OpenSpace/modules/globebrowsing/tile/tilediskcache.cpp

/*****************************************************************************************
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* OpenSpace                                                                             *
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* Copyright (c) 2014-2016                                                               *
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#include <modules/globebrowsing/tile/tilediskcache.h>
#include <modules/globebrowsing/tile/tile.h>

#include <ghoul/logging/logmanager.h>

#include <sstream>
#include <fstream>
#include <algorithm>

namespace {
    const std::string _loggerCat = "TileDiskCache";
}

namespace openspace {
namespace globebrowsing {

    const std::string TileDiskCache::CACHE_ROOT = "tilecache";

    TileDiskCache::TileDiskCache(const std::string& name)
        : _name(name)
    {
        if (!FileSystem::isInitialized()) {
            FileSystem::initialize();
        }

        std::string pathToCacheDir = FileSys.pathByAppendingComponent(CACHE_ROOT, name);
        Directory cacheDir(pathToCacheDir, Directory::RawPath::No);
        if (!FileSys.directoryExists(cacheDir)) {
            FileSys.createDirectory(pathToCacheDir, FileSystem::Recursive::Yes);
        }
        _cacheDir = cacheDir;
    }

    bool TileDiskCache::has(const TileIndex& tileIndex) const {
        File metaFile = getMetaDataFile(tileIndex);
        return FileSys.fileExists(metaFile);
    }

    std::shared_ptr<RawTile> TileDiskCache::get(const TileIndex& tileIndex) {
        File metaDataFile = getMetaDataFile(tileIndex);
        File dataFile = getDataFile(tileIndex);
        if (FileSys.fileExists(metaDataFile) && FileSys.fileExists(dataFile)) {
            // read meta
            std::ifstream ifsMeta;
            ifsMeta.open(metaDataFile.path(), std::ifstream::in);
            RawTile res = RawTile::deserializeMetaData(ifsMeta);
            ifsMeta.close();

            // read data
            std::ifstream ifsData;
            ifsData.open(dataFile.path(), std::ifstream::binary);
            char * buffer = new char[res.nBytesImageData];
            ifsData.read(buffer, res.nBytesImageData);
            res.imageData = buffer;

            return std::make_shared<RawTile>(res);
        }
        return nullptr;
    }

    bool TileDiskCache::put(const TileIndex& tileIndex, std::shared_ptr<RawTile> rawTile) {
        File metaDataFile = getMetaDataFile(tileIndex);
        if (!FileSys.fileExists(metaDataFile)) {
            std::ofstream ofsMeta;
            ofsMeta.open(metaDataFile.path());
            rawTile->serializeMetaData(ofsMeta);
            ofsMeta.close();

            std::ofstream ofsData;
            File dataFile = getDataFile(tileIndex);
            ofsData.open(dataFile.path(), std::ofstream::binary);
            char * data = (char*)rawTile->imageData;
            ofsData.write(data, rawTile->nBytesImageData);
            ofsData.close();
            return true;
        }
        return false;
    }

    std::string TileDiskCache::getFilePath(const TileIndex& tileIndex) const {
        std::stringstream ss;
        ss << tileIndex.level;
        ss << "_" << tileIndex.x;
        ss << "_" << tileIndex.y;
        std::string filePath = FileSys.pathByAppendingComponent(_cacheDir.path(), ss.str());
        return filePath;
    }

    File TileDiskCache::getMetaDataFile(const TileIndex& tileIndex) const {
        return File(getFilePath(tileIndex) + ".meta");
    }

    File TileDiskCache::getDataFile(const TileIndex& tileIndex) const {
        return File(getFilePath(tileIndex) + ".data");
    }

} // namespace globebrowsing
}  // namespace openspace