1 // Copyright 2022 The Abseil Authors
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 // https://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 ABSL_LOG_INTERNAL_APPEND_TRUNCATED_H_
16 #define ABSL_LOG_INTERNAL_APPEND_TRUNCATED_H_
17
18 #include <cstddef>
19 #include <cstring>
20
21 #include "absl/base/config.h"
22 #include "absl/strings/string_view.h"
23 #include "absl/types/span.h"
24
25 namespace absl {
26 ABSL_NAMESPACE_BEGIN
27 namespace log_internal {
28 // Copies into `dst` as many bytes of `src` as will fit, then truncates the
29 // copied bytes from the front of `dst` and returns the number of bytes written.
AppendTruncated(absl::string_view src,absl::Span<char> & dst)30 inline size_t AppendTruncated(absl::string_view src, absl::Span<char> &dst) {
31 if (src.size() > dst.size()) src = src.substr(0, dst.size());
32 memcpy(dst.data(), src.data(), src.size());
33 dst.remove_prefix(src.size());
34 return src.size();
35 }
36 // Likewise, but `n` copies of `c`.
AppendTruncated(char c,size_t n,absl::Span<char> & dst)37 inline size_t AppendTruncated(char c, size_t n, absl::Span<char> &dst) {
38 if (n > dst.size()) n = dst.size();
39 memset(dst.data(), c, n);
40 dst.remove_prefix(n);
41 return n;
42 }
43 } // namespace log_internal
44 ABSL_NAMESPACE_END
45 } // namespace absl
46
47 #endif // ABSL_LOG_INTERNAL_APPEND_TRUNCATED_H_
48