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// Copyright 2010 the V8 project 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 "src/extensions/externalize-string-extension.h"
#include "src/api/api-inl.h"
#include "src/execution/isolate.h"
#include "src/handles/handles.h"
#include "src/objects/objects-inl.h"
namespace v8 {
namespace internal {
template <typename Char, typename Base>
class SimpleStringResource : public Base {
public:
// Takes ownership of |data|.
SimpleStringResource(Char* data, size_t length)
: data_(data),
length_(length) {}
~SimpleStringResource() override { delete[] data_; }
const Char* data() const override { return data_; }
size_t length() const override { return length_; }
private:
Char* const data_;
const size_t length_;
};
using SimpleOneByteStringResource =
SimpleStringResource<char, v8::String::ExternalOneByteStringResource>;
using SimpleTwoByteStringResource =
SimpleStringResource<uc16, v8::String::ExternalStringResource>;
const char* const ExternalizeStringExtension::kSource =
"native function externalizeString();"
"native function isOneByteString();"
"function x() { return 1; }";
v8::Local<v8::FunctionTemplate>
ExternalizeStringExtension::GetNativeFunctionTemplate(
v8::Isolate* isolate, v8::Local<v8::String> str) {
if (strcmp(*v8::String::Utf8Value(isolate, str), "externalizeString") == 0) {
return v8::FunctionTemplate::New(isolate,
ExternalizeStringExtension::Externalize);
} else {
DCHECK_EQ(strcmp(*v8::String::Utf8Value(isolate, str), "isOneByteString"),
0);
return v8::FunctionTemplate::New(isolate,
ExternalizeStringExtension::IsOneByte);
}
}
void ExternalizeStringExtension::Externalize(
const v8::FunctionCallbackInfo<v8::Value>& args) {
if (args.Length() < 1 || !args[0]->IsString()) {
args.GetIsolate()->ThrowError(
"First parameter to externalizeString() must be a string.");
return;
}
bool force_two_byte = false;
if (args.Length() >= 2) {
if (args[1]->IsBoolean()) {
force_two_byte = args[1]->BooleanValue(args.GetIsolate());
} else {
args.GetIsolate()->ThrowError(
"Second parameter to externalizeString() must be a boolean.");
return;
}
}
bool result = false;
Handle<String> string = Utils::OpenHandle(*args[0].As<v8::String>());
if (!string->SupportsExternalization()) {
args.GetIsolate()->ThrowError("string does not support externalization.");
return;
}
if (string->IsOneByteRepresentation() && !force_two_byte) {
uint8_t* data = new uint8_t[string->length()];
String::WriteToFlat(*string, data, 0, string->length());
SimpleOneByteStringResource* resource = new SimpleOneByteStringResource(
reinterpret_cast<char*>(data), string->length());
result = Utils::ToLocal(string)->MakeExternal(resource);
if (!result) delete resource;
} else {
uc16* data = new uc16[string->length()];
String::WriteToFlat(*string, data, 0, string->length());
SimpleTwoByteStringResource* resource = new SimpleTwoByteStringResource(
data, string->length());
result = Utils::ToLocal(string)->MakeExternal(resource);
if (!result) delete resource;
}
if (!result) {
args.GetIsolate()->ThrowError("externalizeString() failed.");
return;
}
}
void ExternalizeStringExtension::IsOneByte(
const v8::FunctionCallbackInfo<v8::Value>& args) {
if (args.Length() != 1 || !args[0]->IsString()) {
args.GetIsolate()->ThrowError(
"isOneByteString() requires a single string argument.");
return;
}
bool is_one_byte =
Utils::OpenHandle(*args[0].As<v8::String>())->IsOneByteRepresentation();
args.GetReturnValue().Set(is_one_byte);
}
} // namespace internal
} // namespace v8
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