1/** 2 * Copyright 2010 Google Inc. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17// Routines to do manipulation of Unicode characters or text 18// 19// The StructurallyValid routines accept buffers of arbitrary bytes. 20// For CoerceToStructurallyValid(), the input buffer and output buffers may 21// point to exactly the same memory. 22// 23// In all other cases, the UTF-8 string must be structurally valid and 24// have all codepoints in the range U+0000 to U+D7FF or U+E000 to U+10FFFF. 25// Debug builds take a fatal error for invalid UTF-8 input. 26// The input and output buffers may not overlap at all. 27// 28// The char32 routines are here only for convenience; they convert to UTF-8 29// internally and use the UTF-8 routines. 30 31#ifndef UTIL_UTF8_UNILIB_H__ 32#define UTIL_UTF8_UNILIB_H__ 33 34#include <string> 35#include "phonenumbers/base/basictypes.h" 36 37namespace i18n { 38namespace phonenumbers { 39namespace UniLib { 40 41// Returns true unless a surrogate code point 42inline bool IsValidCodepoint(char32 c) { 43 // In the range [0, 0xD800) or [0xE000, 0x10FFFF] 44 return (static_cast<uint32>(c) < 0xD800) 45 || (c >= 0xE000 && c <= 0x10FFFF); 46} 47 48// Table of UTF-8 character lengths, based on first byte 49static const unsigned char kUTF8LenTbl[256] = { 50 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 51 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 52 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 53 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 54 55 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 56 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 57 2,2,2,2,2,2,2,2, 2,2,2,2,2,2,2,2, 2,2,2,2,2,2,2,2, 2,2,2,2,2,2,2,2, 58 3,3,3,3,3,3,3,3, 3,3,3,3,3,3,3,3, 4,4,4,4,4,4,4,4, 4,4,4,4,4,4,4,4 59}; 60 61// Return length of a single UTF-8 source character 62inline int OneCharLen(const char* src) { 63 return kUTF8LenTbl[*reinterpret_cast<const uint8*>(src)]; 64} 65 66// Return length of a single UTF-8 source character 67inline int OneCharLen(const uint8* src) { 68 return kUTF8LenTbl[*src]; 69} 70 71// Return true if this byte is a trailing UTF-8 byte (10xx xxxx) 72inline bool IsTrailByte(char x) { 73 // return (x & 0xC0) == 0x80; 74 // Since trail bytes are always in [0x80, 0xBF], we can optimize: 75 return static_cast<signed char>(x) < -0x40; 76} 77 78// Returns the length in bytes of the prefix of src that is all 79// interchange valid UTF-8 80int SpanInterchangeValid(const char* src, int byte_length); 81inline int SpanInterchangeValid(const std::string& src) { 82 return SpanInterchangeValid(src.data(), src.size()); 83} 84 85// Returns true if the source is all interchange valid UTF-8 86// "Interchange valid" is a stronger than structurally valid -- 87// no C0 or C1 control codes (other than CR LF HT FF) and no non-characters. 88inline bool IsInterchangeValid(const char* src, int byte_length) { 89 return (byte_length == SpanInterchangeValid(src, byte_length)); 90} 91inline bool IsInterchangeValid(const std::string& src) { 92 return IsInterchangeValid(src.data(), src.size()); 93} 94 95} // namespace UniLib 96} // namespace phonenumbers 97} // namespace i18n 98 99#endif // UTIL_UTF8_PUBLIC_UNILIB_H_ 100