/*
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* Copyright (C) 2018 The Android Open Source Project
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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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*/
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#include "utils/strings/utf8.h"
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namespace libtextclassifier3 {
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bool IsValidUTF8(const char *src, int size) {
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for (int i = 0; i < size;) {
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const int char_length = ValidUTF8CharLength(src + i, size - i);
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if (char_length <= 0) {
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return false;
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}
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i += char_length;
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}
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return true;
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}
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int ValidUTF8CharLength(const char *src, int size) {
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// Unexpected trail byte.
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if (IsTrailByte(src[0])) {
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return -1;
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}
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const int num_codepoint_bytes = GetNumBytesForUTF8Char(&src[0]);
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if (num_codepoint_bytes <= 0 || num_codepoint_bytes > size) {
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return -1;
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}
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// Check that remaining bytes in the codepoint are trailing bytes.
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for (int k = 1; k < num_codepoint_bytes; k++) {
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if (!IsTrailByte(src[k])) {
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return -1;
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}
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}
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return num_codepoint_bytes;
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}
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} // namespace libtextclassifier3
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