1 // Copyright 2017 Google LLC
2 //
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 // A view over a piece of string. The view is not 0 terminated.
16 #ifndef CPU_FEATURES_INCLUDE_INTERNAL_STRING_VIEW_H_
17 #define CPU_FEATURES_INCLUDE_INTERNAL_STRING_VIEW_H_
18
19 #include <stdbool.h>
20 #include <stddef.h>
21 #include <string.h>
22
23 #include "cpu_features_macros.h"
24
25 CPU_FEATURES_START_CPP_NAMESPACE
26
27 typedef struct {
28 const char* ptr;
29 size_t size;
30 } StringView;
31
32 #ifdef __cplusplus
33 static const StringView kEmptyStringView = {NULL, 0};
34 #else
35 static const StringView kEmptyStringView;
36 #endif
37
38 // Returns a StringView from the provided string.
39 // Passing NULL is valid only if size is 0.
view(const char * str,const size_t size)40 static inline StringView view(const char* str, const size_t size) {
41 StringView view;
42 view.ptr = str;
43 view.size = size;
44 return view;
45 }
46
str(const char * str)47 static inline StringView str(const char* str) { return view(str, strlen(str)); }
48
49 // Returns the index of the first occurrence of c in view or -1 if not found.
50 int CpuFeatures_StringView_IndexOfChar(const StringView view, char c);
51
52 // Returns the index of the first occurrence of sub_view in view or -1 if not
53 // found.
54 int CpuFeatures_StringView_IndexOf(const StringView view,
55 const StringView sub_view);
56
57 // Returns whether a is equal to b (same content).
58 bool CpuFeatures_StringView_IsEquals(const StringView a, const StringView b);
59
60 // Returns whether a starts with b.
61 bool CpuFeatures_StringView_StartsWith(const StringView a, const StringView b);
62
63 // Removes count characters from the beginning of view or kEmptyStringView if
64 // count if greater than view.size.
65 StringView CpuFeatures_StringView_PopFront(const StringView str_view,
66 size_t count);
67
68 // Removes count characters from the end of view or kEmptyStringView if count if
69 // greater than view.size.
70 StringView CpuFeatures_StringView_PopBack(const StringView str_view,
71 size_t count);
72
73 // Keeps the count first characters of view or view if count if greater than
74 // view.size.
75 StringView CpuFeatures_StringView_KeepFront(const StringView str_view,
76 size_t count);
77
78 // Retrieves the first character of view. If view is empty the behavior is
79 // undefined.
80 char CpuFeatures_StringView_Front(const StringView view);
81
82 // Retrieves the last character of view. If view is empty the behavior is
83 // undefined.
84 char CpuFeatures_StringView_Back(const StringView view);
85
86 // Removes leading and tailing space characters.
87 StringView CpuFeatures_StringView_TrimWhitespace(StringView view);
88
89 // Convert StringView to positive integer. e.g. "42", "0x2a".
90 // Returns -1 on error.
91 int CpuFeatures_StringView_ParsePositiveNumber(const StringView view);
92
93 // Copies src StringView to dst buffer.
94 void CpuFeatures_StringView_CopyString(const StringView src, char* dst,
95 size_t dst_size);
96
97 // Checks if line contains the specified whitespace separated word.
98 bool CpuFeatures_StringView_HasWord(const StringView line,
99 const char* const word);
100
101 // Get key/value from line. key and value are separated by ": ".
102 // key and value are cleaned up from leading and trailing whitespaces.
103 bool CpuFeatures_StringView_GetAttributeKeyValue(const StringView line,
104 StringView* key,
105 StringView* value);
106
107 CPU_FEATURES_END_CPP_NAMESPACE
108
109 #endif // CPU_FEATURES_INCLUDE_INTERNAL_STRING_VIEW_H_
110