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Diffstat (limited to 'lib/ngtcp2_acktr.h')
| -rw-r--r-- | lib/ngtcp2_acktr.h | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/lib/ngtcp2_acktr.h b/lib/ngtcp2_acktr.h new file mode 100644 index 0000000..70a3c71 --- /dev/null +++ b/lib/ngtcp2_acktr.h @@ -0,0 +1,221 @@ +/* + * 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_def(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 */ |