/*
 * Copyright (C) Igor Sysoev
 */


#ifndef _NGX_HTTP_VARIABLES_H_INCLUDED_
#define _NGX_HTTP_VARIABLES_H_INCLUDED_


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


typedef ngx_variable_value_t  ngx_http_variable_value_t;

#define ngx_http_variable(v)     { sizeof(v) - 1, 1, 0, 0, 0, (u_char *) v }

typedef struct ngx_http_variable_s  ngx_http_variable_t;

typedef void (*ngx_http_set_variable_pt) (ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
typedef ngx_int_t (*ngx_http_get_variable_pt) (ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);


#define NGX_HTTP_VAR_CHANGEABLE   1
#define NGX_HTTP_VAR_NOCACHEABLE  2
#define NGX_HTTP_VAR_INDEXED      4
#define NGX_HTTP_VAR_NOHASH       8


struct ngx_http_variable_s {
    ngx_str_t                     name;   /* must be first to build the hash */
    ngx_http_set_variable_pt      set_handler;
    ngx_http_get_variable_pt      get_handler;
    uintptr_t                     data;
    ngx_uint_t                    flags;
    ngx_uint_t                    index;
};


ngx_http_variable_t *ngx_http_add_variable(ngx_conf_t *cf, ngx_str_t *name,
    ngx_uint_t flags);
ngx_int_t ngx_http_get_variable_index(ngx_conf_t *cf, ngx_str_t *name);
ngx_http_variable_value_t *ngx_http_get_indexed_variable(ngx_http_request_t *r,
    ngx_uint_t index);
ngx_http_variable_value_t *ngx_http_get_flushed_variable(ngx_http_request_t *r,
    ngx_uint_t index);

ngx_http_variable_value_t *ngx_http_get_variable(ngx_http_request_t *r,
    ngx_str_t *name, ngx_uint_t key, ngx_uint_t nowarn);

ngx_int_t ngx_http_variable_unknown_header(ngx_http_variable_value_t *v,
    ngx_str_t *var, ngx_list_part_t *part, size_t prefix);


#define ngx_http_clear_variable(r, index) r->variables0[index].text.data = NULL;


ngx_int_t ngx_http_variables_add_core_vars(ngx_conf_t *cf);
ngx_int_t ngx_http_variables_init_vars(ngx_conf_t *cf);


typedef struct {
    ngx_rbtree_node_t             node;
    size_t                        len;
    ngx_http_variable_value_t    *value;
} ngx_http_variable_value_node_t;


void ngx_http_variable_value_rbtree_insert(ngx_rbtree_node_t *temp,
    ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel);
ngx_http_variable_value_t *ngx_http_variable_value_lookup(ngx_rbtree_t *rbtree,
    ngx_str_t *name, uint32_t hash);


extern ngx_http_variable_value_t  ngx_http_variable_null_value;
extern ngx_http_variable_value_t  ngx_http_variable_true_value;


#endif /* _NGX_HTTP_VARIABLES_H_INCLUDED_ */