New class QTemporaryDir.

As discussed on qt5-feedback / development lists.

Change-Id: If1733369d12daa29054776ec2cbd78e63679768e
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@nokia.com>

4 files changed, 347 insertions, 3 deletions

diff --git a/src/corelib/io/io.pri b/src/corelib/io/io.pri
index 4fa5ed035e..ef11621679 100644
--- a/src/corelib/io/io.pri
+++ b/src/corelib/io/io.pri
@@ -20,6 +20,7 @@ HEADERS +=  \
         io/qprocess.h \
         io/qprocess_p.h \
         io/qtextstream.h \
+        io/qtemporarydir.h \
         io/qtemporaryfile.h \
         io/qresource_p.h \
         io/qresource_iterator_p.h \
@@ -54,6 +55,7 @@ SOURCES += \
         io/qnoncontiguousbytedevice.cpp \
         io/qprocess.cpp \
         io/qtextstream.cpp \
+        io/qtemporarydir.cpp \
         io/qtemporaryfile.cpp \
         io/qresource.cpp \
         io/qresource_iterator.cpp \
diff --git a/src/corelib/io/qdir_p.h b/src/corelib/io/qdir_p.h
index 7644a0391e..a34427a716 100644
--- a/src/corelib/io/qdir_p.h
+++ b/src/corelib/io/qdir_p.h
@@ -67,11 +67,11 @@ public:
 
     static inline QStringList splitFilters(const QString &nameFilter, QChar sep = 0);
 
-    inline void setPath(const QString &path);
+    void setPath(const QString &path);
 
-    inline void clearFileLists();
+    void clearFileLists();
 
-    inline void resolveAbsoluteEntry() const;
+    void resolveAbsoluteEntry() const;
 
