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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
// Copyright (c) 2006-2008 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.
#ifndef CHROME_COMMON_IPC_MESSAGE_UTILS_H_
#define CHROME_COMMON_IPC_MESSAGE_UTILS_H_
#include <cstdint>
#include <iterator>
#include <map>
#include <unordered_map>
#include <string>
#include <type_traits>
#include <utility>
#include <vector>
#include "ErrorList.h"
#include "base/basictypes.h"
#include "base/compiler_specific.h"
#include "base/logging.h"
#include "base/pickle.h"
#include "base/string_util.h"
#include "chrome/common/ipc_message.h"
#include "mozilla/CheckedInt.h"
#include "mozilla/IntegerRange.h"
#if defined(XP_WIN)
# include <windows.h>
#endif
template <typename T>
class RefPtr;
template <typename T>
class nsCOMPtr;
namespace mozilla::ipc {
class IProtocol;
template <typename P>
struct IPDLParamTraits;
class SharedMemory;
// Implemented in ProtocolUtils.cpp
MOZ_NEVER_INLINE void PickleFatalError(const char* aMsg, IProtocol* aActor);
} // namespace mozilla::ipc
namespace IPC {
/**
* Context used to serialize into an IPC::Message. Provides relevant context
* used when serializing.
*/
class MOZ_STACK_CLASS MessageWriter final {
public:
explicit MessageWriter(Message& message,
mozilla::ipc::IProtocol* actor = nullptr)
: message_(message), actor_(actor) {}
MessageWriter(const MessageWriter&) = delete;
MessageWriter& operator=(const MessageWriter&) = delete;
mozilla::ipc::IProtocol* GetActor() const { return actor_; }
#define FORWARD_WRITE(name, type) \
bool Write##name(const type& result) { return message_.Write##name(result); }
FORWARD_WRITE(Bool, bool)
FORWARD_WRITE(Int16, int16_t)
FORWARD_WRITE(UInt16, uint16_t)
FORWARD_WRITE(Int, int)
FORWARD_WRITE(Long, long)
FORWARD_WRITE(ULong, unsigned long)
FORWARD_WRITE(Int32, int32_t)
FORWARD_WRITE(UInt32, uint32_t)
FORWARD_WRITE(Int64, int64_t)
FORWARD_WRITE(UInt64, uint64_t)
FORWARD_WRITE(Double, double)
FORWARD_WRITE(IntPtr, intptr_t)
FORWARD_WRITE(UnsignedChar, unsigned char)
FORWARD_WRITE(String, std::string)
FORWARD_WRITE(WString, std::wstring)
#undef FORWARD_WRITE
bool WriteData(const char* data, uint32_t length) {
return message_.WriteData(data, length);
}
bool WriteBytes(const void* data, uint32_t data_len) {
return message_.WriteBytes(data, data_len);
}
bool WriteBytesZeroCopy(void* data, uint32_t data_len, uint32_t capacity) {
return message_.WriteBytesZeroCopy(data, data_len, capacity);
}
bool WriteSentinel(uint32_t sentinel) {
return message_.WriteSentinel(sentinel);
}
bool WriteFileHandle(mozilla::UniqueFileHandle handle) {
return message_.WriteFileHandle(std::move(handle));
}
void WritePort(mozilla::ipc::ScopedPort port) {
message_.WritePort(std::move(port));
}
#if defined(XP_DARWIN)
bool WriteMachSendRight(mozilla::UniqueMachSendRight port) {
return message_.WriteMachSendRight(std::move(port));
}
#endif
void FatalError(const char* aErrorMsg) const {
mozilla::ipc::PickleFatalError(aErrorMsg, actor_);
}
private:
Message& message_;
mozilla::ipc::IProtocol* actor_;
};
/**
* Context used to read data from an IPC::Message. Provides relevant context
* used when deserializing and tracks iteration.
