asynchronousfileloadingworkunit.cpp

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// The DAGFrameScheduler is a Multi-Threaded lock free and wait free scheduling library.
// © Copyright 2010 - 2016 BlackTopp Studios Inc.
/* This file is part of The DAGFrameScheduler.

    The DAGFrameScheduler is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
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*/
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*/
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#ifndef _asynchronousfileloadingworkunit_cpp
#define _asynchronousfileloadingworkunit_cpp

#include "asynchronousfileloadingworkunit.h"
#include "atomicoperations.h"

#include <iterator>

/// @file
/// @brief The implementation of the @ref Mezzanine::Threading::AsynchronousFileLoadWorkUnit "AsynchronousFileLoadWorkUnit" a workunit that loads a listing of files asynchronously.

namespace Mezzanine
{
    namespace Threading
    {
        void ThreadLoading(void* WU)
        {
            AsynchronousFileLoadWorkUnit& Unit = *((AsynchronousFileLoadWorkUnit*)WU);
            try{
                Unit.FilesRaw.reserve(Unit.Filenames.size());
            }catch (std::exception&){
                while(Unit.Status!=AtomicCompareAndSwap32(&(Unit.Status), Unit.Status, Failed));
                return;
            }
            for(std::vector<String>::iterator CurrentFileName = Unit.Filenames.begin(); CurrentFileName!=Unit.Filenames.end(); CurrentFileName++)
            {
                std::ifstream File(CurrentFileName->c_str(), std::ios::binary | std::ios::ate);
                if (File)
                {
                    MaxInt FileLength = File.tellg();
                    File.seekg(0,std::ios::beg);

                    RawFile* Loading;
                    try{
                        Loading = new RawFile(FileLength);
                    }catch (std::exception&){
                        while(Unit.Status!=AtomicCompareAndSwap32(&(Unit.Status), Unit.Status, Failed));
                        return;
                    }

                    File.read((char*)Loading->Data, FileLength);
                    Unit.FilesRaw.push_back(Loading);
                }else{
                    while(Unit.Status!=AtomicCompareAndSwap32(&(Unit.Status), Unit.Status, Failed));
                    break;
                }

            }
            while(Unit.Status!=AtomicCompareAndSwap32(&(Unit.Status), Unit.Status, Complete));
        }

        AsynchronousFileLoadWorkUnit::AsynchronousFileLoadWorkUnit() :
            LoadingThread(0),
            Status(NotStarted)
        {}

        AsynchronousFileLoadWorkUnit::~AsynchronousFileLoadWorkUnit()
            { DeleteLoadedFiles(); }

        RunningState AsynchronousFileLoadWorkUnit::BeginLoading(const std::vector<String>& Filenames_)
        {
            if(Running!=AtomicCompareAndSwap32(&Status, Status, Running))
            {
                //DeleteLoadedFiles();
                FilesRaw.clear();
                Filenames = Filenames_;
                LoadingThread = new Thread(ThreadLoading, this);
                return Starting;
            }else{
                //throw?
                return (RunningState)Status;
            }
        }

        void AsynchronousFileLoadWorkUnit::DoWork(DefaultThreadSpecificStorage::Type &)
        {
            if(Complete==Status&&0!=LoadingThread)
            {
                LoadingThread->join();
                delete LoadingThread;
                LoadingThread=0;
            }
        }

        RunningState AsynchronousFileLoadWorkUnit::IsWorkDone()
            { return (RunningState)Status; }

        RawFile* AsynchronousFileLoadWorkUnit::GetFile(const String& FileName) const
        {
            Whole Index=0;
            for(std::vector<String>::const_iterator CurrentFileName = Filenames.begin();
                CurrentFileName!=Filenames.end();
                CurrentFileName++, Index++)
            {
                if(*CurrentFileName==FileName)
                    { return GetFile(Index); }
            }
            return 0;
        }

        RawFile* AsynchronousFileLoadWorkUnit::GetFile(const Whole& Index) const
        {
            if(FilesRaw.size()<=Index)
                { return 0; }
            return FilesRaw[Index];
        }

        void AsynchronousFileLoadWorkUnit::DeleteLoadedFiles()
        {
            if(LoadingThread)
                { delete LoadingThread; }
            for(RawFileContainer::iterator Iter=FilesRaw.begin(); Iter!=FilesRaw.end(); ++Iter)
                { delete *Iter; }
        }
    } // \Threading
} // \Mezzanine
#endif