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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.
*/
#include "ngtcp2_acktr.h"
#include <assert.h>
int ngtcp2_acktr_entry_new(ngtcp2_acktr_entry **ent, int64_t pkt_num,
ngtcp2_tstamp tstamp, const ngtcp2_mem *mem) {
*ent = ngtcp2_mem_malloc(mem, sizeof(ngtcp2_acktr_entry));
if (*ent == NULL) {
return NGTCP2_ERR_NOMEM;
}
(*ent)->pkt_num = pkt_num;
(*ent)->len = 1;
(*ent)->tstamp = tstamp;
return 0;
}
void ngtcp2_acktr_entry_del(ngtcp2_acktr_entry *ent, const ngtcp2_mem *mem) {
ngtcp2_mem_free(mem, ent);
}
static int greater(const ngtcp2_ksl_key *lhs, const ngtcp2_ksl_key *rhs) {
return *(int64_t *)lhs > *(int64_t *)rhs;
}
int ngtcp2_acktr_init(ngtcp2_acktr *acktr, ngtcp2_log *log,
const ngtcp2_mem *mem) {
int rv;
rv = ngtcp2_ringbuf_init(&acktr->acks, 128, sizeof(ngtcp2_acktr_ack_entry),
mem);
if (rv != 0) {
return rv;
}
rv = ngtcp2_ksl_init(&acktr->ents, greater, sizeof(int64_t), mem);
if (rv != 0) {
ngtcp2_ringbuf_free(&acktr->acks);
return rv;
}
acktr->log = log;
acktr->mem = mem;
acktr->flags = NGTCP2_ACKTR_FLAG_NONE;
acktr->first_unacked_ts = UINT64_MAX;
acktr->rx_npkt = 0;
return 0;
}
void ngtcp2_acktr_free(ngtcp2_acktr *acktr) {
ngtcp2_ksl_it it;
if (acktr == NULL) {
return;
}
for (it = ngtcp2_ksl_begin(&acktr->ents); !ngtcp2_ksl_it_end(&it);
ngtcp2_ksl_it_next(&it)) {
ngtcp2_acktr_entry_del(ngtcp2_ksl_it_get(&it), acktr->mem);
}
ngtcp2_ksl_free(&acktr->ents);
ngtcp2_ringbuf_free(&acktr->acks);
}
int ngtcp2_acktr_add(ngtcp2_acktr *acktr, int64_t pkt_num, int active_ack,
ngtcp2_tstamp ts) {
ngtcp2_ksl_it it;
ngtcp2_acktr_entry *ent, *prev_ent, *delent;
int rv;
int added = 0;
if (ngtcp2_ksl_len(&acktr->ents)) {
it = ngtcp2_ksl_lower_bound(&acktr->ents, &pkt_num);
if (ngtcp2_ksl_it_end(&it)) {
ngtcp2_ksl_it_prev(&it);
ent = ngtcp2_ksl_it_get(&it);
assert(ent->pkt_num >= pkt_num + (int64_t)ent->len);
if (ent->pkt_num == pkt_num + (int64_t)ent->len) {
++ent->len;
added = 1;
}
} else {
ent = ngtcp2_ksl_it_get(&it);
assert(ent->pkt_num != pkt_num);
if (ngtcp2_ksl_it_begin(&it)) {
if (ent->pkt_num + 1 == pkt_num) {
ngtcp2_ksl_update_key(&acktr->ents, &ent->pkt_num, &pkt_num);
ent->pkt_num = pkt_num;
ent->tstamp = ts;
++ent->len;
added = 1;
}
} else {
ngtcp2_ksl_it_prev(&it);
prev_ent = ngtcp2_ksl_it_get(&it);
assert(prev_ent->pkt_num >= pkt_num + (int64_t)prev_ent->len);
if (ent->pkt_num + 1 == pkt_num) {
if (prev_ent->pkt_num == pkt_num + (int64_t)prev_ent->len) {
prev_ent->len += ent->len + 1;
ngtcp2_ksl_remove(&acktr->ents, NULL, &ent->pkt_num);
ngtcp2_acktr_entry_del(ent, acktr->mem);
added = 1;
} else {
ngtcp2_ksl_update_key(&acktr->ents, &ent->pkt_num, &pkt_num);
ent->pkt_num = pkt_num;
ent->tstamp = ts;
++ent->len;
added = 1;
}
} else if (prev_ent->pkt_num == pkt_num + (int64_t)prev_ent->len) {
++prev_ent->len;
added = 1;
}
}
}
}
if (!added) {
rv = ngtcp2_acktr_entry_new(&ent, pkt_num, ts, acktr->mem);
if (rv != 0) {
return rv;
}
rv = ngtcp2_ksl_insert(&acktr->ents, NULL, &ent->pkt_num, ent);
if (rv != 0) {
ngtcp2_acktr_entry_del(ent, acktr->mem);
return rv;
}
}
if (active_ack) {
acktr->flags |= NGTCP2_ACKTR_FLAG_ACTIVE_ACK;
if (acktr->first_unacked_ts == UINT64_MAX) {
acktr->first_unacked_ts = ts;
}
}
if (ngtcp2_ksl_len(&acktr->ents) > NGTCP2_ACKTR_MAX_ENT) {
it = ngtcp2_ksl_end(&acktr->ents);
ngtcp2_ksl_it_prev(&it);
delent = ngtcp2_ksl_it_get(&it);
ngtcp2_ksl_remove(&acktr->ents, NULL, &delent->pkt_num);
ngtcp2_acktr_entry_del(delent, acktr->mem);
}
return 0;
}
void ngtcp2_acktr_forget(ngtcp2_acktr *acktr, ngtcp2_acktr_entry *ent) {
ngtcp2_ksl_it it;
it = ngtcp2_ksl_lower_bound(&acktr->ents, &ent->pkt_num);
assert(*(int64_t *)ngtcp2_ksl_it_key(&it) == (int64_t)ent->pkt_num);
for (; !ngtcp2_ksl_it_end(&it);) {
ent = ngtcp2_ksl_it_get(&it);
ngtcp2_ksl_remove(&acktr->ents, &it, &ent->pkt_num);
ngtcp2_acktr_entry_del(ent, acktr->mem);
}
}
ngtcp2_ksl_it ngtcp2_acktr_get(ngtcp2_acktr *acktr) {
return ngtcp2_ksl_begin(&acktr->ents);
}
int ngtcp2_acktr_empty(ngtcp2_acktr *acktr) {
ngtcp2_ksl_it it = ngtcp2_ksl_begin(&acktr->ents);
return ngtcp2_ksl_it_end(&it);
}
ngtcp2_acktr_ack_entry *ngtcp2_acktr_add_ack(ngtcp2_acktr *acktr,
int64_t pkt_num,
int64_t largest_ack) {
ngtcp2_acktr_ack_entry *ent = ngtcp2_ringbuf_push_front(&acktr->acks);
ent->largest_ack = largest_ack;
ent->pkt_num = pkt_num;
return ent;
}
/*
* acktr_remove removes |ent| from |acktr|. The iterator which points
* to the entry next to |ent| is assigned to |it|.
