view src/core/ngx_hash.h @ 9225:1c9264603adc

Syslog: introduced ngx_syslog_send() error logging moderation. Errors when logging to syslog are now logged at most once per second. This ensures that persistent errors won't flood other logs, and spontaneous errors, such as ENOBUFS as observed on BSD systems when syslogd cannot cope with load, or EAGAIN as seen in similar situation on Linux, won't further overload logging subsystem, leading to more errors. Further, errors now can only trigger reconnects at most once per second. This ensures that persistent errors, which cannot be fixed with reconnects, don't trigger too much unneeded work. Additionally, in case of connection errors, such as when syslogd is not running, connection attempts are only made once per second.
author Maxim Dounin <mdounin@mdounin.ru>
date Fri, 01 Mar 2024 05:42:12 +0300
parents f8f6b9fee66a
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_HASH_H_INCLUDED_
#define _NGX_HASH_H_INCLUDED_


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


typedef struct {
    void             *value;
    u_short           len;
    u_char            name[1];
} ngx_hash_elt_t;


typedef struct {
    ngx_hash_elt_t  **buckets;
    ngx_uint_t        size;
} ngx_hash_t;


typedef struct {
    ngx_hash_t        hash;
    void             *value;
} ngx_hash_wildcard_t;


typedef struct {
    ngx_str_t         key;
    ngx_uint_t        key_hash;
    void             *value;
} ngx_hash_key_t;


typedef ngx_uint_t (*ngx_hash_key_pt) (u_char *data, size_t len);


typedef struct {
    ngx_hash_t            hash;
    ngx_hash_wildcard_t  *wc_head;
    ngx_hash_wildcard_t  *wc_tail;
} ngx_hash_combined_t;


typedef struct {
    ngx_hash_t       *hash;
    ngx_hash_key_pt   key;

    ngx_uint_t        max_size;
    ngx_uint_t        bucket_size;

    char             *name;
    ngx_pool_t       *pool;
    ngx_pool_t       *temp_pool;
} ngx_hash_init_t;


#define NGX_HASH_SMALL            1
#define NGX_HASH_LARGE            2

#define NGX_HASH_LARGE_ASIZE      16384
#define NGX_HASH_LARGE_HSIZE      10007

#define NGX_HASH_WILDCARD_KEY     1
#define NGX_HASH_READONLY_KEY     2


typedef struct {
    ngx_uint_t        hsize;

    ngx_pool_t       *pool;
    ngx_pool_t       *temp_pool;

    ngx_array_t       keys;
    ngx_array_t      *keys_hash;

    ngx_array_t       dns_wc_head;
    ngx_array_t      *dns_wc_head_hash;

    ngx_array_t       dns_wc_tail;
    ngx_array_t      *dns_wc_tail_hash;
} ngx_hash_keys_arrays_t;


typedef struct ngx_table_elt_s  ngx_table_elt_t;

struct ngx_table_elt_s {
    ngx_uint_t        hash;
    ngx_str_t         key;
    ngx_str_t         value;
    u_char           *lowcase_key;
    ngx_table_elt_t  *next;
};


void *ngx_hash_find(ngx_hash_t *hash, ngx_uint_t key, u_char *name, size_t len);
void *ngx_hash_find_wc_head(ngx_hash_wildcard_t *hwc, u_char *name, size_t len);
void *ngx_hash_find_wc_tail(ngx_hash_wildcard_t *hwc, u_char *name, size_t len);
void *ngx_hash_find_combined(ngx_hash_combined_t *hash, ngx_uint_t key,
    u_char *name, size_t len);

ngx_int_t ngx_hash_init(ngx_hash_init_t *hinit, ngx_hash_key_t *names,
    ngx_uint_t nelts);
ngx_int_t ngx_hash_wildcard_init(ngx_hash_init_t *hinit, ngx_hash_key_t *names,
    ngx_uint_t nelts);

#define ngx_hash(key, c)   ((ngx_uint_t) key * 31 + c)
ngx_uint_t ngx_hash_key(u_char *data, size_t len);
ngx_uint_t ngx_hash_key_lc(u_char *data, size_t len);
ngx_uint_t ngx_hash_strlow(u_char *dst, u_char *src, size_t n);


ngx_int_t ngx_hash_keys_array_init(ngx_hash_keys_arrays_t *ha, ngx_uint_t type);
ngx_int_t ngx_hash_add_key(ngx_hash_keys_arrays_t *ha, ngx_str_t *key,
    void *value, ngx_uint_t flags);


#endif /* _NGX_HASH_H_INCLUDED_ */