view src/os/win32/ngx_errno.c @ 8759:56dec0d4e5b1 quic

QUIC: avoid excessive buffer allocations in stream output. Previously, when a few bytes were send to a QUIC stream by the application, a 4K buffer was allocated for these bytes. Then a STREAM frame was created and that entire buffer was used as data for that frame. The frame with the buffer were in use up until the frame was acked by client. Meanwhile, when more bytes were send to the stream, more buffers were allocated and assigned as data to newer STREAM frames. In this scenario most buffer memory is unused. Now the unused part of the stream output buffer is available for further stream output while earlier parts of the buffer are waiting to be acked. This is achieved by splitting the output buffer.
author Roman Arutyunyan <arut@nginx.com>
date Fri, 24 Dec 2021 18:13:51 +0300
parents 746567d633ac
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


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


u_char *
ngx_strerror(ngx_err_t err, u_char *errstr, size_t size)
{
    u_int          len;
    static u_long  lang = MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US);

    if (size == 0) {
        return errstr;
    }

    len = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM,
                        NULL, err, lang, (char *) errstr, size, NULL);

    if (len == 0 && lang) {

        /*
         * Try to use English messages first and fallback to a language,
         * based on locale: non-English Windows have no English messages
         * at all.  This way allows to use English messages at least on
         * Windows with MUI.
         */

        lang = 0;

        len = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM,
                            NULL, err, lang, (char *) errstr, size, NULL);
    }

    if (len == 0) {
        return ngx_snprintf(errstr, size,
                            "FormatMessage() error:(%d)", GetLastError());
    }

    /* remove ".\r\n\0" */
    while (errstr[len] == '\0' || errstr[len] == CR
           || errstr[len] == LF || errstr[len] == '.')
    {
        --len;
    }

    return &errstr[++len];
}


ngx_int_t
ngx_strerror_init(void)
{
    return NGX_OK;
}