDOMWrapper(v8::Handle<v8::Value> value)
    146 {
    147     if (value.IsEmpty() || !value->IsObject())
    148         return false;
    149 
    150     v8::Handle<v8::Object> wrapper = v8::Handle<v8::Object>::Cast(value);
    151     if (wrapper->InternalFieldCount() < v8DefaultWrapperInternalFieldCount)
    152         return false;
    153     ASSERT(wrapper->GetAlignedPointerFromInternalField(v8DOMWrapperObjectIndex));
    154     ASSERT(wrapper->GetAlignedPointerFromInternalField(v8DOMWrapperTypeIndex));
    155 
    156     // FIXME: Add class id checks.
    157     return true;
    158 }
    159 
    160 bool V8DOMWrapper::isWrapperOfType(v8::Handle<v8::Value> value, WrapperTypeInfo* type)
    161 {
    162     if (!hasInternalField(value))
    163         return false;
    164 
    165     v8::Handle<v8::Object> wrapper = v8::Handle<v8::Object>::Cast(value);
    166     ASSERT(wrapper->InternalFieldCount() >= v8DefaultWrapperInternalFieldCount);
    167     ASSERT(wrapper->GetAlignedPointerFromInternalField(v8DOMWrapperObjectIndex));
    168 
    169     WrapperTypeInfo* typeInfo = static_cast<WrapperTypeInfo*>(wrapper->GetAlignedPointerFromInternalField(v8DOMWrapperTypeIndex));
    170     return typeInfo == type;
    171 }
    172 
    173 }  // namespace WebCore
    174