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 writeReqs the write requests that will be checked against the available quota
35 * @param estimateWriteSize the write size that will be checked against the available quota
36 * @param readReqs the read requests that will be checked against the available quota
37 * @param estimateReadSize the read size that will be checked against the available quota
38 * @throws ThrottlingException thrown if not enough avialable resources to perform operation.
39 */
40 void checkQuota(long writeReqs, long estimateWriteSize, long readReqs, long estimateReadSize)
41 throws ThrottlingException;
42
43 /**
44 * Removes the specified write and read amount from the quota.
45 * At this point the write and read amount will be an estimate,
46 * that will be later adjusted with a consumeWrite()/consumeRead() call.
47 *
48 * @param writeReqs the write requests that will be removed from the current quota
49 * @param writeSize the write size that will be removed from the current quota
50 * @param readReqs the read requests that will be removed from the current quota
51 * @param readSize the read size that will be removed from the current quota
52 */
53 void grabQuota(long writeReqs, long writeSize, long readReqs, long readSize);
54
55 /**
56 * Removes or add back some write amount to the quota.
57 * (called at the end of an operation in case the estimate quota was off)
58 */
59 void consumeWrite(long size);
60
61 /**
62 * Removes or add back some read amount to the quota.
63 * (called at the end of an operation in case the estimate quota was off)
64 */
65 void consumeRead(long size);
66
67 /** @return true if the limiter is a noop */
68 boolean isBypass();
69
70 /** @return the number of bytes available to read to avoid exceeding the quota */
71 long getReadAvailable();
72
73 /** @return the number of bytes available to write to avoid exceeding the quota */
74 long getWriteAvailable();
75 }