blob: 62c1136117c6a629cf5c3987d53b928751bc5559 [file] [log] [blame]
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "content/renderer/v8_value_converter_impl.h"
#include <string>
#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/float_util.h"
#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "base/values.h"
#include "third_party/WebKit/public/web/WebArrayBuffer.h"
#include "third_party/WebKit/public/web/WebArrayBufferConverter.h"
#include "third_party/WebKit/public/web/WebArrayBufferView.h"
#include "v8/include/v8.h"
namespace content {
// Default implementation of V8ValueConverter::Strategy
bool V8ValueConverter::Strategy::FromV8Object(
v8::Handle<v8::Object> value,
base::Value** out,
v8::Isolate* isolate,
const FromV8ValueCallback& callback) const {
return false;
}
bool V8ValueConverter::Strategy::FromV8Array(
v8::Handle<v8::Array> value,
base::Value** out,
v8::Isolate* isolate,
const FromV8ValueCallback& callback) const {
return false;
}
bool V8ValueConverter::Strategy::FromV8ArrayBuffer(v8::Handle<v8::Object> value,
base::Value** out,
v8::Isolate* isolate) const {
return false;
}
bool V8ValueConverter::Strategy::FromV8Number(v8::Handle<v8::Number> value,
base::Value** out) const {
return false;
}
bool V8ValueConverter::Strategy::FromV8Undefined(base::Value** out) const {
return false;
}
namespace {
// For the sake of the storage API, make this quite large.
const int kMaxRecursionDepth = 100;
} // namespace
// The state of a call to FromV8Value.
class V8ValueConverterImpl::FromV8ValueState {
public:
// Level scope which updates the current depth of some FromV8ValueState.
class Level {
public:
explicit Level(FromV8ValueState* state) : state_(state) {
state_->max_recursion_depth_--;
}
~Level() {
state_->max_recursion_depth_++;
}
private:
FromV8ValueState* state_;
};
explicit FromV8ValueState(bool avoid_identity_hash_for_testing)
: max_recursion_depth_(kMaxRecursionDepth),
avoid_identity_hash_for_testing_(avoid_identity_hash_for_testing) {}
// If |handle| is not in |unique_map_|, then add it to |unique_map_| and
// return true.
//
// Otherwise do nothing and return false. Here "A is unique" means that no
// other handle B in the map points to the same object as A. Note that A can
// be unique even if there already is another handle with the same identity
// hash (key) in the map, because two objects can have the same hash.
bool UpdateAndCheckUniqueness(v8::Handle<v8::Object> handle) {
typedef HashToHandleMap::const_iterator Iterator;
int hash = avoid_identity_hash_for_testing_ ? 0 : handle->GetIdentityHash();
// We only compare using == with handles to objects with the same identity
// hash. Different hash obviously means different objects, but two objects
// in a couple of thousands could have the same identity hash.
std::pair<Iterator, Iterator> range = unique_map_.equal_range(hash);
for (Iterator it = range.first; it != range.second; ++it) {
// Operator == for handles actually compares the underlying objects.
if (it->second == handle)
return false;
}
unique_map_.insert(std::make_pair(hash, handle));
return true;
}
bool HasReachedMaxRecursionDepth() {
return max_recursion_depth_ < 0;
}
private:
typedef std::multimap<int, v8::Handle<v8::Object> > HashToHandleMap;
HashToHandleMap unique_map_;
int max_recursion_depth_;
bool avoid_identity_hash_for_testing_;
};
V8ValueConverter* V8ValueConverter::create() {
return new V8ValueConverterImpl();
}
V8ValueConverterImpl::V8ValueConverterImpl()
: date_allowed_(false),
reg_exp_allowed_(false),
function_allowed_(false),
strip_null_from_objects_(false),
avoid_identity_hash_for_testing_(false),
strategy_(NULL) {}
void V8ValueConverterImpl::SetDateAllowed(bool val) {
date_allowed_ = val;
}
void V8ValueConverterImpl::SetRegExpAllowed(bool val) {
reg_exp_allowed_ = val;
}
void V8ValueConverterImpl::SetFunctionAllowed(bool val) {
function_allowed_ = val;
}
void V8ValueConverterImpl::SetStripNullFromObjects(bool val) {
strip_null_from_objects_ = val;
}
void V8ValueConverterImpl::SetStrategy(Strategy* strategy) {
strategy_ = strategy;
}
v8::Handle<v8::Value> V8ValueConverterImpl::ToV8Value(
const base::Value* value, v8::Handle<v8::Context> context) const {
v8::Context::Scope context_scope(context);
v8::EscapableHandleScope handle_scope(context->GetIsolate());
return handle_scope.Escape(
ToV8ValueImpl(context->GetIsolate(), context->Global(), value));
}
base::Value* V8ValueConverterImpl::FromV8Value(
