зеркало из https://github.com/mozilla/gecko-dev.git
754 строки
29 KiB
C++
754 строки
29 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
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* vim: set ts=8 sts=2 et sw=2 tw=80:
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#ifndef js_StructuredClone_h
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#define js_StructuredClone_h
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#include "mozilla/Attributes.h"
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#include "mozilla/BufferList.h"
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#include "mozilla/MemoryReporting.h"
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#include <stdint.h>
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#include <utility>
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#include "jstypes.h"
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#include "js/AllocPolicy.h"
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#include "js/RootingAPI.h"
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#include "js/TypeDecls.h"
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#include "js/Value.h"
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#include "js/Vector.h"
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/*
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* API for safe passing of structured data, HTML 2018 Feb 21 section 2.7.
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* <https://html.spec.whatwg.org/multipage/structured-data.html>
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*
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* This is a serialization scheme for JS values, somewhat like JSON. It
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* preserves some aspects of JS objects (strings, numbers, own data properties
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* with string keys, array elements) but not others (methods, getters and
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* setters, prototype chains). Unlike JSON, structured data:
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*
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* - can contain cyclic references.
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*
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* - handles Maps, Sets, and some other object types.
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*
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* - supports *transferring* objects of certain types from one realm to
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* another, rather than cloning them.
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*
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* - is specified by a living standard, and continues to evolve.
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*
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* - is encoded in a nonstandard binary format, and is never exposed to Web
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* content in its serialized form. It's used internally by the browser to
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* send data from one thread/realm/domain to another, not across the
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* network.
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*/
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struct JSStructuredCloneReader;
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struct JSStructuredCloneWriter;
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/**
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* The structured-clone serialization format version number.
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*
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* When serialized data is stored as bytes, e.g. in your Firefox profile, later
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* versions of the engine may have to read it. When you upgrade Firefox, we
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* don't crawl through your whole profile converting all saved data from the
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* previous version of the serialization format to the latest version. So it is
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* normal to have data in old formats stored in your profile.
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*
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* The JS engine can *write* data only in the current format version.
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*
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* It can *read* any data written in the current version, and data written for
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* DifferentProcess scope in earlier versions.
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*
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*
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* ## When to bump this version number
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*
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* When making a change so drastic that the JS engine needs to know whether
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* it's reading old or new serialized data in order to handle both correctly,
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* increment this version number. Make sure the engine can still read all
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* old data written with previous versions.
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*
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* If StructuredClone.cpp doesn't contain code that distinguishes between
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* version 8 and version 9, there should not be a version 9.
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*
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* Do not increment for changes that only affect SameProcess encoding.
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*
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* Increment only for changes that would otherwise break old serialized data.
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* Do not increment for new data types. (Rationale: Modulo bugs, older versions
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* of the JS engine can already correctly throw errors when they encounter new,
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* unrecognized features. A version number bump does not actually help them.)
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*/
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#define JS_STRUCTURED_CLONE_VERSION 8
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namespace JS {
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/**
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* Indicates the "scope of validity" of serialized data.
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*
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* Writing plain JS data produces an array of bytes that can be copied and
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* read in another process or whatever. The serialized data is Plain Old Data.
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* However, HTML also supports `Transferable` objects, which, when cloned, can
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* be moved from the source object into the clone, like when you take a
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* photograph of someone and it steals their soul.
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* See <https://developer.mozilla.org/en-US/docs/Web/API/Transferable>.
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* We support cloning and transferring objects of many types.
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*
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* For example, when we transfer an ArrayBuffer (within a process), we "detach"
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* the ArrayBuffer, embed the raw buffer pointer in the serialized data, and
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* later install it in a new ArrayBuffer in the destination realm. Ownership
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* of that buffer memory is transferred from the original ArrayBuffer to the
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* serialized data and then to the clone.
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*
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* This only makes sense within a single address space. When we transfer an
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* ArrayBuffer to another process, the contents of the buffer must be copied
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* into the serialized data. (The original ArrayBuffer is still detached,
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* though, for consistency; in some cases the caller shouldn't know or care if
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* the recipient is in the same process.)
