org.apache.hadoop.fs.s3a.commit.files.PendingSet Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.hadoop.fs.s3a.commit.files;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import com.fasterxml.jackson.annotation.JsonProperty;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.s3a.commit.ValidationFailure;
import org.apache.hadoop.fs.statistics.IOStatisticsSnapshot;
import org.apache.hadoop.fs.statistics.IOStatisticsSource;
import org.apache.hadoop.util.JsonSerialization;
import static org.apache.hadoop.fs.s3a.commit.CommitUtils.validateCollectionClass;
import static org.apache.hadoop.fs.s3a.commit.ValidationFailure.verify;
/**
* Persistent format for multiple pending commits.
* Contains 0 or more {@link SinglePendingCommit} entries; validation logic
* checks those values on load.
*
* The statistics published through the {@link IOStatisticsSource}
* interface are the static ones marshalled with the commit data;
* they may be empty.
*
*
* As single commits are added via {@link #add(SinglePendingCommit)},
* any statistics from those commits are merged into the aggregate
* statistics, and those of the single commit cleared.
*
*/
@SuppressWarnings("unused")
@InterfaceAudience.Private
@InterfaceStability.Unstable
public class PendingSet extends PersistentCommitData
implements IOStatisticsSource {
private static final Logger LOG = LoggerFactory.getLogger(PendingSet.class);
/**
* Supported version value: {@value}.
* If this is changed the value of {@link #serialVersionUID} will change,
* to avoid deserialization problems.
*/
public static final int VERSION = 3;
/**
* Serialization ID: {@value}.
*/
private static final long serialVersionUID = 0x11000 + VERSION;
/** Version marker. */
private int version = VERSION;
/** Job ID, if known. */
private String jobId = "";
/**
* Commit list.
*/
private List commits;
/**
* Any custom extra data committer subclasses may choose to add.
*/
private final Map extraData = new HashMap<>(0);
/**
* IOStatistics.
*/
@JsonProperty("iostatistics")
private IOStatisticsSnapshot iostats = new IOStatisticsSnapshot();
public PendingSet() {
this(0);
}
public PendingSet(int size) {
commits = new ArrayList<>(size);
}
/**
* Get a JSON serializer for this class.
* @return a serializer.
*/
public static JsonSerialization serializer() {
return new JsonSerialization<>(PendingSet.class, false, true);
}
/**
* Load an instance from a file, then validate it.
* @param fs filesystem
* @param path path
* @return the loaded instance
* @throws IOException IO failure
* @throws ValidationFailure if the data is invalid
*/
public static PendingSet load(FileSystem fs, Path path)
throws IOException {
LOG.debug("Reading pending commits in file {}", path);
PendingSet instance = serializer().load(fs, path);
instance.validate();
return instance;
}
/**
* Load an instance from a file, then validate it.
* @param fs filesystem
* @param status status of file to load
* @return the loaded instance
* @throws IOException IO failure
* @throws ValidationFailure if the data is invalid
*/
public static PendingSet load(FileSystem fs, FileStatus status)
throws IOException {
return load(fs, status.getPath());
}
/**
* Add a commit.
* @param commit the single commit
*/
public void add(SinglePendingCommit commit) {
commits.add(commit);
// add any statistics.
IOStatisticsSnapshot st = commit.getIOStatistics();
if (st != null) {
iostats.aggregate(st);
st.clear();
}
}
/**
* Deserialize via java Serialization API: deserialize the instance
* and then call {@link #validate()} to verify that the deserialized
* data is valid.
* @param inStream input stream
* @throws IOException IO problem or validation failure
* @throws ClassNotFoundException reflection problems
*/
private void readObject(ObjectInputStream inStream) throws IOException,
ClassNotFoundException {
inStream.defaultReadObject();
validate();
}
/**
* Validate the data: those fields which must be non empty, must be set.
* @throws ValidationFailure if the data is invalid
*/
public void validate() throws ValidationFailure {
verify(version == VERSION, "Wrong version: %s", version);
validateCollectionClass(extraData.keySet(), String.class);
validateCollectionClass(extraData.values(), String.class);
Set destinations = new HashSet<>(commits.size());
validateCollectionClass(commits, SinglePendingCommit.class);
for (SinglePendingCommit c : commits) {
c.validate();
verify(!destinations.contains(c.getDestinationKey()),
"Destination %s is written to by more than one pending commit",
c.getDestinationKey());
destinations.add(c.getDestinationKey());
}
}
@Override
public byte[] toBytes() throws IOException {
return serializer().toBytes(this);
}
/**
* Number of commits.
* @return the number of commits in this structure.
*/
public int size() {
return commits != null ? commits.size() : 0;
}
@Override
public void save(FileSystem fs, Path path, boolean overwrite)
throws IOException {
serializer().save(fs, path, this, overwrite);
}
/** @return the version marker. */
public int getVersion() {
return version;
}
public void setVersion(int version) {
this.version = version;
}
/**
* @return commit list.
*/
public List getCommits() {
return commits;
}
public void setCommits(List commits) {
this.commits = commits;
}
/**
* Set/Update an extra data entry.
* @param key key
* @param value value
*/
public void putExtraData(String key, String value) {
extraData.put(key, value);
}
/** @return Job ID, if known. */
public String getJobId() {
return jobId;
}
public void setJobId(String jobId) {
this.jobId = jobId;
}
@Override
public IOStatisticsSnapshot getIOStatistics() {
return iostats;
}
public void setIOStatistics(final IOStatisticsSnapshot ioStatistics) {
this.iostats = ioStatistics;
}
}