mod_cache.h revision 3d81f57512275ca06a60a9bcbd23c1f8b429fdf2
/* Copyright 2000-2006 The Apache Software Foundation or its licensors, as
* applicable.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @file mod_cache.h
* @brief Main include file for the Apache Transparent Cache
*
* @defgroup MOD_CACHE mod_cache
* @ingroup APACHE_MODS
* @{
*/
#ifndef MOD_CACHE_H
#define MOD_CACHE_H
#define CORE_PRIVATE
#include "apr_hooks.h"
#include "apr.h"
#include "apr_lib.h"
#include "apr_strings.h"
#include "apr_buckets.h"
#include "apr_md5.h"
#include "apr_pools.h"
#include "apr_strings.h"
#include "apr_optional.h"
#define APR_WANT_STRFUNC
#include "apr_want.h"
#include "httpd.h"
#include "http_config.h"
#include "ap_config.h"
#include "http_core.h"
#include "http_protocol.h"
#include "http_request.h"
#include "http_vhost.h"
#include "http_main.h"
#include "http_log.h"
#include "http_connection.h"
#include "util_filter.h"
#include "apr_date.h"
#include "apr_uri.h"
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#include "apr_atomic.h"
#ifndef MAX
#define MAX(a,b) ((a) > (b) ? (a) : (b))
#endif
#ifndef MIN
#define MIN(a,b) ((a) < (b) ? (a) : (b))
#endif
#define MSEC_ONE_DAY ((apr_time_t)(86400*APR_USEC_PER_SEC)) /* one day, in microseconds */
#define MSEC_ONE_HR ((apr_time_t)(3600*APR_USEC_PER_SEC)) /* one hour, in microseconds */
#define MSEC_ONE_MIN ((apr_time_t)(60*APR_USEC_PER_SEC)) /* one minute, in microseconds */
#define MSEC_ONE_SEC ((apr_time_t)(APR_USEC_PER_SEC)) /* one second, in microseconds */
#define DEFAULT_CACHE_MAXEXPIRE MSEC_ONE_DAY
#define DEFAULT_CACHE_MINEXPIRE 0
#define DEFAULT_CACHE_EXPIRE MSEC_ONE_HR
#define DEFAULT_CACHE_LMFACTOR (0.1)
/* Create a set of PROXY_DECLARE(type), PROXY_DECLARE_NONSTD(type) and
* PROXY_DECLARE_DATA with appropriate export and import tags for the platform
*/
#if !defined(WIN32)
#define CACHE_DECLARE(type) type
#define CACHE_DECLARE_NONSTD(type) type
#define CACHE_DECLARE_DATA
#elif defined(CACHE_DECLARE_STATIC)
#define CACHE_DECLARE(type) type __stdcall
#define CACHE_DECLARE_NONSTD(type) type
#define CACHE_DECLARE_DATA
#elif defined(CACHE_DECLARE_EXPORT)
#define CACHE_DECLARE(type) __declspec(dllexport) type __stdcall
#define CACHE_DECLARE_NONSTD(type) __declspec(dllexport) type
#define CACHE_DECLARE_DATA __declspec(dllexport)
#else
#define CACHE_DECLARE(type) __declspec(dllimport) type __stdcall
#define CACHE_DECLARE_NONSTD(type) __declspec(dllimport) type
#define CACHE_DECLARE_DATA __declspec(dllimport)
#endif
struct cache_enable {
apr_uri_t url;
const char *type;
apr_size_t pathlen;
};
struct cache_disable {
apr_uri_t url;
apr_size_t pathlen;
};
/* static information about the local cache */
typedef struct {
apr_array_header_t *cacheenable; /* URLs to cache */
apr_array_header_t *cachedisable; /* URLs not to cache */
/* Maximum time to keep cached files in msecs */
apr_time_t maxex;
int maxex_set;
/* default time to keep cached file in msecs */
apr_time_t defex;
int defex_set;
/* factor for estimating expires date */
double factor;
int factor_set;
/** ignore the last-modified header when deciding to cache this request */
int no_last_mod_ignore_set;
int no_last_mod_ignore;
/** ignore client's requests for uncached responses */
int ignorecachecontrol;
int ignorecachecontrol_set;
/** ignore Cache-Control: private header from server */
int store_private;
int store_private_set;
/** ignore Cache-Control: no-store header from client or server */
int store_nostore;
int store_nostore_set;
/** store the headers that should not be stored in the cache */
apr_array_header_t *ignore_headers;
/* flag if CacheIgnoreHeader has been set */
#define CACHE_IGNORE_HEADERS_SET 1
#define CACHE_IGNORE_HEADERS_UNSET 0
int ignore_headers_set;
/* Minimum time to keep cached files in msecs */
apr_time_t minex;
int minex_set;
} cache_server_conf;
/* cache info information */
typedef struct cache_info cache_info;
struct cache_info {
/**
* HTTP status code of the cached entity. Though not neccessarily the
* status code finally issued to the request.
