xref: /aosp_15_r20/external/perfetto/src/base/string_splitter.cc (revision 6dbdd20afdafa5e3ca9b8809fa73465d530080dc)
1 /*
2  * Copyright (C) 2018 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "perfetto/ext/base/string_splitter.h"
18 
19 #include <utility>
20 
21 #include "perfetto/base/logging.h"
22 
23 namespace perfetto {
24 namespace base {
25 
StringSplitter(std::string str,char delimiter,EmptyTokenMode empty_token_mode)26 StringSplitter::StringSplitter(std::string str,
27                                char delimiter,
28                                EmptyTokenMode empty_token_mode)
29     : str_(std::move(str)),
30       delimiter_(delimiter),
31       empty_token_mode_(empty_token_mode) {
32   // It's legal to access str[str.size()] in C++11 (it always returns \0),
33   // hence the +1 (which becomes just size() after the -1 in Initialize()).
34   Initialize(&str_[0], str_.size() + 1);
35 }
36 
StringSplitter(char * str,size_t size,char delimiter,EmptyTokenMode empty_token_mode)37 StringSplitter::StringSplitter(char* str,
38                                size_t size,
39                                char delimiter,
40                                EmptyTokenMode empty_token_mode)
41     : delimiter_(delimiter), empty_token_mode_(empty_token_mode) {
42   Initialize(str, size);
43 }
44 
StringSplitter(StringSplitter * outer,char delimiter,EmptyTokenMode empty_token_mode)45 StringSplitter::StringSplitter(StringSplitter* outer,
46                                char delimiter,
47                                EmptyTokenMode empty_token_mode)
48     : delimiter_(delimiter), empty_token_mode_(empty_token_mode) {
49   Initialize(outer->cur_token(), outer->cur_token_size() + 1);
50 }
51 
Initialize(char * str,size_t size)52 void StringSplitter::Initialize(char* str, size_t size) {
53   PERFETTO_DCHECK(!size || str);
54   next_ = str;
55   end_ = str + size;
56   cur_ = nullptr;
57   cur_size_ = 0;
58   if (size)
59     next_[size - 1] = '\0';
60 }
61 
Next()62 bool StringSplitter::Next() {
63   for (; next_ < end_; next_++) {
64     if (*next_ == delimiter_ &&
65         empty_token_mode_ == EmptyTokenMode::DISALLOW_EMPTY_TOKENS) {
66       // If empty tokens are disallowed, find fist non-delimiter character.
67       continue;
68     }
69     cur_ = next_;
70     for (;; next_++) {
71       if (*next_ == delimiter_) {
72         cur_size_ = static_cast<size_t>(next_ - cur_);
73         *(next_++) = '\0';
74         break;
75       }
76       if (*next_ == '\0') {
77         cur_size_ = static_cast<size_t>(next_ - cur_);
78         next_ = end_;
79         break;
80       }
81     }
82     if (*cur_ || empty_token_mode_ == EmptyTokenMode::ALLOW_EMPTY_TOKENS)
83       return true;
84     break;
85   }
86   cur_ = nullptr;
87   cur_size_ = 0;
88   return false;
89 }
90 
91 }  // namespace base
92 }  // namespace perfetto
93