*/
static void acktr_remove(ngtcp2_acktr *acktr, ngtcp2_ksl_it *it,
ngtcp2_acktr_entry *ent) {
ngtcp2_ksl_remove(&acktr->ents, it, &ent->pkt_num);
ngtcp2_acktr_entry_del(ent, acktr->mem);
}
static void acktr_on_ack(ngtcp2_acktr *acktr, ngtcp2_ringbuf *rb,
size_t ack_ent_offset) {
ngtcp2_acktr_ack_entry *ack_ent;
ngtcp2_acktr_entry *ent;
ngtcp2_ksl_it it;
assert(ngtcp2_ringbuf_len(rb));
ack_ent = ngtcp2_ringbuf_get(rb, ack_ent_offset);
/* Assume that ngtcp2_pkt_validate_ack(fr) returns 0 */
it = ngtcp2_ksl_lower_bound(&acktr->ents, &ack_ent->largest_ack);
for (; !ngtcp2_ksl_it_end(&it);) {
ent = ngtcp2_ksl_it_get(&it);
acktr_remove(acktr, &it, ent);
}
if (ngtcp2_ksl_len(&acktr->ents)) {
assert(ngtcp2_ksl_it_end(&it));
ngtcp2_ksl_it_prev(&it);
ent = ngtcp2_ksl_it_get(&it);
if (ent->pkt_num > ack_ent->largest_ack &&
ack_ent->largest_ack >= ent->pkt_num - (int64_t)(ent->len - 1)) {
ent->len = (size_t)(ent->pkt_num - ack_ent->largest_ack);
}
}
ngtcp2_ringbuf_resize(rb, ack_ent_offset);
}
void ngtcp2_acktr_recv_ack(ngtcp2_acktr *acktr, const ngtcp2_ack *fr) {
ngtcp2_acktr_ack_entry *ent;
int64_t largest_ack = fr->largest_ack, min_ack;
size_t i, j;
ngtcp2_ringbuf *rb = &acktr->acks;
size_t nacks = ngtcp2_ringbuf_len(rb);
/* Assume that ngtcp2_pkt_validate_ack(fr) returns 0 */
for (j = 0; j < nacks; ++j) {
ent = ngtcp2_ringbuf_get(rb, j);
if (largest_ack >= ent->pkt_num) {
break;
}
}
if (j == nacks) {
return;
}
min_ack = largest_ack - (int64_t)fr->first_ack_blklen;
if (min_ack <= ent->pkt_num && ent->pkt_num <= largest_ack) {
acktr_on_ack(acktr, rb, j);
return;
}
for (i = 0; i < fr->num_blks && j < nacks; ++i) {
largest_ack = min_ack - (int64_t)fr->blks[i].gap - 2;
min_ack = largest_ack - (int64_t)fr->blks[i].blklen;
for (;;) {
if (ent->pkt_num > largest_ack) {
++j;
if (j == nacks) {
return;
}
ent = ngtcp2_ringbuf_get(rb, j);
continue;
}
if (ent->pkt_num < min_ack) {
break;
}
acktr_on_ack(acktr, rb, j);
return;
}
}
return;
}
void ngtcp2_acktr_commit_ack(ngtcp2_acktr *acktr) {
acktr->flags &= (uint16_t) ~(NGTCP2_ACKTR_FLAG_ACTIVE_ACK |
NGTCP2_ACKTR_FLAG_IMMEDIATE_ACK |
NGTCP2_ACKTR_FLAG_CANCEL_TIMER);
acktr->first_unacked_ts = UINT64_MAX;
acktr->rx_npkt = 0;
}
int ngtcp2_acktr_require_active_ack(ngtcp2_acktr *acktr,
ngtcp2_duration max_ack_delay,
ngtcp2_tstamp ts) {
return acktr->first_unacked_ts <= ts - max_ack_delay;
}
void ngtcp2_acktr_immediate_ack(ngtcp2_acktr *acktr) {
acktr->flags |= NGTCP2_ACKTR_FLAG_IMMEDIATE_ACK;
}
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