package org.infinispan.loader.cluster;
import org.infinispan.AdvancedCache;
import org.infinispan.Cache;
import org.infinispan.commands.remote.ClusteredGetCommand;
import org.infinispan.container.entries.InternalCacheEntry;
import org.infinispan.context.InvocationContext;
import org.infinispan.lifecycle.ComponentStatus;
import org.infinispan.loader.AbstractCacheLoader;
import org.infinispan.loader.CacheLoaderConfig;
import org.infinispan.loader.CacheLoaderException;
import org.infinispan.logging.Log;
import org.infinispan.logging.LogFactory;
import org.infinispan.marshall.Marshaller;
import org.infinispan.remoting.ResponseFilter;
import org.infinispan.remoting.ResponseMode;
import org.infinispan.remoting.RpcManager;
import org.infinispan.remoting.responses.Response;
import org.infinispan.remoting.responses.SuccessfulResponse;
import org.infinispan.remoting.transport.Address;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Set;
/**
* Cache loader that consults other members in the cluster for values. A <code>timeout</code> property is required, a
* <code>long</code> that specifies in milliseconds how long to wait for results before returning a null.
*
* @author Mircea.Markus@jboss.com
*/
public class ClusterCacheLoader extends AbstractCacheLoader {
private static Log log = LogFactory.getLog(ClusterCacheLoader.class);
private ClusterCacheLoaderConfig config;
private RpcManager rpcManager;
private AdvancedCache cache;
public void init(CacheLoaderConfig config, Cache cache, Marshaller m) {
this.config = (ClusterCacheLoaderConfig) config;
this.cache = cache.getAdvancedCache();
rpcManager = this.cache.getRpcManager();
}
public InternalCacheEntry load(Object key) throws CacheLoaderException {
if (!(isCacheReady() && isLocalCall())) return null;
ClusteredGetCommand clusteredGetCommand = new ClusteredGetCommand(key, cache.getName());
List<Response> response = doRemoteCall(clusteredGetCommand);
if (response.isEmpty()) return null;
if (response.size() > 1)
throw new CacheLoaderException("Response length is always 0 or 1, received: " + response);
Response firstResponse = response.get(0);
if (firstResponse.isSuccessful() && firstResponse instanceof SuccessfulResponse) {
return (InternalCacheEntry) ((SuccessfulResponse) firstResponse).getResponseValue();
}
String message = "Unknown response from remote cache: " + response;
log.error(message);
throw new CacheLoaderException(message);
}
@SuppressWarnings(value = "unchecked")
public Set<InternalCacheEntry> loadAll() throws CacheLoaderException {
return Collections.EMPTY_SET;
}
public void start() throws CacheLoaderException {
//nothing to do here
}
public void stop() throws CacheLoaderException {
//nothing to do here
}
public Class<? extends CacheLoaderConfig> getConfigurationClass() {
throw new IllegalStateException("TODO - please implement me!!!");
}
public static class ResponseValidityFilter implements ResponseFilter {
private int numValidResponses = 0;
private List<Address> pendingResponders;
public ResponseValidityFilter(List<Address> expected, Address localAddress) {
this.pendingResponders = new ArrayList<Address>(expected);
// We'll never get a response from ourself
this.pendingResponders.remove(localAddress);
}
public boolean isAcceptable(Response response, Address address) {
pendingResponders.remove(address);
if (response instanceof SuccessfulResponse) numValidResponses++;
// always return true to make sure a response is logged by the JGroups RpcDispatcher.
return true;
}
public boolean needMoreResponses() {
return numValidResponses < 1 && pendingResponders.size() > 0;
}
}
private List<Response> doRemoteCall(ClusteredGetCommand clusteredGetCommand) throws CacheLoaderException {
ResponseValidityFilter filter = new ResponseValidityFilter(rpcManager.getTransport().getMembers(), rpcManager.getLocalAddress());
try {
return rpcManager.invokeRemotely(null, clusteredGetCommand, ResponseMode.WAIT_FOR_VALID_RESPONSE, config.getRemoteCallTimeout(), false, filter, false);
} catch (Exception e) {
log.error("error while doing remote call", e);
throw new CacheLoaderException(e);
}
}
private boolean isLocalCall() {
InvocationContext invocationContext = cache.getInvocationContextContainer().get();
return invocationContext.isOriginLocal();
}
/**
* A test to check whether the cache is in its started state. If not, calls should not be made as the channel may
* not have properly started, blocks due to state transfers may be in progress, etc.
*
* @return true if the cache is in its STARTED state.
*/
protected boolean isCacheReady() {
return cache.getStatus() == ComponentStatus.RUNNING;
}
}