nginx 1.3.10 *) Change: domain names specified in configuration file are now resolved to IPv6 addresses as well as IPv4 ones. *) Change: now if the "include" directive with mask is used on Unix systems, included files are sorted in alphabetical order. *) Change: the "add_header" directive adds headers to 201 responses. *) Feature: the "geo" directive now supports IPv6 addresses in CIDR notation. *) Feature: the "flush" and "gzip" parameters of the "access_log" directive. *) Feature: variables support in the "auth_basic" directive. *) Bugfix: nginx could not be built with the ngx_http_perl_module in some cases. *) Bugfix: a segmentation fault might occur in a worker process if the ngx_http_xslt_module was used. *) Bugfix: nginx could not be built on MacOSX in some cases. Thanks to Piotr Sikora. *) Bugfix: the "limit_rate" directive with high rates might result in truncated responses on 32-bit platforms. Thanks to Alexey Antropov. *) Bugfix: a segmentation fault might occur in a worker process if the "if" directive was used. Thanks to Piotr Sikora. *) Bugfix: a "100 Continue" response was issued with "413 Request Entity Too Large" responses. *) Bugfix: the "image_filter", "image_filter_jpeg_quality" and "image_filter_sharpen" directives might be inherited incorrectly. Thanks to Ian Babrou. *) Bugfix: "crypt_r() failed" errors might appear if the "auth_basic" directive was used on Linux. *) Bugfix: in backup servers handling. Thanks to Thomas Chen. *) Bugfix: proxied HEAD requests might return incorrect response if the "gzip" directive was used.

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


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


/*
 * find the middle queue element if the queue has odd number of elements
 * or the first element of the queue's second part otherwise
 */

ngx_queue_t *
ngx_queue_middle(ngx_queue_t *queue)
{
    ngx_queue_t  *middle, *next;

    middle = ngx_queue_head(queue);

    if (middle == ngx_queue_last(queue)) {
        return middle;
    }

    next = ngx_queue_head(queue);

    for ( ;; ) {
        middle = ngx_queue_next(middle);

        next = ngx_queue_next(next);

        if (next == ngx_queue_last(queue)) {
            return middle;
        }

        next = ngx_queue_next(next);

        if (next == ngx_queue_last(queue)) {
            return middle;
        }
    }
}


/* the stable insertion sort */

void
ngx_queue_sort(ngx_queue_t *queue,
    ngx_int_t (*cmp)(const ngx_queue_t *, const ngx_queue_t *))
{
    ngx_queue_t  *q, *prev, *next;

    q = ngx_queue_head(queue);

    if (q == ngx_queue_last(queue)) {
        return;
    }

    for (q = ngx_queue_next(q); q != ngx_queue_sentinel(queue); q = next) {

        prev = ngx_queue_prev(q);
        next = ngx_queue_next(q);

        ngx_queue_remove(q);

        do {
            if (cmp(prev, q) <= 0) {
                break;
            }

            prev = ngx_queue_prev(prev);

        } while (prev != ngx_queue_sentinel(queue));

        ngx_queue_insert_after(prev, q);
    }
}