54 lines
1.6 KiB
C++
54 lines
1.6 KiB
C++
|
// Copyright 2017 The Abseil Authors.
|
||
|
|
//
|
||
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
||
|
|
// you may not use this file except in compliance with the License.
|
||
|
|
// You may obtain a copy of the License at
|
||
|
|
//
|
||
|
|
// https://www.apache.org/licenses/LICENSE-2.0
|
||
|
|
//
|
||
|
|
// Unless required by applicable law or agreed to in writing, software
|
||
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
||
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
|
|
// See the License for the specific language governing permissions and
|
||
|
|
// limitations under the License.
|
||
|
|
|
||
|
|
// UTF8 utilities, implemented to reduce dependencies.
|
||
|
|
|
||
|
|
#include "absl/strings/internal/utf8.h"
|
||
|
|
|
||
|
|
namespace absl {
|
||
|
|
ABSL_NAMESPACE_BEGIN
|
||
|
|
namespace strings_internal {
|
||
|
|
|
||
|
|
size_t EncodeUTF8Char(char *buffer, char32_t utf8_char) {
|
||
|
|
if (utf8_char <= 0x7F) {
|
||
|
|
*buffer = static_cast<char>(utf8_char);
|
||
|
|
return 1;
|
||
|
|
} else if (utf8_char <= 0x7FF) {
|
||
|
|
buffer[1] = 0x80 | (utf8_char & 0x3F);
|
||
|
|
utf8_char >>= 6;
|
||
|
|
buffer[0] = 0xC0 | utf8_char;
|
||
|
|
return 2;
|
||
|
|
} else if (utf8_char <= 0xFFFF) {
|
||
|
|
buffer[2] = 0x80 | (utf8_char & 0x3F);
|
||
|
|
utf8_char >>= 6;
|
||
|
|
buffer[1] = 0x80 | (utf8_char & 0x3F);
|
||
|
|
utf8_char >>= 6;
|
||
|
|
buffer[0] = 0xE0 | utf8_char;
|
||
|
|
return 3;
|
||
|
|
} else {
|
||
|
|
buffer[3] = 0x80 | (utf8_char & 0x3F);
|
||
|
|
utf8_char >>= 6;
|
||
|
|
buffer[2] = 0x80 | (utf8_char & 0x3F);
|
||
|
|
utf8_char >>= 6;
|
||
|
|
buffer[1] = 0x80 | (utf8_char & 0x3F);
|
||
|
|
utf8_char >>= 6;
|
||
|
|
buffer[0] = 0xF0 | utf8_char;
|
||
|
|
return 4;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
} // namespace strings_internal
|
||
|
|
ABSL_NAMESPACE_END
|
||
|
|
} // namespace absl
|