gnupg2/common/ccparray.c

149 lines
3.5 KiB
C

/* ccparray.c - A simple dynamic array for character pointer.
* Copyright (C) 2016 g10 Code GmbH
*
* This file is part of GnuPG.
*
* This file is free software; you can redistribute it and/or modify
* it under the terms of either
*
* - the GNU Lesser General Public License as published by the Free
* Software Foundation; either version 3 of the License, or (at
* your option) any later version.
*
* or
*
* - the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* or both in parallel, as here.
*
* This file is distributed in the hope that it will 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <stdlib.h>
#include <errno.h>
#include <stdarg.h>
#include "util.h"
#include "ccparray.h"
/* A simple implementation of a dynamic array of const char pointers.
* The example code:
*
* ccparray_t ccp;
* const char **argv;
* int i;
*
* ccparray_init (&ccp, 0);
* ccparray_put (&ccp, "First arg");
* ccparray_put (&ccp, "Second arg");
* ccparray_put (&ccp, NULL);
* ccparray_put (&ccp, "Fourth arg");
* argv = ccparray_get (&ccp, NULL);
* if (!argv)
* die ("error building array: %s\n", strerror (errno));
* for (i=0; argv[i]; i++)
* printf ("[%d] = '%s'\n", i, argv[i]);
* xfree (argv);
*
* will result in this output:
*
* [0] = 'First arg'
* [1] = 'Second arg'
*
* Note that allocation errors are detected but only returned with the
* final ccparray_get(); this helps not to clutter the code with out
* of core checks.
*/
void
ccparray_init (ccparray_t *cpa, unsigned int initialsize)
{
if (!initialsize)
cpa->size = 16;
else if (initialsize < (1<<16))
cpa->size = initialsize;
else
cpa->size = (1<<16);
cpa->count = 0;
cpa->out_of_core = 0;
cpa->array = xtrycalloc (cpa->size, sizeof *cpa->array);
if (!cpa->array)
cpa->out_of_core = errno;
}
void
ccparray_put (ccparray_t *cpa, const char *value)
{
if (cpa->out_of_core)
return;
if (cpa->count + 1 >= cpa->size)
{
const char **newarray;
size_t n, newsize;
if (cpa->size < 8)
newsize = 16;
else if (cpa->size < 4096)
newsize = 2 * cpa->size;
else if (cpa->size < (1<<16))
newsize = cpa->size + 2048;
else
{
cpa->out_of_core = ENOMEM;
return;
}
newarray = xtrycalloc (newsize, sizeof *newarray);
if (!newarray)
{
cpa->out_of_core = errno ? errno : ENOMEM;
return;
}
for (n=0; n < cpa->size; n++)
newarray[n] = cpa->array[n];
xfree (cpa->array);
cpa->array = newarray;
cpa->size = newsize;
}
cpa->array[cpa->count++] = value;
}
const char **
ccparray_get (ccparray_t *cpa, size_t *r_count)
{
const char **result;
if (cpa->out_of_core)
{
if (cpa->array)
{
xfree (cpa->array);
cpa->array = NULL;
}
gpg_err_set_errno (cpa->out_of_core);
return NULL;
}
result= cpa->array;
if (r_count)
*r_count = cpa->count;
cpa->array = NULL;
cpa->out_of_core = ENOMEM; /* hack to make sure it won't get reused. */
return result;
}