*/
class MOZ_STACK_CLASS MessageReader final {
public:
explicit MessageReader(const Message& message,
mozilla::ipc::IProtocol* actor = nullptr)
: message_(message), iter_(message), actor_(actor) {}
MessageReader(const MessageReader&) = delete;
MessageReader& operator=(const MessageReader&) = delete;
mozilla::ipc::IProtocol* GetActor() const { return actor_; }
#define FORWARD_READ(name, type) \
[[nodiscard]] bool Read##name(type* result) { \
return message_.Read##name(&iter_, result); \
}
FORWARD_READ(Bool, bool)
FORWARD_READ(Int16, int16_t)
FORWARD_READ(UInt16, uint16_t)
FORWARD_READ(Short, short)
FORWARD_READ(Int, int)
FORWARD_READ(Long, long)
FORWARD_READ(ULong, unsigned long)
FORWARD_READ(Int32, int32_t)
FORWARD_READ(UInt32, uint32_t)
FORWARD_READ(Int64, int64_t)
FORWARD_READ(UInt64, uint64_t)
FORWARD_READ(Double, double)
FORWARD_READ(IntPtr, intptr_t)
FORWARD_READ(UnsignedChar, unsigned char)
FORWARD_READ(String, std::string)
FORWARD_READ(WString, std::wstring)
// Special version of ReadInt() which rejects negative values
FORWARD_READ(Length, int);
#undef FORWARD_READ
[[nodiscard]] bool ReadBytesInto(void* data, uint32_t length) {
return message_.ReadBytesInto(&iter_, data, length);
}
[[nodiscard]] bool IgnoreBytes(uint32_t length) {
return message_.IgnoreBytes(&iter_, length);
}
[[nodiscard]] bool ReadSentinel(uint32_t sentinel) {
return message_.ReadSentinel(&iter_, sentinel);
}
bool IgnoreSentinel() { return message_.IgnoreSentinel(&iter_); }
bool HasBytesAvailable(uint32_t len) {
return message_.HasBytesAvailable(&iter_, len);
}
void EndRead() { message_.EndRead(iter_, message_.type()); }
[[nodiscard]] bool ConsumeFileHandle(mozilla::UniqueFileHandle* handle) {
return message_.ConsumeFileHandle(&iter_, handle);
}
[[nodiscard]] bool ConsumePort(mozilla::ipc::ScopedPort* port) {
return message_.ConsumePort(&iter_, port);
}
#if defined(XP_DARWIN)
[[nodiscard]] bool ConsumeMachSendRight(mozilla::UniqueMachSendRight* port) {
return message_.ConsumeMachSendRight(&iter_, port);
}
#endif
void FatalError(const char* aErrorMsg) const {
mozilla::ipc::PickleFatalError(aErrorMsg, actor_);
}
private:
const Message& message_;
PickleIterator iter_;
mozilla::ipc::IProtocol* actor_;
};
namespace detail {
// Helper for checking `T::kHasDeprecatedReadParamPrivateConstructor` using a
// fallback when the member isn't defined.
template <typename T>
inline constexpr auto HasDeprecatedReadParamPrivateConstructor(int)
-> decltype(T::kHasDeprecatedReadParamPrivateConstructor) {
return T::kHasDeprecatedReadParamPrivateConstructor;
}
template <typename T>
inline constexpr bool HasDeprecatedReadParamPrivateConstructor(...) {
return false;
}
} // namespace detail
/**
* Result type returned from some `ParamTraits<T>::Read` implementations, and
* from `IPC::ReadParam<T>(MessageReader*)`. Either contains the value or
* indicates a failure to deserialize.
*
* This type can be thought of as a variant on `Maybe<T>`, except that it
* unconditionally constructs the underlying value if it is default
* constructible. This helps keep code size down, especially when calling
*/
template <typename T,
bool = std::is_default_constructible_v<T> ||
detail::HasDeprecatedReadParamPrivateConstructor<T>(0)>
class ReadResult {
public:
ReadResult() = default;
template <typename U, std::enable_if_t<std::is_convertible_v<U, T>, int> = 0>
MOZ_IMPLICIT ReadResult(U&& aData)
: mIsOk(true), mData(std::forward<U>(aData)) {}
template <typename... Args>
explicit ReadResult(std::in_place_t, Args&&... aArgs)
: mIsOk(true), mData(std::forward<Args>(aArgs)...) {}
ReadResult(const ReadResult&) = default;
ReadResult(ReadResult&&) = default;
template <typename U, std::enable_if_t<std::is_convertible_v<U, T>, int> = 0>
MOZ_IMPLICIT ReadResult& operator=(U&& aData) {
mIsOk = true;
mData = std::forward<U>(aData);
return *this;
}
ReadResult& operator=(const ReadResult&) = default;
ReadResult& operator=(ReadResult&&) noexcept = default;
// Check if the ReadResult contains a valid value.
explicit operator bool() const { return isOk(); }
bool isOk() const { return mIsOk; }
// Get the data from this ReadResult.
