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#include "qabstractfileengine.h"

#include "private/qabstractfileengine_p.h"

#include "qdatetime.h"

#include "qreadwritelock.h"

#include "qvariant.h"

// built-in handlers

#include "qfsfileengine.h"

#include "qdiriterator.h"

QT_BEGIN_NAMESPACE

/*!

    \class QAbstractFileEngineHandler

    \reentrant

    \brief The QAbstractFileEngineHandler class provides a way to register

    custom file engines with your application.

    \ingroup io

    \since 4.1

    QAbstractFileEngineHandler is a factory for creating QAbstractFileEngine

    objects (file engines), which are used internally by QFile, QFileInfo, and

    QDir when working with files and directories.

    When you open a file, Qt chooses a suitable file engine by passing the

    file name from QFile or QDir through an internal list of registered file

    engine handlers. The first handler to recognize the file name is used to

    create the engine. Qt provides internal file engines for working with

    regular files and resources, but you can also register your own

    QAbstractFileEngine subclasses.

    To install an application-specific file engine, you subclass

    QAbstractFileEngineHandler and reimplement create(). When you instantiate

    the handler (e.g. by creating an instance on the stack or on the heap), it

    will automatically register with Qt. (The latest registered handler takes

    precedence over existing handlers.)

    For example:

    \snippet doc/src/snippets/code/src_corelib_io_qabstractfileengine.cpp 0

    When the handler is destroyed, it is automatically removed from Qt.

    The most common approach to registering a handler is to create an instance

    as part of the start-up phase of your application. It is also possible to

    limit the scope of the file engine handler to a particular area of

    interest (e.g. a special file dialog that needs a custom file engine). By

    creating the handler inside a local scope, you can precisely control the

    area in which your engine will be applied without disturbing file

    operations in other parts of your application.

    \sa QAbstractFileEngine, QAbstractFileEngine::create()

*/

/*

    All application-wide handlers are stored in this list. The mutex must be

    acquired to ensure thread safety.

 */

Q_GLOBAL_STATIC_WITH_ARGS(QReadWriteLock, fileEngineHandlerMutex, (QReadWriteLock::Recursive))

static bool qt_abstractfileenginehandlerlist_shutDown = false;

class QAbstractFileEngineHandlerList : public QList<QAbstractFileEngineHandler *>

{

public:

    ~QAbstractFileEngineHandlerList()

    {

        QWriteLocker locker(fileEngineHandlerMutex());

        qt_abstractfileenginehandlerlist_shutDown = true;

    }

};

Q_GLOBAL_STATIC(QAbstractFileEngineHandlerList, fileEngineHandlers)

/*!

    Constructs a file handler and registers it with Qt. Once created this

    handler's create() function will be called (along with all the other

    handlers) for any paths used. The most recently created handler that

    recognizes the given path (i.e. that returns a QAbstractFileEngine) is

    used for the new path.

    \sa create()

 */

QAbstractFileEngineHandler::QAbstractFileEngineHandler()

{

    QWriteLocker locker(fileEngineHandlerMutex());

    fileEngineHandlers()->prepend(this);

}

/*!

    Destroys the file handler. This will automatically unregister the handler

    from Qt.

 */

QAbstractFileEngineHandler::~QAbstractFileEngineHandler()

{

    QWriteLocker locker(fileEngineHandlerMutex());

    // Remove this handler from the handler list only if the list is valid.

    if (!qt_abstractfileenginehandlerlist_shutDown)

        fileEngineHandlers()->removeAll(this);

}

/*!

    \fn QAbstractFileEngine *QAbstractFileEngineHandler::create(const QString &fileName) const

    Creates a file engine for file \a fileName. Returns 0 if this

    file handler cannot handle \a fileName.

    Example:

    \snippet doc/src/snippets/code/src_corelib_io_qabstractfileengine.cpp 1

    \sa QAbstractFileEngine::create()

*/

/*!

    Creates and returns a QAbstractFileEngine suitable for processing \a

    fileName.

    You should not need to call this function; use QFile, QFileInfo or

    QDir directly instead.

    If you reimplemnt this function, it should only return file

    engines that knows how to handle \a fileName; otherwise, it should

    return 0.