v8::Handle<v8::Value> val,
v8::Handle<v8::Context> context) const {
v8::Context::Scope context_scope(context);
v8::HandleScope handle_scope(context->GetIsolate());
FromV8ValueState state(avoid_identity_hash_for_testing_);
return FromV8ValueImpl(&state, val, context->GetIsolate());
}
v8::Local<v8::Value> V8ValueConverterImpl::ToV8ValueImpl(
v8::Isolate* isolate,
v8::Handle<v8::Object> creation_context,
const base::Value* value) const {
CHECK(value);
switch (value->GetType()) {
case base::Value::TYPE_NULL:
return v8::Null(isolate);
case base::Value::TYPE_BOOLEAN: {
bool val = false;
CHECK(value->GetAsBoolean(&val));
return v8::Boolean::New(isolate, val);
}
case base::Value::TYPE_INTEGER: {
int val = 0;
CHECK(value->GetAsInteger(&val));
return v8::Integer::New(isolate, val);
}
case base::Value::TYPE_DOUBLE: {
double val = 0.0;
CHECK(value->GetAsDouble(&val));
return v8::Number::New(isolate, val);
}
case base::Value::TYPE_STRING: {
std::string val;
CHECK(value->GetAsString(&val));
return v8::String::NewFromUtf8(
isolate, val.c_str(), v8::String::kNormalString, val.length());
}
case base::Value::TYPE_LIST:
return ToV8Array(isolate,
creation_context,
static_cast<const base::ListValue*>(value));
case base::Value::TYPE_DICTIONARY:
return ToV8Object(isolate,
creation_context,
static_cast<const base::DictionaryValue*>(value));
case base::Value::TYPE_BINARY:
return ToArrayBuffer(isolate,
creation_context,
static_cast<const base::BinaryValue*>(value));
default:
LOG(ERROR) << "Unexpected value type: " << value->GetType();
return v8::Null(isolate);
}
}
v8::Handle<v8::Value> V8ValueConverterImpl::ToV8Array(
v8::Isolate* isolate,
v8::Handle<v8::Object> creation_context,
const base::ListValue* val) const {
v8::Handle<v8::Array> result(v8::Array::New(isolate, val->GetSize()));
for (size_t i = 0; i < val->GetSize(); ++i) {
const base::Value* child = NULL;
CHECK(val->Get(i, &child));
v8::Handle<v8::Value> child_v8 =
ToV8ValueImpl(isolate, creation_context, child);
CHECK(!child_v8.IsEmpty());
v8::TryCatch try_catch;
result->Set(static_cast<uint32>(i), child_v8);
if (try_catch.HasCaught())
LOG(ERROR) << "Setter for index " << i << " threw an exception.";
}
return result;
}
v8::Handle<v8::Value> V8ValueConverterImpl::ToV8Object(
v8::Isolate* isolate,
v8::Handle<v8::Object> creation_context,
const base::DictionaryValue* val) const {
v8::Handle<v8::Object> result(v8::Object::New(isolate));
for (base::DictionaryValue::Iterator iter(*val);
!iter.IsAtEnd(); iter.Advance()) {
const std::string& key = iter.key();
v8::Handle<v8::Value> child_v8 =
ToV8ValueImpl(isolate, creation_context, &iter.value());
CHECK(!child_v8.IsEmpty());
v8::TryCatch try_catch;
result->Set(
v8::String::NewFromUtf8(
isolate, key.c_str(), v8::String::kNormalString, key.length()),
child_v8);
if (try_catch.HasCaught()) {
LOG(ERROR) << "Setter for property " << key.c_str() << " threw an "
<< "exception.";
}
}
return result;
}
v8::Handle<v8::Value> V8ValueConverterImpl::ToArrayBuffer(
v8::Isolate* isolate,
v8::Handle<v8::Object> creation_context,
const base::BinaryValue* value) const {
blink::WebArrayBuffer buffer =
blink::WebArrayBuffer::create(value->GetSize(), 1);
memcpy(buffer.data(), value->GetBuffer(), value->GetSize());
return blink::WebArrayBufferConverter::toV8Value(
&buffer, creation_context, isolate);
}
base::Value* V8ValueConverterImpl::FromV8ValueImpl(
FromV8ValueState* state,
v8::Handle<v8::Value> val,
v8::Isolate* isolate) const {
CHECK(!val.IsEmpty());
FromV8ValueState::Level state_level(state);
if (state->HasReachedMaxRecursionDepth())
return NULL;
if (val->IsNull())
return base::Value::CreateNullValue();
if (val->IsBoolean())
return new base::FundamentalValue(val->ToBoolean(isolate)->Value());
if (val->IsNumber() && strategy_) {
base::Value* out = NULL;
if (strategy_->FromV8Number(val.As<v8::Number>(), &out))
return out;
}
if (val->IsInt32())
return new base::FundamentalValue(val->ToInt32(isolate)->Value());
if (val->IsNumber()) {
double val_as_double = val.As<v8::Number>()->Value();
if (!base::IsFinite(val_as_double))
return NULL;
return new base::FundamentalValue(val_as_double);
}
if (val->IsString()) {
v8::String::Utf8Value utf8(val);
return new base::StringValue(std::string(*utf8, utf8.length()));
}
if (val->IsUndefined()) {
if (strategy_) {
base::Value* out = NULL;
if (strategy_->FromV8Undefined(&out))
return out;
}
// JSON.stringify ignores undefined.
