/**
 * @file lllfsthread.h
 * @brief LLLFSThread base class
 *
 * $LicenseInfo:firstyear=2000&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#ifndef LL_LLLFSTHREAD_H
#define LL_LLLFSTHREAD_H

#include <queue>
#include <string>
#include <map>
#include <set>

#include "llpointer.h"
#include "llqueuedthread.h"

//============================================================================
// Threaded Local File System
//============================================================================

class LLLFSThread : public LLQueuedThread
{
    //------------------------------------------------------------------------
public:
    enum operation_t {
        FILE_READ,
        FILE_WRITE,
        FILE_RENAME,
        FILE_REMOVE
    };

    //------------------------------------------------------------------------
public:

    class Responder : public LLThreadSafeRefCount
    {
    protected:
        ~Responder();
    public:
        virtual void completed(S32 bytes) = 0;
    };

    class Request : public QueuedRequest
    {
    protected:
        virtual ~Request(); // use deleteRequest()

    public:
        Request(LLLFSThread* thread,
                handle_t handle,
                operation_t op, const std::string& filename,
                U8* buffer, S32 offset, S32 numbytes,
                Responder* responder);

        S32 getBytes()
        {
            return mBytes;
        }
        S32 getBytesRead()
        {
            return mBytesRead;
        }
        S32 getOperation()
        {
            return mOperation;
        }
        U8* getBuffer()
        {
            return mBuffer;
        }
        const std::string& getFilename()
        {
            return mFileName;
        }

        /*virtual*/ bool processRequest();
        /*virtual*/ void finishRequest(bool completed);
        /*virtual*/ void deleteRequest();

    private:
        LLLFSThread* mThread;
        operation_t mOperation;

        std::string mFileName;

        U8* mBuffer;    // dest for reads, source for writes, new UUID for rename
        S32 mOffset;    // offset into file, -1 = append (WRITE only)
        S32 mBytes;     // bytes to read from file, -1 = all
        S32 mBytesRead; // bytes read from file

        LLPointer<Responder> mResponder;
    };

    //------------------------------------------------------------------------
public:
    LLLFSThread(bool threaded = true);
    ~LLLFSThread();

    // Return a Request handle
    handle_t read(const std::string& filename,  /* Flawfinder: ignore */
                  U8* buffer, S32 offset, S32 numbytes,
                  Responder* responder);
    handle_t write(const std::string& filename,
                   U8* buffer, S32 offset, S32 numbytes,
                   Responder* responder);

    // static initializers
    static void initClass(bool local_is_threaded = true); // Setup sLocal
    static S32 updateClass(U32 ms_elapsed);
    static void cleanupClass();     // Delete sLocal

public:
    static LLLFSThread* sLocal;     // Default local file thread
};

//============================================================================


#endif // LL_LLLFSTHREAD_H