view src/http/ngx_http_cache.h @ 6412:4ba91a4c66a3

HTTP/2: implemented per request timeouts (closes #626). Previously, there were only three timeouts used globally for the whole HTTP/2 connection: 1. Idle timeout for inactivity when there are no streams in processing (the "http2_idle_timeout" directive); 2. Receive timeout for incomplete frames when there are no streams in processing (the "http2_recv_timeout" directive); 3. Send timeout when there are frames waiting in the output queue (the "send_timeout" directive on a server level). Reaching one of these timeouts leads to HTTP/2 connection close. This left a number of scenarios when a connection can get stuck without any processing and timeouts: 1. A client has sent the headers block partially so nginx starts processing a new stream but cannot continue without the rest of HEADERS and/or CONTINUATION frames; 2. When nginx waits for the request body; 3. All streams are stuck on exhausted connection or stream windows. The first idea that was rejected was to detect when the whole connection gets stuck because of these situations and set the global receive timeout. The disadvantage of such approach would be inconsistent behaviour in some typical use cases. For example, if a user never replies to the browser's question about where to save the downloaded file, the stream will be eventually closed by a timeout. On the other hand, this will not happen if there's some activity in other concurrent streams. Now almost all the request timeouts work like in HTTP/1.x connections, so the "client_header_timeout", "client_body_timeout", and "send_timeout" are respected. These timeouts close the request. The global timeouts work as before. Previously, the c->write->delayed flag was abused to avoid setting timeouts on stream events. Now, the "active" and "ready" flags are manipulated instead to control the processing of individual streams.
author Valentin Bartenev <vbart@nginx.com>
date Wed, 24 Feb 2016 15:58:07 +0300
parents d698c300b9ff
children 043914d19be8
line wrap: on
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/*
 * 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_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;

    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_ */