ChangeLog

2021-11-15  Chris Dumez  <cdumez@apple.com>

        Decoder::unwrapForTesting() is unnecessarily inefficient

        https://bugs.webkit.org/show_bug.cgi?id=233145

        Reviewed by NOBODY (OOPS!).

        Decoder::unwrapForTesting() is unnecessarily inefficient. It can take the whole

        m_attachments data members from the decoder instead of calling removeAttachment()

        repeatedly on the Decoder.

        Also rename removeAttachment() to takeAttachment() since it returns the Attachment.

        Update it to return a std::optional<Attachment> instead of using an out-parameter.

        * Platform/IPC/Attachment.cpp:

        (IPC::Attachment::decode):

        * Platform/IPC/Attachment.h:

        * Platform/IPC/Decoder.cpp:

        (IPC::Decoder::unwrapForTesting):

        (IPC::Decoder::takeAttachment):

        (IPC::Decoder::removeAttachment): Deleted.

        * Platform/IPC/Decoder.h:

        * Platform/IPC/win/AttachmentWin.cpp:

        (IPC::Attachment::decode):

2021-11-15  Chris Dumez  <cdumez@apple.com>

        Remove some dead code from IPC::Encoder / IPC::Decoder

Source/WebKit/Platform/IPC/Attachment.cpp

@@void Attachment::encode(Encoder& encoder) const

    encoder.addAttachment(WTFMove(*const_cast<Attachment*>(this)));

}

59 bool Attachment::decode(Decoder& decoder~~, Attachment& attachment~~)

59std::optional<Attachment> Attachment::decode(Decoder& decoder)

6060{

    if (!decoder.removeAttachment(attachment))

        return false;

    return true;

61 return decoder.takeAttachment();

}

#endif

Source/WebKit/Platform/IPC/Attachment.h

#pragma once

29#include <optional>

30

#if OS(DARWIN) && !USE(UNIX_DOMAIN_SOCKETS)

#include <mach/mach_init.h>

#include <mach/mach_traps.h>

@@public:

#endif

    void encode(Encoder&) const;

101 static W~~ARN_UNUSED_RETURN bool~~ decode(Decoder&~~, Attachment&~~);

103 static std::optional<Attachment> decode(Decoder&);

    
private:

    Type m_type;

Source/WebKit/Platform/IPC/Decoder.cpp

#include <stdio.h>

#include <wtf/StdLibExtras.h>

#if PLATFORM(MAC)

#include "ImportanceAssertion.h"

#endif

namespace IPC {

static const uint8_t* copyBuffer(const uint8_t* buffer, size_t bufferSize)

@@std::unique_ptr<Decoder> Decoder::unwrapForTesting(Decoder& decoder)

{

    ASSERT(decoder.isSyncMessage());

    Vector<Attachment> attachments;

    Attachment attachment;

    while (decoder.removeAttachment(attachment))

        attachments.append(WTFMove(attachment));

    attachments.reverse();

146 Vector<Attachment> attachments = std::exchange(decoder.m_attachments, { });

    DataReference wrappedMessage;

    if (!decoder.decode(wrappedMessage))

@@const uint8_t* Decoder::decodeFixedLengthReference(size_t size, size_t alignment

    return data;

}

221 bool Decoder::~~remov~~eAttachment(~~Attachment& attachment~~)

213std::optional<Attachment> Decoder::takeAttachment()

222214{

223215 if (m_attachments.isEmpty())

        return false;

    attachment = m_attachments.takeLast();

    return true;

216 return std::nullopt;

217 return m_attachments.takeLast();

}

} // namespace IPC

Source/WebKit/Platform/IPC/Decoder.h

#include "Attachment.h"

#include "MessageNames.h"

30 #include "StringReference.h"

31 #include <WebCore/SharedBuffer.h>

#include <wtf/OptionSet.h>

#include <wtf/Vector.h>

#include "ImportanceAssertion.h"

#endif

#if HAVE(QOS_CLASSES)

#include <pthread/qos.h>

#endif

namespace IPC {

enum class MessageFlags : uint8_t;

@@public:

        return bufferIsLargeEnoughToContain(alignof(T), numElements * sizeof(T));

    }

143 bool ~~remov~~eAttachment(~~Attachment&~~);

137 std::optional<Attachment> takeAttachment();

    static constexpr bool isIPCDecoder = true;

Source/WebKit/Platform/IPC/win/AttachmentWin.cpp

@@static bool getDuplicatedHandle(HANDLE sourceHandle, DWORD sourcePID, HANDLE& du

    return success;

}

68 bool Attachment::decode(Decoder& decoder~~, Attachment& attachment~~)

68std::optional<Attachment> Attachment::decode(Decoder& decoder)

6969{

70 ASSERT_ARG(attachment, attachment.m_handle == INVALID_HANDLE_VALUE);

71

7270 uint64_t sourceHandle;

7371 if (!decoder.decode(sourceHandle))

74 return fa~~lse~~;

72 return std::nullopt;

    uint32_t sourcePID;

    if (!decoder.decode(sourcePID))

78 return fa~~lse~~;

76 return std::nullopt;

    HANDLE duplicatedHandle;

    if (!getDuplicatedHandle(reinterpret_cast<HANDLE>(sourceHandle), sourcePID, duplicatedHandle))

82 return fa~~lse~~;

80 return std::nullopt;

8381

84 attachment.m_handle = duplicatedHandle;

85 return true;

82 return Attachment { duplicatedHandle };

}

} // namespace IPC