/**
* 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.quotas;
import java.util.List;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.classification.InterfaceStability;
import org.apache.hadoop.hbase.client.Mutation;
import org.apache.hadoop.hbase.client.Result;
/**
* Interface that allows to check the quota available for an operation.
*/
@InterfaceAudience.Private
@InterfaceStability.Evolving
public interface OperationQuota {
public enum OperationType { MUTATE, GET, SCAN }
/**
* Checks if it is possible to execute the specified operation.
* The quota will be estimated based on the number of operations to perform
* and the average size accumulated during time.
*
* @param numWrites number of write operation that will be performed
* @param numReads number of small-read operation that will be performed
* @param numScans number of long-read operation that will be performed
* @throws ThrottlingException if the operation cannot be performed
*/
void checkQuota(int numWrites, int numReads, int numScans)
throws ThrottlingException;
/** Cleanup method on operation completion */
void close();
/**
* Add a get result. This will be used to calculate the exact quota and
* have a better short-read average size for the next time.
*/
void addGetResult(Result result);
/**
* Add a scan result. This will be used to calculate the exact quota and
* have a better long-read average size for the next time.
*/
void addScanResult(List<Result> results);
/**
* Add a mutation result. This will be used to calculate the exact quota and
* have a better mutation average size for the next time.
*/
void addMutation(Mutation mutation);
/** @return the number of bytes available to read to avoid exceeding the quota */
long getReadAvailable();
/** @return the number of bytes available to write to avoid exceeding the quota */
long getWriteAvailable();
}