     QStringList nameFilters;
     QDir::SortFlags sort;
diff --git a/src/corelib/io/qtemporarydir.cpp b/src/corelib/io/qtemporarydir.cpp
new file mode 100644
index 0000000000..c3a41fdd4c
--- /dev/null
+++ b/src/corelib/io/qtemporarydir.cpp
@@ -0,0 +1,258 @@
+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** GNU Lesser General Public License Usage
+** This file may be used under the terms of the GNU Lesser General Public
+** License version 2.1 as published by the Free Software Foundation and
+** appearing in the file LICENSE.LGPL included in the packaging of this
+** file. Please review the following information to ensure the GNU Lesser
+** General Public License version 2.1 requirements will be met:
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU General
+** Public License version 3.0 as published by the Free Software Foundation
+** and appearing in the file LICENSE.GPL included in the packaging of this
+** file. Please review the following information to ensure the GNU General
+** Public License version 3.0 requirements will be met:
+** http://www.gnu.org/copyleft/gpl.html.
+**
+** Other Usage
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qtemporarydir.h"
+
+#ifndef QT_NO_TEMPORARYFILE
+
+#include "qdiriterator.h"
+#include "qplatformdefs.h"
+#include "private/qdir_p.h"
+#include <QDebug>
+
+#if defined(QT_BUILD_CORE_LIB)
+#include "qcoreapplication.h"
+#endif
+
+#include <stdlib.h> // mkdtemp
+#ifdef Q_OS_WIN
+#include <windows.h>
+#include <private/qfsfileengine_p.h>
+#endif
+
+QT_BEGIN_NAMESPACE
+
+//************* QTemporaryDirPrivate
+class QTemporaryDirPrivate
+{
+public:
+    QTemporaryDirPrivate();
+    ~QTemporaryDirPrivate();
+
+    QString defaultTemplateName() const;
+    void create(const QString &templateName);
+
+    QString path;
+    bool autoRemove;
+    bool success;
+};
+
+QTemporaryDirPrivate::QTemporaryDirPrivate()
+    : autoRemove(true),
+      success(false)
+{
+}
+
+QTemporaryDirPrivate::~QTemporaryDirPrivate()
+{
+}
+
+QString QTemporaryDirPrivate::defaultTemplateName() const
+{
+    QString baseName;
+#if defined(QT_BUILD_CORE_LIB)
+    baseName = QCoreApplication::applicationName();
+    if (baseName.isEmpty())
+#endif
+        baseName = QLatin1String("qt_temp");
+
+    return QDir::tempPath() + QLatin1Char('/') + baseName + QLatin1String("-XXXXXX");
+}
+
+void QTemporaryDirPrivate::create(const QString &templateName)
+{
+#ifdef Q_OS_WIN
+    QString buffer = templateName;
+    // Windows' mktemp believes 26 temp files per process ought to be enough for everyone (!)
+    // Let's add a few random chars then, before the XXXXXX template.
+    for (int i = 0 ; i < 4 ; ++i)
+        buffer += QChar((qrand() & 0xffff) % (26) + 'A');
+    if (!buffer.endsWith(QLatin1String("XXXXXX")))
+        buffer += QLatin1String("XXXXXX");
+    QFileSystemEntry baseEntry(buffer);
+    QFileSystemEntry::NativePath basePath = baseEntry.nativeFilePath();
+    wchar_t* array = (wchar_t*)basePath.utf16();
+    if (_wmktemp(array) && ::CreateDirectory(array, 0)) {
+        success = true;
+        QFileSystemEntry entry(QString::fromWCharArray(array), QFileSystemEntry::FromNativePath());
+        path = entry.filePath();
+    }
+#else
+    QByteArray buffer = QFile::encodeName(templateName);
+    if (!buffer.endsWith("XXXXXX"))
+        buffer += "XXXXXX";
+    if (mkdtemp(buffer.data())) { // modifies buffer
+        success = true;
+        path = QFile::decodeName(buffer.constData());
+    }
+#endif
+}
+
+//************* QTemporaryDir
+
+/*!
+    \class QTemporaryDir
+    \reentrant
+    \brief The QTemporaryDir class creates a unique directory for temporary use.
+
+    \ingroup io
+
+
+    QTemporaryDir is used to create unique temporary dirs safely.
+    The dir itself is created by the constructor. The name of the
+    temporary directory is guaranteed to be unique (i.e., you are
+    guaranteed to not overwrite an existing dir), and the directory will
+    subsequently be removed upon destruction of the QTemporaryDir
+    object. The directory name is either auto-generated, or created based
+    on a template, which is passed to QTemporaryDir's constructor.
+
+    Example:
+
+    \snippet doc/src/snippets/code/src_corelib_io_qtemporarydir.cpp 0
+
+    It is very important to test that the temporary directory could be
+    created, using isValid(). Do not use exists(), since a default-constructed
+    QDir represents the current directory, which exists.
+
+    The path to the temporary dir can be found by calling path().
