mod_cache.h revision 6d14bedccc13d7a5f95fb9328eb6d1a07b58731b
/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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
#include "httpd.h"
#include "apr_date.h"
#include "apr_optional.h"
/* 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
/* cache info information */
typedef struct cache_info cache_info;
struct cache_info {
/**
* 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;
/**
* HTTP status code of the cached entity. Though not necessarily the
* status code finally issued to the request.
*/
int status;
};
/* cache handle information */
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;
};
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 *in,
apr_bucket_brigade *out);
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, apr_bucket_brigade *bb);
int (*open_entity) (cache_handle_t *h, request_rec *r,
const char *urlkey);
int (*remove_url) (cache_handle_t *h, apr_pool_t *p);
apr_status_t (*commit_entity)(cache_handle_t *h, request_rec *r);
} cache_provider;
/* 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 whether the request allows a cached object to be served as per RFC2616
* section 14.9.4 (Cache Revalidation and Reload Controls)
* @param h cache_handle_t
* @param r request_rec
* @return 0 ==> cache object may not be served, 1 ==> cache object may be served
*/
CACHE_DECLARE(int) ap_cache_check_allowed(request_rec *r);
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(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 an
* headers table that are allowed to be stored in a cache.
*/
CACHE_DECLARE(apr_table_t *)ap_cache_cacheable_headers(apr_pool_t *pool,
apr_table_t *t,
server_rec *s);
/* Create a new table consisting of those elements from an input
* headers table that are allowed to be stored in a cache.
*/
CACHE_DECLARE(apr_table_t *)ap_cache_cacheable_headers_in(request_rec *r);
/* Create a new table consisting of those elements from an output
* headers table that are allowed to be stored in a cache;
* ensure there is a content type and capture any errors.
*/
CACHE_DECLARE(apr_table_t *)ap_cache_cacheable_headers_out(request_rec *r);
/* hooks */
APR_DECLARE_OPTIONAL_FN(apr_status_t,
ap_cache_generate_key,
(request_rec *r, apr_pool_t*p, const char **key));
#endif /*MOD_CACHE_H*/
/** @} */