return NULL;
}
if (val->IsDate()) {
if (!date_allowed_)
// JSON.stringify would convert this to a string, but an object is more
// consistent within this class.
return FromV8Object(val->ToObject(isolate), state, isolate);
v8::Date* date = v8::Date::Cast(*val);
return new base::FundamentalValue(date->ValueOf() / 1000.0);
}
if (val->IsRegExp()) {
if (!reg_exp_allowed_)
// JSON.stringify converts to an object.
return FromV8Object(val.As<v8::Object>(), state, isolate);
return new base::StringValue(*v8::String::Utf8Value(val));
}
// v8::Value doesn't have a ToArray() method for some reason.
if (val->IsArray())
return FromV8Array(val.As<v8::Array>(), state, isolate);
if (val->IsFunction()) {
if (!function_allowed_)
// JSON.stringify refuses to convert function(){}.
return NULL;
return FromV8Object(val.As<v8::Object>(), state, isolate);
}
if (val->IsArrayBuffer() || val->IsArrayBufferView())
return FromV8ArrayBuffer(val.As<v8::Object>(), isolate);
if (val->IsObject())
return FromV8Object(val.As<v8::Object>(), state, isolate);
LOG(ERROR) << "Unexpected v8 value type encountered.";
return NULL;
}
base::Value* V8ValueConverterImpl::FromV8Array(
v8::Handle<v8::Array> val,
FromV8ValueState* state,
v8::Isolate* isolate) const {
if (!state->UpdateAndCheckUniqueness(val))
return base::Value::CreateNullValue();
scoped_ptr<v8::Context::Scope> scope;
// If val was created in a different context than our current one, change to
// that context, but change back after val is converted.
if (!val->CreationContext().IsEmpty() &&
val->CreationContext() != isolate->GetCurrentContext())
scope.reset(new v8::Context::Scope(val->CreationContext()));
if (strategy_) {
// These base::Unretained's are safe, because Strategy::FromV8Value should
// be synchronous, so this object can't be out of scope.
V8ValueConverter::Strategy::FromV8ValueCallback callback =
base::Bind(&V8ValueConverterImpl::FromV8ValueImpl,
base::Unretained(this),
base::Unretained(state));
base::Value* out = NULL;
if (strategy_->FromV8Array(val, &out, isolate, callback))
return out;
}
base::ListValue* result = new base::ListValue();
// Only fields with integer keys are carried over to the ListValue.
for (uint32 i = 0; i < val->Length(); ++i) {
v8::TryCatch try_catch;
v8::Handle<v8::Value> child_v8 = val->Get(i);
if (try_catch.HasCaught()) {
LOG(ERROR) << "Getter for index " << i << " threw an exception.";
child_v8 = v8::Null(isolate);
}
if (!val->HasRealIndexedProperty(i)) {
result->Append(base::Value::CreateNullValue());
continue;
}
base::Value* child = FromV8ValueImpl(state, child_v8, isolate);
if (child)
result->Append(child);
else
// JSON.stringify puts null in places where values don't serialize, for
// example undefined and functions. Emulate that behavior.