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*
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* ArrayBuffers are actually a lucky case; some objects (like MessagePorts)
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* can't reasonably be stored by value in serialized data -- it's pointers or
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* nothing.
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*
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* So there is a tradeoff between scope of validity -- how far away the
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* serialized data may be sent and still make sense -- and efficiency or
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* features. The read and write algorithms therefore take an argument of this
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* type, allowing the user to control those trade-offs.
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*/
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enum class StructuredCloneScope : uint32_t {
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/**
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* The most restrictive scope, with greatest efficiency and features.
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*
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* When writing, this means: The caller promises that the serialized data
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* will **not** be shipped off to a different process or stored in a
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* database. However, it may be shipped to another thread. It's OK to
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* produce serialized data that contains pointers to data that is safe to
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* send across threads, such as array buffers. In Rust terms, the
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* serialized data will be treated as `Send` but not `Copy`.
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*
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* When reading, this means: Accept transferred objects and buffers
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* (pointers). The caller promises that the serialized data was written
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* using this API (otherwise, the serialized data may contain bogus
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* pointers, leading to undefined behavior).
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*
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* Starts from 1 because there used to be a SameProcessSameThread enum value
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* of 0 and these values are encoded into the structured serialization format
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* as part of the SCTAG_HEADER, and IndexedDB persists the representation to
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* disk.
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*/
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SameProcess = 1,
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/**
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* When writing, this means we're writing for an audience in a different
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* process. Produce serialized data that can be sent to other processes,
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* bitwise copied, or even stored as bytes in a database and read by later
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* versions of Firefox years from now. The HTML5 spec refers to this as
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* "ForStorage" as in StructuredSerializeForStorage, though we use
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* DifferentProcess for IPC as well as storage.
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*
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* Transferable objects are limited to ArrayBuffers, whose contents are
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* copied into the serialized data (rather than just writing a pointer).
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*
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* When reading, this means: Do not accept pointers.
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*/
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DifferentProcess,
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/**
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* Handle a backwards-compatibility case with IndexedDB (bug 1434308): when
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* reading, this means to treat legacy SameProcess data as if it were
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* DifferentProcess.
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*
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* Do not use this for writing; use DifferentProcess instead.
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*/
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DifferentProcessForIndexedDB,
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/**
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* Existing code wants to be able to create an uninitialized
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* JSStructuredCloneData without knowing the scope, then populate it with
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* data (at which point the scope *is* known.)
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*/
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Unassigned,
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/**
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* This scope is used when the deserialization context is unknown. When
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* writing, DifferentProcess or SameProcess scope is chosen based on the
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* nature of the object.
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*/
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UnknownDestination,
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};
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enum TransferableOwnership {
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/** Transferable data has not been filled in yet */
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SCTAG_TMO_UNFILLED = 0,
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/** Structured clone buffer does not yet own the data */
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SCTAG_TMO_UNOWNED = 1,
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/** All values at least this large are owned by the clone buffer */
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SCTAG_TMO_FIRST_OWNED = 2,
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/** Data is a pointer that can be freed */
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SCTAG_TMO_ALLOC_DATA = 2,
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/** Data is a memory mapped pointer */
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SCTAG_TMO_MAPPED_DATA = 3,
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/**
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* Data is embedding-specific. The engine can free it by calling the
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* freeTransfer op. The embedding can also use SCTAG_TMO_USER_MIN and
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* greater, up to 32 bits, to distinguish specific ownership variants.
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*/
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SCTAG_TMO_CUSTOM = 4,
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SCTAG_TMO_USER_MIN
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};
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class CloneDataPolicy {
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bool allowIntraClusterClonableSharedObjects_;
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bool allowSharedMemoryObjects_;
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public:
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// The default is to deny all policy-controlled aspects.
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CloneDataPolicy()
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: allowIntraClusterClonableSharedObjects_(false),
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allowSharedMemoryObjects_(false) {}
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// SharedArrayBuffers and WASM modules can only be cloned intra-process
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// because the shared memory areas are allocated in process-private memory or
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// because there are security issues of sharing them cross agent clusters.
