view src/core/ngx_array.h @ 9167:3038bd4d7816

Core: changed ngx_queue_sort() to use merge sort. This improves nginx startup times significantly when using very large number of locations due to computational complexity of the sorting algorithm being used: insertion sort is O(n*n) on average, while merge sort is O(n*log(n)). In particular, in a test configuration with 20k locations total startup time is reduced from 8 seconds to 0.9 seconds. Prodded by Yusuke Nojima, https://mailman.nginx.org/pipermail/nginx-devel/2023-September/NUL3Y2FPPFSHMPTFTL65KXSXNTX3NQMK.html
author Maxim Dounin <mdounin@mdounin.ru>
date Wed, 18 Oct 2023 04:30:11 +0300
parents 65b895cd0dfa
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_ARRAY_H_INCLUDED_
#define _NGX_ARRAY_H_INCLUDED_


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


typedef struct {
    void        *elts;
    ngx_uint_t   nelts;
    size_t       size;
    ngx_uint_t   nalloc;
    ngx_pool_t  *pool;
} ngx_array_t;


ngx_array_t *ngx_array_create(ngx_pool_t *p, ngx_uint_t n, size_t size);
void ngx_array_destroy(ngx_array_t *a);
void *ngx_array_push(ngx_array_t *a);
void *ngx_array_push_n(ngx_array_t *a, ngx_uint_t n);


static ngx_inline ngx_int_t
ngx_array_init(ngx_array_t *array, ngx_pool_t *pool, ngx_uint_t n, size_t size)
{
    /*
     * set "array->nelts" before "array->elts", otherwise MSVC thinks
     * that "array->nelts" may be used without having been initialized
     */

    array->nelts = 0;
    array->size = size;
    array->nalloc = n;
    array->pool = pool;

    array->elts = ngx_palloc(pool, n * size);
    if (array->elts == NULL) {
        return NGX_ERROR;
    }

    return NGX_OK;
}


#endif /* _NGX_ARRAY_H_INCLUDED_ */