1 /**
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18
19 package org.apache.hadoop.hbase.quotas;
20
21 import org.apache.hadoop.hbase.classification.InterfaceAudience;
22 import org.apache.hadoop.hbase.classification.InterfaceStability;
23 import org.apache.hadoop.hbase.quotas.OperationQuota.OperationType;
24
25 /**
26 * Internal interface used to interact with the user/table quota.
27 */
28 @InterfaceAudience.Private
29 @InterfaceStability.Evolving
30 public interface QuotaLimiter {
31 /**
32 * Checks if it is possible to execute the specified operation.
33 *
34 * @param estimateWriteSize the write size that will be checked against the available quota
35 * @param estimateReadSize the read size that will be checked against the available quota
36 * @throws ThrottlingException thrown if not enough avialable resources to perform operation.
37 */
38 void checkQuota(long estimateWriteSize, long estimateReadSize)
39 throws ThrottlingException;
40
41 /**
42 * Removes the specified write and read amount from the quota.
43 * At this point the write and read amount will be an estimate,
44 * that will be later adjusted with a consumeWrite()/consumeRead() call.
45 *
46 * @param writeSize the write size that will be removed from the current quota
47 * @param readSize the read size that will be removed from the current quota
48 */
49 void grabQuota(long writeSize, long readSize);
50
51 /**
52 * Removes or add back some write amount to the quota.
53 * (called at the end of an operation in case the estimate quota was off)
54 */
55 void consumeWrite(long size);
56
57 /**
58 * Removes or add back some read amount to the quota.
59 * (called at the end of an operation in case the estimate quota was off)
60 */
61 void consumeRead(long size);
62
63 /** @return true if the limiter is a noop */
64 boolean isBypass();
65
66 /** @return the number of bytes available to read to avoid exceeding the quota */
67 long getReadAvailable();
68
69 /** @return the number of bytes available to write to avoid exceeding the quota */
70 long getWriteAvailable();
71
72 /**
73 * Add the average size of the specified operation type.
74 * The average will be used as estimate for the next operations.
75 */
76 void addOperationSize(OperationType type, long size);
77
78 /** @return the average data size of the specified operation */
79 long getAvgOperationSize(OperationType type);
80 }