Function setupSessionTemporaryDirectory

kdevplatform/shell/core.cpp:97–142

* Initialize per-session temporary directory and ensure its cleanup. * * When KDevelop crashes, it leaves many files, some of which are huge, in the temporary directory. * These files are not automatically removed until system restart. No space may be left in the * temporary directory after multiple crashes. This function removes the temporary directory for the * active session on KDevelop st

 *         or the system temporary directory path in case of error.
 */
QString setupSessionTemporaryDirectory(const KDevelop::ISession& session)
{
    QString systemTempDirPath = QDir::tempPath();

    // Session IDs are generated via QUuid::createUuid(), so they should be unique across all users in a system.
    // However, users could copy/share session directories and thus get equal session IDs. If two users are logged
    // in a system and have equal-ID KDevelop sessions open, the per-session temporary directory paths would coincide.
    // Prevent such conflicts by including the real user ID in the temporary directory path.
    const QString userId = KUserId::currentUserId().toString();

    // The temporary directory path does not contain the session ID in test mode, because most KDevelop
    // tests create a temporary session with a unique id on each run. Such temporary sessions are never
    // loaded again, and so their temporary files cannot possibly be removed on next start. Including
    // session IDs in temporary directory names for test sessions are only harmful then: empty directories
    // accumulate (and even nonempty directories as some tests don't remove their files during cleanup).
    // The session name is used in place of the session ID in test mode. TestCore::initializeNonStatic() sets most
    // test session names to "test-" + <test executable name>. The few custom test session names are also sufficiently
    // verbose and unique. Separate temporary directories for different tests allow running tests concurrently.
    // QStandardPaths::isTestModeEnabled() is undocumented internal API. But KSharedConfig::openConfig() relies on it.
    // So we venture to use this API here despite the risk of removal without notice in a future Qt version.
    const QString subdirName = QStandardPaths::isTestModeEnabled() ? session.name() : session.id().toString();

    QString tempDirPath = QLatin1String("%1/kdevelop-%2/%3").arg(systemTempDirPath, userId, subdirName);
    QDir tempDir(tempDirPath);

    // Remove files left after a possible previous crash of this session.
    if (!tempDir.removeRecursively()) {
        qCWarning(SHELL) << "couldn't delete the session temporary directory" << tempDirPath;
        return systemTempDirPath;
    }

    // Create the session temporary directory.
    if (!tempDir.mkpath(tempDirPath)) {
        qCWarning(SHELL) << "couldn't create the session temporary directory" << tempDirPath;
        return systemTempDirPath;
    }

    // Allow only the owner to access the temporary directory, just like QTemporaryDir() does.
    if (!QFile::setPermissions(tempDirPath, QFile::ReadOwner | QFile::WriteOwner | QFile::ExeOwner)) {
        qCWarning(SHELL) << "couldn't set permissions for the session temporary directory" << tempDirPath;
        return systemTempDirPath;
    }

    qCDebug(SHELL) << "set up the session temporary directory" << tempDirPath;
    return tempDirPath;
}
} // unnamed namespace

namespace KDevelop {