/*
* Copyright 2008-2013 LinkedIn, Inc
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package voldemort.server.protocol.admin;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import voldemort.client.protocol.pb.ProtoUtils;
import voldemort.client.protocol.pb.VAdminProto;
import voldemort.client.protocol.pb.VAdminProto.FetchPartitionEntriesRequest;
import voldemort.routing.StoreRoutingPlan;
import voldemort.server.StoreRepository;
import voldemort.server.VoldemortConfig;
import voldemort.store.ErrorCodeMapper;
import voldemort.store.metadata.MetadataStore;
import voldemort.store.stats.StreamingStats.Operation;
import voldemort.utils.ByteArray;
import voldemort.utils.ClosableIterator;
import voldemort.utils.NetworkClassLoader;
import com.google.protobuf.Message;
/**
* Fetches keys using an efficient partition scan. Of course, only works if
* isPartitionScanSupported() is true for the storage engine to be scanned..
*
*/
public class PartitionScanFetchKeysRequestHandler extends PartitionScanFetchStreamRequestHandler {
protected ClosableIterator<ByteArray> keysPartitionIterator;
public PartitionScanFetchKeysRequestHandler(FetchPartitionEntriesRequest request,
MetadataStore metadataStore,
ErrorCodeMapper errorCodeMapper,
VoldemortConfig voldemortConfig,
StoreRepository storeRepository,
NetworkClassLoader networkClassLoader) {
super(request,
metadataStore,
errorCodeMapper,
voldemortConfig,
storeRepository,
networkClassLoader,
Operation.FETCH_KEYS);
logger.info("Starting fetch keys for store '" + storageEngine.getName()
+ "' with replica to partition mapping " + partitionIds);
keysPartitionIterator = null;
}
@Override
public StreamRequestHandlerState handleRequest(DataInputStream inputStream,
DataOutputStream outputStream)
throws IOException {
// process the next partition
if(keysPartitionIterator == null) {
if(currentIndex == partitionList.size()) {
return StreamRequestHandlerState.COMPLETE;
}
// find the next partition to scan and set currentIndex.
boolean found = false;
while(!found && (currentIndex < partitionList.size())) {
currentPartition = partitionList.get(currentIndex);
if(!fetchedPartitions.contains(currentPartition)
&& StoreRoutingPlan.checkPartitionBelongsToNode(currentPartition,
nodeId,
initialCluster,
storeDef)) {
found = true;
completedFetchingCurrentPartition();
keysPartitionIterator = storageEngine.keys(currentPartition);
statusInfoMessage("Starting fetch keys");
}
currentIndex++;
}
} else {
long startNs = System.nanoTime();
// do a check before reading in case partition has 0 elements
if(keysPartitionIterator.hasNext()) {
ByteArray key = keysPartitionIterator.next();
reportStorageOpTime(startNs);
throttler.maybeThrottle(key.length());
if(filter.accept(key, null)) {
recordFetched();
VAdminProto.FetchPartitionEntriesResponse.Builder response = VAdminProto.FetchPartitionEntriesResponse.newBuilder();
response.setKey(ProtoUtils.encodeBytes(key));
Message message = response.build();
sendMessage(outputStream, message);
}
accountForScanProgress("keys");
}
if(!keysPartitionIterator.hasNext() || fetchedEnoughForCurrentPartition()) {
// Finished current partition. Reset iterator. Info status.
keysPartitionIterator.close();
keysPartitionIterator = null;
statusInfoMessage("Finished fetch keys");
progressInfoMessage("Fetch keys (end of partition)");
}
}
return StreamRequestHandlerState.WRITING;
}
@Override
public final void close(DataOutputStream outputStream) throws IOException {
if(null != keysPartitionIterator)
keysPartitionIterator.close();
super.close(outputStream);
}
}