linux_dsm_epyc7002/fs/unicode/utf8n.h
Gabriel Krisman Bertazi 9d53690f0d unicode: implement higher level API for string handling
This patch integrates the utf8n patches with some higher level API to
perform UTF-8 string comparison, normalization and casefolding
operations.  Implemented is a variation of NFD, and casefold is
performed by doing full casefold on top of NFD.  These algorithms are
based on the core implemented by Olaf Weber from SGI.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-04-25 13:51:22 -04:00

118 lines
3.5 KiB
C

/*
* Copyright (c) 2014 SGI.
* All rights reserved.
*
* 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.
*
* This program is distributed in the hope that it would 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 UTF8NORM_H
#define UTF8NORM_H
#include <linux/types.h>
#include <linux/export.h>
#include <linux/string.h>
#include <linux/module.h>
/* Encoding a unicode version number as a single unsigned int. */
#define UNICODE_MAJ_SHIFT (16)
#define UNICODE_MIN_SHIFT (8)
#define UNICODE_AGE(MAJ, MIN, REV) \
(((unsigned int)(MAJ) << UNICODE_MAJ_SHIFT) | \
((unsigned int)(MIN) << UNICODE_MIN_SHIFT) | \
((unsigned int)(REV)))
/* Highest unicode version supported by the data tables. */
extern int utf8version_is_supported(u8 maj, u8 min, u8 rev);
extern int utf8version_latest(void);
/*
* Look for the correct const struct utf8data for a unicode version.
* Returns NULL if the version requested is too new.
*
* Two normalization forms are supported: nfdi and nfdicf.
*
* nfdi:
* - Apply unicode normalization form NFD.
* - Remove any Default_Ignorable_Code_Point.
*
* nfdicf:
* - Apply unicode normalization form NFD.
* - Remove any Default_Ignorable_Code_Point.
* - Apply a full casefold (C + F).
*/
extern const struct utf8data *utf8nfdi(unsigned int maxage);
extern const struct utf8data *utf8nfdicf(unsigned int maxage);
/*
* Determine the maximum age of any unicode character in the string.
* Returns 0 if only unassigned code points are present.
* Returns -1 if the input is not valid UTF-8.
*/
extern int utf8agemax(const struct utf8data *data, const char *s);
extern int utf8nagemax(const struct utf8data *data, const char *s, size_t len);
/*
* Determine the minimum age of any unicode character in the string.
* Returns 0 if any unassigned code points are present.
* Returns -1 if the input is not valid UTF-8.
*/
extern int utf8agemin(const struct utf8data *data, const char *s);
extern int utf8nagemin(const struct utf8data *data, const char *s, size_t len);
/*
* Determine the length of the normalized from of the string,
* excluding any terminating NULL byte.
* Returns 0 if only ignorable code points are present.
* Returns -1 if the input is not valid UTF-8.
*/
extern ssize_t utf8len(const struct utf8data *data, const char *s);
extern ssize_t utf8nlen(const struct utf8data *data, const char *s, size_t len);
/* Needed in struct utf8cursor below. */
#define UTF8HANGULLEAF (12)
/*
* Cursor structure used by the normalizer.
*/
struct utf8cursor {
const struct utf8data *data;
const char *s;
const char *p;
const char *ss;
const char *sp;
unsigned int len;
unsigned int slen;
short int ccc;
short int nccc;
unsigned char hangul[UTF8HANGULLEAF];
};
/*
* Initialize a utf8cursor to normalize a string.
* Returns 0 on success.
* Returns -1 on failure.
*/
extern int utf8cursor(struct utf8cursor *u8c, const struct utf8data *data,
const char *s);
extern int utf8ncursor(struct utf8cursor *u8c, const struct utf8data *data,
const char *s, size_t len);
/*
* Get the next byte in the normalization.
* Returns a value > 0 && < 256 on success.
* Returns 0 when the end of the normalization is reached.
* Returns -1 if the string being normalized is not valid UTF-8.
*/
extern int utf8byte(struct utf8cursor *u8c);
#endif /* UTF8NORM_H */