T& get() {
MOZ_ASSERT(mIsOk);
return mData;
}
const T& get() const {
MOZ_ASSERT(mIsOk);
return mData;
}
T& operator*() { return get(); }
const T& operator*() const { return get(); }
T* operator->() { return &get(); }
const T* operator->() const { return &get(); }
// Try to extract a `Maybe<T>` from this ReadResult.
mozilla::Maybe<T> TakeMaybe() {
if (mIsOk) {
mIsOk = false;
return mozilla::Some(std::move(mData));
}
return mozilla::Nothing();
}
// Get the underlying data from this ReadResult, even if not OK.
//
// This is only available for types which are default constructible, and is
// used to optimize old-style `ReadParam` calls.
T& GetStorage() { return mData; }
// Compliment to `GetStorage` used to set the ReadResult into an OK state
// without constructing the underlying value.
void SetOk(bool aIsOk) { mIsOk = aIsOk; }
private:
bool mIsOk = false;
T mData{};
};
template <typename T>
class ReadResult<T, false> {
public:
ReadResult() = default;
template <typename U, std::enable_if_t<std::is_convertible_v<U, T>, int> = 0>
MOZ_IMPLICIT ReadResult(U&& aData)
: mData(std::in_place, std::forward<U>(aData)) {}
template <typename... Args>
explicit ReadResult(std::in_place_t, Args&&... aArgs)
: mData(std::in_place, std::forward<Args>(aArgs)...) {}
ReadResult(const ReadResult&) = default;
ReadResult(ReadResult&&) = default;
template <typename U, std::enable_if_t<std::is_convertible_v<U, T>, int> = 0>
MOZ_IMPLICIT ReadResult& operator=(U&& aData) {
mData.reset();
mData.emplace(std::forward<U>(aData));
return *this;
}
ReadResult& operator=(const ReadResult&) = default;
ReadResult& operator=(ReadResult&&) noexcept = default;
// Check if the ReadResult contains a valid value.
explicit operator bool() const { return isOk(); }
bool isOk() const { return mData.isSome(); }
// Get the data from this ReadResult.
T& get() { return mData.ref(); }
const T& get() const { return mData.ref(); }
T& operator*() { return get(); }
const T& operator*() const { return get(); }
T* operator->() { return &get(); }
const T* operator->() const { return &get(); }
// Try to extract a `Maybe<T>` from this ReadResult.
mozilla::Maybe<T> TakeMaybe() { return std::move(mData); }
// These methods are only available if the type is default constructible.
T& GetStorage() = delete;
void SetOk(bool aIsOk) = delete;
private:
mozilla::Maybe<T> mData;
};
//-----------------------------------------------------------------------------
// An iterator class for reading the fields contained within a Message.
class MessageIterator {
public:
explicit MessageIterator(const Message& m) : msg_(m), iter_(m) {}
int NextInt() const {
int val;
if (!msg_.ReadInt(&iter_, &val)) NOTREACHED();
return val;
}
intptr_t NextIntPtr() const {
intptr_t val;
if (!msg_.ReadIntPtr(&iter_, &val)) NOTREACHED();
return val;
}
const std::string NextString() const {
std::string val;
if (!msg_.ReadString(&iter_, &val)) NOTREACHED();
return val;
}
const std::wstring NextWString() const {
std::wstring val;
if (!msg_.ReadWString(&iter_, &val)) NOTREACHED();
return val;
}
private:
const Message& msg_;
mutable PickleIterator iter_;
};
//-----------------------------------------------------------------------------
// ParamTraits specializations, etc.
//
// The full set of types ParamTraits is specialized upon contains *possibly*
// repeated types: unsigned long may be uint32_t or size_t, unsigned long long
// may be uint64_t or size_t, nsresult may be uint32_t, and so on. You can't
// have ParamTraits<unsigned int> *and* ParamTraits<uint32_t> if unsigned int
// is uint32_t -- that's multiple definitions, and you can only have one.
//
// You could use #ifs and macro conditions to avoid duplicates, but they'd be
// hairy: heavily dependent upon OS and compiler author choices, forced to
// address all conflicts by hand. Happily there's a better way. The basic
// idea looks like this, where T -> U represents T inheriting from U:
//
// class ParamTraits<P>
// |
// --> class ParamTraits1<P>
// |
// --> class ParamTraits2<P>
// |
// --> class ParamTraitsN<P> // or however many levels
//
// The default specialization of ParamTraits{M}<P> is an empty class that
// inherits from ParamTraits{M + 1}<P> (or nothing in the base case).
