/*
 * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef RCONN_H
#define RCONN_H 1

#include <stdbool.h>
#include <stdint.h>
#include <time.h>

/* A wrapper around vconn that provides queuing and optionally reliability.
 *
 * An rconn maintains a message transmission queue of bounded length specified
 * by the caller.  The rconn does not guarantee reliable delivery of
 * queued messages: all queued messages are dropped when reconnection becomes
 * necessary.
 *
 * An rconn optionally provides reliable communication, in this sense: the
 * rconn will re-connect, with exponential backoff, when the underlying vconn
 * disconnects.
 */

struct vconn;
struct rconn_packet_counter;

struct rconn *rconn_create(int inactivity_probe_interval, int max_backoff);

void rconn_set_max_backoff(struct rconn *, int max_backoff);
int rconn_get_max_backoff(const struct rconn *);
void rconn_set_probe_interval(struct rconn *, int inactivity_probe_interval);
int rconn_get_probe_interval(const struct rconn *);

void rconn_connect(struct rconn *, const char *target, const char *name);
void rconn_connect_unreliably(struct rconn *,
                              struct vconn *, const char *name);
void rconn_reconnect(struct rconn *);
void rconn_disconnect(struct rconn *);
void rconn_destroy(struct rconn *);

void rconn_run(struct rconn *);
void rconn_run_wait(struct rconn *);
struct ofpbuf *rconn_recv(struct rconn *);
void rconn_recv_wait(struct rconn *);
int rconn_send(struct rconn *, struct ofpbuf *, struct rconn_packet_counter *);
int rconn_send_with_limit(struct rconn *, struct ofpbuf *,
                          struct rconn_packet_counter *, int queue_limit);
unsigned int rconn_packets_sent(const struct rconn *);
unsigned int rconn_packets_received(const struct rconn *);

void rconn_add_monitor(struct rconn *, struct vconn *);

const char *rconn_get_name(const struct rconn *);
void rconn_set_name(struct rconn *, const char *new_name);
const char *rconn_get_target(const struct rconn *);

bool rconn_is_alive(const struct rconn *);
bool rconn_is_connected(const struct rconn *);
bool rconn_is_admitted(const struct rconn *);
int rconn_failure_duration(const struct rconn *);

uint32_t rconn_get_remote_ip(const struct rconn *);
uint16_t rconn_get_remote_port(const struct rconn *);
uint32_t rconn_get_local_ip(const struct rconn *);
uint16_t rconn_get_local_port(const struct rconn *);

const char *rconn_get_state(const struct rconn *);
unsigned int rconn_get_attempted_connections(const struct rconn *);
unsigned int rconn_get_successful_connections(const struct rconn *);
time_t rconn_get_last_connection(const struct rconn *);
time_t rconn_get_last_disconnect(const struct rconn *);
time_t rconn_get_last_received(const struct rconn *);
time_t rconn_get_creation_time(const struct rconn *);
unsigned long int rconn_get_total_time_connected(const struct rconn *);
int rconn_get_backoff(const struct rconn *);
unsigned int rconn_get_state_elapsed(const struct rconn *);
unsigned int rconn_get_connection_seqno(const struct rconn *);
int rconn_get_last_error(const struct rconn *);

/* Counts the number of packets queued into an rconn by a given source. */
struct rconn_packet_counter {
    int n;                      /* Number of packets queued. */
    int ref_cnt;                /* Number of owners. */
};

struct rconn_packet_counter *rconn_packet_counter_create(void);
void rconn_packet_counter_destroy(struct rconn_packet_counter *);
void rconn_packet_counter_inc(struct rconn_packet_counter *);
void rconn_packet_counter_dec(struct rconn_packet_counter *);

static inline int
rconn_packet_counter_read(const struct rconn_packet_counter *counter)
{
    return counter->n;
}

#endif /* rconn.h */