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// y default, we don't allow shared-memory and intra-cluster objects. Clients
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// should therefore enable these 2 clone features when needed.
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void allowIntraClusterClonableSharedObjects() {
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allowIntraClusterClonableSharedObjects_ = true;
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}
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bool areIntraClusterClonableSharedObjectsAllowed() const {
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return allowIntraClusterClonableSharedObjects_;
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}
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void allowSharedMemoryObjects() { allowSharedMemoryObjects_ = true; }
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bool areSharedMemoryObjectsAllowed() const {
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return allowSharedMemoryObjects_;
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}
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};
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} /* namespace JS */
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/**
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* Read structured data from the reader r. This hook is used to read a value
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* previously serialized by a call to the WriteStructuredCloneOp hook.
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*
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* tag and data are the pair of uint32_t values from the header. The callback
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* may use the JS_Read* APIs to read any other relevant parts of the object
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* from the reader r. closure is any value passed to the JS_ReadStructuredClone
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* function. Return the new object on success, nullptr on error/exception.
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*/
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typedef JSObject* (*ReadStructuredCloneOp)(
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JSContext* cx, JSStructuredCloneReader* r,
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const JS::CloneDataPolicy& cloneDataPolicy, uint32_t tag, uint32_t data,
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void* closure);
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/**
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* Structured data serialization hook. The engine can write primitive values,
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* Objects, Arrays, Dates, RegExps, TypedArrays, ArrayBuffers, Sets, Maps,
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* and SharedTypedArrays. Any other type of object requires application support.
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* This callback must first use the JS_WriteUint32Pair API to write an object
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* header, passing a value greater than JS_SCTAG_USER to the tag parameter.
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* Then it can use the JS_Write* APIs to write any other relevant parts of
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* the value v to the writer w. closure is any value passed to the
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* JS_WriteStructuredClone function.
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*
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* Return true on success, false on error/exception.
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*/
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typedef bool (*WriteStructuredCloneOp)(JSContext* cx,
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JSStructuredCloneWriter* w,
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JS::HandleObject obj,
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bool* sameProcessScopeRequired,
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void* closure);
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/**
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* This is called when JS_WriteStructuredClone is given an invalid transferable.
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* To follow HTML5, the application must throw a DATA_CLONE_ERR DOMException
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* with error set to one of the JS_SCERR_* values.
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*/
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typedef void (*StructuredCloneErrorOp)(JSContext* cx, uint32_t errorid,
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void* closure, const char* errorMessage);
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/**
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* This is called when JS_ReadStructuredClone receives a transferable object
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* not known to the engine. If this hook does not exist or returns false, the
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* JS engine calls the reportError op if set, otherwise it throws a
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* DATA_CLONE_ERR DOM Exception. This method is called before any other
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* callback and must return a non-null object in returnObject on success.
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*/
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typedef bool (*ReadTransferStructuredCloneOp)(
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JSContext* cx, JSStructuredCloneReader* r, uint32_t tag, void* content,
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uint64_t extraData, void* closure, JS::MutableHandleObject returnObject);
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/**
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* Called when JS_WriteStructuredClone receives a transferable object not
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* handled by the engine. If this hook does not exist or returns false, the JS
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* engine will call the reportError hook or fall back to throwing a
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* DATA_CLONE_ERR DOM Exception. This method is called before any other
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* callback.
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*
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* tag: indicates what type of transferable this is. Must be greater than
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* 0xFFFF0201 (value of the internal SCTAG_TRANSFER_MAP_PENDING_ENTRY)
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*
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* ownership: see TransferableOwnership, above. Used to communicate any needed
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* ownership info to the FreeTransferStructuredCloneOp.
