OsmAnd/Osmand-kernel/osmand/utf8.cpp
2012-04-30 15:58:02 +02:00

117 lines
4 KiB
C++

///////////////////////////////////////////////////////////////////
//
// Fast, small, simple, robust UTF-8 decoder in C
//
// Copyright (c) 2008-2009 Bjoern Hoehrmann <bjo...@hoehrmann.de>
//
// This program is free software: you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation, either version 3 of
// the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
///////////////////////////////////////////////////////////////////
#ifndef _UTF_8_CPP
#define _UTF_8_CPP
#include <stdio.h>
#include <stdlib.h>
#ifdef _MSC_VER
typedef unsigned __int8 uint8_t;
typedef unsigned __int32 uint32_t;
#else
#include <stdint.h>
#endif
#define ASCII_IN_TABLE 1
/*
The first 128 entries are tuples of 4 bit values. The lower bits
are a mask that when xor'd with a byte removes the leading utf-8
bits. The upper bits are a character class number. The remaining
160 entries are a minimal deterministic finite automaton. It has
10 states and each state has 13 character class transitions, and
3 unused transitions for padding reasons. When the automaton en-
ters state zero, it has found a complete valid utf-8 code point;
if it enters state one then the input sequence is not utf-8. The
start state is state nine. Note the mixture of octal and decimal
for stylistic reasons. The ASCII_IN_TABLE macro makes the array
bigger and the code simpler--but not necessarily faster--if set.
*/
static const uint8_t utf8d[] = {
#if ASCII_IN_TABLE
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
#endif
070,070,070,070,070,070,070,070,070,070,070,070,070,070,070,070,
050,050,050,050,050,050,050,050,050,050,050,050,050,050,050,050,
030,030,030,030,030,030,030,030,030,030,030,030,030,030,030,030,
030,030,030,030,030,030,030,030,030,030,030,030,030,030,030,030,
204,204,188,188,188,188,188,188,188,188,188,188,188,188,188,188,
188,188,188,188,188,188,188,188,188,188,188,188,188,188,188,188,
174,158,158,158,158,158,158,158,158,158,158,158,158,142,126,126,
111, 95, 95, 95, 79,207,207,207,207,207,207,207,207,207,207,207,
0,1,1,1,8,7,6,4,5,4,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
1,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
1,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,2,1,1,1,1,1,1,1,1,1,1,1,1,
1,4,4,1,1,1,1,1,1,1,1,1,1,1,1,1,1,4,4,4,1,1,1,1,1,1,1,1,1,1,1,1,
1,1,1,4,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,8,7,6,4,5,4,3,2,1,1,1,1,
};
int nextWord(uint8_t* s) {
uint8_t data, byte, stat = 9;
uint32_t unic = 0;
uint8_t counter = 0;
// http://lists.w3.org/Archives/Public/www-archive/2009Apr/0000
while ((byte = *s++)) {
counter ++;
data = utf8d[ byte ];
stat = utf8d[ 256 + (stat << 4) + (data >> 4) ];
byte = (byte ^ (uint8_t)(data << 4));
unic = (unic << 6) | byte;
#if ASCII_IN_TABLE
data = utf8d[ byte ];
stat = utf8d[ 256 + (stat << 4) + (data >> 4) ];
byte = (byte ^ (uint8_t)(data << 4));
#else
if (byte < 0x80) {
stat = utf8d[ 128 + (stat << 4) ];
} else {
data = utf8d[ byte ];
stat = utf8d[ 128 + (stat << 4) + (data >> 4) ];
byte = (byte ^ (uint8_t)(data << 4));
}
#endif
if (!stat) {
// find delimeters (is whitespace)
if(unic == ' ' || unic == '\t') {
return counter;
}
// unic is now a proper code point, we just print it out.
unic = 0;
}
if (stat == 1) {
// the byte is not allowed here; the state would have to
// be reset to continue meaningful reading of the string
}
}
return -1;
}
#endif