mirror of
https://github.com/gnif/LookingGlass.git
synced 2024-12-23 06:11:46 +00:00
153 lines
3.2 KiB
C
153 lines
3.2 KiB
C
/**
|
|
* Looking Glass
|
|
* Copyright © 2017-2021 The Looking Glass Authors
|
|
* https://looking-glass.io
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of 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.
|
|
*
|
|
* This program 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, write to the Free Software Foundation, Inc., 59
|
|
* Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
|
|
#include "common/ringbuffer.h"
|
|
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
struct RingBuffer
|
|
{
|
|
RingBufferValueFn preOverwriteFn;
|
|
void * preOverwriteUdata;
|
|
|
|
int length;
|
|
size_t valueSize;
|
|
int start, pos, count;
|
|
char values[0];
|
|
};
|
|
|
|
RingBuffer ringbuffer_new(int length, size_t valueSize)
|
|
{
|
|
struct RingBuffer * rb = calloc(1, sizeof(*rb) + valueSize * length);
|
|
rb->length = length;
|
|
rb->valueSize = valueSize;
|
|
return rb;
|
|
}
|
|
|
|
void ringbuffer_free(RingBuffer * rb)
|
|
{
|
|
if (!*rb)
|
|
return;
|
|
|
|
free(*rb);
|
|
*rb = NULL;
|
|
}
|
|
|
|
void ringbuffer_push(RingBuffer rb, const void * value)
|
|
{
|
|
void * dst = rb->values + rb->pos * rb->valueSize;
|
|
|
|
if (rb->count < rb->length)
|
|
++rb->count;
|
|
else
|
|
{
|
|
if (++rb->start == rb->length)
|
|
rb->start = 0;
|
|
|
|
if (rb->preOverwriteFn)
|
|
rb->preOverwriteFn(dst, rb->preOverwriteUdata);
|
|
}
|
|
|
|
memcpy(dst, value, rb->valueSize);
|
|
|
|
if (++rb->pos == rb->length)
|
|
rb->pos = 0;
|
|
}
|
|
|
|
void ringbuffer_reset(RingBuffer rb)
|
|
{
|
|
rb->start = 0;
|
|
rb->pos = 0;
|
|
rb->count = 0;
|
|
}
|
|
|
|
int ringbuffer_getLength(const RingBuffer rb)
|
|
{
|
|
return rb->length;
|
|
}
|
|
|
|
int ringbuffer_getStart(const RingBuffer rb)
|
|
{
|
|
return rb->start;
|
|
}
|
|
|
|
int ringbuffer_getCount(const RingBuffer rb)
|
|
{
|
|
return rb->count;
|
|
}
|
|
|
|
void * ringbuffer_getValues(const RingBuffer rb)
|
|
{
|
|
return rb->values;
|
|
}
|
|
|
|
void * ringBuffer_getLastValue(const RingBuffer rb)
|
|
{
|
|
if (rb->count == 0)
|
|
return NULL;
|
|
|
|
int index = rb->start + rb->count - 1;
|
|
if (index >= rb->length)
|
|
index -= rb->length;
|
|
|
|
return rb->values + index * rb->valueSize;
|
|
}
|
|
|
|
void ringbuffer_setPreOverwriteFn(const RingBuffer rb, RingBufferValueFn fn,
|
|
void * udata)
|
|
{
|
|
rb->preOverwriteFn = fn;
|
|
rb->preOverwriteUdata = udata;
|
|
}
|
|
|
|
void ringbuffer_forEach(const RingBuffer rb, RingBufferIterator fn, void * udata,
|
|
bool reverse)
|
|
{
|
|
if (reverse)
|
|
{
|
|
int index = rb->start + rb->count - 1;
|
|
if (index >= rb->length)
|
|
index -= rb->length;
|
|
|
|
for(int i = 0; i < rb->count; ++i)
|
|
{
|
|
void * value = rb->values + index * rb->valueSize;
|
|
if (--index == -1)
|
|
index = rb->length - 1;
|
|
|
|
if (!fn(i, value, udata))
|
|
break;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
int index = rb->start;
|
|
for(int i = 0; i < rb->count; ++i)
|
|
{
|
|
void * value = rb->values + index * rb->valueSize;
|
|
if (++index == rb->length)
|
|
index = 0;
|
|
|
|
if (!fn(i, value, udata))
|
|
break;
|
|
}
|
|
}
|
|
}
|