lsquic_senhist.h revision 16a9b66a 
1/* Copyright (c) 2017 LiteSpeed Technologies Inc.  See LICENSE. */
2/*
3 * lsquic_senhist.h -- History sent packets.
4 *
5 * We need to keep track of packet numbers in order to verify ACKs.  To
6 * speed up processing, we make sure that there is never a gap in the
7 * packet number sequence we generate.
8 */
9
10#ifndef LSQUIC_SENHIST_H
11#define LSQUIC_SENHIST_H 1
12
13#ifndef LSQUIC_SENHIST_FATAL
14#   define LSQUIC_SENHIST_FATAL 0
15#endif
16
17typedef struct lsquic_senhist {
18    lsquic_packno_t             sh_last_sent;
19#if !LSQUIC_SENHIST_FATAL
20    enum {
21        SH_WARNED   = 1 << 0,   /* Warn once */
22    }                           sh_flags;
23#endif
24} lsquic_senhist_t;
25
26#define lsquic_senhist_init(hist) do {                                  \
27    (hist)->sh_last_sent = 0;                                           \
28} while (0)
29
30#define lsquic_senhist_cleanup(hist)
31
32#if LSQUIC_SENHIST_FATAL
33#define lsquic_senhist_add(hist, packno) do {                           \
34    assert((hist)->sh_last_sent == packno - 1);                         \
35    (hist)->sh_last_sent = packno;                                      \
36} while (0)
37#else
38#define lsquic_senhist_add(hist, packno) do {                           \
39    if ((hist)->sh_last_sent == packno - 1)                             \
40        (hist)->sh_last_sent = packno;                                  \
41    else                                                                \
42    {                                                                   \
43        if (!((hist)->sh_flags & SH_WARNED))                            \
44        {                                                               \
45            LSQ_WARN("send history gap %"PRIu64" - %"PRIu64,            \
46                (hist)->sh_last_sent, packno);                          \
47            (hist)->sh_flags |= SH_WARNED;                              \
48        }                                                               \
49        (hist)->sh_last_sent = packno;                                  \
50    }                                                                   \
51} while (0)
52#endif
53
54/* Returns 0 if no packets have been sent yet */
55#define lsquic_senhist_largest(hist) (+(hist)->sh_last_sent)
56
57void
58lsquic_senhist_tostr (lsquic_senhist_t *hist, char *buf, size_t bufsz);
59
60#define lsquic_senhist_mem_used(hist) (sizeof(*(hist)))
61
62#endif
63