//
// Now partition the set of parameter types into sets without duplicates.
// Assign each set of types to a level M. Then specialize ParamTraitsM for
// each of those types. A reference to ParamTraits<P> will consist of some
// number of empty classes inheriting in sequence, ending in a non-empty
// ParamTraits{N}<P>. It's okay for the parameter types to be duplicative:
// either name of a type will resolve to the same ParamTraits{N}<P>.
//
// The nice thing is that because templates are instantiated lazily, if we
// indeed have uint32_t == unsigned int, say, with the former in level N and
// the latter in M > N, ParamTraitsM<unsigned int> won't be created (as long as
// nobody uses ParamTraitsM<unsigned int>, but why would you), and no duplicate
// code will be compiled or extra symbols generated. It's as efficient at
// runtime as manually figuring out and avoiding conflicts by #ifs.
//
// The scheme we follow below names the various classes according to the types
// in them, and the number of ParamTraits levels is larger, but otherwise it's
// exactly the above idea.
//
template <class P>
struct ParamTraits;
template <typename P>
inline void WriteParam(MessageWriter* writer, P&& p) {
ParamTraits<std::decay_t<P>>::Write(writer, std::forward<P>(p));
}
namespace detail {
template <typename P>
inline constexpr auto ParamTraitsReadUsesOutParam()
-> decltype(ParamTraits<P>::Read(std::declval<MessageReader*>(),
std::declval<P*>())) {
return true;
}
template <typename P>
inline constexpr auto ParamTraitsReadUsesOutParam()
-> decltype(ParamTraits<P>::Read(std::declval<MessageReader*>()), bool{}) {
return false;
}
} // namespace detail
template <typename P>
inline bool WARN_UNUSED_RESULT ReadParam(MessageReader* reader, P* p) {
if constexpr (!detail::ParamTraitsReadUsesOutParam<P>()) {
auto maybe = ParamTraits<P>::Read(reader);
if (maybe) {
*p = std::move(*maybe);
return true;
}
return false;
} else {
return ParamTraits<P>::Read(reader, p);
}
}
template <typename P>
inline ReadResult<P> WARN_UNUSED_RESULT ReadParam(MessageReader* reader) {
if constexpr (!detail::ParamTraitsReadUsesOutParam<P>()) {
return ParamTraits<P>::Read(reader);
} else {
ReadResult<P> p;
p.SetOk(ParamTraits<P>::Read(reader, &p.GetStorage()));
return p;
}
}
class MOZ_STACK_CLASS MessageBufferWriter {
public:
// Create a MessageBufferWriter to write `full_len` bytes into `writer`.
// If the length exceeds a threshold, a shared memory region may be used
// instead of including the data inline.
//
// NOTE: This does _NOT_ write out the length of the buffer.
// NOTE: Data written this way _MUST_ be read using `MessageBufferReader`.
MessageBufferWriter(MessageWriter* writer, uint32_t full_len);
~MessageBufferWriter();
MessageBufferWriter(const MessageBufferWriter&) = delete;
MessageBufferWriter& operator=(const MessageBufferWriter&) = delete;
// Write `len` bytes from `data` into the message.
//
// Exactly `full_len` bytes should be written across multiple calls before the
// `MessageBufferWriter` is destroyed.
//
// WARNING: all writes (other than the last write) must be multiples of 4
// bytes in length. Not doing this will lead to padding being introduced into
// the payload and break things. This can probably be improved in the future
// with deeper integration between `MessageBufferWriter` and `Pickle`.
bool WriteBytes(const void* data, uint32_t len);
private:
MessageWriter* writer_;
RefPtr<mozilla::ipc::SharedMemory> shmem_;
char* buffer_ = nullptr;
uint32_t remaining_ = 0;
};
class MOZ_STACK_CLASS MessageBufferReader {
public:
// Create a MessageBufferReader to read `full_len` bytes from `reader` which
// were written using `MessageBufferWriter`.
//
// NOTE: This may consume a shared memory region from the message, meaning
// that the same data cannot be read multiple times.
// NOTE: Data read this way _MUST_ be written using `MessageBufferWriter`.
