ClickHouse/base/poco/Foundation/include/Poco/RecursiveDirectoryIterator.h

//
// RecursiveDirectoryIterator.h
//
// Library: Foundation
// Package: Filesystem
// Module:  RecursiveDirectoryIterator
//
// Definition of the RecursiveDirectoryIterator class.
//
// Copyright (c) 2012, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier:	BSL-1.0
//


#ifndef Foundation_RecursiveDirectoryIterator_INCLUDED
#define Foundation_RecursiveDirectoryIterator_INCLUDED


#include "Poco/DirectoryIteratorStrategy.h"
#include "Poco/File.h"
#include "Poco/Foundation.h"
#include "Poco/Path.h"
#include "Poco/RecursiveDirectoryIteratorImpl.h"


namespace Poco
{


class DirectoryIterator;


template <class TTravStr>
class RecursiveDirectoryIteratorImpl;


template <class TTravStr = ChildrenFirstTraverse>
class RecursiveDirectoryIterator
/// The RecursiveDirectoryIterator class is used to enumerate
/// all files in a directory and its subdirectories.
///
/// RecursiveDirectoryIterator has some limitations:
///   * only forward iteration (++) is supported
///   * an iterator copied from another one will always
///     point to the same file as the original iterator,
///     even is the original iterator has been advanced
///     (all copies of an iterator share their state with
///     the original iterator)
///
/// The class can follow different traversal strategies:
///     * depth-first strategy;
///     * siblings-first strategy.
/// The strategies are set by template parameter.
/// There are two corresponding typedefs:
///     * SimpleRecursiveDirectoryIterator;
///     * SiblingsFirstRecursiveDirectoryIterator.
///
/// The depth of traversal can be limited by constructor
/// parameter maxDepth (which sets the infinite depth by default).
{
public:
    typedef RecursiveDirectoryIterator<TTravStr> MyType;

    enum
    {
        D_INFINITE = 0 /// Constant for infinite traverse depth.
    };

    RecursiveDirectoryIterator()
        /// Creates the end iterator.
        : _pImpl(0)
    {
    }

    RecursiveDirectoryIterator(const std::string & path, UInt16 maxDepth = D_INFINITE)
        /// Creates a recursive directory iterator for the given path.
        : _pImpl(new ImplType(path, maxDepth)), _path(Path(_pImpl->get())), _file(_path)
    {
    }

    RecursiveDirectoryIterator(const MyType & iterator)
        : /// Creates a copy of another recursive directory iterator.
        _pImpl(iterator._pImpl)
        , _path(iterator._path)
        , _file(iterator._file)
    {
    }

    RecursiveDirectoryIterator(const DirectoryIterator & iterator, UInt16 maxDepth = D_INFINITE)
        : /// Creates a recursive directory iterator for the path of
        /// non-recursive directory iterator.
        _pImpl(new ImplType(iterator->path(), maxDepth))
        , _path(Path(_pImpl->get()))
        , _file(_path)
    {
    }

    RecursiveDirectoryIterator(const File & file, UInt16 maxDepth = D_INFINITE)
        : /// Creates a recursive directory iterator for the given path.
        _pImpl(new ImplType(file.path(), maxDepth))
        , _path(Path(_pImpl->get()))
        , _file(_path)
    {
    }

    RecursiveDirectoryIterator(const Path & path, UInt16 maxDepth = D_INFINITE)
        : /// Creates a recursive directory iterator for the given path.
        _pImpl(new ImplType(path.toString(), maxDepth))
        , _path(Path(_pImpl->get()))
        , _file(_path)
    {
    }

    ~RecursiveDirectoryIterator()
    /// Destroys the DirectoryIterator.
    {
        if (_pImpl)
            _pImpl->release();
    }

    const std::string & name() const
    /// Returns the current filename.
    {
        return _path.getFileName();
    }

    const Poco::Path & path() const
    /// Returns the current path.
    {
        return _path;
    }

    UInt16 depth() const
    /// Depth of recursion (counting from 1).
    {
        return _pImpl->depth();
    }

    UInt16 maxDepth() const
    /// Max depth of recursion (counting from 1).
    {
        return _pImpl->maxDepth();
    }


    MyType & operator=(const MyType & it)
    {
        if (_pImpl)
            _pImpl->release();
        _pImpl = it._pImpl;
        if (_pImpl)
        {
            _pImpl->duplicate();
            _path = it._path;
            _file = _path;
        }
        return *this;
    }

    MyType & operator=(const File & file)
    {
        if (_pImpl)
            _pImpl->release();
        _pImpl = new ImplType(file.path());
        _path = Path(_pImpl->get());
        _file = _path;
        return *this;
    }


    MyType & operator=(const Path & path)
    {
        if (_pImpl)
            _pImpl->release();
        _pImpl = new ImplType(path.toString());
        _path = Path(_pImpl->get());
        _file = _path;
        return *this;
    }

    MyType & operator=(const std::string & path)
    {
        if (_pImpl)
            _pImpl->release();
        _pImpl = new ImplType(path);
        _path = Path(_pImpl->get());
        _file = _path;
        return *this;
    }

    MyType & operator++()
    {
        if (_pImpl)
        {
            _path = Path(_pImpl->next());
            _file = _path;
        }
        return *this;
    }

    const File & operator*() const { return _file; }

    File & operator*() { return _file; }

    const File * operator->() const { return &_file; }

    File * operator->() { return &_file; }

    template <class T1, class T2>
    friend inline bool operator==(const RecursiveDirectoryIterator<T1> & a, const RecursiveDirectoryIterator<T2> & b);
    template <class T1, class T2>
    friend inline bool operator!=(const RecursiveDirectoryIterator<T1> & a, const RecursiveDirectoryIterator<T2> & b);

private:
    typedef RecursiveDirectoryIteratorImpl<TTravStr> ImplType;

    ImplType * _pImpl;
    Path _path;
    File _file;
};


//
// friend comparison operators
//
template <class T1, class T2>
inline bool operator==(const RecursiveDirectoryIterator<T1> & a, const RecursiveDirectoryIterator<T2> & b)
{
    return a.path().toString() == b.path().toString();
    ;
}

template <class T1, class T2>
inline bool operator!=(const RecursiveDirectoryIterator<T1> & a, const RecursiveDirectoryIterator<T2> & b)
{
    return a.path().toString() != b.path().toString();
    ;
}


//
// typedefs
//
typedef RecursiveDirectoryIterator<ChildrenFirstTraverse> SimpleRecursiveDirectoryIterator;
typedef RecursiveDirectoryIterator<SiblingsFirstTraverse> SiblingsFirstRecursiveDirectoryIterator;


} // namespace Poco


#endif // Foundation_RecursiveDirectoryIterator_INCLUDED