1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
|
/* 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"
#include "apr_hooks.h"
#include "cache_common.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 actually 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;
/* cached cache-control */
cache_control_t control;
};
/* 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, request_rec *r);
apr_status_t (*commit_entity)(cache_handle_t *h, request_rec *r);
apr_status_t (*invalidate_entity)(cache_handle_t *h, request_rec *r);
} cache_provider;
typedef enum {
AP_CACHE_HIT,
AP_CACHE_REVALIDATE,
AP_CACHE_MISS,
AP_CACHE_INVALIDATE
} ap_cache_status_e;
#define AP_CACHE_HIT_ENV "cache-hit"
#define AP_CACHE_REVALIDATE_ENV "cache-revalidate"
#define AP_CACHE_MISS_ENV "cache-miss"
#define AP_CACHE_INVALIDATE_ENV "cache-invalidate"
#define AP_CACHE_STATUS_ENV "cache-status"
/* 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);
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(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);
/**
* Parse the Cache-Control and Pragma headers in one go, marking
* which tokens appear within the header. Populate the structure
* passed in.
*/
int ap_cache_control(request_rec *r, cache_control_t *cc, const char *cc_header,
const char *pragma_header, apr_table_t *headers);
/* hooks */
/**
* Cache status hook.
* This hook is called as soon as the cache has made a decision as to whether
* an entity should be served from cache (hit), should be served from cache
* after a successful validation (revalidate), or served from the backend
* and potentially cached (miss).
*
* A basic implementation of this hook exists in mod_cache which writes this
* information to the subprocess environment, and optionally to request
* headers. Further implementations may add hooks as appropriate to perform
* more advanced processing, or to store statistics about the cache behaviour.
*/
APR_DECLARE_EXTERNAL_HOOK(cache, CACHE, int, cache_status, (cache_handle_t *h,
request_rec *r, apr_table_t *headers, ap_cache_status_e status,
const char *reason))
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*/
/** @} */
|