MessageBufferReader(MessageReader* reader, uint32_t full_len);
~MessageBufferReader();
MessageBufferReader(const MessageBufferReader&) = delete;
MessageBufferReader& operator=(const MessageBufferReader&) = delete;
// Read `count` bytes from the message into `data`.
//
// Exactly `full_len` bytes should be read across multiple calls before the
// `MessageBufferReader` is destroyed.
//
// WARNING: all reads (other than the last read) must be multiples of 4 bytes
// in length. Not doing this will lead to bytes being skipped in the payload
// and break things. This can probably be improved in the future with deeper
// integration between `MessageBufferReader` and `Pickle`.
[[nodiscard]] bool ReadBytesInto(void* data, uint32_t len);
private:
MessageReader* reader_;
RefPtr<mozilla::ipc::SharedMemory> shmem_;
const char* buffer_ = nullptr;
uint32_t remaining_ = 0;
};
// Whether or not it is safe to serialize the given type using
// `WriteBytesOrShmem`.
template <typename P>
constexpr bool kUseWriteBytes =
!std::is_same_v<std::remove_const_t<std::remove_reference_t<P>>, bool> &&
(std::is_integral_v<std::remove_const_t<std::remove_reference_t<P>>> ||
std::is_floating_point_v<std::remove_const_t<std::remove_reference_t<P>>>);
/**
* Helper for writing a contiguous sequence (such as for a string or array) into
* a message, with optimizations for basic integral and floating point types.
*
* Integral types will be copied into shared memory if the sequence exceeds 64k
* bytes in size.
*
* Values written with this method must be read with `ReadSequenceParam`.
*
* The type parameter specifies the semantics to use, and should generally
* either be `P&&` or `const P&`. The constness of the `data` argument should
* match this parameter.
*/
template <typename P>
void WriteSequenceParam(MessageWriter* writer, std::remove_reference_t<P>* data,
size_t length) {
mozilla::CheckedUint32 ipc_length(length);
if (!ipc_length.isValid()) {
writer->FatalError("invalid length passed to WriteSequenceParam");
return;
}
writer->WriteUInt32(ipc_length.value());
if constexpr (kUseWriteBytes<P>) {
mozilla::CheckedUint32 byte_length =
ipc_length * sizeof(std::remove_reference_t<P>);
if (!byte_length.isValid()) {
writer->FatalError("invalid byte length in WriteSequenceParam");
return;
}
MessageBufferWriter buf_writer(writer, byte_length.value());
buf_writer.WriteBytes(data, byte_length.value());
} else {
auto* end = data + length;
for (auto* it = data; it != end; ++it) {
WriteParam(writer, std::forward<P>(*it));
}
}
}
template <typename P>
bool ReadSequenceParamImpl(MessageReader* reader, P* data, uint32_t length) {
if (length == 0) {
return true;
}
if (!data) {
reader->FatalError("allocation failed in ReadSequenceParam");
return false;
}
if constexpr (kUseWriteBytes<P>) {
mozilla::CheckedUint32 byte_length(length);
byte_length *= sizeof(P);
if (!byte_length.isValid()) {
reader->FatalError("invalid byte length in ReadSequenceParam");
return false;
}
MessageBufferReader buf_reader(reader, byte_length.value());
return buf_reader.ReadBytesInto(data, byte_length.value());
} else {
P* end = data + length;
for (auto* it = data; it != end; ++it) {
if (!ReadParam(reader, it)) {
return false;
}
}
return true;
}
}
template <typename P, typename I>
bool ReadSequenceParamImpl(MessageReader* reader, mozilla::Maybe<I>&& data,
uint32_t length) {
static_assert(!kUseWriteBytes<P>,
"Cannot return an output iterator if !kUseWriteBytes<P>");
static_assert(
std::is_base_of_v<std::output_iterator_tag,
typename std::iterator_traits<I>::iterator_category>,
"must be Maybe<output iterator>");
if (length == 0) {
return true;
}
if (!data) {
reader->FatalError("allocation failed in ReadSequenceParam");
return false;
}
for (uint32_t i = 0; i < length; ++i) {
auto elt = ReadParam<P>(reader);
if (!elt) {
return false;
}
*data.ref() = std::move(*elt);
++data.ref();
}
return true;
}
/**
* Helper for reading a contiguous sequence (such as a string or array) into a
* message which was previously written using `WriteSequenceParam`.
