/**
* 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.hbase.filter;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.TreeSet;
import java.util.ArrayList;
import org.apache.hadoop.hbase.KeyValue;
import com.google.common.base.Preconditions;
/**
* Filter that returns only cells whose timestamp (version) is
* in the specified list of timestamps (versions).
* <p>
* Note: Use of this filter overrides any time range/time stamp
* options specified using {@link org.apache.hadoop.hbase.client.Get#setTimeRange(long, long)},
* {@link org.apache.hadoop.hbase.client.Scan#setTimeRange(long, long)}, {@link org.apache.hadoop.hbase.client.Get#setTimeStamp(long)},
* or {@link org.apache.hadoop.hbase.client.Scan#setTimeStamp(long)}.
*/
public class TimestampsFilter extends FilterBase {
TreeSet<Long> timestamps;
private static final int MAX_LOG_TIMESTAMPS = 5;
// Used during scans to hint the scan to stop early
// once the timestamps fall below the minTimeStamp.
long minTimeStamp = Long.MAX_VALUE;
/**
* Used during deserialization. Do not use otherwise.
*/
public TimestampsFilter() {
super();
}
/**
* Constructor for filter that retains only those
* cells whose timestamp (version) is in the specified
* list of timestamps.
*
* @param timestamps
*/
public TimestampsFilter(List<Long> timestamps) {
for (Long timestamp : timestamps) {
Preconditions.checkArgument(timestamp >= 0, "must be positive %s", timestamp);
}
this.timestamps = new TreeSet<Long>(timestamps);
init();
}
/**
* @return the list of timestamps
*/
public List<Long> getTimestamps() {
List<Long> list = new ArrayList<Long>(timestamps.size());
list.addAll(timestamps);
return list;
}
private void init() {
if (this.timestamps.size() > 0) {
minTimeStamp = this.timestamps.first();
}
}
/**
* Gets the minimum timestamp requested by filter.
* @return minimum timestamp requested by filter.
*/
public long getMin() {
return minTimeStamp;
}
@Override
public ReturnCode filterKeyValue(KeyValue v) {
if (this.timestamps.contains(v.getTimestamp())) {
return ReturnCode.INCLUDE;
} else if (v.getTimestamp() < minTimeStamp) {
// The remaining versions of this column are guaranteed
// to be lesser than all of the other values.
return ReturnCode.NEXT_COL;
}
return ReturnCode.SKIP;
}
public static Filter createFilterFromArguments(ArrayList<byte []> filterArguments) {
ArrayList<Long> timestamps = new ArrayList<Long>();
for (int i = 0; i<filterArguments.size(); i++) {
long timestamp = ParseFilter.convertByteArrayToLong(filterArguments.get(i));
timestamps.add(timestamp);
}
return new TimestampsFilter(timestamps);
}
@Override
public void readFields(DataInput in) throws IOException {
int numTimestamps = in.readInt();
this.timestamps = new TreeSet<Long>();
for (int idx = 0; idx < numTimestamps; idx++) {
this.timestamps.add(in.readLong());
}
init();
}
@Override
public void write(DataOutput out) throws IOException {
int numTimestamps = this.timestamps.size();
out.writeInt(numTimestamps);
for (Long timestamp : this.timestamps) {
out.writeLong(timestamp);
}
}
@Override
public String toString() {
return toString(MAX_LOG_TIMESTAMPS);
}
protected String toString(int maxTimestamps) {
StringBuilder tsList = new StringBuilder();
int count = 0;
for (Long ts : this.timestamps) {
if (count >= maxTimestamps) {
break;
}
++count;
tsList.append(ts.toString());
if (count < this.timestamps.size() && count < maxTimestamps) {
tsList.append(", ");
}
}
return String.format("%s (%d/%d): [%s]", this.getClass().getSimpleName(),
count, this.timestamps.size(), tsList.toString());
}
}