LibIPC: Add IPC::take_over_accepted_client_from_system_server<Client>()

This is an encapsulation of the common work done by all of our
single-client IPC servers on startup:

    1. Create a Core::LocalSocket, taking over an accepted fd.
    2. Create an application-specific ClientConnection object,
       wrapping the socket.

It's not a huge change in terms of lines saved, but I do feel that it
improves expressiveness. :^)

Userland/DevTools/HackStudio/LanguageServers/ClientConnection.cpp

@@ -14,10 +14,10 @@ namespace LanguageServers {
 
 static HashMap<int, RefPtr<ClientConnection>> s_connections;
 
-ClientConnection::ClientConnection(NonnullRefPtr<Core::LocalSocket> socket, int client_id)
-    : IPC::ClientConnection<LanguageClientEndpoint, LanguageServerEndpoint>(*this, move(socket), client_id)
+ClientConnection::ClientConnection(NonnullRefPtr<Core::LocalSocket> socket)
+    : IPC::ClientConnection<LanguageClientEndpoint, LanguageServerEndpoint>(*this, move(socket), 1)
 {
-    s_connections.set(client_id, *this);
+    s_connections.set(1, *this);
 }
 
 ClientConnection::~ClientConnection()

Userland/DevTools/HackStudio/LanguageServers/ClientConnection.h

@@ -20,7 +20,7 @@ namespace LanguageServers {
 
 class ClientConnection : public IPC::ClientConnection<LanguageClientEndpoint, LanguageServerEndpoint> {
 public:
-    explicit ClientConnection(NonnullRefPtr<Core::LocalSocket>, int client_id);
+    explicit ClientConnection(NonnullRefPtr<Core::LocalSocket>);
     ~ClientConnection() override;
 
     virtual void die() override;

Userland/DevTools/HackStudio/LanguageServers/Cpp/ClientConnection.h

@@ -15,8 +15,8 @@ class ClientConnection final : public LanguageServers::ClientConnection {
     C_OBJECT(ClientConnection);
 
 private:
-    ClientConnection(NonnullRefPtr<Core::LocalSocket> socket, int client_id)
-        : LanguageServers::ClientConnection(move(socket), client_id)
+    ClientConnection(NonnullRefPtr<Core::LocalSocket> socket)
+        : LanguageServers::ClientConnection(move(socket))
     {
         m_autocomplete_engine = make<CppComprehensionEngine>(m_filedb);
         m_autocomplete_engine->set_declarations_of_document_callback = [this](const String& filename, Vector<GUI::AutocompleteProvider::Declaration>&& declarations) {

Userland/DevTools/HackStudio/LanguageServers/Cpp/main.cpp

@@ -6,14 +6,12 @@
 
 #include "ClientConnection.h"
 #include "Tests.h"
-#include <AK/LexicalPath.h>
 #include <LibCore/ArgsParser.h>
 #include <LibCore/EventLoop.h>
 #include <LibCore/LocalServer.h>
 #include <LibCore/System.h>
-#include <LibIPC/ClientConnection.h>
+#include <LibIPC/SingleServer.h>
 #include <LibMain/Main.h>
-#include <unistd.h>
 
 static ErrorOr<int> mode_server();
 
@@ -36,8 +34,7 @@ ErrorOr<int> mode_server()
     Core::EventLoop event_loop;
     TRY(Core::System::pledge("stdio unix recvfd rpath"));
 
-    auto socket = TRY(Core::LocalSocket::take_over_accepted_socket_from_system_server());
-    (void)IPC::new_client_connection<LanguageServers::Cpp::ClientConnection>(move(socket), 1);
+    auto client = TRY(IPC::take_over_accepted_client_from_system_server<LanguageServers::Cpp::ClientConnection>());
 
     TRY(Core::System::pledge("stdio recvfd rpath"));
     TRY(Core::System::unveil("/usr/include", "r"));

