view src/os/unix/ngx_udp_send.c @ 8824:81a3429db8b0 quic

HTTP/3: delayed Insert Count Increment instruction. Sending the instruction is delayed until the end of the current event cycle. Delaying the instruction is allowed by quic-qpack-21, section 2.2.2.3. The goal is to reduce the amount of data sent back to client by accumulating several inserts in one instruction and sometimes not sending the instruction at all, if Section Acknowledgement was sent just before it.
author Roman Arutyunyan <arut@nginx.com>
date Thu, 27 Jan 2022 12:20:47 +0300
parents 8f038068f4bc
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


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


ssize_t
ngx_udp_unix_send(ngx_connection_t *c, u_char *buf, size_t size)
{
    ssize_t       n;
    ngx_err_t     err;
    ngx_event_t  *wev;

    wev = c->write;

    for ( ;; ) {
        n = sendto(c->fd, buf, size, 0, c->sockaddr, c->socklen);

        ngx_log_debug4(NGX_LOG_DEBUG_EVENT, c->log, 0,
                       "sendto: fd:%d %z of %uz to \"%V\"",
                       c->fd, n, size, &c->addr_text);

        if (n >= 0) {
            if ((size_t) n != size) {
                wev->error = 1;
                (void) ngx_connection_error(c, 0, "sendto() incomplete");
                return NGX_ERROR;
            }

            c->sent += n;

            return n;
        }

        err = ngx_socket_errno;

        if (err == NGX_EAGAIN) {
            wev->ready = 0;
            ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, NGX_EAGAIN,
                           "sendto() not ready");
            return NGX_AGAIN;
        }

        if (err != NGX_EINTR) {
            wev->error = 1;
            (void) ngx_connection_error(c, err, "sendto() failed");
            return NGX_ERROR;
        }
    }
}