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*
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* content, extraData: what the ReadTransferStructuredCloneOp will receive
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*/
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typedef bool (*TransferStructuredCloneOp)(JSContext* cx,
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JS::Handle<JSObject*> obj,
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void* closure,
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// Output:
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uint32_t* tag,
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JS::TransferableOwnership* ownership,
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void** content, uint64_t* extraData);
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/**
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* Called when freeing an unknown transferable object. Note that it
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* should never trigger a garbage collection (and will assert in a
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* debug build if it does.)
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*/
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typedef void (*FreeTransferStructuredCloneOp)(
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uint32_t tag, JS::TransferableOwnership ownership, void* content,
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uint64_t extraData, void* closure);
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/**
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* Called when the transferring objects are checked. If this function returns
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* false, the serialization ends throwing a DataCloneError exception.
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*/
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typedef bool (*CanTransferStructuredCloneOp)(JSContext* cx,
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JS::Handle<JSObject*> obj,
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bool* sameProcessScopeRequired,
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void* closure);
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/**
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* Called when a SharedArrayBuffer (including one owned by a Wasm memory object)
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* has been processed in context `cx` by structured cloning. If `receiving` is
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* true then the SAB has been received from a channel and a new SAB object has
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* been created; if false then an existing SAB has been serialized onto a
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* channel.
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*
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* If the callback returns false then the clone operation (read or write) will
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* signal a failure.
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*/
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typedef bool (*SharedArrayBufferClonedOp)(JSContext* cx, bool receiving,
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void* closure);
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struct JSStructuredCloneCallbacks {
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ReadStructuredCloneOp read;
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WriteStructuredCloneOp write;
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StructuredCloneErrorOp reportError;
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ReadTransferStructuredCloneOp readTransfer;
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TransferStructuredCloneOp writeTransfer;
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FreeTransferStructuredCloneOp freeTransfer;
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CanTransferStructuredCloneOp canTransfer;
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SharedArrayBufferClonedOp sabCloned;
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};
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enum OwnTransferablePolicy {
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/**
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* The buffer owns any Transferables that it might contain, and should
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* properly release them upon destruction.
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*/
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OwnsTransferablesIfAny,
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/**
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* Do not free any Transferables within this buffer when deleting it. This
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* is used to mark as clone buffer as containing data from another process,
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* and so it can't legitimately contain pointers. If the buffer claims to
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* have transferables, it's a bug or an attack. This is also used for
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* abandon(), where a buffer still contains raw data but the ownership has
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* been given over to some other entity.
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*/
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IgnoreTransferablesIfAny,
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/**
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* A buffer that cannot contain Transferables at all. This usually means
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* the buffer is empty (not yet filled in, or having been cleared).
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*/
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NoTransferables
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};
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namespace js {
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class SharedArrayRawBuffer;
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class SharedArrayRawBufferRefs {
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public:
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SharedArrayRawBufferRefs() = default;
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SharedArrayRawBufferRefs(SharedArrayRawBufferRefs&& other) = default;
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SharedArrayRawBufferRefs& operator=(SharedArrayRawBufferRefs&& other);
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~SharedArrayRawBufferRefs();
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[[nodiscard]] bool acquire(JSContext* cx, SharedArrayRawBuffer* rawbuf);
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[[nodiscard]] bool acquireAll(JSContext* cx,
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const SharedArrayRawBufferRefs& that);
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void takeOwnership(SharedArrayRawBufferRefs&&);
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void releaseAll();
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private:
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js::Vector<js::SharedArrayRawBuffer*, 0, js::SystemAllocPolicy> refs_;
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};
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template <typename T, typename AllocPolicy>
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struct BufferIterator;
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} // namespace js
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/**
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* JSStructuredCloneData represents structured clone data together with the
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* information needed to read/write/transfer/free the records within it, in the
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* form of a set of callbacks.
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*/
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class MOZ_NON_MEMMOVABLE JS_PUBLIC_API JSStructuredCloneData {
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public:
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using BufferList = mozilla::BufferList<js::SystemAllocPolicy>;
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using Iterator = BufferList::IterImpl;
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private:
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static const size_t kStandardCapacity = 4096;
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BufferList bufList_;
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// The (address space, thread) scope within which this clone is valid. Note
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// that this must be either set during construction, or start out as
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// Unassigned and transition once to something else.
