Core: error logging rate limiting. With this change, error logging to files can be rate-limited with the "rate=" parameter. The parameter specifies allowed log messages rate to a particular file (per worker), in messages per second (m/s). By default, "rate=1000m/s" is used. Rate limiting is implemented using the "leaky bucket" method, similarly to the limit_req module. Maximum burst size is set to the number of log messages per second for each severity level, so "error" messages are logged even if the rate limit is hit by "info" messages (but not vice versa). When the limit is reached for a particular level, the "too many log messages, limiting" message is logged at this level. If debug logging is enabled, either for the particular log file or for the particular connection, rate limiting is not used.

/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>


int
ngx_nonblocking(ngx_socket_t s)
{
    unsigned long  nb = 1;

    return ioctlsocket(s, FIONBIO, &nb);
}


int
ngx_blocking(ngx_socket_t s)
{
    unsigned long  nb = 0;

    return ioctlsocket(s, FIONBIO, &nb);
}


int
ngx_socket_nread(ngx_socket_t s, int *n)
{
    unsigned long  nread;

    if (ioctlsocket(s, FIONREAD, &nread) == -1) {
        return -1;
    }

    *n = nread;

    return 0;
}


int
ngx_tcp_push(ngx_socket_t s)
{
    return 0;
}