| /** |
| * Copyright 2010 Google Inc. |
| * |
| * 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 |
| * |
| * http://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. |
| */ |
| |
| // Routines to do manipulation of Unicode characters or text |
| // |
| // The StructurallyValid routines accept buffers of arbitrary bytes. |
| // For CoerceToStructurallyValid(), the input buffer and output buffers may |
| // point to exactly the same memory. |
| // |
| // In all other cases, the UTF-8 string must be structurally valid and |
| // have all codepoints in the range U+0000 to U+D7FF or U+E000 to U+10FFFF. |
| // Debug builds take a fatal error for invalid UTF-8 input. |
| // The input and output buffers may not overlap at all. |
| // |
| // The char32 routines are here only for convenience; they convert to UTF-8 |
| // internally and use the UTF-8 routines. |
| |
| #ifndef UTIL_UTF8_UNILIB_H__ |
| #define UTIL_UTF8_UNILIB_H__ |
| |
| #include <string> |
| #include "base/basictypes.h" |
| |
| namespace UniLib { |
| |
| // Returns true unless a surrogate code point |
| inline bool IsValidCodepoint(char32 c) { |
| // In the range [0, 0xD800) or [0xE000, 0x10FFFF] |
| return (static_cast<uint32>(c) < 0xD800) |
| || (c >= 0xE000 && c <= 0x10FFFF); |
| } |
| |
| // Table of UTF-8 character lengths, based on first byte |
| static const unsigned char kUTF8LenTbl[256] = { |
| 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, |
| 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, |
| 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, |
| 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, |
| |
| 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, |
| 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, |
| 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, |
| 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 |
| }; |
| |
| // Return length of a single UTF-8 source character |
| inline int OneCharLen(const char* src) { |
| return kUTF8LenTbl[*reinterpret_cast<const uint8*>(src)]; |
| } |
| |
| // Return length of a single UTF-8 source character |
| inline int OneCharLen(const uint8* src) { |
| return kUTF8LenTbl[*src]; |
| } |
| |
| // Return true if this byte is a trailing UTF-8 byte (10xx xxxx) |
| inline bool IsTrailByte(char x) { |
| // return (x & 0xC0) == 0x80; |
| // Since trail bytes are always in [0x80, 0xBF], we can optimize: |
| return static_cast<signed char>(x) < -0x40; |
| } |
| |
| // Returns the length in bytes of the prefix of src that is all |
| // interchange valid UTF-8 |
| int SpanInterchangeValid(const char* src, int byte_length); |
| inline int SpanInterchangeValid(const std::string& src) { |
| return SpanInterchangeValid(src.data(), src.size()); |
| } |
| |
| // Returns true if the source is all interchange valid UTF-8 |
| // "Interchange valid" is a stronger than structurally valid -- |
| // no C0 or C1 control codes (other than CR LF HT FF) and no non-characters. |
| inline bool IsInterchangeValid(const char* src, int byte_length) { |
| return (byte_length == SpanInterchangeValid(src, byte_length)); |
| } |
| inline bool IsInterchangeValid(const std::string& src) { |
| return IsInterchangeValid(src.data(), src.size()); |
| } |
| |
| } // namespace UniLib |
| |
| #endif // UTIL_UTF8_PUBLIC_UNILIB_H_ |