result->Append(base::Value::CreateNullValue());
}
return result;
}
base::Value* V8ValueConverterImpl::FromV8ArrayBuffer(
v8::Handle<v8::Object> val,
v8::Isolate* isolate) const {
if (strategy_) {
base::Value* out = NULL;
if (strategy_->FromV8ArrayBuffer(val, &out, isolate))
return out;
}
char* data = NULL;
size_t length = 0;
scoped_ptr<blink::WebArrayBuffer> array_buffer(
blink::WebArrayBufferConverter::createFromV8Value(val, isolate));
scoped_ptr<blink::WebArrayBufferView> view;
if (array_buffer) {
data = reinterpret_cast<char*>(array_buffer->data());
length = array_buffer->byteLength();
} else {
view.reset(blink::WebArrayBufferView::createFromV8Value(val));
if (view) {
data = reinterpret_cast<char*>(view->baseAddress()) + view->byteOffset();
length = view->byteLength();
}
}
if (data)
return base::BinaryValue::CreateWithCopiedBuffer(data, length);
else
return NULL;
}
base::Value* V8ValueConverterImpl::FromV8Object(
v8::Handle<v8::Object> val,
FromV8ValueState* state,
v8::Isolate* isolate) const {
if (!state->UpdateAndCheckUniqueness(val))
return base::Value::CreateNullValue();
scoped_ptr<v8::Context::Scope> scope;
// If val was created in a different context than our current one, change to
// that context, but change back after val is converted.
if (!val->CreationContext().IsEmpty() &&
val->CreationContext() != isolate->GetCurrentContext())
scope.reset(new v8::Context::Scope(val->CreationContext()));
if (strategy_) {
// These base::Unretained's are safe, because Strategy::FromV8Value should
// be synchronous, so this object can't be out of scope.
V8ValueConverter::Strategy::FromV8ValueCallback callback =
base::Bind(&V8ValueConverterImpl::FromV8ValueImpl,
base::Unretained(this),
base::Unretained(state));
base::Value* out = NULL;
if (strategy_->FromV8Object(val, &out, isolate, callback))
return out;
}
// Don't consider DOM objects. This check matches isHostObject() in Blink's
// bindings/v8/V8Binding.h used in structured cloning. It reads:
//
// If the object has any internal fields, then we won't be able to serialize
// or deserialize them; conveniently, this is also a quick way to detect DOM
// wrapper objects, because the mechanism for these relies on data stored in
// these fields.
//
// NOTE: check this after |strategy_| so that callers have a chance to
// do something else, such as convert to the node's name rather than NULL.
//
// ANOTHER NOTE: returning an empty dictionary here to minimise surprise.
// See also http://crbug.com/330559.
if (val->InternalFieldCount())
return new base::DictionaryValue();
scoped_ptr<base::DictionaryValue> result(new base::DictionaryValue());
v8::Handle<v8::Array> property_names(val->GetOwnPropertyNames());
for (uint32 i = 0; i < property_names->Length(); ++i) {
v8::Handle<v8::Value> key(property_names->Get(i));
// Extend this test to cover more types as necessary and if sensible.
if (!key->IsString() &&
!key->IsNumber()) {
NOTREACHED() << "Key \"" << *v8::String::Utf8Value(key) << "\" "
"is neither a string nor a number";
continue;
}
v8::String::Utf8Value name_utf8(key);
v8::TryCatch try_catch;
v8::Handle<v8::Value> child_v8 = val->Get(key);
if (try_catch.HasCaught()) {
LOG(WARNING) << "Getter for property " << *name_utf8
<< " threw an exception.";
child_v8 = v8::Null(isolate);
}
scoped_ptr<base::Value> child(FromV8ValueImpl(state, child_v8, isolate));
if (!child)
// JSON.stringify skips properties whose values don't serialize, for
// example undefined and functions. Emulate that behavior.
continue;
// Strip null if asked (and since undefined is turned into null, undefined
// too). The use case for supporting this is JSON-schema support,
// specifically for extensions, where "optional" JSON properties may be
// represented as null, yet due to buggy legacy code elsewhere isn't
// treated as such (potentially causing crashes). For example, the
// "tabs.create" function takes an object as its first argument with an
// optional "windowId" property.
//
// Given just
//
// tabs.create({})
//
// this will work as expected on code that only checks for the existence of
// a "windowId" property (such as that legacy code). However given
//
// tabs.create({windowId: null})
//
// there *is* a "windowId" property, but since it should be an int, code
// on the browser which doesn't additionally check for null will fail.
// We can avoid all bugs related to this by stripping null.
if (strip_null_from_objects_ && child->IsType(base::Value::TYPE_NULL))
continue;
result->SetWithoutPathExpansion(std::string(*name_utf8, name_utf8.length()),
child.release());
}
return result.release();
}
} // namespace content