path: root/dozentenmodul/src/main/java/org/openslx/dozmod/thrift/cache/MetaDataCache.java

package org.openslx.dozmod.thrift.cache;

import java.util.List;

import org.apache.log4j.Logger;
import org.apache.thrift.TException;
import org.openslx.bwlp.thrift.iface.OperatingSystem;
import org.openslx.bwlp.thrift.iface.Virtualizer;
import org.openslx.thrifthelper.ThriftManager;
import org.openslx.util.GenericDataCache;
import org.openslx.util.GenericDataCache.CacheMode;

public class MetaDataCache {

	private static final Logger LOGGER = Logger.getLogger(MetaDataCache.class);

	/**
	 * How long to cache data.
	 */
	private static final int CACHE_TIME_MS = 60 * 60 * 1000;

	private static final GenericDataCache<List<OperatingSystem>> osCache = new GenericDataCache<List<OperatingSystem>>(
			CACHE_TIME_MS) {
		@Override
		protected List<OperatingSystem> update() throws TException {
			try {
				return ThriftManager.getSatClient().getOperatingSystems();
			} catch (Exception e) {
				LOGGER.warn("Could not get OS list from satellite, trying master for backup...", e);
			}
			return ThriftManager.getMasterClient().getOperatingSystems();
		}
	};

	private static final GenericDataCache<List<Virtualizer>> virtualizerCache = new GenericDataCache<List<Virtualizer>>(
			CACHE_TIME_MS) {
		@Override
		protected List<Virtualizer> update() throws TException {
			try {
				return ThriftManager.getSatClient().getVirtualizers();
			} catch (TException e) {
				LOGGER.warn("Could not get virtualizer list from satellite, trying master for backup...", e);
			}
			return ThriftManager.getMasterClient().getVirtualizers();
		}
	};

	/**
	 * Get all known/valid operating systems an image can be marked as.
	 * 
	 * @return
	 */
	public static List<OperatingSystem> getOperatingSystems() {
		return osCache.get();
	}

	public static OperatingSystem getOsById(int id) {
		return getOsById(id, false);
	}
	
	public static OperatingSystem getOsById(int id, boolean forceCache) {
		// First, try in "always cached" mode
		List<OperatingSystem> list = osCache.get(CacheMode.FORCE_CACHED);
		OperatingSystem os = getOsById(id, list);
		if (os != null || forceCache)
			return os;
		// Try again with a potential refresh
		List<OperatingSystem> newList = osCache.get(CacheMode.DEFAULT);
		if (list == newList) // Returned list from cache as it was still recent enough
			return null;
		return getOsById(id, newList);
	}

	private static OperatingSystem getOsById(int id, List<OperatingSystem> list) {
		if (list != null) {
			for (OperatingSystem os : list) {
				if (os.getOsId() == id)
					return os;
			}
		}
		return null;
	}

	/**
	 * Get all supported virtualizers an image can be declared to be run as.
	 * 
	 * @return
	 */
	public static List<Virtualizer> getVirtualizers() {
		return virtualizerCache.get();
	}
	
	public static Virtualizer getVirtualizerById(String virtId) {
		return getVirtualizerById(virtId, false);
	}

	public static Virtualizer getVirtualizerById(String virtId, boolean forceCache) {
		// First, try in "always cached" mode
		List<Virtualizer> list = virtualizerCache.get(CacheMode.FORCE_CACHED);
		Virtualizer virt = getVirtualizerById(virtId, list);
		if (virt != null || forceCache)
			return virt;
		// Try again with a potential refresh
		List<Virtualizer> newList = virtualizerCache.get(CacheMode.DEFAULT);
		if (list == newList) // Returned list from cache as it was still recent enough
			return null;
		return getVirtualizerById(virtId, newList);
	}

	private static Virtualizer getVirtualizerById(String virtId, List<Virtualizer> list) {
		if (list != null) {
			for (Virtualizer virt : list) {
				if (virt.getVirtId().equals(virtId))
					return virt;
			}
		}
		return null;
	}

}