freebsd-dev/contrib/csup/pathcomp.c

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2006-03-03 04:11:29 +00:00
/*-
* Copyright (c) 2006, Maxime Henrion <mux@FreeBSD.org>
* 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.
*
* $FreeBSD$
*/
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include "misc.h"
#include "pathcomp.h"
struct pathcomp {
char *target;
size_t targetlen;
char *trashed;
char *prev;
size_t prevlen;
size_t goal;
size_t curlen;
};
struct pathcomp *
pathcomp_new(void)
{
struct pathcomp *pc;
pc = xmalloc(sizeof(struct pathcomp));
pc->curlen = 0;
pc->target = NULL;
pc->targetlen = 0;
pc->trashed = NULL;
pc->prev = NULL;
pc->prevlen = 0;
return (pc);
}
int
pathcomp_put(struct pathcomp *pc, int type, char *path)
{
char *cp;
assert(pc->target == NULL);
if (*path == '/')
return (-1);
switch (type) {
case PC_DIRDOWN:
pc->target = path;
pc->targetlen = strlen(path);
break;
case PC_FILE:
case PC_DIRUP:
cp = strrchr(path, '/');
pc->target = path;
if (cp != NULL)
pc->targetlen = cp - path;
else
pc->targetlen = 0;
break;
}
if (pc->prev != NULL)
pc->goal = commonpathlength(pc->prev, pc->prevlen, pc->target,
pc->targetlen);
else
pc->goal = 0;
if (pc->curlen == pc->goal) /* No need to go up. */
pc->goal = pc->targetlen;
return (0);
}
int
pathcomp_get(struct pathcomp *pc, int *type, char **name)
{
char *cp;
size_t slashpos, start;
if (pc->curlen > pc->goal) { /* Going up. */
assert(pc->prev != NULL);
pc->prev[pc->curlen] = '\0';
cp = pc->prev + pc->curlen - 1;
while (cp >= pc->prev) {
if (*cp == '/')
break;
cp--;
}
if (cp >= pc->prev)
slashpos = cp - pc->prev;
else
slashpos = 0;
pc->curlen = slashpos;
if (pc->curlen <= pc->goal) { /* Done going up. */
assert(pc->curlen == pc->goal);
pc->goal = pc->targetlen;
}
*type = PC_DIRUP;
*name = pc->prev;
return (1);
} else if (pc->curlen < pc->goal) { /* Going down. */
/* Restore the previously overwritten '/' character. */
if (pc->trashed != NULL) {
*pc->trashed = '/';
pc->trashed = NULL;
}
if (pc->curlen == 0)
start = pc->curlen;
else
start = pc->curlen + 1;
slashpos = start;
while (slashpos < pc->goal) {
if (pc->target[slashpos] == '/')
break;
slashpos++;
}
if (pc->target[slashpos] != '\0') {
assert(pc->target[slashpos] == '/');
pc->trashed = pc->target + slashpos;
pc->target[slashpos] = '\0';
}
pc->curlen = slashpos;
*type = PC_DIRDOWN;
*name = pc->target;
return (1);
} else { /* Done. */
if (pc->target != NULL) {
if (pc->trashed != NULL) {
*pc->trashed = '/';
pc->trashed = NULL;
}
if (pc->prev != NULL)
free(pc->prev);
pc->prev = xmalloc(pc->targetlen + 1);
memcpy(pc->prev, pc->target, pc->targetlen);
pc->prev[pc->targetlen] = '\0';
pc->prevlen = pc->targetlen;
pc->target = NULL;
pc->targetlen = 0;
}
return (0);
}
}
void
pathcomp_finish(struct pathcomp *pc)
{
pc->target = NULL;
pc->targetlen = 0;
pc->goal = 0;
}
void
pathcomp_free(struct pathcomp *pc)
{
if (pc->prev != NULL)
free(pc->prev);
free(pc);
}