nginx/src/http/ngx_http_cache.h
Dmitry Volyntsev b18ba1e9f6 Cache: added watermark to reduce IO load when keys_zone is full.
When a keys_zone is full then each next request to the cache is
penalized.  That is, the cache has to evict older files to get a
slot from the keys_zone synchronously.  The patch introduces new
behavior in this scenario.  Manager will try to maintain available
free slots in the keys_zone by cleaning old files in the background.
2016-03-18 15:08:21 +03:00

191 lines
6.2 KiB
C

/*
* Copyright (C) Igor Sysoev
* Copyright (C) Nginx, Inc.
*/
#ifndef _NGX_HTTP_CACHE_H_INCLUDED_
#define _NGX_HTTP_CACHE_H_INCLUDED_
#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>
#define NGX_HTTP_CACHE_MISS 1
#define NGX_HTTP_CACHE_BYPASS 2
#define NGX_HTTP_CACHE_EXPIRED 3
#define NGX_HTTP_CACHE_STALE 4
#define NGX_HTTP_CACHE_UPDATING 5
#define NGX_HTTP_CACHE_REVALIDATED 6
#define NGX_HTTP_CACHE_HIT 7
#define NGX_HTTP_CACHE_SCARCE 8
#define NGX_HTTP_CACHE_KEY_LEN 16
#define NGX_HTTP_CACHE_ETAG_LEN 42
#define NGX_HTTP_CACHE_VARY_LEN 42
#define NGX_HTTP_CACHE_VERSION 3
typedef struct {
ngx_uint_t status;
time_t valid;
} ngx_http_cache_valid_t;
typedef struct {
ngx_rbtree_node_t node;
ngx_queue_t queue;
u_char key[NGX_HTTP_CACHE_KEY_LEN
- sizeof(ngx_rbtree_key_t)];
unsigned count:20;
unsigned uses:10;
unsigned valid_msec:10;
unsigned error:10;
unsigned exists:1;
unsigned updating:1;
unsigned deleting:1;
/* 11 unused bits */
ngx_file_uniq_t uniq;
time_t expire;
time_t valid_sec;
size_t body_start;
off_t fs_size;
ngx_msec_t lock_time;
} ngx_http_file_cache_node_t;
struct ngx_http_cache_s {
ngx_file_t file;
ngx_array_t keys;
uint32_t crc32;
u_char key[NGX_HTTP_CACHE_KEY_LEN];
u_char main[NGX_HTTP_CACHE_KEY_LEN];
ngx_file_uniq_t uniq;
time_t valid_sec;
time_t last_modified;
time_t date;
ngx_str_t etag;
ngx_str_t vary;
u_char variant[NGX_HTTP_CACHE_KEY_LEN];
size_t header_start;
size_t body_start;
off_t length;
off_t fs_size;
ngx_uint_t min_uses;
ngx_uint_t error;
ngx_uint_t valid_msec;
ngx_buf_t *buf;
ngx_http_file_cache_t *file_cache;
ngx_http_file_cache_node_t *node;
#if (NGX_THREADS)
ngx_thread_task_t *thread_task;
#endif
ngx_msec_t lock_timeout;
ngx_msec_t lock_age;
ngx_msec_t lock_time;
ngx_msec_t wait_time;
ngx_event_t wait_event;
unsigned lock:1;
unsigned waiting:1;
unsigned updated:1;
unsigned updating:1;
unsigned exists:1;
unsigned temp_file:1;
unsigned reading:1;
unsigned secondary:1;
};
typedef struct {
ngx_uint_t version;
time_t valid_sec;
time_t last_modified;
time_t date;
uint32_t crc32;
u_short valid_msec;
u_short header_start;
u_short body_start;
u_char etag_len;
u_char etag[NGX_HTTP_CACHE_ETAG_LEN];
u_char vary_len;
u_char vary[NGX_HTTP_CACHE_VARY_LEN];
u_char variant[NGX_HTTP_CACHE_KEY_LEN];
} ngx_http_file_cache_header_t;
typedef struct {
ngx_rbtree_t rbtree;
ngx_rbtree_node_t sentinel;
ngx_queue_t queue;
ngx_atomic_t cold;
ngx_atomic_t loading;
off_t size;
ngx_uint_t count;
ngx_uint_t watermark;
} ngx_http_file_cache_sh_t;
struct ngx_http_file_cache_s {
ngx_http_file_cache_sh_t *sh;
ngx_slab_pool_t *shpool;
ngx_path_t *path;
ngx_path_t *temp_path;
off_t max_size;
size_t bsize;
time_t inactive;
time_t fail_time;
ngx_uint_t files;
ngx_uint_t loader_files;
ngx_msec_t last;
ngx_msec_t loader_sleep;
ngx_msec_t loader_threshold;
ngx_shm_zone_t *shm_zone;
};
ngx_int_t ngx_http_file_cache_new(ngx_http_request_t *r);
ngx_int_t ngx_http_file_cache_create(ngx_http_request_t *r);
void ngx_http_file_cache_create_key(ngx_http_request_t *r);
ngx_int_t ngx_http_file_cache_open(ngx_http_request_t *r);
ngx_int_t ngx_http_file_cache_set_header(ngx_http_request_t *r, u_char *buf);
void ngx_http_file_cache_update(ngx_http_request_t *r, ngx_temp_file_t *tf);
void ngx_http_file_cache_update_header(ngx_http_request_t *r);
ngx_int_t ngx_http_cache_send(ngx_http_request_t *);
void ngx_http_file_cache_free(ngx_http_cache_t *c, ngx_temp_file_t *tf);
time_t ngx_http_file_cache_valid(ngx_array_t *cache_valid, ngx_uint_t status);
char *ngx_http_file_cache_set_slot(ngx_conf_t *cf, ngx_command_t *cmd,
void *conf);
char *ngx_http_file_cache_valid_set_slot(ngx_conf_t *cf, ngx_command_t *cmd,
void *conf);
extern ngx_str_t ngx_http_cache_status[];
#endif /* _NGX_HTTP_CACHE_H_INCLUDED_ */