com.yugabyte.driver.core.PartitionMetadata Maven / Gradle / Ivy
// Copyright (c) YugaByte, 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 com.yugabyte.driver.core;
import com.datastax.driver.core.Host;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
/**
* The metadata for one table partition. It maintains the partition's range (start and end key) and
* hosts (leader and followers).
*/
public class PartitionMetadata {
// The partition start -- inclusive bound.
private final Integer startKey;
// The partition end -- exclusive bound.
private final Integer endKey;
// The list of hosts -- first one should be the leader, then the followers in no particular order.
// TODO We should make the leader explicit here and in the return type of the getQueryPlan method
// to be able to distinguish the case where the leader is missing so the hosts are all followers.
private final List hosts;
/** Creates a new {@code PartitionMetadata}. */
public PartitionMetadata(Integer startKey, Integer endKey, List hosts) {
this.startKey = startKey;
this.endKey = endKey;
this.hosts = (hosts != null) ? hosts : Collections.emptyList();
}
/**
* Returns the start key (inclusive lower bound) of this partition.
*
* @return the start key
*/
public Integer getStartKey() {
return startKey;
}
/**
* Returns the end key (exclusive upper bound) of this partition.
*
* @return the end key
*/
public Integer getEndKey() {
return endKey;
}
/**
* Returns the hosts (leader and followers) of this partition.
*
* @return the hosts, or the empty list if host list is unavailable.
*/
public List getHosts() {
return hosts;
}
@Override
public String toString() {
return String.format("[%d, %d) -> %s", startKey, endKey, Arrays.toString(hosts.toArray()));
}
}