/vp_plugins/qt_single_apps/qtlocalpeer.cpp

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 46
 47
 48#include "qtlocalpeer.h"
 49#include <QtCore/QCoreApplication>
 50#include <QtCore/QTime>
 51
 52#if defined(Q_OS_WIN)
 53#include <QtCore/QLibrary>
 54#include <QtCore/qt_windows.h>
 55typedef BOOL(WINAPI*PProcessIdToSessionId)(DWORD,DWORD*);
 56static PProcessIdToSessionId pProcessIdToSessionId = 0;
 57#endif
 58#if defined(Q_OS_UNIX)
 59#include <time.h>
 60#endif
 61
 62namespace QtLP_Private {
 63#include "qtlockedfile.cpp"
 64#if defined(Q_OS_WIN)
 65#include "qtlockedfile_win.cpp"
 66#else
 67#include "qtlockedfile_unix.cpp"
 68#endif
 69}
 70
 71const char* QtLocalPeer::ack = "ack";
 72
 73QtLocalPeer::QtLocalPeer(QObject* parent, const QString &appId)
 74    : QObject(parent), id(appId)
 75{
 76    QString prefix = id;
 77    if (id.isEmpty()) {
 78        id = QCoreApplication::applicationFilePath();
 79#if defined(Q_OS_WIN)
 80        id = id.toLower();
 81#endif
 82        prefix = id.section(QLatin1Char('/'), -1);
 83    }
 84    prefix.remove(QRegExp("[^a-zA-Z]"));
 85    prefix.truncate(6);
 86
 87    QByteArray idc = id.toUtf8();
 88    quint16 idNum = qChecksum(idc.constData(), idc.size());
 89    socketName = QLatin1String("qtsingleapp-") + prefix
 90                 + QLatin1Char('-') + QString::number(idNum, 16);
 91
 92#if defined(Q_OS_WIN)
 93    if (!pProcessIdToSessionId) {
 94        QLibrary lib("kernel32");
 95        pProcessIdToSessionId = (PProcessIdToSessionId)lib.resolve("ProcessIdToSessionId");
 96    }
 97    if (pProcessIdToSessionId) {
 98        DWORD sessionId = 0;
 99        pProcessIdToSessionId(GetCurrentProcessId(), &sessionId);
100        socketName += QLatin1Char('-') + QString::number(sessionId, 16);
101    }
102#else
103    socketName += QLatin1Char('-') + QString::number(::getuid(), 16);
104#endif
105
106    server = new QLocalServer(this);
107    QString lockName = QDir(QDir::tempPath()).absolutePath()
108                       + QLatin1Char('/') + socketName
109                       + QLatin1String("-lockfile");
110    lockFile.setFileName(lockName);
111    lockFile.open(QIODevice::ReadWrite);
112}
113
114
115
116bool QtLocalPeer::isClient()
117{
118    if (lockFile.isLocked())
119        return false;
120
121    if (!lockFile.lock(QtLP_Private::QtLockedFile::WriteLock, false))
122        return true;
123
124    bool res = server->listen(socketName);
125#if defined(Q_OS_UNIX) && (QT_VERSION >= QT_VERSION_CHECK(4,5,0))
126    // ### Workaround
127    if (!res && server->serverError() == QAbstractSocket::AddressInUseError) {
128        QFile::remove(QDir::cleanPath(QDir::tempPath())+QLatin1Char('/')+socketName);
129        res = server->listen(socketName);
130    }
131#endif
132    if (!res)
133        qWarning("QtSingleCoreApplication: listen on local socket failed, %s", qPrintable(server->errorString()));
134    QObject::connect(server, SIGNAL(newConnection()), SLOT(receiveConnection()));
135    return false;
136}
137
138
139bool QtLocalPeer::sendMessage(const QString &message, int timeout)
140{
141    if (!isClient())
142        return false;
143
144    QLocalSocket socket;
145    bool connOk = false;
146    for(int i = 0; i < 2; i++) {
147        // Try twice, in case the other instance is just starting up
148        socket.connectToServer(socketName);
149        connOk = socket.waitForConnected(timeout/2);
150        if (connOk || i)
151            break;
152        int ms = 250;
153#if defined(Q_OS_WIN)
154        Sleep(DWORD(ms));
155#else
156        struct timespec ts = { ms / 1000, (ms % 1000) * 1000 * 1000 };
157        nanosleep(&ts, NULL);
158#endif
159    }
160    if (!connOk)
161        return false;
162
163    QByteArray uMsg(message.toUtf8());
164    QDataStream ds(&socket);
165    ds.writeBytes(uMsg.constData(), uMsg.size());
166    bool res = socket.waitForBytesWritten(timeout);
167    res &= socket.waitForReadyRead(timeout);   // wait for ack
168    res &= (socket.read(qstrlen(ack)) == ack);
169    return res;
170}
171
172
173void QtLocalPeer::receiveConnection()
174{
175    QLocalSocket* socket = server->nextPendingConnection();
176    if (!socket)
177        return;
178
179    while (socket->bytesAvailable() < (int)sizeof(quint32))
180        socket->waitForReadyRead();
181    QDataStream ds(socket);
182    QByteArray uMsg;
183    quint32 remaining;
184    ds >> remaining;
185    uMsg.resize(remaining);
186    int got = 0;
187    char* uMsgBuf = uMsg.data();
188    do {
189        got = ds.readRawData(uMsgBuf, remaining);
190        remaining -= got;
191        uMsgBuf += got;
192    } while (remaining && got >= 0 && socket->waitForReadyRead(2000));
193    if (got < 0) {
194        qWarning() << "QtLocalPeer: Message reception failed" << socket->errorString();
195        delete socket;
196        return;
197    }
198    QString message(QString::fromUtf8(uMsg));
199    socket->write(ack, qstrlen(ack));
200    socket->waitForBytesWritten(1000);
201    delete socket;
202    emit messageReceived(message); //### (might take a long time to return)
203}