mirror of
https://github.com/open62541/open62541.git
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84 lines
2.6 KiB
C
84 lines
2.6 KiB
C
/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/.
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*
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* Copyright 2024 (c) Fraunhofer IOSB (Author: Julius Pfrommer)
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*/
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#ifndef UTF8_H_
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#define UTF8_H_
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#include <stddef.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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#ifdef _MSC_VER
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# define UTF_INLINE __inline
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#else
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# define UTF_INLINE inline
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#endif
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#if defined(__GNUC__) || defined(__clang__)
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# define UTF_LIKELY(x) __builtin_expect((x), 1)
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# define UTF_UNLIKELY(x) __builtin_expect((x), 0)
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#else
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# define UTF_LIKELY(x) (x)
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# define UTF_UNLIKELY(x) (x)
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#endif
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/* Extract the next utf8 codepoint from the buffer. Returns the length (1-4) of
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* the codepoint encoding or 0 upon an error. */
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unsigned
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utf8_to_codepoint(const unsigned char *str, size_t len, unsigned *codepoint);
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/* Encodes the codepoint in utf8. The string needs to have enough space (at most
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* four byte) available. Returns the encoding length. */
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static UTF_INLINE unsigned
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utf8_from_codepoint(unsigned char *str, unsigned codepoint) {
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if(UTF_LIKELY(codepoint <= 0x7F)) { /* Plain ASCII */
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str[0] = (unsigned char)codepoint;
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return 1;
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}
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if(UTF_LIKELY(codepoint <= 0x07FF)) { /* 2-byte unicode */
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str[0] = (unsigned char)(((codepoint >> 6) & 0x1F) | 0xC0);
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str[1] = (unsigned char)(((codepoint >> 0) & 0x3F) | 0x80);
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return 2;
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}
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if(UTF_LIKELY(codepoint <= 0xFFFF)) { /* 3-byte unicode */
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str[0] = (unsigned char)(((codepoint >> 12) & 0x0F) | 0xE0);
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str[1] = (unsigned char)(((codepoint >> 6) & 0x3F) | 0x80);
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str[2] = (unsigned char)(((codepoint >> 0) & 0x3F) | 0x80);
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return 3;
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}
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if(UTF_LIKELY(codepoint <= 0x10FFFF)) { /* 4-byte unicode */
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str[0] = (unsigned char)(((codepoint >> 18) & 0x07) | 0xF0);
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str[1] = (unsigned char)(((codepoint >> 12) & 0x3F) | 0x80);
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str[2] = (unsigned char)(((codepoint >> 6) & 0x3F) | 0x80);
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str[3] = (unsigned char)(((codepoint >> 0) & 0x3F) | 0x80);
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return 4;
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}
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return 0; /* Not a unicode codepoint */
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}
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/* Returns the encoding length of the codepoint */
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static UTF_INLINE unsigned
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utf8_length(unsigned codepoint) {
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if(UTF_LIKELY(codepoint <= 0x7F))
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return 1; /* Plain ASCII */
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if(UTF_LIKELY(codepoint <= 0x07FF))
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return 2; /* 2-byte unicode */
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if(UTF_LIKELY(codepoint <= 0xFFFF))
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return 3; /* 3-byte unicode */
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if(UTF_LIKELY(codepoint <= 0x10FFFF))
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return 4; /* 4-byte unicode */
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return 0; /* Not a unicode codepoint */
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}
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#ifdef __cplusplus
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}
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#endif
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#endif /* UTF8_H_ */
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