*/
int status;
/**
* the original time corresponding to the 'Date:' header of the request
* served
*/
apr_time_t date;
/** a time when the cached entity is due to expire */
apr_time_t expire;
/** r->request_time from the same request */
apr_time_t request_time;
/** apr_time_now() at the time the entity was acutally cached */
apr_time_t response_time;
};
/* cache handle information */
/* XXX TODO On the next structure change/MMN bump,
* count must become an apr_off_t, representing
* the potential size of disk cached objects.
* Then dig for
* "XXX Bad Temporary Cast - see cache_object_t notes"
*/
typedef struct cache_object cache_object_t;
struct cache_object {
const char *key;
cache_object_t *next;
cache_info info;
/* Opaque portion (specific to the implementation) of the cache object */
void *vobj;
/* FIXME: These are only required for mod_mem_cache. */
apr_size_t count; /* Number of body bytes written to the cache so far */
int complete;
apr_uint32_t refcount; /* refcount and bit flag to cleanup object */
};
typedef struct cache_handle cache_handle_t;
struct cache_handle {
cache_object_t *cache_obj;
apr_table_t *req_hdrs; /* cached request headers */
apr_table_t *resp_hdrs; /* cached response headers */
};
#define CACHE_PROVIDER_GROUP "cache"
typedef struct {
int (*remove_entity) (cache_handle_t *h);
apr_status_t (*store_headers)(cache_handle_t *h, request_rec *r, cache_info *i);
apr_status_t (*store_body)(cache_handle_t *h, request_rec *r, apr_bucket_brigade *b);
apr_status_t (*recall_headers) (cache_handle_t *h, request_rec *r);
apr_status_t (*recall_body) (cache_handle_t *h, apr_pool_t *p, apr_bucket_brigade *bb);
int (*create_entity) (cache_handle_t *h, request_rec *r,
const char *urlkey, apr_off_t len);
int (*open_entity) (cache_handle_t *h, request_rec *r,
const char *urlkey);
int (*remove_url) (cache_handle_t *h, apr_pool_t *p);
} cache_provider;
/* A linked-list of authn providers. */
typedef struct cache_provider_list cache_provider_list;
struct cache_provider_list {
const char *provider_name;
const cache_provider *provider;
cache_provider_list *next;
};
/* per request cache information */
typedef struct {
cache_provider_list *providers; /* possible cache providers */
const cache_provider *provider; /* current cache provider */
const char *provider_name; /* current cache provider name */
int fresh; /* is the entitey fresh? */
cache_handle_t *handle; /* current cache handle */
cache_handle_t *stale_handle; /* stale cache handle */
apr_table_t *stale_headers; /* original request headers. */
int in_checked; /* CACHE_SAVE must cache the entity */
int block_response; /* CACHE_SAVE must block response. */
apr_bucket_brigade *saved_brigade; /* copy of partial response */
apr_off_t saved_size; /* length of saved_brigade */
apr_time_t exp; /* expiration */
apr_time_t lastmod; /* last-modified time */
cache_info *info; /* current cache info */
ap_filter_t *remove_url_filter; /* Enable us to remove the filter */
} cache_request_rec;
/* cache_util.c */
/* do a HTTP/1.1 age calculation */
CACHE_DECLARE(apr_time_t) ap_cache_current_age(cache_info *info, const apr_time_t age_value,
apr_time_t now);
/**
* Check the freshness of the cache object per RFC2616 section 13.2 (Expiration Model)
* @param h cache_handle_t
* @param r request_rec
* @return 0 ==> cache object is stale, 1 ==> cache object is fresh
*/
CACHE_DECLARE(int) ap_cache_check_freshness(cache_handle_t *h, request_rec *r);
/**
* Merge in cached headers into the response
* @param h cache_handle_t
* @param r request_rec
* @param preserve_orig If 1, the values in r->headers_out are preserved.
