From 5e61585d76ae77fd5e9e96ebabb57afa4d74880d Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 14:06:34 +0200 Subject: Adding upstream version 3.5.24. Signed-off-by: Daniel Baumann --- src/util/msg_rate_delay.c | 138 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 138 insertions(+) create mode 100644 src/util/msg_rate_delay.c (limited to 'src/util/msg_rate_delay.c') diff --git a/src/util/msg_rate_delay.c b/src/util/msg_rate_delay.c new file mode 100644 index 0000000..e21b021 --- /dev/null +++ b/src/util/msg_rate_delay.c @@ -0,0 +1,138 @@ +/*++ +/* NAME +/* msg_rate_delay 3 +/* SUMMARY +/* diagnostic interface +/* SYNOPSIS +/* #include +/* +/* void msg_rate_delay(stamp, delay, log_fn, fmt, ...) +/* time_t *stamp; +/* int delay; +/* void (*log_fn)(const char *fmt, ...); +/* const char *fmt; +/* DESCRIPTION +/* msg_rate_delay() produces log output at a reduced rate: no +/* more than one message per 'delay' seconds. It discards log +/* output that would violate the output rate policy. +/* +/* This is typically used to log errors accessing a cache with +/* high-frequency access but low-value information, to avoid +/* spamming the logfile with the same kind of message. +/* +/* Arguments: +/* .IP stamp +/* Time stamp of last log output; specify a zero time stamp +/* on the first call. This is an input-output parameter. +/* This parameter is ignored when verbose logging is enabled +/* or when the delay value is zero. +/* .IP delay +/* The minimum time between log outputs; specify zero to log +/* all output for debugging purposes. This parameter is ignored +/* when verbose logging is enabled. +/* .IP log_fn +/* The function that produces log output. Typically, this will +/* be msg_info() or msg_warn(). +/* .IP fmt +/* Format string as used with msg(3) routines. +/* SEE ALSO +/* msg(3) diagnostics interface +/* DIAGNOSTICS +/* Fatal errors: memory allocation problem. +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* AUTHOR(S) +/* Wietse Venema +/* IBM T.J. Watson Research +/* P.O. Box 704 +/* Yorktown Heights, NY 10598, USA +/*--*/ + + +/* System library. */ + +#include +#include + +/* Utility library. */ + +#include +#include +#include + +/* SLMs. */ + +#define STR(x) vstring_str(x) + +/* msg_rate_delay - rate-limit message logging */ + +void msg_rate_delay(time_t *stamp, int delay, + void (*log_fn) (const char *,...), + const char *fmt,...) +{ + const char *myname = "msg_rate_delay"; + static time_t saved_event_time; + time_t now; + VSTRING *buf; + va_list ap; + + /* + * Sanity check. + */ + if (delay < 0) + msg_panic("%s: bad message rate delay: %d", myname, delay); + + /* + * This function may be called frequently. Avoid an unnecessary syscall + * if possible. Deal with the possibility that a program does not use the + * events(3) engine, so that event_time() always produces the same + * result. + */ + if (msg_verbose == 0 && delay > 0) { + if (saved_event_time == 0) + now = saved_event_time = event_time(); + else if ((now = event_time()) == saved_event_time) + now = time((time_t *) 0); + + /* + * Don't log if time is too early. + */ + if (*stamp + delay > now) + return; + *stamp = now; + } + + /* + * OK to log. This is a low-rate event, so we can afford some overhead. + */ + buf = vstring_alloc(100); + va_start(ap, fmt); + vstring_vsprintf(buf, fmt, ap); + va_end(ap); + log_fn("%s", STR(buf)); + vstring_free(buf); +} + +#ifdef TEST + + /* + * Proof-of-concept test program: log messages but skip messages during a + * two-second gap. + */ +#include + +int main(int argc, char **argv) +{ + int n; + time_t stamp = 0; + + for (n = 0; n < 6; n++) { + msg_rate_delay(&stamp, 2, msg_info, "text here %d", n); + sleep(1); + } + return (0); +} + +#endif -- cgit v1.2.3