org.apache.bookkeeper.bookie.CheckpointSource 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.bookkeeper.bookie;
import java.io.IOException;
/**
* Interface to communicate checkpoint progress.
*/
public interface CheckpointSource {
/**
* A checkpoint presented a time point. All entries added before this checkpoint are already persisted.
*/
interface Checkpoint extends Comparable {
Checkpoint MAX = new Checkpoint() {
@Override
public int compareTo(Checkpoint o) {
if (o == MAX) {
return 0;
}
return 1;
}
@Override
public boolean equals(Object o) {
return this == o;
}
@Override
public String toString() {
return "MAX";
}
};
Checkpoint MIN = new Checkpoint() {
@Override
public int compareTo(Checkpoint o) {
if (o == MIN) {
return 0;
}
return -1;
}
@Override
public boolean equals(Object o) {
return this == o;
}
@Override
public String toString() {
return "MIN";
}
};
}
/**
* Request a new a checkpoint.
*
* @return checkpoint.
*/
Checkpoint newCheckpoint();
/**
* Tell checkpoint source that the checkpoint is completed.
* If compact is true, the implementation could compact
* to reduce size of data containing old checkpoints.
*
* @param checkpoint
* The checkpoint that has been completed
* @param compact
* Flag to compact old checkpoints.
*/
void checkpointComplete(Checkpoint checkpoint, boolean compact) throws IOException;
CheckpointSource DEFAULT = new CheckpointSource() {
@Override
public Checkpoint newCheckpoint() {
return Checkpoint.MIN;
}
@Override
public void checkpointComplete(Checkpoint checkpoint, boolean compact) {}
};
}