Userland/DevTools/HackStudio/LanguageServers/Shell/ClientConnection.h

@@ -16,8 +16,8 @@ class ClientConnection final : public LanguageServers::ClientConnection {
     C_OBJECT(ClientConnection);
 
 private:
-    ClientConnection(NonnullRefPtr<Core::LocalSocket> socket, int client_id)
-        : LanguageServers::ClientConnection(move(socket), client_id)
+    ClientConnection(NonnullRefPtr<Core::LocalSocket> socket)
+        : LanguageServers::ClientConnection(move(socket))
     {
         m_autocomplete_engine = make<ShellComprehensionEngine>(m_filedb);
         m_autocomplete_engine->set_declarations_of_document_callback = [this](const String& filename, Vector<GUI::AutocompleteProvider::Declaration>&& declarations) {

Userland/DevTools/HackStudio/LanguageServers/Shell/main.cpp

@@ -8,7 +8,7 @@
 #include <LibCore/EventLoop.h>
 #include <LibCore/LocalServer.h>
 #include <LibCore/System.h>
-#include <LibIPC/ClientConnection.h>
+#include <LibIPC/SingleServer.h>
 #include <LibMain/Main.h>
 
 ErrorOr<int> serenity_main(Main::Arguments)
@@ -16,8 +16,8 @@ ErrorOr<int> serenity_main(Main::Arguments)
     Core::EventLoop event_loop;
     TRY(Core::System::pledge("stdio unix rpath recvfd"));
 
-    auto socket = TRY(Core::LocalSocket::take_over_accepted_socket_from_system_server());
-    (void)IPC::new_client_connection<LanguageServers::Shell::ClientConnection>(move(socket), 1);
+    auto client = TRY(IPC::take_over_accepted_client_from_system_server<LanguageServers::Shell::ClientConnection>());
+
     TRY(Core::System::pledge("stdio rpath recvfd"));
     TRY(Core::System::unveil("/etc/passwd", "r"));
 

Userland/Libraries/LibIPC/SingleServer.h

@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibIPC/ClientConnection.h>
+
+namespace IPC {
+
+template<typename ClientConnectionType>
+ErrorOr<NonnullRefPtr<ClientConnectionType>> take_over_accepted_client_from_system_server()
+{
+    auto socket = TRY(Core::LocalSocket::take_over_accepted_socket_from_system_server());
+    return IPC::new_client_connection<ClientConnectionType>(move(socket));
+}
+
+}

Userland/Services/FileSystemAccessServer/ClientConnection.cpp

@@ -20,10 +20,10 @@ namespace FileSystemAccessServer {
 
 static HashMap<int, NonnullRefPtr<ClientConnection>> s_connections;
 
-ClientConnection::ClientConnection(NonnullRefPtr<Core::LocalSocket> socket, int client_id)
-    : IPC::ClientConnection<FileSystemAccessClientEndpoint, FileSystemAccessServerEndpoint>(*this, move(socket), client_id)
+ClientConnection::ClientConnection(NonnullRefPtr<Core::LocalSocket> socket)
+    : IPC::ClientConnection<FileSystemAccessClientEndpoint, FileSystemAccessServerEndpoint>(*this, move(socket), 1)
 {
-    s_connections.set(client_id, *this);
+    s_connections.set(1, *this);
 }
 
 ClientConnection::~ClientConnection()

Userland/Services/FileSystemAccessServer/ClientConnection.h

@@ -25,7 +25,7 @@ public:
     virtual void die() override;
 
 private:
-    explicit ClientConnection(NonnullRefPtr<Core::LocalSocket>, int client_id);
+    explicit ClientConnection(NonnullRefPtr<Core::LocalSocket>);
 
     virtual void request_file_read_only_approved(i32, i32, String const&) override;
     virtual void request_file(i32, i32, String const&, Core::OpenMode const&) override;

Userland/Services/FileSystemAccessServer/main.cpp

@@ -5,10 +5,9 @@
  */
 
 #include <FileSystemAccessServer/ClientConnection.h>
-#include <LibCore/LocalServer.h>
 #include <LibCore/System.h>
 #include <LibGUI/Application.h>
-#include <LibIPC/ClientConnection.h>
+#include <LibIPC/SingleServer.h>
 #include <LibMain/Main.h>
 
