tor-android/external/badvpn_dns/misc/grow_array.h

140 lines
4.5 KiB
C

/**
* @file grow_array.h
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* 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.
* 3. Neither the name of the author nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 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.
*/
// Preprocessor inputs:
// GROWARRAY_NAME - prefix of of functions to define
// GROWARRAY_OBJECT_TYPE - type of structure where array and capacity sizes are
// GROWARRAY_ARRAY_MEMBER - array member
// GROWARRAY_CAPACITY_MEMBER - capacity member
// GROWARRAY_MAX_CAPACITY - max value of capacity member
#include <limits.h>
#include <string.h>
#include <stddef.h>
#include <misc/debug.h>
#include <misc/balloc.h>
#include <misc/merge.h>
#define GrowArrayObject GROWARRAY_OBJECT_TYPE
#define GrowArray_Init MERGE(GROWARRAY_NAME, _Init)
#define GrowArray_InitEmpty MERGE(GROWARRAY_NAME, _InitEmpty)
#define GrowArray_Free MERGE(GROWARRAY_NAME, _Free)
#define GrowArray_DoubleUp MERGE(GROWARRAY_NAME, _DoubleUp)
#define GrowArray_DoubleUpLimit MERGE(GROWARRAY_NAME, _DoubleUpLimit)
static int GrowArray_Init (GrowArrayObject *o, size_t capacity) WARN_UNUSED;
static void GrowArray_InitEmpty (GrowArrayObject *o);
static void GrowArray_Free (GrowArrayObject *o);
static int GrowArray_DoubleUp (GrowArrayObject *o) WARN_UNUSED;
static int GrowArray_DoubleUpLimit (GrowArrayObject *o, size_t limit) WARN_UNUSED;
static int GrowArray_Init (GrowArrayObject *o, size_t capacity)
{
if (capacity > GROWARRAY_MAX_CAPACITY) {
return 0;
}
if (capacity == 0) {
o->GROWARRAY_ARRAY_MEMBER = NULL;
} else {
if (!(o->GROWARRAY_ARRAY_MEMBER = BAllocArray(capacity, sizeof(o->GROWARRAY_ARRAY_MEMBER[0])))) {
return 0;
}
}
o->GROWARRAY_CAPACITY_MEMBER = capacity;
return 1;
}
static void GrowArray_InitEmpty (GrowArrayObject *o)
{
o->GROWARRAY_ARRAY_MEMBER = NULL;
o->GROWARRAY_CAPACITY_MEMBER = 0;
}
static void GrowArray_Free (GrowArrayObject *o)
{
if (o->GROWARRAY_ARRAY_MEMBER) {
BFree(o->GROWARRAY_ARRAY_MEMBER);
}
}
static int GrowArray_DoubleUp (GrowArrayObject *o)
{
return GrowArray_DoubleUpLimit(o, SIZE_MAX);
}
static int GrowArray_DoubleUpLimit (GrowArrayObject *o, size_t limit)
{
if (o->GROWARRAY_CAPACITY_MEMBER > SIZE_MAX / 2 || o->GROWARRAY_CAPACITY_MEMBER > GROWARRAY_MAX_CAPACITY / 2) {
return 0;
}
size_t newcap = 2 * o->GROWARRAY_CAPACITY_MEMBER;
if (newcap == 0) {
newcap = 1;
}
if (newcap > limit) {
newcap = limit;
if (newcap == o->GROWARRAY_CAPACITY_MEMBER) {
return 0;
}
}
void *newarr = BAllocArray(newcap, sizeof(o->GROWARRAY_ARRAY_MEMBER[0]));
if (!newarr) {
return 0;
}
memcpy(newarr, o->GROWARRAY_ARRAY_MEMBER, o->GROWARRAY_CAPACITY_MEMBER * sizeof(o->GROWARRAY_ARRAY_MEMBER[0]));
BFree(o->GROWARRAY_ARRAY_MEMBER);
o->GROWARRAY_ARRAY_MEMBER = newarr;
o->GROWARRAY_CAPACITY_MEMBER = newcap;
return 1;
}
#undef GROWARRAY_NAME
#undef GROWARRAY_OBJECT_TYPE
#undef GROWARRAY_ARRAY_MEMBER
#undef GROWARRAY_CAPACITY_MEMBER
#undef GROWARRAY_MAX_CAPACITY
#undef GrowArrayObject
#undef GrowArray_Init
#undef GrowArray_InitEmpty
#undef GrowArray_Free
#undef GrowArray_DoubleUp
#undef GrowArray_DoubleUpLimit