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JS::StructuredCloneScope scope_;
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const JSStructuredCloneCallbacks* callbacks_ = nullptr;
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void* closure_ = nullptr;
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OwnTransferablePolicy ownTransferables_ =
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OwnTransferablePolicy::NoTransferables;
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js::SharedArrayRawBufferRefs refsHeld_;
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friend struct JSStructuredCloneWriter;
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friend class JS_PUBLIC_API JSAutoStructuredCloneBuffer;
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template <typename T, typename AllocPolicy>
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friend struct js::BufferIterator;
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public:
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// The constructor must be infallible but SystemAllocPolicy is not, so both
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// the initial size and initial capacity of the BufferList must be zero.
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explicit JSStructuredCloneData(JS::StructuredCloneScope scope)
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: bufList_(0, 0, kStandardCapacity, js::SystemAllocPolicy()),
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scope_(scope),
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callbacks_(nullptr),
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closure_(nullptr),
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ownTransferables_(OwnTransferablePolicy::NoTransferables) {}
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// Steal the raw data from a BufferList. In this case, we don't know the
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// scope and none of the callback info is assigned yet.
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JSStructuredCloneData(BufferList&& buffers, JS::StructuredCloneScope scope)
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: bufList_(std::move(buffers)),
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scope_(scope),
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callbacks_(nullptr),
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closure_(nullptr),
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ownTransferables_(OwnTransferablePolicy::NoTransferables) {}
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MOZ_IMPLICIT JSStructuredCloneData(BufferList&& buffers)
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: JSStructuredCloneData(std::move(buffers),
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JS::StructuredCloneScope::Unassigned) {}
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JSStructuredCloneData(JSStructuredCloneData&& other) = default;
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JSStructuredCloneData& operator=(JSStructuredCloneData&& other) = default;
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~JSStructuredCloneData();
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void setCallbacks(const JSStructuredCloneCallbacks* callbacks, void* closure,
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OwnTransferablePolicy policy) {
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callbacks_ = callbacks;
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closure_ = closure;
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ownTransferables_ = policy;
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}
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[[nodiscard]] bool Init(size_t initialCapacity = 0) {
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return bufList_.Init(0, initialCapacity);
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}
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JS::StructuredCloneScope scope() const {
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if (scope_ == JS::StructuredCloneScope::UnknownDestination) {
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return JS::StructuredCloneScope::DifferentProcess;
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}
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return scope_;
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}
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void sameProcessScopeRequired() {
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if (scope_ == JS::StructuredCloneScope::UnknownDestination) {
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scope_ = JS::StructuredCloneScope::SameProcess;
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}
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}
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void initScope(JS::StructuredCloneScope newScope) {
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MOZ_ASSERT(Size() == 0, "initScope() of nonempty JSStructuredCloneData");
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if (scope() != JS::StructuredCloneScope::Unassigned) {
|
|
MOZ_ASSERT(scope() == newScope,
|
|
"Cannot change scope after it has been initialized");
|
|
}
|
|
scope_ = newScope;
|
|
}
|
|
|
|
size_t Size() const { return bufList_.Size(); }
|
|
|
|
const Iterator Start() const { return bufList_.Iter(); }
|
|
|
|
[[nodiscard]] bool Advance(Iterator& iter, size_t distance) const {
|
|
return iter.AdvanceAcrossSegments(bufList_, distance);
|
|
}
|
|
|
|
[[nodiscard]] bool ReadBytes(Iterator& iter, char* buffer,
|
|
size_t size) const {
|
|
return bufList_.ReadBytes(iter, buffer, size);
|
|
}
|
|
|
|
// Append new data to the end of the buffer.
|
|
[[nodiscard]] bool AppendBytes(const char* data, size_t size) {
|
|
MOZ_ASSERT(scope() != JS::StructuredCloneScope::Unassigned);
|
|
return bufList_.WriteBytes(data, size);
|
|
}
|
|
|
|
// Update data stored within the existing buffer. There must be at least
|
|
// 'size' bytes between the position of 'iter' and the end of the buffer.
