/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
#define C_LUCY_STRINGHELPER
#include <string.h>
#define LUCY_USE_SHORT_NAMES
#define CHY_USE_SHORT_NAMES
#include "Lucy/Util/StringHelper.h"
#include "Lucy/Object/Err.h"
#include "Lucy/Util/Memory.h"
const uint8_t lucy_StrHelp_UTF8_COUNT[] = {
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,
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,
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, 0, 0, 0, 0, 0, 0, 0, 0,
};
int32_t
StrHelp_overlap(const char *a, const char *b, size_t a_len, size_t b_len) {
size_t i;
const size_t len = a_len <= b_len ? a_len : b_len;
for (i = 0; i < len; i++) {
if (*a++ != *b++) { break; }
}
return i;
}
static const char base36_chars[] = "0123456789abcdefghijklmnopqrstuvwxyz";
uint32_t
StrHelp_to_base36(uint64_t num, void *buffer) {
char my_buf[StrHelp_MAX_BASE36_BYTES];
char *buf = my_buf + StrHelp_MAX_BASE36_BYTES - 1;
char *end = buf;
// Null terminate.
*buf = '\0';
// Convert to base 36 characters.
do {
*(--buf) = base36_chars[num % 36];
num /= 36;
} while (num > 0);
uint32_t size = end - buf;
memcpy(buffer, buf, size + 1);
return size;
}
bool_t
StrHelp_utf8_valid(const char *ptr, size_t size) {
const uint8_t *string = (const uint8_t*)ptr;
const uint8_t *const end = string + size;
while (string < end) {
const uint8_t header_byte = *string++;
int count = StrHelp_UTF8_COUNT[header_byte] & 0x7;
switch (count & 0x7) {
case 1:
// ASCII
break;
case 2:
if (string == end) { return false; }
// Disallow non-shortest-form ASCII.
if (!(header_byte & 0x1E)) { return false; }
if ((*string++ & 0xC0) != 0x80) { return false; }
break;
case 3:
if (end - string < 2) { return false; }
if (header_byte == 0xED) {
if (*string < 0x80 || *string > 0x9F) {
return false;
}
}
else if (!(header_byte & 0x0F)) {
if (!(*string & 0x20)) {
return false;
}
}
if ((*string++ & 0xC0) != 0x80) { return false; }
if ((*string++ & 0xC0) != 0x80) { return false; }
break;
case 4:
if (end - string < 3) { return false; }
if (!(header_byte & 0x07)) {
if (!(*string & 0x30)) {
return false;
}
}
if ((*string++ & 0xC0) != 0x80) { return false; }
if ((*string++ & 0xC0) != 0x80) { return false; }
if ((*string++ & 0xC0) != 0x80) { return false; }
break;
default:
return false;
}
}
return true;
}
bool_t
StrHelp_is_whitespace(uint32_t code_point) {
switch (code_point) {
// <control-0009>..<control-000D>
case 0x0009: case 0x000A: case 0x000B: case 0x000C: case 0x000D:
case 0x0020: // SPACE
case 0x0085: // <control-0085>
case 0x00A0: // NO-BREAK SPACE
case 0x1680: // OGHAM SPACE MARK
case 0x180E: // MONGOLIAN VOWEL SEPARATOR
// EN QUAD..HAIR SPACE
case 0x2000: case 0x2001: case 0x2002: case 0x2003: case 0x2004:
case 0x2005: case 0x2006: case 0x2007: case 0x2008: case 0x2009:
case 0x200A:
case 0x2028: // LINE SEPARATOR
case 0x2029: // PARAGRAPH SEPARATOR
case 0x202F: // NARROW NO-BREAK SPACE
case 0x205F: // MEDIUM MATHEMATICAL SPACE
case 0x3000: // IDEOGRAPHIC SPACE
return true;
default:
return false;
}
}
uint32_t
StrHelp_encode_utf8_char(uint32_t code_point, void *buffer) {
uint8_t *buf = (uint8_t*)buffer;
if (code_point <= 0x7F) { // ASCII
buf[0] = (uint8_t)code_point;
return 1;
}
else if (code_point <= 0x07FF) { // 2 byte range
buf[0] = (uint8_t)(0xC0 | (code_point >> 6));
buf[1] = (uint8_t)(0x80 | (code_point & 0x3f));
return 2;
}
else if (code_point <= 0xFFFF) { // 3 byte range
buf[0] = (uint8_t)(0xE0 | (code_point >> 12));
buf[1] = (uint8_t)(0x80 | ((code_point >> 6) & 0x3F));
buf[2] = (uint8_t)(0x80 | (code_point & 0x3f));
return 3;
}
else if (code_point <= 0x10FFFF) { // 4 byte range
buf[0] = (uint8_t)(0xF0 | (code_point >> 18));
buf[1] = (uint8_t)(0x80 | ((code_point >> 12) & 0x3F));
buf[2] = (uint8_t)(0x80 | ((code_point >> 6) & 0x3F));
buf[3] = (uint8_t)(0x80 | (code_point & 0x3f));
return 4;
}
else {
THROW(ERR, "Illegal Unicode code point: %u32", code_point);
UNREACHABLE_RETURN(uint32_t);
}
}
uint32_t
StrHelp_decode_utf8_char(const char *ptr) {
const uint8_t *const string = (const uint8_t*)ptr;
uint32_t retval = *string;
int bytes = StrHelp_UTF8_COUNT[retval];
switch (bytes & 0x7) {
case 1:
break;
case 2:
retval = ((retval & 0x1F) << 6)
| (string[1] & 0x3F);
break;
case 3:
retval = ((retval & 0x0F) << 12)
| ((string[1] & 0x3F) << 6)
| (string[2] & 0x3F);
break;
case 4:
retval = ((retval & 0x07) << 18)
| ((string[1] & 0x3F) << 12)
| ((string[2] & 0x3F) << 6)
| (string[3] & 0x3F);
break;
default:
THROW(ERR, "Invalid UTF-8 header byte: %x32", retval);
}
return retval;
}
const char*
StrHelp_back_utf8_char(const char *ptr, char *start) {
while (--ptr >= start) {
if ((*ptr & 0xC0) != 0x80) { return ptr; }
}
return NULL;
}