1/********************************************************************
2 * Copyright (c) 2013 - 2014, Pivotal Inc.
3 * All rights reserved.
4 *
5 * Author: Zhanwei Wang
6 ********************************************************************/
7/********************************************************************
8 * 2014 -
9 * open source under Apache License Version 2.0
10 ********************************************************************/
11/**
12 * Licensed to the Apache Software Foundation (ASF) under one
13 * or more contributor license agreements. See the NOTICE file
14 * distributed with this work for additional information
15 * regarding copyright ownership. The ASF licenses this file
16 * to you under the Apache License, Version 2.0 (the
17 * "License"); you may not use this file except in compliance
18 * with the License. You may obtain a copy of the License at
19 *
20 * http://www.apache.org/licenses/LICENSE-2.0
21 *
22 * Unless required by applicable law or agreed to in writing, software
23 * distributed under the License is distributed on an "AS IS" BASIS,
24 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
25 * See the License for the specific language governing permissions and
26 * limitations under the License.
27 */
28#ifndef _HDFS_LIBHDFS3_CLIENT_BLOCKREADER_H_
29#define _HDFS_LIBHDFS3_CLIENT_BLOCKREADER_H_
30
31#include <stdint.h>
32
33namespace Hdfs {
34namespace Internal {
35
36class BlockReader {
37public:
38 virtual ~BlockReader() {
39 }
40
41 /**
42 * Get how many bytes can be read without blocking.
43 * @return The number of bytes can be read without blocking.
44 */
45 virtual int64_t available() = 0;
46
47 /**
48 * To read data from block.
49 * @param buf the buffer used to filled.
50 * @param size the number of bytes to be read.
51 * @return return the number of bytes filled in the buffer,
52 * it may less than size. Return 0 if reach the end of block.
53 */
54 virtual int32_t read(char * buf, int32_t size) = 0;
55
56 /**
57 * Move the cursor forward len bytes.
58 * @param len The number of bytes to skip.
59 */
60 virtual void skip(int64_t len) = 0;
61};
62
63}
64}
65
66#endif /* _HDFS_LIBHDFS3_CLIENT_BLOCKREADER_H_ */
67