|
|
[[nodiscard]] bool UpdateBytes(Iterator& iter, const char* data,
|
|
size_t size) const {
|
|
MOZ_ASSERT(scope() != JS::StructuredCloneScope::Unassigned);
|
|
while (size > 0) {
|
|
size_t remaining = iter.RemainingInSegment();
|
|
size_t nbytes = std::min(remaining, size);
|
|
memcpy(iter.Data(), data, nbytes);
|
|
data += nbytes;
|
|
size -= nbytes;
|
|
iter.Advance(bufList_, nbytes);
|
|
}
|
|
return true;
|
|
}
|
|
|
|
char* AllocateBytes(size_t maxSize, size_t* size) {
|
|
return bufList_.AllocateBytes(maxSize, size);
|
|
}
|
|
|
|
void Clear() {
|
|
discardTransferables();
|
|
bufList_.Clear();
|
|
}
|
|
|
|
// Return a new read-only JSStructuredCloneData that "borrows" the contents
|
|
// of |this|. Its lifetime should not exceed the donor's. This is only
|
|
// allowed for DifferentProcess clones, so finalization of the borrowing
|
|
// clone will do nothing.
|
|
JSStructuredCloneData Borrow(Iterator& iter, size_t size,
|
|
bool* success) const {
|
|
MOZ_ASSERT(scope() == JS::StructuredCloneScope::DifferentProcess);
|
|
return JSStructuredCloneData(
|
|
bufList_.Borrow<js::SystemAllocPolicy>(iter, size, success), scope());
|
|
}
|
|
|
|
// Iterate over all contained data, one BufferList segment's worth at a
|
|
// time, and invoke the given FunctionToApply with the data pointer and
|
|
// size. The function should return a bool value, and this loop will exit
|
|
// with false if the function ever returns false.
|
|
template <typename FunctionToApply>
|
|
bool ForEachDataChunk(FunctionToApply&& function) const {
|
|
Iterator iter = bufList_.Iter();
|
|
while (!iter.Done()) {
|
|
if (!function(iter.Data(), iter.RemainingInSegment())) {
|
|
return false;
|
|
}
|
|
iter.Advance(bufList_, iter.RemainingInSegment());
|
|
}
|
|
return true;
|
|
}
|
|
|
|
// Append the entire contents of other's bufList_ to our own.
|
|
[[nodiscard]] bool Append(const JSStructuredCloneData& other) {
|
|
MOZ_ASSERT(scope() == other.scope());
|
|
return other.ForEachDataChunk(
|
|
[&](const char* data, size_t size) { return AppendBytes(data, size); });
|
|
}
|
|
|
|
size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) {
|
|
return bufList_.SizeOfExcludingThis(mallocSizeOf);
|
|
}
|
|
|
|
void discardTransferables();
|
|
|
|
private:
|
|
// This internal method exposes the real value of scope_. It's meant to be
|
|
// used only when starting the writing.
|
|
JS::StructuredCloneScope scopeForInternalWriting() const { return scope_; }
|
|
};
|
|
|
|
/**
|
|
* Implements StructuredDeserialize and StructuredDeserializeWithTransfer.
|
|
*
|
|
* Note: If `data` contains transferable objects, it can be read only once.
|
|
*/
|
|
JS_PUBLIC_API bool JS_ReadStructuredClone(
|
|
JSContext* cx, const JSStructuredCloneData& data, uint32_t version,
|
|
JS::StructuredCloneScope scope, JS::MutableHandleValue vp,
|
|
const JS::CloneDataPolicy& cloneDataPolicy,
|
|
const JSStructuredCloneCallbacks* optionalCallbacks, void* closure);
|
|
|
|
/**
|
|
* Implements StructuredSerialize, StructuredSerializeForStorage, and
|
|
* StructuredSerializeWithTransfer.
