1 | // Licensed to the Apache Software Foundation (ASF) under one |
2 | // or more contributor license agreements. See the NOTICE file |
3 | // distributed with this work for additional information |
4 | // regarding copyright ownership. The ASF licenses this file |
5 | // to you under the Apache License, Version 2.0 (the |
6 | // "License"); you may not use this file except in compliance |
7 | // with the License. You may obtain a copy of the License at |
8 | // |
9 | // http://www.apache.org/licenses/LICENSE-2.0 |
10 | // |
11 | // Unless required by applicable law or agreed to in writing, |
12 | // software distributed under the License is distributed on an |
13 | // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
14 | // KIND, either express or implied. See the License for the |
15 | // specific language governing permissions and limitations |
16 | // under the License. |
17 | |
18 | // Date: Wed Aug 8 05:51:33 PDT 2018 |
19 | |
20 | #ifndef BUTIL_READER_WRITER_H |
21 | #define BUTIL_READER_WRITER_H |
22 | |
23 | #include <sys/uio.h> // iovec |
24 | |
25 | namespace butil { |
26 | |
27 | // Abstraction for reading data. |
28 | // The simplest implementation is to embed a file descriptor and read from it. |
29 | class IReader { |
30 | public: |
31 | virtual ~IReader() {} |
32 | |
33 | // Semantics of parameters and return value are same as readv(2) except that |
34 | // there's no `fd'. |
35 | virtual ssize_t ReadV(const iovec* iov, int iovcnt) = 0; |
36 | }; |
37 | |
38 | // Abstraction for writing data. |
39 | // The simplest implementation is to embed a file descriptor and writev into it. |
40 | class IWriter { |
41 | public: |
42 | virtual ~IWriter() {} |
43 | |
44 | // Semantics of parameters and return value are same as writev(2) except that |
45 | // there's no `fd'. |
46 | // WriteV is required to submit data gathered by multiple appends in one |
47 | // run and enable the possibility of atomic writes. |
48 | virtual ssize_t WriteV(const iovec* iov, int iovcnt) = 0; |
49 | }; |
50 | |
51 | } // namespace butil |
52 | |
53 | #endif // BUTIL_READER_WRITER_H |
54 | |