/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef txResultRecycler_h__

#define txResultRecycler_h__

#include "nsCOMPtr.h"

#include "nsAutoPtr.h"

#include "txStack.h"

class txAExprResult;

class StringResult;

class txNodeSet;

class txXPathNode;

class NumberResult;

class BooleanResult;

class txResultRecycler

{

public:

    txResultRecycler();

    ~txResultRecycler();

    void AddRef()

    {

        ++mRefCnt;

        NS_LOG_ADDREF(this, mRefCnt, "txResultRecycler", sizeof(*this));

    }

    void Release()

    {

        --mRefCnt;

        NS_LOG_RELEASE(this, mRefCnt, "txResultRecycler");

        if (mRefCnt == 0) {

            mRefCnt = 1; //stabilize

            delete this;

        }

    }

    /**

     * Returns an txAExprResult to this recycler for reuse.

     * @param aResult  result to recycle

     */

    void recycle(txAExprResult* aResult);

    /**

     * Functions to return results that will be fully used by the caller.

     * Returns nullptr on out-of-memory and an inited result otherwise.

     */

    nsresult getStringResult(StringResult** aResult);

    nsresult getStringResult(const nsAString& aValue, txAExprResult** aResult);

    nsresult getNodeSet(txNodeSet** aResult);

    nsresult getNodeSet(txNodeSet* aNodeSet, txNodeSet** aResult);

    nsresult getNodeSet(const txXPathNode& aNode, txAExprResult** aResult);

    nsresult getNumberResult(double aValue, txAExprResult** aResult);

    /**

     * Functions to return a txAExprResult that is shared across several

     * clients and must not be modified. Never returns nullptr.

     */

    void getEmptyStringResult(txAExprResult** aResult);

    void getBoolResult(bool aValue, txAExprResult** aResult);

    /**

     * Functions that return non-shared resultsobjects

     */

    nsresult getNonSharedNodeSet(txNodeSet* aNodeSet, txNodeSet** aResult);

private:

    nsAutoRefCnt mRefCnt;

    txStack mStringResults;

    txStack mNodeSetResults;

    txStack mNumberResults;

    RefPtr<StringResult> mEmptyStringResult;

    RefPtr<BooleanResult> mTrueResult;

    RefPtr<BooleanResult> mFalseResult;

};

#endif //txResultRecycler_h__