strawberry-audio-player-win.../3rdparty/kdsingleapplication/kdsingleapplication_localso...

316 lines
10 KiB
C++

/*
This file is part of KDSingleApplication.
SPDX-FileCopyrightText: 2019-2023 Klarälvdalens Datakonsult AB, a KDAB Group company <info@kdab.com>
SPDX-License-Identifier: MIT
Contact KDAB at <info@kdab.com> for commercial licensing options.
*/
#include "kdsingleapplication_localsocket_p.h"
#include <QtCore/QDir>
#include <QtCore/QDeadlineTimer>
#include <QtCore/QTimer>
#include <QtCore/QLockFile>
#include <QtCore/QDataStream>
#include <QtCore/QtDebug>
#include <QtCore/QLoggingCategory>
#include <QtNetwork/QLocalServer>
#include <QtNetwork/QLocalSocket>
#include <chrono>
#include <algorithm>
#ifdef Q_OS_UNIX
// for ::getuid()
# include <sys/types.h>
# include <unistd.h>
#endif
#ifdef Q_OS_WIN
# include <qt_windows.h>
#endif
namespace {
static constexpr auto LOCALSOCKET_CONNECTION_TIMEOUT = std::chrono::seconds(5);
static constexpr char LOCALSOCKET_PROTOCOL_VERSION = 2;
} // namespace
#ifdef __GNUC__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wmissing-declarations"
#endif
Q_LOGGING_CATEGORY(kdsaLocalSocket, "kdsingleapplication.localsocket", QtWarningMsg)
#ifdef __GNUC__
#pragma GCC diagnostic pop
#endif
KDSingleApplicationLocalSocket::KDSingleApplicationLocalSocket(const QString &name, QObject *parent)
: QObject(parent)
{
#if defined(Q_OS_UNIX)
/* cppcheck-suppress useInitializationList */
m_socketName = QStringLiteral("kdsingleapp-%1-%2")
.arg(::getuid())
.arg(name);
#elif defined(Q_OS_WIN)
// I'm not sure of a "global session identifier" on Windows; are
// multiple logins from the same user a possibility? For now, following this:
// https://docs.microsoft.com/en-us/windows/desktop/devnotes/getting-the-session-id-of-the-current-process
DWORD sessionId;
BOOL haveSessionId = ProcessIdToSessionId(GetCurrentProcessId(), &sessionId);
m_socketName = QString::fromUtf8("kdsingleapp-%1-%2")
.arg(haveSessionId ? sessionId : 0)
.arg(name);
#else
#error "KDSingleApplication has not been ported to this platform"
#endif
const QString lockFilePath =
QDir::tempPath() + QLatin1Char('/') + m_socketName + QLatin1String(".lock");
qCDebug(kdsaLocalSocket) << "Socket name is" << m_socketName;
qCDebug(kdsaLocalSocket) << "Lock file path is" << lockFilePath;
std::unique_ptr<QLockFile> lockFile(new QLockFile(lockFilePath));
lockFile->setStaleLockTime(0);
if (!lockFile->tryLock()) {
// someone else has the lock => we're secondary
qCDebug(kdsaLocalSocket) << "Secondary instance";
return;
}
qCDebug(kdsaLocalSocket) << "Primary instance";
std::unique_ptr<QLocalServer> server = std::make_unique<QLocalServer>();
if (!server->listen(m_socketName)) {
// maybe the primary crashed, leaving a stale socket; delete it and try again
QLocalServer::removeServer(m_socketName);
if (!server->listen(m_socketName)) {
// TODO: better error handling.
qWarning("KDSingleApplication: unable to make the primary instance listen on %ls: %ls",
qUtf16Printable(m_socketName),
qUtf16Printable(server->errorString()));
return;
}
}
connect(server.get(), &QLocalServer::newConnection,
this, &KDSingleApplicationLocalSocket::handleNewConnection);
m_lockFile = std::move(lockFile);
m_localServer = std::move(server);
}
KDSingleApplicationLocalSocket::~KDSingleApplicationLocalSocket() = default;
bool KDSingleApplicationLocalSocket::isPrimaryInstance() const
{
return m_localServer != nullptr;
}
bool KDSingleApplicationLocalSocket::sendMessage(const QByteArray &message, int timeout)
{
Q_ASSERT(!isPrimaryInstance());
QLocalSocket socket;
qCDebug(kdsaLocalSocket) << "Preparing to send message" << message << "with timeout" << timeout;
QDeadlineTimer deadline(timeout);
// There is an inherent race here with the setup of the server side.
// Even if the socket lock is held by the server, the server may not
// be listening yet. So this connection may fail; keep retrying
// until we hit the timeout.
do {
socket.connectToServer(m_socketName);
if (socket.waitForConnected(static_cast<int>(deadline.remainingTime())))
break;
} while (!deadline.hasExpired());
qCDebug(kdsaLocalSocket) << "Socket state:" << socket.state() << "Timer remaining" << deadline.remainingTime() << "Expired?" << deadline.hasExpired();
if (deadline.hasExpired()) {
qCWarning(kdsaLocalSocket) << "Connection timed out";
return false;
}
socket.write(&LOCALSOCKET_PROTOCOL_VERSION, 1);
{
QByteArray encodedMessage;
QDataStream ds(&encodedMessage, QIODevice::WriteOnly);
ds << message;
socket.write(encodedMessage);
}
qCDebug(kdsaLocalSocket) << "Wrote message in the socket"
<< "Timer remaining" << deadline.remainingTime() << "Expired?" << deadline.hasExpired();
// There is no acknowledgement mechanism here.