*
* The function argument `allocator` will be called with the length of the
* sequence, and must return either a pointer to the memory region which the
* sequence should be read into, or a Maybe of a C++ output iterator which will
* infallibly accept length elements, and append them to the output sequence.
*
* If the type satisfies kUseWriteBytes, output iterators are not supported.
*/
template <typename P, typename F>
bool WARN_UNUSED_RESULT ReadSequenceParam(MessageReader* reader,
F&& allocator) {
uint32_t length = 0;
if (!reader->ReadUInt32(&length)) {
reader->FatalError("failed to read byte length in ReadSequenceParam");
return false;
}
return ReadSequenceParamImpl<P>(reader, allocator(length), length);
}
// Temporary fallback class to allow types to declare serialization using the
// IPDLParamTraits type class. Will be removed once all remaining
template <class P>
struct ParamTraitsIPDLFallback {
template <class R>
static auto Write(MessageWriter* writer, R&& p)
-> decltype(mozilla::ipc::IPDLParamTraits<P>::Write(writer,
writer->GetActor(),
std::forward<R>(p))) {
mozilla::ipc::IPDLParamTraits<P>::Write(writer, writer->GetActor(),
std::forward<R>(p));
}
template <class R>
static auto Read(MessageReader* reader, R* r)
-> decltype(mozilla::ipc::IPDLParamTraits<P>::Read(reader,
reader->GetActor(),
r)) {
return mozilla::ipc::IPDLParamTraits<P>::Read(reader, reader->GetActor(),
r);
}
};
// Fundamental types.
template <class P>
struct ParamTraitsFundamental : ParamTraitsIPDLFallback<P> {};
template <>
struct ParamTraitsFundamental<bool> {
typedef bool param_type;
static void Write(MessageWriter* writer, const param_type& p) {
writer->WriteBool(p);
}
static bool Read(MessageReader* reader, param_type* r) {
return reader->ReadBool(r);
}
};
template <>
struct ParamTraitsFundamental<int> {
typedef int param_type;
static void Write(MessageWriter* writer, const param_type& p) {
writer->WriteInt(p);
}
static bool Read(MessageReader* reader, param_type* r) {
return reader->ReadInt(r);
}
};
template <>
struct ParamTraitsFundamental<long> {
typedef long param_type;
static void Write(MessageWriter* writer, const param_type& p) {
writer->WriteLong(p);
}
static bool Read(MessageReader* reader, param_type* r) {
return reader->ReadLong(r);
}
};
template <>
struct ParamTraitsFundamental<unsigned long> {
typedef unsigned long param_type;
static void Write(MessageWriter* writer, const param_type& p) {
writer->WriteULong(p);
}
static bool Read(MessageReader* reader, param_type* r) {
return reader->ReadULong(r);
}
};
template <>
struct ParamTraitsFundamental<long long> {
typedef long long param_type;
static void Write(MessageWriter* writer, const param_type& p) {
writer->WriteBytes(&p, sizeof(param_type));
}
static bool Read(MessageReader* reader, param_type* r) {
return reader->ReadBytesInto(r, sizeof(*r));
}
};
template <>
struct ParamTraitsFundamental<unsigned long long> {
typedef unsigned long long param_type;
static void Write(MessageWriter* writer, const param_type& p) {
writer->WriteBytes(&p, sizeof(param_type));
}
static bool Read(MessageReader* reader, param_type* r) {
return reader->ReadBytesInto(r, sizeof(*r));
}
};
template <>
struct ParamTraitsFundamental<double> {
typedef double param_type;
static void Write(MessageWriter* writer, const param_type& p) {
writer->WriteDouble(p);
}
static bool Read(MessageReader* reader, param_type* r) {
return reader->ReadDouble(r);
}
};
// Fixed-size <stdint.h> types.
