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// Copyright 2021 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.
#ifndef INCLUDE_V8_WASM_H_
#define INCLUDE_V8_WASM_H_
#include <functional>
#include <memory>
#include <string>
#include "v8-local-handle.h" // NOLINT(build/include_directory)
#include "v8-memory-span.h" // NOLINT(build/include_directory)
#include "v8-object.h" // NOLINT(build/include_directory)
#include "v8config.h" // NOLINT(build/include_directory)
namespace v8 {
class ArrayBuffer;
class Promise;
namespace internal {
namespace wasm {
class NativeModule;
class StreamingDecoder;
} // namespace wasm
} // namespace internal
/**
* An owned byte buffer with associated size.
*/
struct OwnedBuffer {
std::unique_ptr<const uint8_t[]> buffer;
size_t size = 0;
OwnedBuffer(std::unique_ptr<const uint8_t[]> buffer, size_t size)
: buffer(std::move(buffer)), size(size) {}
OwnedBuffer() = default;
};
// Wrapper around a compiled WebAssembly module, which is potentially shared by
// different WasmModuleObjects.
class V8_EXPORT CompiledWasmModule {
public:
/**
* Serialize the compiled module. The serialized data does not include the
* wire bytes.
*/
OwnedBuffer Serialize();
/**
* Get the (wasm-encoded) wire bytes that were used to compile this module.
*/
MemorySpan<const uint8_t> GetWireBytesRef();
const std::string& source_url() const { return source_url_; }
private:
friend class WasmModuleObject;
friend class WasmStreaming;
explicit CompiledWasmModule(std::shared_ptr<internal::wasm::NativeModule>,
const char* source_url, size_t url_length);
const std::shared_ptr<internal::wasm::NativeModule> native_module_;
const std::string source_url_;
};
// An instance of WebAssembly.Memory.
class V8_EXPORT WasmMemoryObject : public Object {
public:
WasmMemoryObject() = delete;
/**
* Returns underlying ArrayBuffer.
*/
Local<ArrayBuffer> Buffer();
V8_INLINE static WasmMemoryObject* Cast(Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<WasmMemoryObject*>(value);
}
private:
static void CheckCast(Value* object);
};
// An instance of WebAssembly.Module.
class V8_EXPORT WasmModuleObject : public Object {
public:
WasmModuleObject() = delete;
/**
* Efficiently re-create a WasmModuleObject, without recompiling, from
* a CompiledWasmModule.
*/
static MaybeLocal<WasmModuleObject> FromCompiledModule(
Isolate* isolate, const CompiledWasmModule&);
/**
* Get the compiled module for this module object. The compiled module can be
* shared by several module objects.
*/
CompiledWasmModule GetCompiledModule();
/**
* Compile a Wasm module from the provided uncompiled bytes.
*/
static MaybeLocal<WasmModuleObject> Compile(
Isolate* isolate, MemorySpan<const uint8_t> wire_bytes);
V8_INLINE static WasmModuleObject* Cast(Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<WasmModuleObject*>(value);
}
private:
static void CheckCast(Value* obj);
};
/**
* The V8 interface for WebAssembly streaming compilation. When streaming
* compilation is initiated, V8 passes a {WasmStreaming} object to the embedder
* such that the embedder can pass the input bytes for streaming compilation to
* V8.
*/
class V8_EXPORT WasmStreaming final {
public:
class WasmStreamingImpl;
explicit WasmStreaming(std::unique_ptr<WasmStreamingImpl> impl);
~WasmStreaming();
/**
* Pass a new chunk of bytes to WebAssembly streaming compilation.
* The buffer passed into {OnBytesReceived} is owned by the caller.
*/
void OnBytesReceived(const uint8_t* bytes, size_t size);
/**
* {Finish} should be called after all received bytes where passed to
* {OnBytesReceived} to tell V8 that there will be no more bytes. {Finish}
* must not be called after {Abort} has been called already.
* If {can_use_compiled_module} is true and {SetCompiledModuleBytes} was
* previously called, the compiled module bytes can be used.
* If {can_use_compiled_module} is false, the compiled module bytes previously
* set by {SetCompiledModuleBytes} should not be used.
*/
void Finish(bool can_use_compiled_module = true);
/**
* Abort streaming compilation. If {exception} has a value, then the promise
* associated with streaming compilation is rejected with that value. If
* {exception} does not have value, the promise does not get rejected.
* {Abort} must not be called repeatedly, or after {Finish}.
*/
void Abort(MaybeLocal<Value> exception);
/**
* Passes previously compiled module bytes. This must be called before
* {OnBytesReceived}, {Finish}, or {Abort}. Returns true if the module bytes
* can be used, false otherwise. The buffer passed via {bytes} and {size}
* is owned by the caller. If {SetCompiledModuleBytes} returns true, the
* buffer must remain valid until either {Finish} or {Abort} completes.
* The compiled module bytes should not be used until {Finish(true)} is
* called, because they can be invalidated later by {Finish(false)}.
*/
bool SetCompiledModuleBytes(const uint8_t* bytes, size_t size);
/**
* Sets a callback which is called whenever a significant number of new
* functions are ready for serialization.
*/
void SetMoreFunctionsCanBeSerializedCallback(
std::function<void(CompiledWasmModule)>);
/*
* Sets the UTF-8 encoded source URL for the {Script} object. This must be
* called before {Finish}.
*/
void SetUrl(const char* url, size_t length);
/**
* Unpacks a {WasmStreaming} object wrapped in a {Managed} for the embedder.
* Since the embedder is on the other side of the API, it cannot unpack the
* {Managed} itself.
*/
static std::shared_ptr<WasmStreaming> Unpack(Isolate* isolate,
Local<Value> value);
private:
std::unique_ptr<WasmStreamingImpl> impl_;
};
} // namespace v8
#endif // INCLUDE_V8_WASM_H_
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