 ErrorOr<int> serenity_main(Main::Arguments)
@@ -18,7 +17,6 @@ ErrorOr<int> serenity_main(Main::Arguments)
     auto app = GUI::Application::construct(0, nullptr);
     app->set_quit_when_last_window_deleted(false);
 
-    auto socket = TRY(Core::LocalSocket::take_over_accepted_socket_from_system_server());
-    (void)IPC::new_client_connection<FileSystemAccessServer::ClientConnection>(move(socket), 1);
+    auto client = TRY(IPC::take_over_accepted_client_from_system_server<FileSystemAccessServer::ClientConnection>());
     return app->exec();
 }

Userland/Services/ImageDecoder/main.cpp

@@ -6,9 +6,8 @@
 
 #include <ImageDecoder/ClientConnection.h>
 #include <LibCore/EventLoop.h>
-#include <LibCore/LocalServer.h>
 #include <LibCore/System.h>
-#include <LibIPC/ClientConnection.h>
+#include <LibIPC/SingleServer.h>
 #include <LibMain/Main.h>
 
 ErrorOr<int> serenity_main(Main::Arguments)
@@ -17,8 +16,8 @@ ErrorOr<int> serenity_main(Main::Arguments)
     TRY(Core::System::pledge("stdio recvfd sendfd unix"));
     TRY(Core::System::unveil(nullptr, nullptr));
 
-    auto socket = TRY(Core::LocalSocket::take_over_accepted_socket_from_system_server());
-    auto client = IPC::new_client_connection<ImageDecoder::ClientConnection>(move(socket));
+    auto client = TRY(IPC::take_over_accepted_client_from_system_server<ImageDecoder::ClientConnection>());
+
     TRY(Core::System::pledge("stdio recvfd sendfd"));
     return event_loop.exec();
 }

Userland/Services/RequestServer/ClientConnection.cpp

@@ -15,10 +15,10 @@ namespace RequestServer {
 
 static HashMap<int, RefPtr<ClientConnection>> s_connections;
 
-ClientConnection::ClientConnection(NonnullRefPtr<Core::LocalSocket> socket, int client_id)
-    : IPC::ClientConnection<RequestClientEndpoint, RequestServerEndpoint>(*this, move(socket), client_id)
+ClientConnection::ClientConnection(NonnullRefPtr<Core::LocalSocket> socket)
+    : IPC::ClientConnection<RequestClientEndpoint, RequestServerEndpoint>(*this, move(socket), 1)
 {
-    s_connections.set(client_id, *this);
+    s_connections.set(1, *this);
 }
 
 ClientConnection::~ClientConnection()

Userland/Services/RequestServer/ClientConnection.h

@@ -29,7 +29,7 @@ public:
     void did_request_certificates(Badge<Request>, Request&);
 
 private:
-    explicit ClientConnection(NonnullRefPtr<Core::LocalSocket>, int client_id);
+    explicit ClientConnection(NonnullRefPtr<Core::LocalSocket>);
 
     virtual Messages::RequestServer::IsSupportedProtocolResponse is_supported_protocol(String const&) override;
     virtual Messages::RequestServer::StartRequestResponse start_request(String const&, URL const&, IPC::Dictionary const&, ByteBuffer const&) override;

Userland/Services/RequestServer/main.cpp

@@ -8,7 +8,7 @@
 #include <LibCore/EventLoop.h>
 #include <LibCore/LocalServer.h>
 #include <LibCore/System.h>
-#include <LibIPC/ClientConnection.h>
+#include <LibIPC/SingleServer.h>
 #include <LibMain/Main.h>
 #include <LibTLS/Certificate.h>
 #include <RequestServer/ClientConnection.h>
@@ -36,8 +36,8 @@ ErrorOr<int> serenity_main(Main::Arguments)
     [[maybe_unused]] auto http = make<RequestServer::HttpProtocol>();
     [[maybe_unused]] auto https = make<RequestServer::HttpsProtocol>();
 
-    auto socket = TRY(Core::LocalSocket::take_over_accepted_socket_from_system_server());
-    (void)IPC::new_client_connection<RequestServer::ClientConnection>(move(socket), 1);
+    auto client = TRY(IPC::take_over_accepted_client_from_system_server<RequestServer::ClientConnection>());
+
     auto result = event_loop.exec();
 
     // FIXME: We exit instead of returning, so that protocol destructors don't get called.