template <class P>
struct ParamTraitsFixed : ParamTraitsFundamental<P> {};
template <>
struct ParamTraitsFixed<int16_t> {
typedef int16_t param_type;
static void Write(MessageWriter* writer, const param_type& p) {
writer->WriteInt16(p);
}
static bool Read(MessageReader* reader, param_type* r) {
return reader->ReadInt16(r);
}
};
template <>
struct ParamTraitsFixed<uint16_t> {
typedef uint16_t param_type;
static void Write(MessageWriter* writer, const param_type& p) {
writer->WriteUInt16(p);
}
static bool Read(MessageReader* reader, param_type* r) {
return reader->ReadUInt16(r);
}
};
template <>
struct ParamTraitsFixed<uint32_t> {
typedef uint32_t param_type;
static void Write(MessageWriter* writer, const param_type& p) {
writer->WriteUInt32(p);
}
static bool Read(MessageReader* reader, param_type* r) {
return reader->ReadUInt32(r);
}
};
template <>
struct ParamTraitsFixed<int64_t> {
typedef int64_t param_type;
static void Write(MessageWriter* writer, const param_type& p) {
writer->WriteInt64(p);
}
static bool Read(MessageReader* reader, param_type* r) {
return reader->ReadInt64(r);
}
};
template <>
struct ParamTraitsFixed<uint64_t> {
typedef uint64_t param_type;
static void Write(MessageWriter* writer, const param_type& p) {
writer->WriteInt64(static_cast<int64_t>(p));
}
static bool Read(MessageReader* reader, param_type* r) {
return reader->ReadInt64(reinterpret_cast<int64_t*>(r));
}
};
// std::* types.
template <class P>
struct ParamTraitsStd : ParamTraitsFixed<P> {};
template <class T>
struct ParamTraitsStd<std::basic_string<T>> {
typedef std::basic_string<T> param_type;
static void Write(MessageWriter* writer, const param_type& p) {
WriteSequenceParam<const T&>(writer, p.data(), p.size());
}
static bool Read(MessageReader* reader, param_type* r) {
return ReadSequenceParam<T>(reader, [&](uint32_t length) -> T* {
r->resize(length);
return r->data();
});
}
};
template <class K, class V>
struct ParamTraitsStd<std::map<K, V>> {
typedef std::map<K, V> param_type;
static void Write(MessageWriter* writer, const param_type& p) {
WriteParam(writer, static_cast<int>(p.size()));
typename param_type::const_iterator iter;
for (iter = p.begin(); iter != p.end(); ++iter) {
WriteParam(writer, iter->first);
WriteParam(writer, iter->second);
}
}
static bool Read(MessageReader* reader, param_type* r) {
int size;
if (!ReadParam(reader, &size) || size < 0) return false;
for (int i = 0; i < size; ++i) {
K k;
if (!ReadParam(reader, &k)) return false;
V& value = (*r)[k];
if (!ReadParam(reader, &value)) return false;
}
return true;
}
};
// Windows-specific types.
template <class P>
struct ParamTraitsWindows : ParamTraitsStd<P> {};
#if defined(XP_WIN)
template <>
struct ParamTraitsWindows<HANDLE> {
static_assert(sizeof(HANDLE) == sizeof(intptr_t), "Wrong size for HANDLE?");
static void Write(MessageWriter* writer, HANDLE p) {
writer->WriteIntPtr(reinterpret_cast<intptr_t>(p));
}
static bool Read(MessageReader* reader, HANDLE* r) {
return reader->ReadIntPtr(reinterpret_cast<intptr_t*>(r));
}
};
template <>
struct ParamTraitsWindows<HWND> {
static_assert(sizeof(HWND) == sizeof(intptr_t), "Wrong size for HWND?");
static void Write(MessageWriter* writer, HWND p) {
writer->WriteIntPtr(reinterpret_cast<intptr_t>(p));
}
static bool Read(MessageReader* reader, HWND* r) {
return reader->ReadIntPtr(reinterpret_cast<intptr_t*>(r));
}
};
#endif // defined(XP_WIN)
// Various ipc/chromium types.
template <class P>
struct ParamTraitsIPC : ParamTraitsWindows<P> {};
// `UniqueFileHandle` may be serialized over IPC channels. On the receiving
// side, the UniqueFileHandle is a valid duplicate of the handle which was
// transmitted.
//
// When sending a UniqueFileHandle, the handle must be valid at the time of
// transmission. As transmission is asynchronous, this requires passing
// ownership of the handle to IPC.
