/**
* 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 org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.classification.InterfaceStability;
import org.apache.hadoop.hbase.quotas.OperationQuota.OperationType;
/**
* Internal interface used to interact with the user/table quota.
*/
@InterfaceAudience.Private
@InterfaceStability.Evolving
public interface QuotaLimiter {
/**
* Checks if it is possible to execute the specified operation.
*
* @param estimateWriteSize the write size that will be checked against the available quota
* @param estimateReadSize the read size that will be checked against the available quota
* @throws ThrottlingException thrown if not enough avialable resources to perform operation.
*/
void checkQuota(long estimateWriteSize, long estimateReadSize)
throws ThrottlingException;
/**
* Removes the specified write and read amount from the quota.
* At this point the write and read amount will be an estimate,
* that will be later adjusted with a consumeWrite()/consumeRead() call.
*
* @param writeSize the write size that will be removed from the current quota
* @param readSize the read size that will be removed from the current quota
*/
void grabQuota(long writeSize, long readSize);
/**
* Removes or add back some write amount to the quota.
* (called at the end of an operation in case the estimate quota was off)
*/
void consumeWrite(long size);
/**
* Removes or add back some read amount to the quota.
* (called at the end of an operation in case the estimate quota was off)
*/
void consumeRead(long size);
/** @return true if the limiter is a noop */
boolean isBypass();
/** @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();
}