1 
2 /**
3  *    Copyright (C) 2018-present MongoDB, Inc.
4  *
5  *    This program is free software: you can redistribute it and/or modify
6  *    it under the terms of the Server Side Public License, version 1,
7  *    as published by MongoDB, Inc.
8  *
9  *    This program is distributed in the hope that it will be useful,
10  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
11  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  *    Server Side Public License for more details.
13  *
14  *    You should have received a copy of the Server Side Public License
15  *    along with this program. If not, see
16  *    <http://www.mongodb.com/licensing/server-side-public-license>.
17  *
18  *    As a special exception, the copyright holders give permission to link the
19  *    code of portions of this program with the OpenSSL library under certain
20  *    conditions as described in each individual source file and distribute
21  *    linked combinations including the program with the OpenSSL library. You
22  *    must comply with the Server Side Public License in all respects for
23  *    all of the code used other than as permitted herein. If you modify file(s)
24  *    with this exception, you may extend this exception to your version of the
25  *    file(s), but you are not obligated to do so. If you do not wish to do so,
26  *    delete this exception statement from your version. If you delete this
27  *    exception statement from all source files in the program, then also delete
28  *    it in the license file.
29  */
30 
31 #pragma once
32 
33 #include <cstring>
34 #include <iosfwd>
35 #include <string>
36 
37 #include "mongo/base/disallow_copying.h"
38 #include "mongo/base/string_data.h"
39 
40 namespace mongo {
41 
42 /**
43  * this is a thread safe string
44  * you will never get a bad pointer, though data may be mungedd
45  */
46 class ThreadSafeString {
47     MONGO_DISALLOW_COPYING(ThreadSafeString);
48 
49 public:
_size(size)50     ThreadSafeString(size_t size = 256) : _size(size), _buf(new char[size]) {
51         memset(_buf, '\0', _size);
52     }
53 
~ThreadSafeString()54     ~ThreadSafeString() {
55         delete[] _buf;
56     }
57 
toString()58     std::string toString() const {
59         return _buf;
60     }
61 
62     ThreadSafeString& operator=(StringData str) {
63         size_t s = str.size();
64         if (s >= _size - 2)
65             s = _size - 2;
66         strncpy(_buf, str.rawData(), s);
67         _buf[s] = '\0';
68         return *this;
69     }
70 
empty()71     bool empty() const {
72         return _buf[0] == '\0';
73     }
74 
75 private:
76     const size_t _size;
77     char* const _buf;
78 };
79 
80 std::ostream& operator<<(std::ostream& s, const ThreadSafeString& o);
81 
82 }  // namespace mongo
83