mirror of https://github.com/ipxe/ipxe.git
70 lines
1.6 KiB
C
70 lines
1.6 KiB
C
#ifndef _IPXE_UTF8_H
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#define _IPXE_UTF8_H
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/** @file
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*
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* UTF-8 Unicode encoding
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*
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*/
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FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
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#include <stdint.h>
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/** Maximum length of UTF-8 sequence */
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#define UTF8_MAX_LEN 4
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/** Minimum legal value for two-byte UTF-8 sequence */
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#define UTF8_MIN_TWO 0x80
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/** Minimum legal value for three-byte UTF-8 sequence */
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#define UTF8_MIN_THREE 0x800
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/** Minimum legal value for four-byte UTF-8 sequence */
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#define UTF8_MIN_FOUR 0x10000
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/** High bit of UTF-8 bytes */
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#define UTF8_HIGH_BIT 0x80
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/** Number of data bits in each continuation byte */
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#define UTF8_CONTINUATION_BITS 6
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/** Bit mask for data bits in a continuation byte */
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#define UTF8_CONTINUATION_MASK ( ( 1 << UTF8_CONTINUATION_BITS ) - 1 )
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/** Non-data bits in a continuation byte */
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#define UTF8_CONTINUATION 0x80
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/** Check for a continuation byte
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*
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* @v byte UTF-8 byte
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* @ret is_continuation Byte is a continuation byte
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*/
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#define UTF8_IS_CONTINUATION( byte ) \
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( ( (byte) & ~UTF8_CONTINUATION_MASK ) == UTF8_CONTINUATION )
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/** Check for an ASCII byte
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*
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* @v byte UTF-8 byte
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* @ret is_ascii Byte is an ASCII byte
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*/
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#define UTF8_IS_ASCII( byte ) ( ! ( (byte) & UTF8_HIGH_BIT ) )
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/** Invalid character returned when decoding fails */
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#define UTF8_INVALID 0xfffd
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/** A UTF-8 character accumulator */
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struct utf8_accumulator {
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/** Character in progress */
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unsigned int character;
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/** Number of remaining continuation bytes */
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unsigned int remaining;
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/** Minimum legal character */
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unsigned int min;
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};
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extern unsigned int utf8_accumulate ( struct utf8_accumulator *utf8,
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uint8_t byte );
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#endif /* _IPXE_UTF8_H */
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