+
+    A temporary directory will have some static part of the name and some
+    part that is calculated to be unique. The default path will be
+    determined from QCoreApplication::applicationName() (otherwise \c qt_temp) and will
+    be placed into the temporary path as returned by QDir::tempPath().
+    If you specify your own path, a relative path will not be placed in the
+    temporary directory by default, but be relative to the current working directory.
+    In all cases, a random string will be appended to the path in order to make it unique.
+
+    \sa QDir::tempPath(), QDir, QTemporaryFile
+*/
+
+QTemporaryDir::QTemporaryDir()
+    : d_ptr(new QTemporaryDirPrivate)
+{
+    d_ptr->create(d_ptr->defaultTemplateName());
+}
+
+QTemporaryDir::QTemporaryDir(const QString &templateName)
+    : d_ptr(new QTemporaryDirPrivate)
+{
+    if (templateName.isEmpty())
+        d_ptr->create(d_ptr->defaultTemplateName());
+    else
+        d_ptr->create(templateName);
+}
+
+/*!
+    Destroys the temporary directory object.
+    If auto remove mode was set, it will automatically delete the directory
+    including all its contents.
+
+    \sa autoRemove()
+*/
+QTemporaryDir::~QTemporaryDir()
+{
+    if (d_ptr->success && d_ptr->autoRemove)
+        remove();
+    delete d_ptr;
+}
+
+/*!
+   Returns true if the QTemporaryDir was created successfully.
+*/
+bool QTemporaryDir::isValid() const
+{
+    return d_ptr->success;
+}
+
+/*!
+   Returns the path to the temporary directory.
+   Empty if the QTemporaryDir could not be created.
+*/
+QString QTemporaryDir::path() const
+{
+    return d_ptr->path;
+}
+
+/*!
+   Returns true if the QTemporaryDir is in auto remove
+   mode. Auto-remove mode will automatically delete the directory from
+   disk upon destruction. This makes it very easy to create your
+   QTemporaryDir object on the stack, fill it with files, do something with
+   the files, and finally on function return it will automatically clean up
+   after itself.
+
+   Auto-remove is on by default.
+
+   \sa setAutoRemove(), remove()
+*/
+bool QTemporaryDir::autoRemove() const
+{
+    return d_ptr->autoRemove;
+}
+
+/*!
+    Sets the QTemporaryDir into auto-remove mode if \a b is true.
+
+    Auto-remove is on by default.
+
+    \sa autoRemove(), remove()
+*/
+void QTemporaryDir::setAutoRemove(bool b)
+{
+    d_ptr->autoRemove = b;
+}
+
+/*!
+    Removes the temporary directory, including all its contents.
+*/
+bool QTemporaryDir::remove()
+{
+    if (!d_ptr->success)
+        return false;
+    Q_ASSERT(!path().isEmpty());
+    Q_ASSERT(path() != QLatin1String("."));
+
+    return QDir(path()).removeRecursively();
+}
+
+QT_END_NAMESPACE
+
+#endif // QT_NO_TEMPORARYFILE
diff --git a/src/corelib/io/qtemporarydir.h b/src/corelib/io/qtemporarydir.h
new file mode 100644
index 0000000000..96dc18d952
--- /dev/null
+++ b/src/corelib/io/qtemporarydir.h
@@ -0,0 +1,84 @@
+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** GNU Lesser General Public License Usage
+** This file may be used under the terms of the GNU Lesser General Public
+** License version 2.1 as published by the Free Software Foundation and
+** appearing in the file LICENSE.LGPL included in the packaging of this
+** file. Please review the following information to ensure the GNU Lesser
+** General Public License version 2.1 requirements will be met:
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU General
+** Public License version 3.0 as published by the Free Software Foundation
+** and appearing in the file LICENSE.GPL included in the packaging of this
+** file. Please review the following information to ensure the GNU General
+** Public License version 3.0 requirements will be met:
+** http://www.gnu.org/copyleft/gpl.html.
+**
+** Other Usage
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QTEMPORARYDIR_H
+#define QTEMPORARYDIR_H
+
+#include <QtCore/qdir.h>
+
+QT_BEGIN_HEADER
+
+QT_BEGIN_NAMESPACE
+
+QT_MODULE(Core)
+
+#ifndef QT_NO_TEMPORARYFILE
+
+class QTemporaryDirPrivate;
+
+class Q_CORE_EXPORT QTemporaryDir
+{
+public:
+    QTemporaryDir();
+    explicit QTemporaryDir(const QString &templateName);
+    ~QTemporaryDir();
+
+    bool isValid() const;
+
+    bool autoRemove() const;
+    void setAutoRemove(bool b);
+    bool remove();
+
+    QString path() const;
+
+private:
+    QTemporaryDirPrivate* const d_ptr;
+
+    Q_DISABLE_COPY(QTemporaryDir)
+};
+
+#endif // QT_NO_TEMPORARYFILE
+
+QT_END_NAMESPACE
+
+QT_END_HEADER
+
+#endif // QTEMPORARYDIR_H