Userland/Services/WebContent/main.cpp

@@ -7,7 +7,7 @@
 #include <LibCore/EventLoop.h>
 #include <LibCore/LocalServer.h>
 #include <LibCore/System.h>
-#include <LibIPC/ClientConnection.h>
+#include <LibIPC/SingleServer.h>
 #include <LibMain/Main.h>
 #include <WebContent/ClientConnection.h>
 
@@ -21,7 +21,6 @@ ErrorOr<int> serenity_main(Main::Arguments)
     TRY(Core::System::unveil("/tmp/portal/websocket", "rw"));
     TRY(Core::System::unveil(nullptr, nullptr));
 
-    auto socket = TRY(Core::LocalSocket::take_over_accepted_socket_from_system_server());
-    auto client = IPC::new_client_connection<WebContent::ClientConnection>(move(socket));
+    auto client = IPC::take_over_accepted_client_from_system_server<WebContent::ClientConnection>();
     return event_loop.exec();
 }

Userland/Services/WebSocket/ClientConnection.cpp

@@ -13,10 +13,10 @@ namespace WebSocket {
 
 static HashMap<int, RefPtr<ClientConnection>> s_connections;
 
-ClientConnection::ClientConnection(NonnullRefPtr<Core::LocalSocket> socket, int client_id)
-    : IPC::ClientConnection<WebSocketClientEndpoint, WebSocketServerEndpoint>(*this, move(socket), client_id)
+ClientConnection::ClientConnection(NonnullRefPtr<Core::LocalSocket> socket)
+    : IPC::ClientConnection<WebSocketClientEndpoint, WebSocketServerEndpoint>(*this, move(socket), 1)
 {
-    s_connections.set(client_id, *this);
+    s_connections.set(1, *this);
 }
 
 ClientConnection::~ClientConnection()

Userland/Services/WebSocket/ClientConnection.h

@@ -24,7 +24,7 @@ public:
     virtual void die() override;
 
 private:
-    explicit ClientConnection(NonnullRefPtr<Core::LocalSocket>, int client_id);
+    explicit ClientConnection(NonnullRefPtr<Core::LocalSocket>);
 
     virtual Messages::WebSocketServer::ConnectResponse connect(URL const&, String const&, Vector<String> const&, Vector<String> const&, IPC::Dictionary const&) override;
     virtual Messages::WebSocketServer::ReadyStateResponse ready_state(i32) override;

Userland/Services/WebSocket/main.cpp

@@ -7,7 +7,7 @@
 #include <LibCore/EventLoop.h>
 #include <LibCore/LocalServer.h>
 #include <LibCore/System.h>
-#include <LibIPC/ClientConnection.h>
+#include <LibIPC/SingleServer.h>
 #include <LibMain/Main.h>
 #include <LibTLS/Certificate.h>
 #include <WebSocket/ClientConnection.h>
@@ -25,7 +25,7 @@ ErrorOr<int> serenity_main(Main::Arguments)
     TRY(Core::System::unveil("/tmp/portal/lookup", "rw"));
     TRY(Core::System::unveil(nullptr, nullptr));
 
-    auto socket = TRY(Core::LocalSocket::take_over_accepted_socket_from_system_server());
-    (void)IPC::new_client_connection<WebSocket::ClientConnection>(move(socket), 1);
+    auto client = TRY(IPC::take_over_accepted_client_from_system_server<WebSocket::ClientConnection>());
+
     return event_loop.exec();
 }