view base/TempDirectory.cpp @ 299:576be0d0d218

* Merge transform directory from sv-match-alignment branch
  (the previous comment included notes for this stuff, but I missed it
  in the actual merge)
* Fix crash when a transform fails to create an output model and the
  thread that created the transform then deletes its input model thinking
  it's no longer needed, even though the transform run thread is still
  using it -- fix is to wait() on the transform before returning the
  null output model

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2006 Chris Cannam.
    
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
    published by the Free Software Foundation; either version 2 of the
    License, or (at your option) any later version.  See the file
    COPYING included with this distribution for more information.
*/

#include "TempDirectory.h"
#include "system/System.h"
#include "Exceptions.h"

#include <QDir>
#include <QFile>
#include <QMutexLocker>
#include <QSettings>

#include <iostream>
#include <cassert>

TempDirectory *
TempDirectory::m_instance = new TempDirectory;

TempDirectory *
TempDirectory::getInstance()
{
    return m_instance;
}

TempDirectory::TempDirectory() :
    m_tmpdir("")
{
}

TempDirectory::~TempDirectory()
{
    std::cerr << "TempDirectory::~TempDirectory" << std::endl;

    cleanup();
}

void
TempDirectory::cleanup()
{
    cleanupDirectory("");
}

QString
TempDirectory::getPath()
{
    QMutexLocker locker(&m_mutex);
    
    if (m_tmpdir != "") return m_tmpdir;

    QSettings settings;
    settings.beginGroup("TempDirectory");
    QString svDirParent = settings.value("create-in", "$HOME").toString();
    settings.endGroup();

    svDirParent.replace("$HOME", QDir::home().absolutePath());

    QString svDirBase = ".sv1";
    QString svDir = QDir(svDirParent).filePath(svDirBase);
    if (!QFileInfo(svDir).exists()) {
        if (!QDir(svDirParent).mkdir(svDirBase)) {
            throw DirectoryCreationFailed(QString("%1 directory in %2")
                                          .arg(svDirBase).arg(svDirParent));
        }
    } else if (!QFileInfo(svDir).isDir()) {
        throw DirectoryCreationFailed(QString("%1/%2 is not a directory")
                                      .arg(svDirParent).arg(svDirBase));
    }

    cleanupAbandonedDirectories(svDir);

    return createTempDirectoryIn(svDir);
}

QString
TempDirectory::createTempDirectoryIn(QString dir)
{
    // Entered with mutex held.

    QDir tempDirBase(dir);

    // Generate a temporary directory.  Qt4.1 doesn't seem to be able
    // to do this for us, and mkdtemp is not standard.  This method is
    // based on the way glibc does mkdtemp.

    static QString chars =
        "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";

    QString suffix;
    int padlen = 6, attempts = 100;
    unsigned int r = time(0) ^ getpid();

    for (int i = 0; i < padlen; ++i) {
        suffix += "X";
    }
    
    for (int j = 0; j < attempts; ++j) {

        unsigned int v = r;
        
        for (int i = 0; i < padlen; ++i) {
            suffix[i] = chars[v % 62];
            v /= 62;
        }

        QString candidate = QString("sv_%1").arg(suffix);

        if (tempDirBase.mkpath(candidate)) {
            m_tmpdir = tempDirBase.filePath(candidate);
            break;
        }

        r = r + 7777;
    }

    if (m_tmpdir == "") {
        throw DirectoryCreationFailed(QString("temporary subdirectory in %1")
                                      .arg(tempDirBase.canonicalPath()));
    }

    QString pidpath = QDir(m_tmpdir).filePath(QString("%1.pid").arg(getpid()));
    QFile pidfile(pidpath);

    if (!pidfile.open(QIODevice::WriteOnly)) {
        throw DirectoryCreationFailed(QString("pid file creation in %1")
                                      .arg(m_tmpdir));
    } else {
        pidfile.close();
    }

    return m_tmpdir;
}

QString
TempDirectory::getSubDirectoryPath(QString subdir)
{
    QString tmpdirpath = getPath();
    
    QMutexLocker locker(&m_mutex);

    QDir tmpdir(tmpdirpath);
    QFileInfo fi(tmpdir.filePath(subdir));

    if (!fi.exists()) {
        if (!tmpdir.mkdir(subdir)) {
            throw DirectoryCreationFailed(fi.filePath());
        } else {
            return fi.filePath();
        }
    } else if (fi.isDir()) {
        return fi.filePath();
    } else {
        throw DirectoryCreationFailed(fi.filePath());
    }
}

void
TempDirectory::cleanupDirectory(QString tmpdir)
{
    bool isRoot = false;

    if (tmpdir == "") {

        m_mutex.lock();

        isRoot = true;
        tmpdir = m_tmpdir;

        if (tmpdir == "") {
            m_mutex.unlock();
            return;
        }
    }

    QDir dir(tmpdir);
    dir.setFilter(QDir::Dirs | QDir::Files);

    for (unsigned int i = 0; i < dir.count(); ++i) {

        if (dir[i] == "." || dir[i] == "..") continue;
        QFileInfo fi(dir.filePath(dir[i]));

        if (fi.isDir()) {
            cleanupDirectory(fi.absoluteFilePath());
        } else {
            if (!QFile(fi.absoluteFilePath()).remove()) {
                std::cerr << "WARNING: TempDirectory::cleanup: "
                          << "Failed to unlink file \""
                          << fi.absoluteFilePath().toStdString() << "\""
                          << std::endl;
            }
        }
    }

    QString dirname = dir.dirName();
    if (dirname != "") {
        if (!dir.cdUp()) {
            std::cerr << "WARNING: TempDirectory::cleanup: "
                      << "Failed to cd to parent directory of "
                      << tmpdir.toStdString() << std::endl;
            return;
        }
        if (!dir.rmdir(dirname)) {
            std::cerr << "WARNING: TempDirectory::cleanup: "
                      << "Failed to remove directory "
                      << dirname.toStdString() << std::endl;
        } 
    }

    if (isRoot) {
        m_tmpdir = "";
        m_mutex.unlock();
    }
}

void
TempDirectory::cleanupAbandonedDirectories(QString svDir)
{
    QDir dir(svDir, "sv_*", QDir::Name, QDir::Dirs);

    for (unsigned int i = 0; i < dir.count(); ++i) {
        
        QDir subdir(dir.filePath(dir[i]), "*.pid", QDir::Name, QDir::Files);

        for (unsigned int j = 0; j < subdir.count(); ++j) {

            bool ok = false;
            int pid = QFileInfo(subdir[j]).baseName().toInt(&ok);
            if (!ok) continue;

            if (GetProcessStatus(pid) == ProcessNotRunning) {
                std::cerr << "INFO: Found abandoned temporary directory from "
                          << "an old Sonic Visualiser process\n(pid=" << pid
                          << ", directory=\""
                          << dir.filePath(dir[i]).toStdString()
                          << "\").  Removing it..." << std::endl;
                cleanupDirectory(dir.filePath(dir[i]));
                std::cerr << "...done." << std::endl;
                break;
            }
        }
    }
}