1/* Copyright (c) 2017 - 2022 LiteSpeed Technologies Inc.  See LICENSE. */
2/*
3 * lsquic_rechist.h -- History of received packets.
4 *
5 * The purpose of received packet history is to generate ACK frames.
6 */
7
8#ifndef LSQUIC_RECHIST_H
9#define LSQUIC_RECHIST_H 1
10
11#ifndef LSQUIC_TEST
12#define LSQUIC_TEST 0
13#endif
14
15/* Structure is exposed to facilitate some manipulations in unit tests. */
16struct rechist_elem {
17    lsquic_packno_t     re_low;
18    unsigned            re_count;
19    unsigned            re_next;    /* UINT_MAX means no next element */
20};
21
22
23struct lsquic_rechist {
24    /* elems and masks are allocated in contiguous memory */
25    struct rechist_elem            *rh_elems;
26    uintptr_t                      *rh_masks;
27    lsquic_packno_t                 rh_cutoff;
28    lsquic_time_t                   rh_largest_acked_received;
29    unsigned                        rh_n_masks;
30    unsigned                        rh_n_alloced;
31    unsigned                        rh_n_used;
32    unsigned                        rh_head;
33    unsigned                        rh_max_ranges;
34    enum {
35        RH_CUTOFF_SET   = (1 << 0),
36    }                               rh_flags;
37    struct
38    {
39        struct lsquic_packno_range      range;
40        unsigned                        next;
41    }                               rh_iter;
42#if LSQUIC_TEST
43    unsigned                        rh_n_ops;
44#endif
45};
46
47typedef struct lsquic_rechist lsquic_rechist_t;
48
49void
50lsquic_rechist_init (struct lsquic_rechist *, int is_ietf, unsigned max_ranges);
51
52void
53lsquic_rechist_cleanup (struct lsquic_rechist *);
54
55enum received_st {
56    REC_ST_OK,
57    REC_ST_DUP,
58    REC_ST_ERR,
59};
60
61enum received_st
62lsquic_rechist_received (lsquic_rechist_t *, lsquic_packno_t,
63                         lsquic_time_t now);
64
65void
66lsquic_rechist_stop_wait (lsquic_rechist_t *, lsquic_packno_t);
67
68const struct lsquic_packno_range *
69lsquic_rechist_first (lsquic_rechist_t *);
70
71const struct lsquic_packno_range *
72lsquic_rechist_next (lsquic_rechist_t *);
73
74lsquic_packno_t
75lsquic_rechist_largest_packno (const lsquic_rechist_t *);
76
77lsquic_packno_t
78lsquic_rechist_cutoff (const lsquic_rechist_t *);
79
80lsquic_time_t
81lsquic_rechist_largest_recv (const lsquic_rechist_t *);
82
83size_t
84lsquic_rechist_mem_used (const struct lsquic_rechist *);
85
86const struct lsquic_packno_range *
87lsquic_rechist_peek (struct lsquic_rechist *);
88
89#define lsquic_rechist_is_empty(rechist_) ((rechist_)->rh_n_used == 0)
90
91int
92lsquic_rechist_copy_ranges (struct lsquic_rechist *, void *rechist_ctx,
93    const struct lsquic_packno_range * (*first) (void *),
94    const struct lsquic_packno_range * (*next) (void *));
95
96#endif
97