C++ CacheBin::readString方法代码示例

CacheBin*
TerrainLayer::getCacheBin(const Profile* profile)
{
    if ( !_openCalled )
    {
        OE_WARN << LC << "Illegal- called getCacheBin() before layer is open.. did you call open()?\n";
        return 0L;
    }

    CacheSettings* cacheSettings = getCacheSettings();
    if (!cacheSettings)
        return 0L;

    if (cacheSettings->cachePolicy()->isCacheDisabled())
        return 0L;

    CacheBin* bin = cacheSettings->getCacheBin();
    if (!bin)
        return 0L;

    // does the metadata need initializing?
    std::string metaKey = getMetadataKey(profile);

    Threading::ScopedMutexLock lock(_mutex);

    CacheBinMetadataMap::iterator i = _cacheBinMetadata.find(metaKey);
    if (i == _cacheBinMetadata.end())
    {
        //std::string cacheId = _runtimeOptions->cacheId().get();

        // read the metadata record from the cache bin:
        ReadResult rr = bin->readString(metaKey, _readOptions.get());
            
        osg::ref_ptr<CacheBinMetadata> meta;
        bool metadataOK = false;

        if (rr.succeeded())
        {
            // Try to parse the metadata record:
            Config conf;
            conf.fromJSON(rr.getString());
            meta = new CacheBinMetadata(conf);

            if (meta->isOK())
            {
                metadataOK = true;

                // verify that the cache if compatible with the open tile source:
                if ( getTileSource() && getProfile() )
                {
                    //todo: check the profile too
                    if ( meta->_sourceDriver.get() != getTileSource()->getOptions().getDriver() )
                    {                     
                        OE_WARN << LC 
                            << "Layer \"" << getName() << "\" is requesting a \""
                            << getTileSource()->getOptions().getDriver() << "\" cache, but a \""
                            << meta->_sourceDriver.get() << "\" cache exists at the specified location. "
                            << "The cache will ignored for this layer.\n";

                        cacheSettings->cachePolicy() = CachePolicy::NO_CACHE;
                        return 0L;
                    }
                }   

                // if not, see if we're in cache-only mode and still need a profile:
                else if (cacheSettings->cachePolicy()->isCacheOnly() && !_profile.valid())
                {
                    // in cacheonly mode, create a profile from the first cache bin accessed
                    // (they SHOULD all be the same...)
                    setProfile( Profile::create(meta->_sourceProfile.get()) );
                    _tileSize = meta->_sourceTileSize.get();
                }

                bin->setMetadata(meta.get());
            }
            else
            {
                OE_WARN << LC << "Metadata appears to be corrupt.\n";
            }
        }

        if (!metadataOK)
        {
            // cache metadata does not exist, so try to create it.
            if ( getProfile() )
            {
                meta = new CacheBinMetadata();

                // no existing metadata; create some.
                meta->_cacheBinId      = _runtimeCacheId;
                meta->_sourceName      = this->getName();
                meta->_sourceTileSize  = getTileSize();
                meta->_sourceProfile   = getProfile()->toProfileOptions();
                meta->_cacheProfile    = profile->toProfileOptions();
                meta->_cacheCreateTime = DateTime().asTimeStamp();
                meta->_dataExtents     = getDataExtents();

                if (getTileSource())
                {
                    meta->_sourceDriver = getTileSource()->getOptions().getDriver();
//.........这里部分代码省略.........