|
|
*
|
|
* Note: If the scope is DifferentProcess then the cloneDataPolicy must deny
|
|
* shared-memory objects, or an error will be signaled if a shared memory object
|
|
* is seen.
|
|
*/
|
|
JS_PUBLIC_API bool JS_WriteStructuredClone(
|
|
JSContext* cx, JS::HandleValue v, JSStructuredCloneData* data,
|
|
JS::StructuredCloneScope scope, const JS::CloneDataPolicy& cloneDataPolicy,
|
|
const JSStructuredCloneCallbacks* optionalCallbacks, void* closure,
|
|
JS::HandleValue transferable);
|
|
|
|
JS_PUBLIC_API bool JS_StructuredCloneHasTransferables(
|
|
JSStructuredCloneData& data, bool* hasTransferable);
|
|
|
|
JS_PUBLIC_API bool JS_StructuredClone(
|
|
JSContext* cx, JS::HandleValue v, JS::MutableHandleValue vp,
|
|
const JSStructuredCloneCallbacks* optionalCallbacks, void* closure);
|
|
|
|
/**
|
|
* The C-style API calls to read and write structured clones are fragile --
|
|
* they rely on the caller to properly handle ownership of the clone data, and
|
|
* the handling of the input data as well as the interpretation of the contents
|
|
* of the clone buffer are dependent on the callbacks passed in. If you
|
|
* serialize and deserialize with different callbacks, the results are
|
|
* questionable.
|
|
*
|
|
* JSAutoStructuredCloneBuffer wraps things up in an RAII class for data
|
|
* management, and uses the same callbacks for both writing and reading
|
|
* (serializing and deserializing).
|
|
*/
|
|
class JS_PUBLIC_API JSAutoStructuredCloneBuffer {
|
|
JSStructuredCloneData data_;
|
|
uint32_t version_;
|
|
|
|
public:
|
|
JSAutoStructuredCloneBuffer(JS::StructuredCloneScope scope,
|
|
const JSStructuredCloneCallbacks* callbacks,
|
|
void* closure)
|
|
: data_(scope), version_(JS_STRUCTURED_CLONE_VERSION) {
|
|
data_.setCallbacks(callbacks, closure,
|
|
OwnTransferablePolicy::NoTransferables);
|
|
}
|
|
|
|
JSAutoStructuredCloneBuffer(JSAutoStructuredCloneBuffer&& other);
|
|
JSAutoStructuredCloneBuffer& operator=(JSAutoStructuredCloneBuffer&& other);
|
|
|
|
~JSAutoStructuredCloneBuffer() { clear(); }
|
|
|
|
JSStructuredCloneData& data() { return data_; }
|
|
bool empty() const { return !data_.Size(); }
|
|
|
|
void clear();
|
|
|
|
JS::StructuredCloneScope scope() const { return data_.scope(); }
|
|
|
|
/**
|
|
* Adopt some memory. It will be automatically freed by the destructor.
|
|
* data must have been allocated by the JS engine (e.g., extracted via
|
|
* JSAutoStructuredCloneBuffer::steal).
|
|
*/
|
|
void adopt(JSStructuredCloneData&& data,
|
|
uint32_t version = JS_STRUCTURED_CLONE_VERSION,
|
|
const JSStructuredCloneCallbacks* callbacks = nullptr,
|
|
void* closure = nullptr);
|
|
|
|
/**
|
|
* Release the buffer and transfer ownership to the caller.
|
|
*/
|
|
void steal(JSStructuredCloneData* data, uint32_t* versionp = nullptr,
|
|
const JSStructuredCloneCallbacks** callbacks = nullptr,
|
|
void** closure = nullptr);
|
|
|
|
/**
|
|
* Abandon ownership of any transferable objects stored in the buffer,
|
|
* without freeing the buffer itself. Useful when copying the data out into
|
|
* an external container, though note that you will need to use adopt() to
|
|
* properly release that data eventually.