    \sa QAbstractFileEngineHandler

*/

QAbstractFileEngine *QAbstractFileEngine::create(const QString &fileName)

{

    {

        QReadLocker locker(fileEngineHandlerMutex());

        // check for registered handlers that can load the file

        for (int i = 0; i < fileEngineHandlers()->size(); i++) {

            if (QAbstractFileEngine *ret = fileEngineHandlers()->at(i)->create(fileName))

                return ret;

        }

    }

#ifdef QT_BUILD_CORE_LIB

    if (!fileName.startsWith(QLatin1Char('/'))) {

        int prefixSeparator = fileName.indexOf(QLatin1Char(':'));

        if (prefixSeparator > 1) {

            QString prefix = fileName.left(prefixSeparator);

            QString fileNameWithoutPrefix = fileName.mid(prefixSeparator + 1).prepend(QLatin1Char('/'));

            const QStringList &paths = QDir::searchPaths(prefix);

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

                QString path = paths.at(i);

                path.append(fileNameWithoutPrefix);

                QAbstractFileEngine *engine = create(path);

                if (engine && (engine->fileFlags(QAbstractFileEngine::FlagsMask) & QAbstractFileEngine::ExistsFlag)) {

                    return engine;

                }

                delete engine;

            }

        }

    }

#endif

#ifdef QT_NO_FSFILEENGINE

    return 0;

#else

    // fall back to regular file engine

    return new QFSFileEngine(fileName);

#endif

}

/*!

    \class QAbstractFileEngine

    \reentrant

    \brief The QAbstractFileEngine class provides an abstraction for accessing

    the filesystem.

    \ingroup io

    \since 4.1

    The QDir, QFile, and QFileInfo classes all make use of a

    QAbstractFileEngine internally. If you create your own QAbstractFileEngine

    subclass (and register it with Qt by creating a QAbstractFileEngineHandler

    subclass), your file engine will be used when the path is one that your

    file engine handles.

    A QAbstractFileEngine refers to one file or one directory. If the referent

    is a file, the setFileName(), rename(), and remove() functions are

    applicable. If the referent is a directory the mkdir(), rmdir(), and

    entryList() functions are applicable. In all cases the caseSensitive(),

    isRelativePath(), fileFlags(), ownerId(), owner(), and fileTime()

    functions are applicable.

    A QAbstractFileEngine subclass can be created to do synchronous network I/O

    based file system operations, local file system operations, or to operate

    as a resource system to access file based resources.

   \sa QAbstractFileEngineHandler

*/

/*!

    \enum QAbstractFileEngine::FileName

    These values are used to request a file name in a particular

    format.

    \value DefaultName The same filename that was passed to the

    QAbstractFileEngine.

    \value BaseName The name of the file excluding the path.

    \value PathName The path to the file excluding the base name.

    \value AbsoluteName The absolute path to the file (including

    the base name).

    \value AbsolutePathName The absolute path to the file (excluding

    the base name).

    \value LinkName The full file name of the file that this file is a

    link to. (This will be empty if this file is not a link.)

    \value CanonicalName Often very similar to LinkName. Will return the true path to the file.

    \value CanonicalPathName Same as CanonicalName, excluding the base name.

    \value BundleName Returns the name of the bundle implies BundleType is set.

    \omitvalue NFileNames

    \sa fileName(), setFileName()

*/

/*!

    \enum QAbstractFileEngine::FileFlag

    The permissions and types of a file, suitable for OR'ing together.

    \value ReadOwnerPerm The owner of the file has permission to read

    it.

    \value WriteOwnerPerm The owner of the file has permission to

    write to it.

    \value ExeOwnerPerm The owner of the file has permission to

    execute it.

    \value ReadUserPerm The current user has permission to read the

    file.

    \value WriteUserPerm The current user has permission to write to

    the file.

    \value ExeUserPerm The current user has permission to execute the

    file.

    \value ReadGroupPerm Members of the current user's group have

    permission to read the file.

    \value WriteGroupPerm Members of the current user's group have

    permission to write to the file.

    \value ExeGroupPerm Members of the current user's group have

    permission to execute the file.

    \value ReadOtherPerm All users have permission to read the file.

    \value WriteOtherPerm All users have permission to write to the

    file.

    \value ExeOtherPerm All users have permission to execute the file.

    \value LinkType The file is a link to another file (or link) in

    the file system (i.e. not a file or directory).

    \value FileType The file is a regular file to the file system

    (i.e. not a link or directory)

    \value BundleType The file is a Mac OS X bundle implies DirectoryType

    \value DirectoryType The file is a directory in the file system

    (i.e. not a link or file).

    \value HiddenFlag The file is hidden.

    \value ExistsFlag The file actually exists in the file system.

    \value RootFlag  The file or the file pointed to is the root of the filesystem.

    \value LocalDiskFlag The file resides on the local disk and can be passed to standard file functions.

    \value Refresh Passing this flag will force the file engine to refresh all flags.

    \omitvalue PermsMask

    \omitvalue TypesMask

    \omitvalue FlagsMask

    \omitvalue FileInfoAll

    \sa fileFlags(), setFileName()

*/

/*!

    \enum QAbstractFileEngine::FileTime

    These are used by the fileTime() function.

    \value CreationTime When the file was created.

    \value ModificationTime When the file was most recently modified.

    \value AccessTime When the file was most recently accessed (e.g.

    read or written to).

    \sa setFileName()

*/

/*!

    \enum QAbstractFileEngine::FileOwner

    \value OwnerUser The user who owns the file.

    \value OwnerGroup The group who owns the file.

