port/locale/wcscoll.c

	wcscoll.c revision 6b5e5868e7ebf1aff3a5abd7d0c4ef0e5fbf3648
/*
 * Copyright 2010 Nexenta Systems, Inc.  All rights reserved.
 * Copyright (c) 2002 Tim J. Robbins
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "lint.h"
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <wchar.h>
#include <assert.h>
#include "collate.h"

int
wcscoll(const wchar_t *ws1, const wchar_t *ws2)
{
    int len1, len2, pri1, pri2, ret;
    wchar_t *tr1 = NULL, *tr2 = NULL;
    int direc, pass;

    collate_info_t *info = _collate_info;

    if (_collate_load_error)
        /*
         * Locale has no special collating order or could not be
         * loaded, do a fast binary comparison.
         */
        return (wcscmp(ws1, ws2));

    ret = 0;

    /*
     * Once upon a time we had code to try to optimize this, but
     * it turns out that you really can't make many assumptions
     * safely.  You absolutely have to run this pass by pass,
     * because some passes will be ignored for a given character,
     * while others will not.  Simpler locales will benefit from
     * having fewer passes, and most comparisions should resolve
     * during the primary pass anyway.
     *
     * Note that we do one final extra pass at the end to pick
     * up UNDEFINED elements.  There is special handling for them.
     */
    for (pass = 0; pass <= info->directive_count; pass++) {

        int32_t *st1 = NULL;
        int32_t *st2 = NULL;
        const wchar_t   *w1 = ws1;
        const wchar_t   *w2 = ws2;

        /* special pass for UNDEFINED */
        if (pass == info->directive_count) {
            direc = DIRECTIVE_FORWARD | DIRECTIVE_UNDEFINED;
        } else {
            direc = info->directive[pass];
        }

        if (direc & DIRECTIVE_BACKWARD) {
            wchar_t *bp, *fp, c;
            if ((tr1 = wcsdup(w1)) == NULL)
                goto fail;
            bp = tr1;
            fp = tr1 + wcslen(tr1) - 1;
            while (bp < fp) {
                c = *bp;
                *bp++ = *fp;
                *fp-- = c;
            }
            if ((tr2 = wcsdup(w2)) == NULL)
                goto fail;
            bp = tr2;
            fp = tr2 + wcslen(tr2) - 1;
            while (bp < fp) {
                c = *bp;
                *bp++ = *fp;
                *fp-- = c;
            }
            w1 = tr1;
            w2 = tr2;
        }

        if (direc & DIRECTIVE_POSITION) {
            while ((*w1 || st1) && (*w2 || st2)) {
                pri1 = pri2 = 0;
                _collate_lookup(w1, &len1, &pri1, pass, &st1);
                if (pri1 <= 0) {
                    if (pri1 < 0) {
                        errno = EINVAL;
                        goto fail;
                    }
                    pri1 = COLLATE_MAX_PRIORITY;
                }
                _collate_lookup(w2, &len2, &pri2, pass, &st2);
                if (pri2 <= 0) {
                    if (pri2 < 0) {
                        errno = EINVAL;
                        goto fail;
                    }
                    pri2 = COLLATE_MAX_PRIORITY;
                }
                if (pri1 != pri2) {
                    ret = pri1 - pri2;
                    goto end;
                }
                w1 += len1;
                w2 += len2;
            }
        } else {
            while ((*w1 || st1) && (*w2 || st2)) {
                pri1 = pri2 = 0;
                while (*w1) {
                    _collate_lookup(w1, &len1,
                        &pri1, pass, &st1);
                    if (pri1 > 0)
                        break;
                    if (pri1 < 0) {
                        errno = EINVAL;
                        goto fail;
                    }
                    w1 += len1;
                }
                while (*w2) {
                    _collate_lookup(w2, &len2,
                        &pri2, pass, &st2);
                    if (pri2 > 0)
                        break;
                    if (pri2 < 0) {
                        errno = EINVAL;
                        goto fail;
                    }
                    w2 += len2;
                }
                if (!pri1 || !pri2)
                    break;
                if (pri1 != pri2) {
                    ret = pri1 - pri2;
                    goto end;
                }
                w1 += len1;
                w2 += len2;
            }
        }
        if (!*w1) {
            if (*w2) {
                ret = -(int)*w2;
                goto end;
            }
        } else {
            ret = *w1;
            goto end;
        }
    }
    ret = 0;

end:
    if (tr1)
        free(tr1);
    if (tr2)
        free(tr2);

    return (ret);

fail:
    ret = wcscmp(ws1, ws2);
    goto end;
}