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/*##############################################################################
# Copyright (c) 2017 ZTE Coreporation and others.
# hu.zhijiang@zte.com.cn
# All rights reserved. This program and the accompanying materials
# are made available under the terms of the Apache License, Version 2.0
# which accompanies this distribution, and is available at
# http://www.apache.org/licenses/LICENSE-2.0
##############################################################################*/
#include <stdlib.h>
#include <string.h>
#include "buffer.h"
#include "misc.h"
struct buffer_ctl buffctl;
struct packet_ctl *packetctl[PACKETS_PER_BUFFER];
struct packet_ctl empty;
void buffer_init()
{
int i;
for (i = 0; i < PACKETS_PER_BUFFER; i++) {
packetctl[i] = (struct packet_ctl *)wrapper_malloc(PACKET_SIZE);
memset(packetctl[i], 0, PACKET_SIZE);
packetctl[i]->data_size = 0;
packetctl[i]->seq = 0;
}
buffctl.buffer_id = 0;
buffctl.packet_id_base = 0;
buffctl.pkt_count = 0;
empty.data_size = 0;
}
void packetctl_precheck()
{
int i;
for (i = 0; i < PACKETS_PER_BUFFER; i++) {
if (packetctl[i]->data_size != 0) {
crit("Error precheck packet slot %d,%d", i, packetctl[i]->data_size);
}
}
}
// Calculate packet checksum
uint32_t packet_csum(uint8_t *data, int len)
{
uint32_t *item, sum = 0;
int i = 0;
while (len % 4) {
data[len] = 0; len++;
}
while (i < len) {
item = (uint32_t *)((char *)data + i);
sum += *item;
i += 4;
}
return sum;
}
// Fill buffers from file descriptor
long buffer_fill(int fd)
{
int s = 0;
int r = PACKET_PAYLOAD_SIZE;
buffctl.buffer_id++;
buffctl.packet_id_base += buffctl.pkt_count;
buffctl.buffer_size = 0;
while (r > 0 && s < PACKETS_PER_BUFFER) {
if ((r = read(fd, packetctl[s]->data, PACKET_PAYLOAD_SIZE)) < 0) {
crit("Error reading data from stdin");
}
// r == 0 means EOF
if (r > 0) {
buffctl.buffer_size += r;
packetctl[s]->data_size = r;
packetctl[s]->seq = buffctl.packet_id_base + s;
packetctl[s]->crc = packet_csum(packetctl[s]->data, r);
s++;
}
}
log(6, "input %d bytes of data in %d packets", buffctl.buffer_size, s);
buffctl.pkt_count = s;
return s;
}
long buffer_flush(int fd)
{
int s = 0;
while (buffctl.pkt_count--) {
write(fd, packetctl[s]->data, packetctl[s]->data_size);
buffctl.buffer_size -= packetctl[s]->data_size;
packetctl[s]->data_size = 0;
packetctl[s]->seq = 0;
packetctl[s]->crc = 0;
s++;
}
return s;
}
/* Caller should use new_pkt as packet buffer again if this returns NULL */
struct packet_ctl *packet_put(struct packet_ctl *new_pkt)
{
struct packet_ctl *freed_pkt;
uint32_t i;
if (new_pkt->seq < buffctl.packet_id_base ||
new_pkt->seq - buffctl.packet_id_base >= buffctl.pkt_count) {
return NULL;
}
if (new_pkt->data_size == 0) {
return NULL;
}
i = packet_csum(new_pkt->data, new_pkt->data_size);
if (new_pkt->crc != i) {
return NULL;
}
i = new_pkt->seq - buffctl.packet_id_base;
freed_pkt = packetctl[i];
packetctl[i] = new_pkt;
return freed_pkt;
}
struct packet_ctl *packet_get(uint32_t seq)
{
empty.seq = seq;
if (seq < buffctl.packet_id_base ||
seq - buffctl.packet_id_base >= buffctl.pkt_count) {
return ∅
}
if (packetctl[seq - buffctl.packet_id_base]->data_size == 0) {
return ∅
}
return packetctl[seq - buffctl.packet_id_base];
}
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