/***********************************************************************************************************************
* Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
*
* 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 eu.stratosphere.nephele.services.accumulators;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import eu.stratosphere.api.common.accumulators.Accumulator;
import eu.stratosphere.core.io.IOReadableWritable;
import eu.stratosphere.nephele.execution.librarycache.LibraryCacheManager;
import eu.stratosphere.nephele.jobgraph.JobID;
import eu.stratosphere.util.StringUtils;
/**
* This class encapsulates a map of accumulators for a single job. It is used
* for the transfer from TaskManagers to the JobManager and from the JobManager
* to the Client.
*/
public class AccumulatorEvent implements IOReadableWritable {
private JobID jobID;
private Map<String, Accumulator<?, ?>> accumulators = new HashMap<String, Accumulator<?, ?>>();
private boolean useUserClassLoader = false;
// Removing this causes an EOFException in the RPC service. The RPC should
// be improved in this regard (error message is very unspecific).
public AccumulatorEvent() {
}
public AccumulatorEvent(JobID jobID,
Map<String, Accumulator<?, ?>> accumulators,
boolean useUserClassLoader) {
this.accumulators = accumulators;
this.jobID = jobID;
this.useUserClassLoader = useUserClassLoader;
}
public JobID getJobID() {
return this.jobID;
}
public Map<String, Accumulator<?, ?>> getAccumulators() {
return this.accumulators;
}
@Override
public void write(DataOutput out) throws IOException {
out.writeBoolean(this.useUserClassLoader);
jobID.write(out);
out.writeInt(accumulators.size());
for (Map.Entry<String, Accumulator<?, ?>> entry : this.accumulators
.entrySet()) {
out.writeUTF(entry.getKey());
out.writeUTF(entry.getValue().getClass().getName());
entry.getValue().write(out);
}
}
@SuppressWarnings("unchecked")
@Override
public void read(DataInput in) throws IOException {
this.useUserClassLoader = in.readBoolean();
jobID = new JobID();
jobID.read(in);
int numberOfMapEntries = in.readInt();
this.accumulators = new HashMap<String, Accumulator<?, ?>>(
numberOfMapEntries);
// Get user class loader. This is required at the JobManager, but not at
// the
// client.
ClassLoader classLoader = null;
if (this.useUserClassLoader) {
classLoader = LibraryCacheManager.getClassLoader(jobID);
} else {
classLoader = this.getClass().getClassLoader();
}
for (int i = 0; i < numberOfMapEntries; i++) {
String key = in.readUTF();
final String valueType = in.readUTF();
Class<Accumulator<?, ?>> valueClass = null;
try {
valueClass = (Class<Accumulator<?, ?>>) Class.forName(
valueType, true, classLoader);
} catch (ClassNotFoundException e) {
throw new IOException(StringUtils.stringifyException(e));
}
Accumulator<?, ?> value = null;
try {
value = valueClass.newInstance();
} catch (Exception e) {
throw new IOException(StringUtils.stringifyException(e));
}
value.read(in);
this.accumulators.put(key, value);
}
}
}