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