core/ipc: add ipc server/client

Currently can only kill a remote instance.

src/core/ipc.cpp

@@ -0,0 +1,119 @@
+#include "ipc.hpp"
+#include <functional>
+
+#include <qlocalserver.h>
+#include <qlocalsocket.h>
+#include <qlogging.h>
+#include <qloggingcategory.h>
+#include <qobject.h>
+
+#include "generation.hpp"
+#include "paths.hpp"
+
+namespace qs::ipc {
+
+Q_LOGGING_CATEGORY(logIpc, "quickshell.ipc", QtWarningMsg);
+
+IpcServer::IpcServer(const QString& path) {
+	QObject::connect(&this->server, &QLocalServer::newConnection, this, &IpcServer::onNewConnection);
+
+	QLocalServer::removeServer(path);
+
+	if (!this->server.listen(path)) {
+		qCCritical(logIpc) << "Failed to start IPC server on path" << path;
+		return;
+	}
+
+	qCInfo(logIpc) << "Started IPC server on path" << path;
+}
+
+void IpcServer::start() {
+	if (auto* run = QsPaths::instance()->instanceRunDir()) {
+		auto path = run->filePath("ipc.sock");
+		new IpcServer(path);
+	} else {
+		qCCritical(logIpc
+		) << "Could not start IPC server as the instance runtime path could not be created.";
+	}
+}
+
+void IpcServer::onNewConnection() {
+	while (auto* connection = this->server.nextPendingConnection()) {
+		new IpcServerConnection(connection, this);
+	}
+}
+
+IpcServerConnection::IpcServerConnection(QLocalSocket* socket, IpcServer* server)
+    : QObject(server)
+    , socket(socket) {
+	socket->setParent(this);
+	this->stream.setDevice(socket);
+	QObject::connect(socket, &QLocalSocket::disconnected, this, &IpcServerConnection::onDisconnected);
+	QObject::connect(socket, &QLocalSocket::readyRead, this, &IpcServerConnection::onReadyRead);
+
+	qCInfo(logIpc) << "New IPC connection" << this;
+}
+
+void IpcServerConnection::onDisconnected() {
+	qCInfo(logIpc) << "IPC connection disconnected" << this;
+}
+
+void IpcServerConnection::onReadyRead() {
+	this->stream.startTransaction();
+
+	this->stream.startTransaction();
+	auto command = IpcCommand::Unknown;
+	this->stream >> command;
+	if (!this->stream.commitTransaction()) return;
+
+	switch (command) {
+	case IpcCommand::Kill:
+		qInfo() << "Exiting due to IPC request.";
+		EngineGeneration::currentGeneration()->quit();
+		break;
+	default:
+		qCCritical(logIpc) << "Received invalid IPC command from" << this;
+		this->socket->disconnectFromServer();
+		break;
+	}
+
+	if (!this->stream.commitTransaction()) return;
+}
+
+IpcClient::IpcClient(const QString& path) {
+	QObject::connect(&this->socket, &QLocalSocket::connected, this, &IpcClient::connected);
+	QObject::connect(&this->socket, &QLocalSocket::disconnected, this, &IpcClient::disconnected);
+	QObject::connect(&this->socket, &QLocalSocket::errorOccurred, this, &IpcClient::onError);
+
+	this->socket.connectToServer(path);
+	this->stream.setDevice(&this->socket);
+}
+
+bool IpcClient::isConnected() const { return this->socket.isValid(); }
+
+void IpcClient::waitForConnected() { this->socket.waitForConnected(); }
+void IpcClient::waitForDisconnected() { this->socket.waitForDisconnected(); }
+
+void IpcClient::kill() {
+	qCDebug(logIpc) << "Sending kill command...";
+	this->stream << IpcCommand::Kill;
+	this->socket.flush();
+}
+
+void IpcClient::onError(QLocalSocket::LocalSocketError error) {
+	qCCritical(logIpc) << "Socket Error" << error;
+}
+
+bool IpcClient::connect(const QString& id, const std::function<void(IpcClient& client)>& callback) {
+	auto path = QsPaths::ipcPath(id);
+	auto client = IpcClient(path);
+	qCDebug(logIpc) << "Connecting to instance" << id << "at" << path;
+
+	client.waitForConnected();
+	if (!client.isConnected()) return false;
+	qCDebug(logIpc) << "Connected.";
+
+	callback(client);
+	return true;
+}
+} // namespace qs::ipc