ladybird/Libraries/LibDevTools/Connection.cpp
Andreas Kling 0c7292e05c LibDevTools: Fix sending large messages over DevTools connection
Use blocking mode for socket writes to ensure large response bodies
(like 1MB+ HTML pages) are fully written without EAGAIN errors. The
socket is temporarily set to blocking mode during the write operation.

Also improve error handling by logging failed sends with the message
size and error details.

Additionally, when response content claims to be text but isn't valid
UTF-8, fall back to base64 encoding instead of returning empty content.
2026-01-15 20:10:19 +01:00

106 lines
3.3 KiB
C++

/*
* Copyright (c) 2025, Tim Flynn <trflynn89@ladybird.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Debug.h>
#include <AK/JsonObject.h>
#include <AK/JsonValue.h>
#include <LibCore/EventLoop.h>
#include <LibDevTools/Connection.h>
namespace DevTools {
NonnullRefPtr<Connection> Connection::create(NonnullOwnPtr<Core::BufferedTCPSocket> socket)
{
return adopt_ref(*new Connection(move(socket)));
}
Connection::Connection(NonnullOwnPtr<Core::BufferedTCPSocket> socket)
: m_socket(move(socket))
{
m_socket->on_ready_to_read = [this]() {
if (auto result = on_ready_to_read(); result.is_error()) {
if (on_connection_closed)
on_connection_closed();
}
};
}
Connection::~Connection() = default;
// https://firefox-source-docs.mozilla.org/devtools/backend/protocol.html#packets
void Connection::send_message(JsonValue const& message)
{
auto serialized = message.serialized();
if constexpr (DEVTOOLS_DEBUG) {
if (message.is_object() && message.as_object().get("error"sv).has_value())
dbgln("\x1b[1;31m<<\x1b[0m {}", serialized);
else
dbgln("\x1b[1;32m<<\x1b[0m {}", serialized);
}
// Temporarily enable blocking mode for large writes to avoid EAGAIN
(void)m_socket->set_blocking(true);
auto result = m_socket->write_until_depleted(MUST(String::formatted("{}:{}", serialized.byte_count(), serialized)));
(void)m_socket->set_blocking(false);
if (result.is_error()) {
warnln("DevTools: Failed to send message ({} bytes): {}", serialized.byte_count(), result.error());
if (on_connection_closed)
on_connection_closed();
}
}
// https://firefox-source-docs.mozilla.org/devtools/backend/protocol.html#packets
ErrorOr<JsonValue> Connection::read_message()
{
ByteBuffer length_buffer;
// FIXME: `read_until(':')` would be nicer here, but that seems to return immediately without receiving any data.
while (true) {
auto byte = TRY(m_socket->read_value<u8>());
if (byte == ':') {
break;
}
length_buffer.append(byte);
}
auto length = StringView { length_buffer }.to_number<size_t>();
if (!length.has_value())
return Error::from_string_literal("Could not read message length from DevTools client");
ByteBuffer message_buffer;
message_buffer.resize(*length);
TRY(m_socket->read_until_filled(message_buffer));
auto message = TRY(JsonValue::from_string(message_buffer));
dbgln_if(DEVTOOLS_DEBUG, "\x1b[1;33m>>\x1b[0m {}", message);
return message;
}
ErrorOr<void> Connection::on_ready_to_read()
{
// https://firefox-source-docs.mozilla.org/devtools/backend/protocol.html#the-request-reply-pattern
// Note that it is correct for a client to send several requests to a request/reply actor without waiting for a
// reply to each request before sending the next; requests can be pipelined.
while (TRY(m_socket->can_read_without_blocking())) {
auto message = TRY(read_message());
if (!message.is_object())
continue;
Core::deferred_invoke([this, message = move(message)]() mutable {
if (on_message_received)
on_message_received(move(message.as_object()));
});
}
return {};
}
}