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 | |
19 | #ifndef BRPC_DESCRIBABLE_H |
20 | #define BRPC_DESCRIBABLE_H |
21 | |
22 | #include <ostream> |
23 | #include "butil/macros.h" |
24 | #include "butil/class_name.h" |
25 | |
26 | namespace brpc { |
27 | |
28 | struct DescribeOptions { |
29 | DescribeOptions() |
30 | : verbose(true) |
31 | , use_html(false) |
32 | {} |
33 | |
34 | bool verbose; |
35 | bool use_html; |
36 | }; |
37 | |
38 | class Describable { |
39 | public: |
40 | virtual ~Describable() {} |
41 | virtual void Describe(std::ostream& os, const DescribeOptions&) const { |
42 | os << butil::class_name_str(*this); |
43 | } |
44 | }; |
45 | |
46 | class NonConstDescribable { |
47 | public: |
48 | virtual ~NonConstDescribable() {} |
49 | virtual void Describe(std::ostream& os, const DescribeOptions&) { |
50 | os << butil::class_name_str(*this); |
51 | } |
52 | }; |
53 | |
54 | inline std::ostream& operator<<(std::ostream& os, const Describable& obj) { |
55 | DescribeOptions options; |
56 | options.verbose = false; |
57 | obj.Describe(os, options); |
58 | return os; |
59 | } |
60 | |
61 | inline std::ostream& operator<<(std::ostream& os, |
62 | NonConstDescribable& obj) { |
63 | DescribeOptions options; |
64 | options.verbose = false; |
65 | obj.Describe(os, options); |
66 | return os; |
67 | } |
68 | |
69 | // Append `indent' spaces after each newline. |
70 | // Example: |
71 | // IndentingOStream os1(std::cout, 2); |
72 | // IndentingOStream os2(os1, 2); |
73 | // std::cout << "begin1\nhello" << std::endl << "world\nend1" << std::endl; |
74 | // os1 << "begin2\nhello" << std::endl << "world\nend2" << std::endl; |
75 | // os2 << "begin3\nhello" << std::endl << "world\nend3" << std::endl; |
76 | // Output: |
77 | // begin1 |
78 | // hello |
79 | // world |
80 | // end1 |
81 | // begin2 |
82 | // hello |
83 | // world |
84 | // end2 |
85 | // begin3 |
86 | // hello |
87 | // world |
88 | // end3 |
89 | class IndentingOStream : virtual private std::streambuf, public std::ostream { |
90 | public: |
91 | IndentingOStream(std::ostream& dest, int indent) |
92 | : std::ostream(this) |
93 | , _dest(dest.rdbuf()) |
94 | , _is_at_start_of_line(false) |
95 | , _indent(indent, ' ') |
96 | {} |
97 | protected: |
98 | int overflow(int ch) override { |
99 | if (_is_at_start_of_line && ch != '\n' ) { |
100 | _dest->sputn(_indent.data(), _indent.size()); |
101 | } |
102 | _is_at_start_of_line = (ch == '\n'); |
103 | return _dest->sputc(ch); |
104 | } |
105 | private: |
106 | DISALLOW_COPY_AND_ASSIGN(IndentingOStream); |
107 | std::streambuf* _dest; |
108 | bool _is_at_start_of_line; |
109 | std::string _indent; |
110 | }; |
111 | |
112 | } // namespace brpc |
113 | |
114 | #endif // BRPC_DESCRIBABLE_H |
115 | |