Root/libs / capy / include / boost / capy / buffers / span.hpp
Prev Index Next

libs/capy/include/boost/capy/buffers/span.hpp

100.0% Lines (50/50) 100.0% Functions (8/8) 91.7% Branches (22/24)
libs/capy/include/boost/capy/buffers/span.hpp
Line Branch Hits Source Code
1 //
2 // Copyright (c) 2025 Vinnie Falco (vinnie.falco@gmail.com)
3 //
4 // Distributed under the Boost Software License, Version 1.0. (See accompanying
5 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6 //
7 // Official repository: https://github.com/cppalliance/capy
8 //
9
10 #ifndef BOOST_CAPY_BUFFERS_SPAN_HPP
11 #define BOOST_CAPY_BUFFERS_SPAN_HPP
12
13 #include <boost/capy/detail/config.hpp>
14 #include <boost/capy/buffers.hpp>
15 #include <span>
16
17 namespace boost {
18 namespace capy {
19
20 /** Remove bytes from the beginning of a span of const buffers.
21
22 Modifies the span and its buffer contents in-place to
23 remove the first `n` bytes.
24
25 @param bs The span to modify.
26 @param n The number of bytes to remove.
27 */
28 inline
29 void
30 12 remove_span_prefix(
31 std::span<const_buffer>& bs,
32 std::size_t n) noexcept
33 {
34
2/2
✓ Branch 1 taken 15 times.
✓ Branch 2 taken 4 times.
 19 while(bs.size() > 0)
35 {
36
2/2
✓ Branch 2 taken 8 times.
✓ Branch 3 taken 7 times.
 15 if(n < bs.front().size())
37 {
38 8 bs.front() += n;
39 8 return;
40 }
41 7 n -= bs.front().size();
42 7 bs = bs.subspan(1);
43 }
44 }
45
46 /** Remove bytes from the beginning of a span of mutable buffers.
47
48 Modifies the span and its buffer contents in-place to
49 remove the first `n` bytes.
50
51 @param bs The span to modify.
52 @param n The number of bytes to remove.
53 */
54 inline
55 void
56 4 remove_span_prefix(
57 std::span<mutable_buffer>& bs,
58 std::size_t n) noexcept
59 {
60
2/2
✓ Branch 1 taken 4 times.
✓ Branch 2 taken 2 times.
 6 while(bs.size() > 0)
61 {
62
2/2
✓ Branch 2 taken 2 times.
✓ Branch 3 taken 2 times.
 4 if(n < bs.front().size())
63 {
64 2 bs.front() += n;
65 2 return;
66 }
67 2 n -= bs.front().size();
68 2 bs = bs.subspan(1);
69 }
70 }
71
72 /** Remove bytes from the end of a span of const buffers.
73
74 Modifies the span and its buffer contents in-place to
75 remove the last `n` bytes.
76
77 @param bs The span to modify.
78 @param n The number of bytes to remove.
79 */
80 inline
81 void
82 12 remove_span_suffix(
83 std::span<const_buffer>& bs,
84 std::size_t n) noexcept
85 {
86
2/2
✓ Branch 1 taken 15 times.
✓ Branch 2 taken 4 times.
 19 while(bs.size() > 0)
87 {
88
2/2
✓ Branch 2 taken 8 times.
✓ Branch 3 taken 7 times.
 15 if(n < bs.back().size())
89 {
90 8 auto& b = bs.back();
91 8 b = const_buffer(b.data(), b.size() - n);
92 8 return;
93 }
94 7 n -= bs.back().size();
95 7 bs = bs.subspan(0, bs.size() - 1);
96 }
97 }
98
99 /** Remove bytes from the end of a span of mutable buffers.
100
101 Modifies the span and its buffer contents in-place to
102 remove the last `n` bytes.
103
104 @param bs The span to modify.
105 @param n The number of bytes to remove.
106 */
107 inline
108 void
109 4 remove_span_suffix(
110 std::span<mutable_buffer>& bs,
111 std::size_t n) noexcept
112 {
113
2/2
✓ Branch 1 taken 4 times.
✓ Branch 2 taken 2 times.
 6 while(bs.size() > 0)
114 {
115
2/2
✓ Branch 2 taken 2 times.
✓ Branch 3 taken 2 times.
 4 if(n < bs.back().size())
116 {
117 2 auto& b = bs.back();
118 2 b = mutable_buffer(b.data(), b.size() - n);
119 2 return;
120 }
121 2 n -= bs.back().size();
122 2 bs = bs.subspan(0, bs.size() - 1);
123 }
124 }
125
126 /** Keep only the first bytes of a span of const buffers.
127
128 Modifies the span and its buffer contents in-place to
129 keep only the first `n` bytes.
130
131 @param bs The span to modify.
132 @param n The number of bytes to keep.
133 */
134 inline
135 void
136 5 keep_span_prefix(
137 std::span<const_buffer>& bs,
138 std::size_t n) noexcept
139 {
140 5 auto total = buffer_size(bs);
141
2/2
✓ Branch 0 taken 3 times.
✓ Branch 1 taken 2 times.
 5 if(n < total)
142 3 remove_span_suffix(bs, total - n);
143 5 }
144
145 /** Keep only the first bytes of a span of mutable buffers.
146
147 Modifies the span and its buffer contents in-place to
148 keep only the first `n` bytes.
149
150 @param bs The span to modify.
151 @param n The number of bytes to keep.
152 */
153 inline
154 void
155 2 keep_span_prefix(
156 std::span<mutable_buffer>& bs,
157 std::size_t n) noexcept
158 {
159 2 auto total = buffer_size(bs);
160
1/2
✓ Branch 0 taken 2 times.
✗ Branch 1 not taken.
 2 if(n < total)
161 2 remove_span_suffix(bs, total - n);
162 2 }
163
164 /** Keep only the last bytes of a span of const buffers.
165
166 Modifies the span and its buffer contents in-place to
167 keep only the last `n` bytes.
168
169 @param bs The span to modify.
170 @param n The number of bytes to keep.
171 */
172 inline
173 void
174 5 keep_span_suffix(
175 std::span<const_buffer>& bs,
176 std::size_t n) noexcept
177 {
178 5 auto total = buffer_size(bs);
179
2/2
✓ Branch 0 taken 3 times.
✓ Branch 1 taken 2 times.
 5 if(n < total)
180 3 remove_span_prefix(bs, total - n);
181 5 }
182
183 /** Keep only the last bytes of a span of mutable buffers.
184
185 Modifies the span and its buffer contents in-place to
186 keep only the last `n` bytes.
187
188 @param bs The span to modify.
189 @param n The number of bytes to keep.
190 */
191 inline
192 void
193 2 keep_span_suffix(
194 std::span<mutable_buffer>& bs,
195 std::size_t n) noexcept
196 {
197 2 auto total = buffer_size(bs);
198
1/2
✓ Branch 0 taken 2 times.
✗ Branch 1 not taken.
 2 if(n < total)
199 2 remove_span_prefix(bs, total - n);
200 2 }
201
202 } // capy
203 } // boost
204
205 #endif
206