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

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


#ifndef Foundation_RecursiveDirectoryIteratorImpl_INCLUDED
#define Foundation_RecursiveDirectoryIteratorImpl_INCLUDED


#include <functional>
#include <stack>
#include "Poco/DirectoryIteratorStrategy.h"
#include "Poco/Foundation.h"


namespace Poco
{


class ChildrenFirstTraverse;
class SiblingsFirstTraverse;


template <class TTraverseStrategy = ChildrenFirstTraverse>
class RecursiveDirectoryIteratorImpl
{
public:
    enum
    {
        D_INFINITE = 0 /// Special value for infinite traverse depth.
    };

    RecursiveDirectoryIteratorImpl(const std::string & path, UInt16 maxDepth = D_INFINITE)
        : _maxDepth(maxDepth), _traverseStrategy(std::ptr_fun(depthFun), _maxDepth), _isFinished(false), _rc(1)
    {
        _itStack.push(DirectoryIterator(path));
        _current = _itStack.top()->path();
    }

    ~RecursiveDirectoryIteratorImpl() { }

    inline void duplicate() { ++_rc; }

    inline void release()
    {
        if (--_rc == 0)
            delete this;
    }

    inline UInt16 depth() const { return depthFun(_itStack); }

    inline UInt16 maxDepth() const { return _maxDepth; }

    inline const std::string & get() const { return _current; }
    const std::string & next()
    {
        if (_isFinished)
            return _current;

        _current = _traverseStrategy.next(&_itStack, &_isFinished);

        return _current;
    }

private:
    typedef std::stack<DirectoryIterator> Stack;

    static UInt16 depthFun(const Stack & stack)
    /// Function which implements the logic of determining
    /// recursion depth.
    {
        return static_cast<Poco::UInt16>(stack.size());
    }

    UInt16 _maxDepth;
    TTraverseStrategy _traverseStrategy;
    bool _isFinished;
    Stack _itStack;
    std::string _current;
    int _rc;
};


} // namespace Poco


#endif // Foundation_RecursiveDirectoryIteratorImpl_INCLUDED