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/*
* ngtcp2
*
* Copyright (c) 2017 ngtcp2 contributors
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef NGTCP2_ACKTR_H
#define NGTCP2_ACKTR_H
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif /* HAVE_CONFIG_H */
#include <ngtcp2/ngtcp2.h>
#include "ngtcp2_mem.h"
#include "ngtcp2_ringbuf.h"
#include "ngtcp2_ksl.h"
#include "ngtcp2_pkt.h"
#include "ngtcp2_objalloc.h"
/* NGTCP2_ACKTR_MAX_ENT is the maximum number of ngtcp2_acktr_entry
which ngtcp2_acktr stores. */
#define NGTCP2_ACKTR_MAX_ENT 1024
typedef struct ngtcp2_log ngtcp2_log;
/*
* ngtcp2_acktr_entry is a range of packets which need to be acked.
*/
typedef struct ngtcp2_acktr_entry {
union {
struct {
/* pkt_num is the largest packet number to acknowledge in this
range. */
int64_t pkt_num;
/* len is the consecutive packets started from pkt_num which
includes pkt_num itself counting in decreasing order. So pkt_num
= 987 and len = 2, this entry includes packet 987 and 986. */
size_t len;
/* tstamp is the timestamp when a packet denoted by pkt_num is
received. */
ngtcp2_tstamp tstamp;
};
ngtcp2_opl_entry oplent;
};
} ngtcp2_acktr_entry;
ngtcp2_objalloc_decl(acktr_entry, ngtcp2_acktr_entry, oplent);
/*
* ngtcp2_acktr_entry_objalloc_new allocates memory for ent, and
* initializes it with the given parameters. The pointer to the
* allocated object is stored to |*ent|.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGTCP2_ERR_NOMEM
* Out of memory.
*/
int ngtcp2_acktr_entry_objalloc_new(ngtcp2_acktr_entry **ent, int64_t pkt_num,
ngtcp2_tstamp tstamp,
ngtcp2_objalloc *objalloc);
/*
* ngtcp2_acktr_entry_objalloc_del deallocates memory allocated for
* |ent|.
*/
void ngtcp2_acktr_entry_objalloc_del(ngtcp2_acktr_entry *ent,
ngtcp2_objalloc *objalloc);
typedef struct ngtcp2_acktr_ack_entry {
/* largest_ack is the largest packet number in outgoing ACK frame */
int64_t largest_ack;
/* pkt_num is the packet number that ACK frame is included. */
int64_t pkt_num;
} ngtcp2_acktr_ack_entry;
/* NGTCP2_ACKTR_FLAG_NONE indicates that no flag set. */
#define NGTCP2_ACKTR_FLAG_NONE 0x00u
/* NGTCP2_ACKTR_FLAG_IMMEDIATE_ACK indicates that immediate
acknowledgement is required. */
#define NGTCP2_ACKTR_FLAG_IMMEDIATE_ACK 0x01u
/* NGTCP2_ACKTR_FLAG_ACTIVE_ACK indicates that there are pending
protected packet to be acknowledged. */
#define NGTCP2_ACKTR_FLAG_ACTIVE_ACK 0x02u
/* NGTCP2_ACKTR_FLAG_CANCEL_TIMER is set when ACK delay timer is
expired and canceled. */
#define NGTCP2_ACKTR_FLAG_CANCEL_TIMER 0x0100u
/*
* ngtcp2_acktr tracks received packets which we have to send ack.
*/
typedef struct ngtcp2_acktr {
ngtcp2_objalloc objalloc;
ngtcp2_ringbuf acks;
/* ents includes ngtcp2_acktr_entry sorted by decreasing order of
packet number. */
ngtcp2_ksl ents;
ngtcp2_log *log;
const ngtcp2_mem *mem;
/* flags is bitwise OR of zero, or more of NGTCP2_ACKTR_FLAG_*. */
uint16_t flags;
/* first_unacked_ts is timestamp when ngtcp2_acktr_entry is added
first time after the last outgoing ACK frame. */
ngtcp2_tstamp first_unacked_ts;
/* rx_npkt is the number of ACK eliciting packets received without
sending ACK. */
size_t rx_npkt;
} ngtcp2_acktr;
/*
* ngtcp2_acktr_init initializes |acktr|.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGTCP2_ERR_NOMEM
* Out of memory.
*/
int ngtcp2_acktr_init(ngtcp2_acktr *acktr, ngtcp2_log *log,
const ngtcp2_mem *mem);
/*
* ngtcp2_acktr_free frees resources allocated for |acktr|. It frees
* any ngtcp2_acktr_entry added to |acktr|.
*/
void ngtcp2_acktr_free(ngtcp2_acktr *acktr);
/*
* ngtcp2_acktr_add adds packet number |pkt_num| to |acktr|.
* |active_ack| is nonzero if |pkt_num| is retransmittable packet.
*
* This function assumes that |acktr| does not contain |pkt_num|.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGTCP2_ERR_NOMEM
* OUt of memory.
*/
int ngtcp2_acktr_add(ngtcp2_acktr *acktr, int64_t pkt_num, int active_ack,
ngtcp2_tstamp ts);
/*
* ngtcp2_acktr_forget removes all entries which have the packet
* number that is equal to or less than ent->pkt_num. This function
* assumes that |acktr| includes |ent|.
*/
void ngtcp2_acktr_forget(ngtcp2_acktr *acktr, ngtcp2_acktr_entry *ent);
/*
* ngtcp2_acktr_get returns the pointer to pointer to the entry which
* has the largest packet number to be acked. If there is no entry,
* returned value satisfies ngtcp2_ksl_it_end(&it) != 0.
*/
ngtcp2_ksl_it ngtcp2_acktr_get(ngtcp2_acktr *acktr);
/*
* ngtcp2_acktr_empty returns nonzero if it has no packet to
* acknowledge.
*/
int ngtcp2_acktr_empty(ngtcp2_acktr *acktr);
/*
* ngtcp2_acktr_add_ack records outgoing ACK frame whose largest
* acknowledged packet number is |largest_ack|. |pkt_num| is the
* packet number of a packet in which ACK frame is included. This
* function returns a pointer to the object it adds.
*/
ngtcp2_acktr_ack_entry *
ngtcp2_acktr_add_ack(ngtcp2_acktr *acktr, int64_t pkt_num, int64_t largest_ack);
/*
* ngtcp2_acktr_recv_ack processes the incoming ACK frame |fr|.
* |pkt_num| is a packet number which includes |fr|. If we receive
* ACK which acknowledges the ACKs added by ngtcp2_acktr_add_ack,
* ngtcp2_acktr_entry which the outgoing ACK acknowledges is removed.
*/
void ngtcp2_acktr_recv_ack(ngtcp2_acktr *acktr, const ngtcp2_ack *fr);
/*
* ngtcp2_acktr_commit_ack tells |acktr| that ACK frame is generated.
*/
void ngtcp2_acktr_commit_ack(ngtcp2_acktr *acktr);
/*
* ngtcp2_acktr_require_active_ack returns nonzero if ACK frame should
* be generated actively.
*/
int ngtcp2_acktr_require_active_ack(ngtcp2_acktr *acktr,
ngtcp2_duration max_ack_delay,
ngtcp2_tstamp ts);
/*
* ngtcp2_acktr_immediate_ack tells |acktr| that immediate
* acknowledgement is required.
*/
void ngtcp2_acktr_immediate_ack(ngtcp2_acktr *acktr);
#endif /* NGTCP2_ACKTR_H */
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