// Should there be one?
while (socket.bytesToWrite() > 0) {
if (!socket.waitForBytesWritten(static_cast<int>(deadline.remainingTime()))) {
qCWarning(kdsaLocalSocket) << "Message to primary timed out";
return false;
}
}
qCDebug(kdsaLocalSocket) << "Bytes written, now disconnecting"
<< "Timer remaining" << deadline.remainingTime() << "Expired?" << deadline.hasExpired();
socket.disconnectFromServer();
if (socket.state() == QLocalSocket::UnconnectedState) {
qCDebug(kdsaLocalSocket) << "Disconnected -- success!";
return true;
}
if (!socket.waitForDisconnected(static_cast<int>(deadline.remainingTime()))) {
qCWarning(kdsaLocalSocket) << "Disconnection from primary timed out";
return false;
}
qCDebug(kdsaLocalSocket) << "Disconnected -- success!";
return true;
}
void KDSingleApplicationLocalSocket::handleNewConnection()
{
Q_ASSERT(m_localServer);
QLocalSocket *socket = nullptr;
while ((socket = m_localServer->nextPendingConnection())) {
qCDebug(kdsaLocalSocket) << "Got new connection on" << m_socketName << "state" << socket->state();
Connection c(socket);
socket = c.socket.get();
c.readDataConnection = QObjectConnectionHolder(
connect(socket, &QLocalSocket::readyRead,
this, &KDSingleApplicationLocalSocket::readDataFromSecondary));
c.secondaryDisconnectedConnection = QObjectConnectionHolder(
connect(socket, &QLocalSocket::disconnected,
this, &KDSingleApplicationLocalSocket::secondaryDisconnected));
c.abortConnection = QObjectConnectionHolder(
connect(c.timeoutTimer.get(), &QTimer::timeout,
this, &KDSingleApplicationLocalSocket::abortConnectionToSecondary));
m_clients.push_back(std::move(c));
// Note that by the time we get here, the socket could've already been closed,
// and no signals emitted (hello, Windows!). Read what's already in the socket.
if (readDataFromSecondarySocket(socket))
return;
if (socket->state() == QLocalSocket::UnconnectedState)
secondarySocketDisconnected(socket);
}
}
template<typename Container>
static auto findConnectionBySocket(Container &container, QLocalSocket *socket)
{
auto i = std::find_if(container.begin(),
container.end(),
[socket](const auto &c) { return c.socket.get() == socket; });
Q_ASSERT(i != container.end());
return i;
}
template<typename Container>
static auto findConnectionByTimer(Container &container, QTimer *timer)
{
auto i = std::find_if(container.begin(),
container.end(),
[timer](const auto &c) { return c.timeoutTimer.get() == timer; });
Q_ASSERT(i != container.end());
return i;
}
void KDSingleApplicationLocalSocket::readDataFromSecondary()
{
QLocalSocket *socket = static_cast<QLocalSocket *>(sender());
readDataFromSecondarySocket(socket);
}
bool KDSingleApplicationLocalSocket::readDataFromSecondarySocket(QLocalSocket *socket)
{
auto i = findConnectionBySocket(m_clients, socket);
Connection &c = *i;
c.readData.append(socket->readAll());
qCDebug(kdsaLocalSocket) << "Got more data from a secondary. Data read so far:" << c.readData;
const QByteArray &data = c.readData;
if (data.size() >= 1) {
if (data[0] != LOCALSOCKET_PROTOCOL_VERSION) {
qCDebug(kdsaLocalSocket) << "Got an invalid protocol version";
m_clients.erase(i);
return true;
}
}
QDataStream ds(data);
ds.skipRawData(1);
ds.startTransaction();
QByteArray message;
ds >> message;
if (ds.commitTransaction()) {
qCDebug(kdsaLocalSocket) << "Got a complete message:" << message;
Q_EMIT messageReceived(message);
m_clients.erase(i);
return true;
}
return false;
}
void KDSingleApplicationLocalSocket::secondaryDisconnected()
{
QLocalSocket *socket = static_cast<QLocalSocket *>(sender());
secondarySocketDisconnected(socket);
}
void KDSingleApplicationLocalSocket::secondarySocketDisconnected(QLocalSocket *socket)
{
auto i = findConnectionBySocket(m_clients, socket);
Connection c = std::move(*i);
m_clients.erase(i);
qCDebug(kdsaLocalSocket) << "Secondary disconnected. Data read:" << c.readData;
}
void KDSingleApplicationLocalSocket::abortConnectionToSecondary()
{
QTimer *timer = static_cast<QTimer *>(sender());
auto i = findConnectionByTimer(m_clients, timer);
Connection c = std::move(*i);
m_clients.erase(i);
qCDebug(kdsaLocalSocket) << "Secondary timed out. Data read:" << c.readData;
}
KDSingleApplicationLocalSocket::Connection::Connection(QLocalSocket *_socket)
: socket(_socket)
, timeoutTimer(new QTimer)
{
timeoutTimer->start(LOCALSOCKET_CONNECTION_TIMEOUT);
}