//
// A UniqueFileHandle may only be read once. After it has been read once, it
// will be consumed, and future reads will return an invalid handle.
template <>
struct ParamTraitsIPC<mozilla::UniqueFileHandle> {
typedef mozilla::UniqueFileHandle param_type;
static void Write(MessageWriter* writer, param_type&& p) {
const bool valid = p != nullptr;
WriteParam(writer, valid);
if (valid) {
if (!writer->WriteFileHandle(std::move(p))) {
writer->FatalError("Too many file handles for one message!");
NOTREACHED() << "Too many file handles for one message!";
}
}
}
static bool Read(MessageReader* reader, param_type* r) {
bool valid;
if (!ReadParam(reader, &valid)) {
reader->FatalError("Error reading file handle validity");
return false;
}
if (!valid) {
*r = nullptr;
return true;
}
if (!reader->ConsumeFileHandle(r)) {
reader->FatalError("File handle not found in message!");
return false;
}
return true;
}
};
#if defined(XP_DARWIN)
// `UniqueMachSendRight` may be serialized over IPC channels. On the receiving
// side, the UniqueMachSendRight is the local name of the right which was
// transmitted.
//
// When sending a UniqueMachSendRight, the right must be valid at the time of
// transmission. As transmission is asynchronous, this requires passing
// ownership of the handle to IPC.
//
// A UniqueMachSendRight may only be read once. After it has been read once, it
// will be consumed, and future reads will return an invalid right.
template <>
struct ParamTraitsIPC<mozilla::UniqueMachSendRight> {
typedef mozilla::UniqueMachSendRight param_type;
static void Write(MessageWriter* writer, param_type&& p) {
const bool valid = p != nullptr;
WriteParam(writer, valid);
if (valid) {
if (!writer->WriteMachSendRight(std::move(p))) {
writer->FatalError("Too many mach send rights for one message!");
NOTREACHED() << "Too many mach send rights for one message!";
}
}
}
static bool Read(MessageReader* reader, param_type* r) {
bool valid;
if (!ReadParam(reader, &valid)) {
reader->FatalError("Error reading mach send right validity");
return false;
}
if (!valid) {
*r = nullptr;
return true;
}
if (!reader->ConsumeMachSendRight(r)) {
reader->FatalError("Mach send right not found in message!");
return false;
}
return true;
}
};
#endif
// Mozilla-specific types.
template <class P>
struct ParamTraitsMozilla : ParamTraitsIPC<P> {};
// Sending-only specialization for mozilla::Span<T const>. Uses an identical
// serialization format as `const nsTArray<T>&`.
template <class T>
struct ParamTraitsMozilla<mozilla::Span<const T>> {
static void Write(MessageWriter* writer, mozilla::Span<const T> p) {
WriteSequenceParam<const T>(writer, p.Elements(), p.Length());
}
};
template <>
struct ParamTraitsMozilla<nsresult> {
typedef nsresult param_type;
static void Write(MessageWriter* writer, const param_type& p) {
writer->WriteUInt32(static_cast<uint32_t>(p));
}
static bool Read(MessageReader* reader, param_type* r) {
return reader->ReadUInt32(reinterpret_cast<uint32_t*>(r));
}
};
// See comments for the IPDLParamTraits specializations for RefPtr<T> and
// nsCOMPtr<T> for more details.
template <class T>
struct ParamTraitsMozilla<RefPtr<T>> {
static void Write(MessageWriter* writer, const RefPtr<T>& p) {
ParamTraits<T*>::Write(writer, p.get());
}
static bool Read(MessageReader* reader, RefPtr<T>* r) {
return ParamTraits<T*>::Read(reader, r);
}
};
template <class T>
struct ParamTraitsMozilla<nsCOMPtr<T>> {
static void Write(MessageWriter* writer, const nsCOMPtr<T>& p) {
ParamTraits<T*>::Write(writer, p.get());
}
static bool Read(MessageReader* reader, nsCOMPtr<T>* r) {
RefPtr<T> refptr;
if (!ParamTraits<T*>::Read(reader, &refptr)) {
return false;
}
*r = std::move(refptr);
return true;
}
};
template <class T>
struct ParamTraitsMozilla<mozilla::NotNull<T>> {
static void Write(MessageWriter* writer, const mozilla::NotNull<T>& p) {
ParamTraits<T>::Write(writer, p.get());
}
static ReadResult<mozilla::NotNull<T>> Read(MessageReader* reader) {
auto ptr = ReadParam<T>(reader);
if (!ptr) {
return {};
}
if (!*ptr) {
reader->FatalError("unexpected null value");
return {};
}
return mozilla::WrapNotNull(std::move(*ptr));
}
};
// Finally, ParamTraits itself.
template <class P>
struct ParamTraits : ParamTraitsMozilla<P> {};
} // namespace IPC
#endif // CHROME_COMMON_IPC_MESSAGE_UTILS_H_