File Explorer

/proc/self/root/proc/self/root/proc/thread-self/root/node24/include/node

This explorer reads the filesystem of the server it runs on, so /workspace/user isn't present here. Browsing and the terminal still work against this server's own disk from /.

v8-value-serializer.h10.6 KB · 317 lines
// 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_VALUE_SERIALIZER_H_#define INCLUDE_V8_VALUE_SERIALIZER_H_ #include <stddef.h>#include <stdint.h> #include <memory>#include <utility> #include "v8-local-handle.h"  // NOLINT(build/include_directory)#include "v8-maybe.h"         // NOLINT(build/include_directory)#include "v8config.h"         // NOLINT(build/include_directory) namespace v8 { class ArrayBuffer;class Isolate;class Object;class SharedArrayBuffer;class String;class WasmModuleObject;class Value; namespace internal {struct ScriptStreamingData;class SharedObjectConveyorHandles;class ValueDeserializer;class ValueSerializer;}  // namespace internal /** * A move-only class for managing the lifetime of shared value conveyors used * by V8 to keep JS shared values alive in transit when serialized. * * This class is not directly constructible and is always passed to a * ValueSerializer::Delegate via ValueSerializer::SetSharedValueConveyor. * * The embedder must not destruct the SharedValueConveyor until the associated * serialized data will no longer be deserialized. */class V8_EXPORT SharedValueConveyor final { public:  SharedValueConveyor(SharedValueConveyor&&) noexcept;  ~SharedValueConveyor();   SharedValueConveyor& operator=(SharedValueConveyor&&) noexcept;  private:  friend class internal::ValueSerializer;  friend class internal::ValueDeserializer;   explicit SharedValueConveyor(Isolate* isolate);   std::unique_ptr<internal::SharedObjectConveyorHandles> private_;}; /** * Value serialization compatible with the HTML structured clone algorithm. * The format is backward-compatible (i.e. safe to store to disk). */class V8_EXPORT ValueSerializer { public:  class V8_EXPORT Delegate {   public:    virtual ~Delegate() = default;     /**     * Handles the case where a DataCloneError would be thrown in the structured     * clone spec. Other V8 embedders may throw some other appropriate exception     * type.     */    virtual void ThrowDataCloneError(Local<String> message) = 0;     /**     * The embedder overrides this method to enable custom host object filter     * with Delegate::IsHostObject.     *     * This method is called at most once per serializer.     */    virtual bool HasCustomHostObject(Isolate* isolate);     /**     * The embedder overrides this method to determine if an JS object is a     * host object and needs to be serialized by the host.     */    virtual Maybe<bool> IsHostObject(Isolate* isolate, Local<Object> object);     /**     * The embedder overrides this method to write some kind of host object, if     * possible. If not, a suitable exception should be thrown and     * Nothing<bool>() returned.     */    virtual Maybe<bool> WriteHostObject(Isolate* isolate, Local<Object> object);     /**     * Called when the ValueSerializer is going to serialize a     * SharedArrayBuffer object. The embedder must return an ID for the     * object, using the same ID if this SharedArrayBuffer has already been     * serialized in this buffer. When deserializing, this ID will be passed to     * ValueDeserializer::GetSharedArrayBufferFromId as |clone_id|.     *     * If the object cannot be serialized, an     * exception should be thrown and Nothing<uint32_t>() returned.     */    virtual Maybe<uint32_t> GetSharedArrayBufferId(        Isolate* isolate, Local<SharedArrayBuffer> shared_array_buffer);     virtual Maybe<uint32_t> GetWasmModuleTransferId(        Isolate* isolate, Local<WasmModuleObject> module);     /**     * Called when the first shared value is serialized. All subsequent shared     * values will use the same conveyor.     *     * The embedder must ensure the lifetime of the conveyor matches the     * lifetime of the serialized data.     *     * If the embedder supports serializing shared values, this method should     * return true. Otherwise the embedder should throw an exception and return     * false.     *     * This method is called at most once per serializer.     */    virtual bool AdoptSharedValueConveyor(Isolate* isolate,                                          SharedValueConveyor&& conveyor);     /**     * Allocates memory for the buffer of at least the size provided. The actual     * size (which may be greater or equal) is written to |actual_size|. If no     * buffer has been allocated yet, nullptr will be provided.     *     * If the memory cannot be allocated, nullptr should be returned.     * |actual_size| will be ignored. It is assumed that |old_buffer| is still     * valid in this case and has not been modified.     *     * The default implementation uses the stdlib's `realloc()` function.     */    virtual void* ReallocateBufferMemory(void* old_buffer, size_t size,                                         size_t* actual_size);     /**     * Frees a buffer allocated with |ReallocateBufferMemory|.     *     * The default implementation uses the stdlib's `free()` function.     */    virtual void FreeBufferMemory(void* buffer);  };   explicit ValueSerializer(Isolate* isolate);  ValueSerializer(Isolate* isolate, Delegate* delegate);  ~ValueSerializer();   /**   * Writes out a header, which includes the format version.   */  void WriteHeader();   /**   * Serializes a JavaScript value into the buffer.   */  V8_WARN_UNUSED_RESULT Maybe<bool> WriteValue(Local<Context> context,                                               Local<Value> value);   /**   * Returns the stored data (allocated using the delegate's   * ReallocateBufferMemory) and its size. This serializer should not be used   * once the buffer is released. The contents are undefined if a previous write   * has failed. Ownership of the buffer is transferred to the caller.   */  V8_WARN_UNUSED_RESULT std::pair<uint8_t*, size_t> Release();   /**   * Marks an ArrayBuffer as havings its contents transferred out of band.   * Pass the corresponding ArrayBuffer in the deserializing context to   * ValueDeserializer::TransferArrayBuffer.   */  void TransferArrayBuffer(uint32_t transfer_id,                           Local<ArrayBuffer> array_buffer);   /**   * Indicate whether to treat ArrayBufferView objects as host objects,   * i.e. pass them to Delegate::WriteHostObject. This should not be   * called when no Delegate was passed.   *   * The default is not to treat ArrayBufferViews as host objects.   */  void SetTreatArrayBufferViewsAsHostObjects(bool mode);   /**   * Write raw data in various common formats to the buffer.   * Note that integer types are written in base-128 varint format, not with a   * binary copy. For use during an override of Delegate::WriteHostObject.   */  void WriteUint32(uint32_t value);  void WriteUint64(uint64_t value);  void WriteDouble(double value);  void WriteRawBytes(const void* source, size_t length);   ValueSerializer(const ValueSerializer&) = delete;  void operator=(const ValueSerializer&) = delete;  private:  struct PrivateData;  PrivateData* private_;}; /** * Deserializes values from data written with ValueSerializer, or a compatible * implementation. */class V8_EXPORT ValueDeserializer { public:  class V8_EXPORT Delegate {   public:    virtual ~Delegate() = default;     /**     * The embedder overrides this method to read some kind of host object, if     * possible. If not, a suitable exception should be thrown and     * MaybeLocal<Object>() returned.     */    virtual MaybeLocal<Object> ReadHostObject(Isolate* isolate);     /**     * Get a WasmModuleObject given a transfer_id previously provided     * by ValueSerializer::Delegate::GetWasmModuleTransferId     */    virtual MaybeLocal<WasmModuleObject> GetWasmModuleFromId(        Isolate* isolate, uint32_t transfer_id);     /**     * Get a SharedArrayBuffer given a clone_id previously provided     * by ValueSerializer::Delegate::GetSharedArrayBufferId     */    virtual MaybeLocal<SharedArrayBuffer> GetSharedArrayBufferFromId(        Isolate* isolate, uint32_t clone_id);     /**     * Get the SharedValueConveyor previously provided by     * ValueSerializer::Delegate::AdoptSharedValueConveyor.     */    virtual const SharedValueConveyor* GetSharedValueConveyor(Isolate* isolate);  };   ValueDeserializer(Isolate* isolate, const uint8_t* data, size_t size);  ValueDeserializer(Isolate* isolate, const uint8_t* data, size_t size,                    Delegate* delegate);  ~ValueDeserializer();   /**   * Reads and validates a header (including the format version).   * May, for example, reject an invalid or unsupported wire format.   */  V8_WARN_UNUSED_RESULT Maybe<bool> ReadHeader(Local<Context> context);   /**   * Deserializes a JavaScript value from the buffer.   */  V8_WARN_UNUSED_RESULT MaybeLocal<Value> ReadValue(Local<Context> context);   /**   * Accepts the array buffer corresponding to the one passed previously to   * ValueSerializer::TransferArrayBuffer.   */  void TransferArrayBuffer(uint32_t transfer_id,                           Local<ArrayBuffer> array_buffer);   /**   * Similar to TransferArrayBuffer, but for SharedArrayBuffer.   * The id is not necessarily in the same namespace as unshared ArrayBuffer   * objects.   */  void TransferSharedArrayBuffer(uint32_t id,                                 Local<SharedArrayBuffer> shared_array_buffer);   /**   * Must be called before ReadHeader to enable support for reading the legacy   * wire format (i.e., which predates this being shipped).   *   * Don't use this unless you need to read data written by previous versions of   * blink::ScriptValueSerializer.   */  void SetSupportsLegacyWireFormat(bool supports_legacy_wire_format);   /**   * Reads the underlying wire format version. Likely mostly to be useful to   * legacy code reading old wire format versions. Must be called after   * ReadHeader.   */  uint32_t GetWireFormatVersion() const;   /**   * Reads raw data in various common formats to the buffer.   * Note that integer types are read in base-128 varint format, not with a   * binary copy. For use during an override of Delegate::ReadHostObject.   */  V8_WARN_UNUSED_RESULT bool ReadUint32(uint32_t* value);  V8_WARN_UNUSED_RESULT bool ReadUint64(uint64_t* value);  V8_WARN_UNUSED_RESULT bool ReadDouble(double* value);  V8_WARN_UNUSED_RESULT bool ReadRawBytes(size_t length, const void** data);   ValueDeserializer(const ValueDeserializer&) = delete;  void operator=(const ValueDeserializer&) = delete;  private:  struct PrivateData;  PrivateData* private_;}; }  // namespace v8 #endif  // INCLUDE_V8_VALUE_SERIALIZER_H_