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.hbase.cell;
20
21 import org.apache.hadoop.classification.InterfaceAudience;
22 import org.apache.hadoop.classification.InterfaceStability;
23 import org.apache.hbase.Cell;
24
25 /**
26 * Accepts a stream of Cells and adds them to its internal data structure. This can be used to build
27 * a block of cells during compactions and flushes, or to build a byte[] to send to the client. This
28 * could be backed by a List<KeyValue>, but more efficient implementations will append results to a
29 * byte[] to eliminate overhead, and possibly encode the cells further.
30 */
31 @InterfaceAudience.Private
32 @InterfaceStability.Evolving
33 public interface CellOutputStream {
34
35 /**
36 * Implementation must copy the entire state of the Cell. If the appended Cell is modified
37 * immediately after the append method returns, the modifications must have absolutely no effect
38 * on the copy of the Cell that was added to the appender. For example, calling someList.add(cell)
39 * is not correct.
40 */
41 void write(Cell cell);
42
43 /**
44 * Let the implementation decide what to do. Usually means writing accumulated data into a byte[]
45 * that can then be read from the implementation to be sent to disk, put in the block cache, or
46 * sent over the network.
47 */
48 void flush();
49
50 }