ladybird/Libraries/LibIPC/Encoder.cpp
Timothy Flynn 68947d55d9 LibIPC: Do not require constructing containers when sending IPC messages
For example, consider the following IPC message:

    do_something(u64 page_id, String string, Vector<Data> data) =|

We would previously generate the following C++ method to encode/transfer
this message:

    void do_something(u64 page_id, String string, Vector<Data> data);

This required the caller to either have to copy the non-trivial types or
`move` them in. In some places, this meant we had to construct temporary
vectors just to send an IPC.

This isn't necessary because we weren't holding onto these parameters
anyways. We would construct an IPC::Message subclass with them (which
does require owning types), but then immediate encode the message to
an IPC::MessageBuffer and send it.

We now generate code such that we don't need to construct a Message. We
can simply encode the parameters directly without needing ownership.
This allows us to take view-types to IPC parameters.

So the above example now becomes:

    void do_something(u64, StringView, ReadonlySpan<Data>);
2025-03-09 11:14:20 -04:00

177 lines
4.1 KiB
C++

/*
* Copyright (c) 2020, Andreas Kling <andreas@ladybird.org>
* Copyright (c) 2021, kleines Filmröllchen <filmroellchen@serenityos.org>
* Copyright (c) 2023, Tim Flynn <trflynn89@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/BitCast.h>
#include <AK/ByteBuffer.h>
#include <AK/ByteString.h>
#include <AK/JsonObject.h>
#include <AK/JsonValue.h>
#include <AK/NumericLimits.h>
#include <AK/String.h>
#include <AK/Time.h>
#include <LibCore/AnonymousBuffer.h>
#include <LibCore/DateTime.h>
#include <LibCore/Proxy.h>
#include <LibCore/System.h>
#include <LibIPC/Encoder.h>
#include <LibIPC/File.h>
#include <LibURL/Origin.h>
#include <LibURL/URL.h>
namespace IPC {
ErrorOr<void> Encoder::encode_size(size_t size)
{
if (static_cast<u64>(size) > static_cast<u64>(NumericLimits<u32>::max()))
return Error::from_string_literal("Container exceeds the maximum allowed size");
return encode(static_cast<u32>(size));
}
template<>
ErrorOr<void> encode(Encoder& encoder, float const& value)
{
return encoder.encode(bit_cast<u32>(value));
}
template<>
ErrorOr<void> encode(Encoder& encoder, double const& value)
{
return encoder.encode(bit_cast<u64>(value));
}
template<>
ErrorOr<void> encode(Encoder& encoder, String const& value)
{
return encoder.encode(value.bytes_as_string_view());
}
template<>
ErrorOr<void> encode(Encoder& encoder, StringView const& value)
{
TRY(encoder.encode_size(value.length()));
TRY(encoder.append(reinterpret_cast<u8 const*>(value.characters_without_null_termination()), value.length()));
return {};
}
template<>
ErrorOr<void> encode(Encoder& encoder, ByteString const& value)
{
return encoder.encode(value.view());
}
template<>
ErrorOr<void> encode(Encoder& encoder, ByteBuffer const& value)
{
TRY(encoder.encode_size(value.size()));
TRY(encoder.append(value.data(), value.size()));
return {};
}
template<>
ErrorOr<void> encode(Encoder& encoder, JsonValue const& value)
{
return encoder.encode(value.serialized());
}
template<>
ErrorOr<void> encode(Encoder& encoder, AK::Duration const& value)
{
return encoder.encode(value.to_nanoseconds());
}
template<>
ErrorOr<void> encode(Encoder& encoder, UnixDateTime const& value)
{
return encoder.encode(value.nanoseconds_since_epoch());
}
template<>
ErrorOr<void> encode(Encoder& encoder, URL::URL const& value)
{
TRY(encoder.encode(value.serialize()));
if (!value.blob_url_entry().has_value())
return encoder.encode(false);
TRY(encoder.encode(true));
auto const& blob = value.blob_url_entry().value();
TRY(encoder.encode(blob.object.type));
TRY(encoder.encode(blob.object.data));
TRY(encoder.encode(blob.environment.origin));
return {};
}
template<>
ErrorOr<void> encode(Encoder& encoder, URL::Origin const& origin)
{
if (origin.is_opaque()) {
TRY(encoder.encode(true));
} else {
TRY(encoder.encode(false));
TRY(encoder.encode(origin.scheme()));
TRY(encoder.encode(origin.host()));
TRY(encoder.encode(origin.port()));
}
return {};
}
template<>
ErrorOr<void> encode(Encoder& encoder, URL::Host const& host)
{
TRY(encoder.encode(host.value()));
return {};
}
template<>
ErrorOr<void> encode(Encoder& encoder, File const& file)
{
int fd = file.take_fd();
TRY(encoder.append_file_descriptor(fd));
return {};
}
template<>
ErrorOr<void> encode(Encoder&, Empty const&)
{
return {};
}
template<>
ErrorOr<void> encode(Encoder& encoder, Core::AnonymousBuffer const& buffer)
{
TRY(encoder.encode(buffer.is_valid()));
if (buffer.is_valid()) {
TRY(encoder.encode_size(buffer.size()));
TRY(encoder.encode(TRY(IPC::File::clone_fd(buffer.fd()))));
}
return {};
}
template<>
ErrorOr<void> encode(Encoder& encoder, Core::DateTime const& datetime)
{
return encoder.encode(static_cast<i64>(datetime.timestamp()));
}
template<>
ErrorOr<void> encode(Encoder& encoder, Core::ProxyData const& proxy)
{
TRY(encoder.encode(proxy.type));
TRY(encoder.encode(proxy.host_ipv4));
TRY(encoder.encode(proxy.port));
return {};
}
}