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/*
This file is part of Kismet
Kismet 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.
Kismet 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 Kismet; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "ringbuf.h"
#include <string.h>
#include <cstring>
RingBuffer::RingBuffer(int in_size) {
ring_len = in_size;
ring_data = new uint8_t[in_size];
ring_rptr = ring_data;
ring_wptr = ring_data;
}
RingBuffer::~RingBuffer() {
delete[] ring_data;
}
int RingBuffer::InsertDummy(int in_len) {
if (ring_wptr == ring_rptr && ring_wptr == ring_data)
return 1;
if (ring_wptr + in_len >= ring_data + ring_len) {
int tail = (ring_data + ring_len) - ring_wptr;
if (ring_data + (in_len - tail) >= ring_rptr)
return 0;
} else {
if ((ring_rptr > ring_wptr) && (ring_wptr + in_len >= ring_rptr))
return 0;
}
return 1;
}
int RingBuffer::InsertData(uint8_t *in_data, int in_len) {
// Will this hit the end of the ring and go back to the beginning?
if ((ring_wptr + in_len) >= (ring_data + ring_len)) {
// How much data gets written to the tail of the ring before we
// wrap?
int tail = (ring_data + ring_len) - ring_wptr;
// If we're going to wrap, will we overrun the read position?
if (ring_data + (in_len - tail) >= ring_rptr)
return 0;
// Copy the data to the end of the loop, move to the beginning
memcpy(ring_wptr, in_data, tail);
memcpy(ring_data, in_data + tail, in_len - tail);
ring_wptr = ring_data + (in_len - tail);
} else {
// Will we surpass the read pointer?
if ((ring_rptr > ring_wptr) && (ring_wptr + in_len >= ring_rptr))
return 0;
// Copy the data to the write pointer
memcpy(ring_wptr, in_data, in_len);
ring_wptr = ring_wptr + in_len;
}
// printf("debug - inserted %d into ring buffer.\n", in_len);
return 1;
}
int RingBuffer::FetchLen() {
int ret = 0;
if (ring_wptr < ring_rptr) {
// If the write pointer is wrapped before the read, add the
// length from read to the end plus the beginning to the write
ret = (ring_data + ring_len) - ring_rptr + (ring_wptr - ring_data);
} else {
ret = (ring_wptr - ring_rptr);
}
//printf("ring begin %p wptr %p rptr %p lt %d len %d\n",
//ring_data, ring_wptr, ring_rptr, ring_wptr < ring_rptr, ret);
return ret;
}
void RingBuffer::FetchPtr(uint8_t *in_dataptr, int in_max, int *in_len) {
// Has the write pointer looped back?
if (ring_wptr < ring_rptr) {
// Copy the read to the end, as much as we can
*in_len = (ring_data + ring_len) - ring_rptr;
// If we have more room than we need
if (*in_len > in_max) {
// printf("debug - ring %d avail, %d requested\n", *in_len, in_max);
*in_len = in_max;
memcpy(in_dataptr, ring_rptr, in_max);
return;
}
// Copy all we can to the end of the array
memcpy(in_dataptr, ring_rptr, *in_len);
// How many bytes can we copy? Whichever is smaller - the head of the
// ring, or the max we can hold after we stocked it before
int copybytes = kismin((ring_wptr - ring_data), (in_max - *in_len));
// Copy it off the header
memcpy(in_dataptr + *in_len, ring_data, copybytes);
*in_len = *in_len + copybytes;
return;
} else {
// Copy out the requested size or as much as we can
*in_len = kismin((ring_wptr - ring_rptr), in_max);
memcpy(in_dataptr, ring_rptr, *in_len);
return;
}
}
void RingBuffer::MarkRead(int in_len) {
// Will we loop the array?
if ((ring_rptr + in_len) >= (ring_data + ring_len)) {
// How much comes off the length before we wrap?
int tail = (ring_data + ring_len) - ring_rptr;
// Catch surpassing the write pointer after the loop
if (ring_data + (in_len - tail) > ring_wptr)
ring_rptr = ring_wptr;
else
ring_rptr = ring_data + (in_len - tail);
} else {
ring_rptr += in_len;
}
//printf("debug - marked %d read in ring\n", in_len);
return;
}
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