1 /*
2  * Copyright (c) 2023 Huawei Device Co., Ltd.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at
6  *
7  *     http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 #ifndef DFXSTRING_H
16 #define DFXSTRING_H
17 #include <stdarg.h>
18 #include <string>
19 #include <cstdio>
20 #include <securec.h>
21 
22 namespace OHOS::Rosen {
23 constexpr int STRING_BUF_SIZE = 4096;
24 class DfxString {
25 public:
DfxString()26     DfxString() : str_() {}
27 
DfxString(const char * c)28     DfxString(const char* c) : str_(c) {}
29 
30     ~DfxString() = default;
31 
AppendFormat(const char * fmt,...)32     void AppendFormat(const char* fmt, ...)
33     {
34         va_list args;
35         va_start(args, fmt);
36         str_.append(AppendFormatInner(fmt, args));
37         va_end(args);
38     }
39 
GetString()40     std::string GetString() const
41     {
42         return str_;
43     }
44 
45 private:
AppendFormatInner(const char * fmt,va_list args)46     std::string AppendFormatInner(const char* fmt, va_list args)
47     {
48         int n;
49         std::string result;
50         va_list tmp_args;
51         char buf[STRING_BUF_SIZE] = {0};
52         va_copy(tmp_args, args);
53         n = vsnprintf_s(buf, sizeof(buf), sizeof(buf) - 1, fmt, tmp_args);
54         va_end(tmp_args);
55         if (n < 0) {
56             result.append("dump info length > 4096, error");
57         } else {
58             result.append(buf, n);
59         }
60         return result;
61     }
62     std::string str_;
63 };
64 } // namespace OHOS::Rosen
65 #endif