106 lines
2.8 KiB
C
106 lines
2.8 KiB
C
/* Tables for conversion to and from ISO-IR-165.
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converting from UCS using gaps.
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Copyright (C) 2000 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@cygnus.com>, 2000.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#ifndef _ISO_IR_165_H
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#define _ISO_IR_165_H 1
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#include <gconv.h>
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#include <stdint.h>
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struct gap
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{
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uint16_t start;
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uint16_t end;
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int32_t idx;
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};
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/* Table for ISO-IR-165 (CCITT Chinese) to UCS4 conversion. */
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#define ISOIR165_FROMSIZE 0x2284
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extern const uint16_t __isoir165_to_tab[ISOIR165_FROMSIZE];
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/* XXX If we at some point need an offset value to decode the byte
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sequences another parameter can be added. */
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static inline uint32_t
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isoir165_to_ucs4 (const unsigned char **s, size_t avail)
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{
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unsigned char ch = *(*s);
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unsigned char ch2;
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uint32_t res;
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if (ch <= 0x20 || ch >= 0x7f)
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return __UNKNOWN_10646_CHAR;
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if (avail < 2)
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return 0;
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ch2 = (*s)[1];
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if (ch2 <= 0x20 || ch2 >= 0x7f)
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return __UNKNOWN_10646_CHAR;
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res = __isoir165_to_tab[(ch - 0x21) * 94 + (ch2 - 0x21)];
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if (res == 0)
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return __UNKNOWN_10646_CHAR;
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*s += 2;
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return res;
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}
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/* Tables for ISO-IR-165 (CCITT Chinese) from UCS4 conversion. */
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extern const struct gap __isoir165_from_idx[];
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extern const char __isoir165_from_tab[];
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static inline size_t
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ucs4_to_isoir165 (uint32_t wch, char *s, size_t avail)
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{
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unsigned int ch = (unsigned int) wch;
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const char *cp;
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const struct gap *rp = __isoir165_from_idx;
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if (ch > 0xffe5)
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/* This is an illegal character. */
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return __UNKNOWN_10646_CHAR;
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while (ch > rp->end)
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++rp;
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if (ch < rp->start)
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/* This is an illegal character. */
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return __UNKNOWN_10646_CHAR;
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/* The two bytes following the index given in this record give the
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encoding in ISO-IR-165. Unless the bytes are zero. */
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cp = &__isoir165_from_tab[(ch + rp->idx) * 2];
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if (*cp == '\0')
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/* This is an illegal character. */
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return __UNKNOWN_10646_CHAR;
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if (avail < 2)
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return 0;
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s[0] = cp[0];
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s[1] = cp[1];
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return 2;
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}
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#endif /* iso-ir-165.h */
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