    \sa owner(), ownerId(), setFileName()

*/

/*!

   Constructs a new QAbstractFileEngine that does not refer to any file or directory.

   \sa setFileName()

 */

QAbstractFileEngine::QAbstractFileEngine() : d_ptr(new QAbstractFileEnginePrivate)

{

    d_ptr->q_ptr = this;

}

/*!

   \internal

   Constructs a QAbstractFileEngine.

 */

QAbstractFileEngine::QAbstractFileEngine(QAbstractFileEnginePrivate &dd) : d_ptr(&dd)

{

    d_ptr->q_ptr = this;

}

/*!

    Destroys the QAbstractFileEngine.

 */

QAbstractFileEngine::~QAbstractFileEngine()

{

}

/*!

    \fn bool QAbstractFileEngine::open(QIODevice::OpenMode mode)

    Opens the file in the specified \a mode. Returns true if the file

    was successfully opened; otherwise returns false.

    The \a mode is an OR combination of QIODevice::OpenMode and

    QIODevice::HandlingMode values.

*/

bool QAbstractFileEngine::open(QIODevice::OpenMode openMode)

{

    Q_UNUSED(openMode);

    return false;

}

/*!

    Closes the file, returning true if successful; otherwise returns false.

    The default implementation always returns false.

*/

bool QAbstractFileEngine::close()

{

    return false;

}

/*!

    Flushes the open file, returning true if successful; otherwise returns

    false.

    The default implementation always returns false.

*/

bool QAbstractFileEngine::flush()

{

    return false;

}

/*!

    Returns the size of the file.

*/

qint64 QAbstractFileEngine::size() const

{

    return 0;

}

/*!

    Returns the current file position.

    This is the position of the data read/write head of the file.

*/

qint64 QAbstractFileEngine::pos() const

{

    return 0;

}

/*!

    \fn bool QAbstractFileEngine::seek(qint64 offset)

    Sets the file position to the given \a offset. Returns true if

    the position was successfully set; otherwise returns false.

    The offset is from the beginning of the file, unless the

    file is sequential.

    \sa isSequential()

*/

bool QAbstractFileEngine::seek(qint64 pos)

{

    Q_UNUSED(pos);

    return false;

}

/*!

    Returns true if the file is a sequential access device; returns

    false if the file is a direct access device.

    Operations involving size() and seek(int) are not valid on

    sequential devices.

*/

bool QAbstractFileEngine::isSequential() const

{

    return false;

}

/*!

    Requests that the file is deleted from the file system. If the

    operation succeeds return true; otherwise return false.

    This virtual function must be reimplemented by all subclasses.

    \sa setFileName() rmdir()

 */

bool QAbstractFileEngine::remove()

{

    return false;

}

/*!

    Copies the contents of this file to a file with the name \a newName.

    Returns true on success; otherwise, false is returned.

*/

bool QAbstractFileEngine::copy(const QString &newName)

{

    Q_UNUSED(newName);

    return false;

}

/*!

    Requests that the file be renamed to \a newName in the file

    system. If the operation succeeds return true; otherwise return

    false.

    This virtual function must be reimplemented by all subclasses.

    \sa setFileName()

 */

bool QAbstractFileEngine::rename(const QString &newName)

{

    Q_UNUSED(newName);

    return false;

}

/*!

    Creates a link from the file currently specified by fileName() to

    \a newName. What a link is depends on the underlying filesystem

    (be it a shortcut on Windows or a symbolic link on Unix). Returns

    true if successful; otherwise returns false.

*/

bool QAbstractFileEngine::link(const QString &newName)

{

    Q_UNUSED(newName);

    return false;

}

/*!

    Requests that the directory \a dirName be created. If

    \a createParentDirectories is true, then any sub-directories in \a dirName

    that don't exist must be created. If \a createParentDirectories is false then

    any sub-directories in \a dirName must already exist for the function to

    succeed. If the operation succeeds return true; otherwise return

    false.

    This virtual function must be reimplemented by all subclasses.

    \sa setFileName() rmdir() isRelativePath()

 */

bool QAbstractFileEngine::mkdir(const QString &dirName, bool createParentDirectories) const

{

    Q_UNUSED(dirName);

    Q_UNUSED(createParentDirectories);

    return false;

}

/*!

    Requests that the directory \a dirName is deleted from the file

    system. When \a recurseParentDirectories is true, then any empty

    parent-directories in \a dirName must also be deleted. If

    \a recurseParentDirectories is false, only the \a dirName leaf-node

    should be deleted. In most file systems a directory cannot be deleted

    using this function if it is non-empty. If the operation succeeds

    return true; otherwise return false.

    This virtual function must be reimplemented by all subclasses.

    \sa setFileName() remove() mkdir() isRelativePath()

 */

bool QAbstractFileEngine::rmdir(const QString &dirName, bool recurseParentDirectories) const

{

    Q_UNUSED(dirName);