|
|
*/
|
|
void abandon() {
|
|
data_.ownTransferables_ = OwnTransferablePolicy::IgnoreTransferablesIfAny;
|
|
}
|
|
|
|
bool read(JSContext* cx, JS::MutableHandleValue vp,
|
|
const JS::CloneDataPolicy& cloneDataPolicy = JS::CloneDataPolicy(),
|
|
const JSStructuredCloneCallbacks* optionalCallbacks = nullptr,
|
|
void* closure = nullptr);
|
|
|
|
bool write(JSContext* cx, JS::HandleValue v,
|
|
const JSStructuredCloneCallbacks* optionalCallbacks = nullptr,
|
|
void* closure = nullptr);
|
|
|
|
bool write(JSContext* cx, JS::HandleValue v, JS::HandleValue transferable,
|
|
const JS::CloneDataPolicy& cloneDataPolicy,
|
|
const JSStructuredCloneCallbacks* optionalCallbacks = nullptr,
|
|
void* closure = nullptr);
|
|
|
|
size_t sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) {
|
|
return data_.SizeOfExcludingThis(mallocSizeOf);
|
|
}
|
|
|
|
size_t sizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) {
|
|
return mallocSizeOf(this) + sizeOfExcludingThis(mallocSizeOf);
|
|
}
|
|
|
|
private:
|
|
// Copy and assignment are not supported.
|
|
JSAutoStructuredCloneBuffer(const JSAutoStructuredCloneBuffer& other) =
|
|
delete;
|
|
JSAutoStructuredCloneBuffer& operator=(
|
|
const JSAutoStructuredCloneBuffer& other) = delete;
|
|
};
|
|
|
|
// The range of tag values the application may use for its own custom object
|
|
// types.
|
|
#define JS_SCTAG_USER_MIN ((uint32_t)0xFFFF8000)
|
|
#define JS_SCTAG_USER_MAX ((uint32_t)0xFFFFFFFF)
|
|
|
|
#define JS_SCERR_RECURSION 0
|
|
#define JS_SCERR_TRANSFERABLE 1
|
|
#define JS_SCERR_DUP_TRANSFERABLE 2
|
|
#define JS_SCERR_UNSUPPORTED_TYPE 3
|
|
#define JS_SCERR_SHMEM_TRANSFERABLE 4
|
|
#define JS_SCERR_TYPED_ARRAY_DETACHED 5
|
|
#define JS_SCERR_WASM_NO_TRANSFER 6
|
|
#define JS_SCERR_NOT_CLONABLE 7
|
|
#define JS_SCERR_NOT_CLONABLE_WITH_COOP_COEP 8
|
|
|
|
JS_PUBLIC_API bool JS_ReadUint32Pair(JSStructuredCloneReader* r, uint32_t* p1,
|
|
uint32_t* p2);
|
|
|
|
JS_PUBLIC_API bool JS_ReadBytes(JSStructuredCloneReader* r, void* p,
|
|
size_t len);
|
|
|
|
JS_PUBLIC_API bool JS_ReadTypedArray(JSStructuredCloneReader* r,
|
|
JS::MutableHandleValue vp);
|
|
|
|
JS_PUBLIC_API bool JS_WriteUint32Pair(JSStructuredCloneWriter* w, uint32_t tag,
|
|
uint32_t data);
|
|
|
|
JS_PUBLIC_API bool JS_WriteBytes(JSStructuredCloneWriter* w, const void* p,
|
|
size_t len);
|
|
|
|
JS_PUBLIC_API bool JS_WriteString(JSStructuredCloneWriter* w,
|
|
JS::HandleString str);
|
|
|
|
JS_PUBLIC_API bool JS_WriteTypedArray(JSStructuredCloneWriter* w,
|
|
JS::HandleValue v);
|
|
|
|
JS_PUBLIC_API bool JS_ObjectNotWritten(JSStructuredCloneWriter* w,
|
|
JS::HandleObject obj);
|
|
|
|
JS_PUBLIC_API JS::StructuredCloneScope JS_GetStructuredCloneScope(
|
|
JSStructuredCloneWriter* w);
|
|
|
|
#endif /* js_StructuredClone_h */
|