* Otherwise, they are overwritten by the cached value.
*/
CACHE_DECLARE(void) ap_cache_accept_headers(cache_handle_t *h, request_rec *r,
int preserve_orig);
CACHE_DECLARE(apr_time_t) ap_cache_hex2usec(const char *x);
CACHE_DECLARE(void) ap_cache_usec2hex(apr_time_t j, char *y);
CACHE_DECLARE(char *) ap_cache_generate_name(apr_pool_t *p, int dirlevels,
int dirlength,
const char *name);
CACHE_DECLARE(cache_provider_list *)ap_cache_get_providers(request_rec *r, cache_server_conf *conf, apr_uri_t uri);
CACHE_DECLARE(int) ap_cache_liststr(apr_pool_t *p, const char *list,
const char *key, char **val);
CACHE_DECLARE(const char *)ap_cache_tokstr(apr_pool_t *p, const char *list, const char **str);
/* Create a new table consisting of those elements from a request_rec's
* headers_out that are allowed to be stored in a cache
*/
CACHE_DECLARE(apr_table_t *)ap_cache_cacheable_hdrs_out(apr_pool_t *pool,
apr_table_t *t,
server_rec *s);
/**
* cache_storage.c
*/
int cache_remove_url(cache_request_rec *cache, apr_pool_t *p);
int cache_create_entity(request_rec *r, apr_off_t size);
int cache_select(request_rec *r);
apr_status_t cache_generate_key_default( request_rec *r, apr_pool_t*p, char**key );
/**
* create a key for the cache based on the request record
* this is the 'default' version, which can be overridden by a default function
*/
const char* cache_create_key( request_rec*r );
/*
apr_status_t cache_store_entity_headers(cache_handle_t *h, request_rec *r, cache_info *info);
apr_status_t cache_store_entity_body(cache_handle_t *h, request_rec *r, apr_bucket_brigade *bb);
apr_status_t cache_recall_entity_headers(cache_handle_t *h, request_rec *r);
apr_status_t cache_recall_entity_body(cache_handle_t *h, apr_pool_t *p, apr_bucket_brigade *bb);
*/
/* hooks */
/* Create a set of CACHE_DECLARE(type), CACHE_DECLARE_NONSTD(type) and
* CACHE_DECLARE_DATA with appropriate export and import tags for the platform
*/
#if !defined(WIN32)
#define CACHE_DECLARE(type) type
#define CACHE_DECLARE_NONSTD(type) type
#define CACHE_DECLARE_DATA
#elif defined(CACHE_DECLARE_STATIC)
#define CACHE_DECLARE(type) type __stdcall
#define CACHE_DECLARE_NONSTD(type) type
#define CACHE_DECLARE_DATA
#elif defined(CACHE_DECLARE_EXPORT)
#define CACHE_DECLARE(type) __declspec(dllexport) type __stdcall
#define CACHE_DECLARE_NONSTD(type) __declspec(dllexport) type
#define CACHE_DECLARE_DATA __declspec(dllexport)
#else
#define CACHE_DECLARE(type) __declspec(dllimport) type __stdcall
#define CACHE_DECLARE_NONSTD(type) __declspec(dllimport) type
#define CACHE_DECLARE_DATA __declspec(dllimport)
#endif
APR_DECLARE_OPTIONAL_FN(apr_status_t,
ap_cache_generate_key,
(request_rec *r, apr_pool_t*p, char**key ));
#endif /*MOD_CACHE_H*/
/** @} */