summaryrefslogtreecommitdiffstats
path: root/include/ap_hooks.h
blob: 43d38e7da7f043a1975cc86400dd858fb604e12c (plain)
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
/* 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 ap_hooks.h
 * @brief ap hook functions and macros
 */

#ifndef AP_HOOKS_H
#define AP_HOOKS_H

/* Although this file doesn't declare any hooks, declare the hook group here */
/**
 * @defgroup hooks Apache Hooks
 * @ingroup  APACHE_CORE
 */

#if defined(AP_HOOK_PROBES_ENABLED) && !defined(APR_HOOK_PROBES_ENABLED)
#define APR_HOOK_PROBES_ENABLED 1
#endif

#ifdef APR_HOOK_PROBES_ENABLED
#include "ap_hook_probes.h"
#endif

#include "apr.h"
#include "apr_hooks.h"
#include "apr_optional_hooks.h"

#ifdef DOXYGEN
/* define these just so doxygen documents them */

/**
 * AP_DECLARE_STATIC is defined when including Apache's Core headers,
 * to provide static linkage when the dynamic library may be unavailable.
 *
 * @see AP_DECLARE_EXPORT
 *
 * AP_DECLARE_STATIC and AP_DECLARE_EXPORT are left undefined when
 * including Apache's Core headers, to import and link the symbols from the
 * dynamic Apache Core library and assure appropriate indirection and calling
 * conventions at compile time.
 */
# define AP_DECLARE_STATIC
/**
 * AP_DECLARE_EXPORT is defined when building the Apache Core dynamic
 * library, so that all public symbols are exported.
 *
 * @see AP_DECLARE_STATIC
 */
# define AP_DECLARE_EXPORT

#endif /* def DOXYGEN */

/**
 * Declare a hook function
 * @param ret The return type of the hook
 * @param name The hook's name (as a literal)
 * @param args The arguments the hook function takes, in brackets.
 */
#define AP_DECLARE_HOOK(ret,name,args) \
        APR_DECLARE_EXTERNAL_HOOK(ap,AP,ret,name,args)

/** @internal */
#define AP_IMPLEMENT_HOOK_BASE(name) \
        APR_IMPLEMENT_EXTERNAL_HOOK_BASE(ap,AP,name)

/**
 * Implement an Apache core hook that has no return code, and
 * therefore runs all of the registered functions. The implementation
 * is called ap_run_<i>name</i>.
 *
 * @param name The name of the hook
 * @param args_decl The declaration of the arguments for the hook, for example
 * "(int x,void *y)"
 * @param args_use The arguments for the hook as used in a call, for example
 * "(x,y)"
 * @note If IMPLEMENTing a hook that is not linked into the Apache core,
 * (e.g. within a dso) see APR_IMPLEMENT_EXTERNAL_HOOK_VOID.
 */
#define AP_IMPLEMENT_HOOK_VOID(name,args_decl,args_use) \
        APR_IMPLEMENT_EXTERNAL_HOOK_VOID(ap,AP,name,args_decl,args_use)

/**
 * Implement an Apache core hook that runs until one of the functions
 * returns something other than ok or decline. That return value is
 * then returned from the hook runner. If the hooks run to completion,
 * then ok is returned. Note that if no hook runs it would probably be
 * more correct to return decline, but this currently does not do
 * so. The implementation is called ap_run_<i>name</i>.
 *
 * @param ret The return type of the hook (and the hook runner)
 * @param name The name of the hook
 * @param args_decl The declaration of the arguments for the hook, for example
 * "(int x,void *y)"
 * @param args_use The arguments for the hook as used in a call, for example
 * "(x,y)"
 * @param ok The "ok" return value
 * @param decline The "decline" return value
 * @return ok, decline or an error.
 * @note If IMPLEMENTing a hook that is not linked into the Apache core,
 * (e.g. within a dso) see APR_IMPLEMENT_EXTERNAL_HOOK_RUN_ALL.
 */
#define AP_IMPLEMENT_HOOK_RUN_ALL(ret,name,args_decl,args_use,ok,decline) \
        APR_IMPLEMENT_EXTERNAL_HOOK_RUN_ALL(ap,AP,ret,name,args_decl, \
                                            args_use,ok,decline)

/**
 * Implement a hook that runs until a function returns something other than
 * decline. If all functions return decline, the hook runner returns decline.
 * The implementation is called ap_run_<i>name</i>.
 *
 * @param ret The return type of the hook (and the hook runner)
 * @param name The name of the hook
 * @param args_decl The declaration of the arguments for the hook, for example
 * "(int x,void *y)"
 * @param args_use The arguments for the hook as used in a call, for example
 * "(x,y)"
 * @param decline The "decline" return value
 * @return decline or an error.
 * @note If IMPLEMENTing a hook that is not linked into the Apache core
 * (e.g. within a dso) see APR_IMPLEMENT_EXTERNAL_HOOK_RUN_FIRST.
 */
#define AP_IMPLEMENT_HOOK_RUN_FIRST(ret,name,args_decl,args_use,decline) \
        APR_IMPLEMENT_EXTERNAL_HOOK_RUN_FIRST(ap,AP,ret,name,args_decl, \
                                              args_use,decline)

/* Note that the other optional hook implementations are straightforward but
 * have not yet been needed
 */

/**
 * Implement an optional hook. This is exactly the same as a standard hook
 * implementation, except the hook is optional.
 * @see AP_IMPLEMENT_HOOK_RUN_ALL
 */
#define AP_IMPLEMENT_OPTIONAL_HOOK_RUN_ALL(ret,name,args_decl,args_use,ok, \
                                           decline) \
        APR_IMPLEMENT_OPTIONAL_HOOK_RUN_ALL(ap,AP,ret,name,args_decl, \
                                            args_use,ok,decline)

/**
 * Hook an optional hook. Unlike static hooks, this uses a macro instead of a
 * function.
 */
#define AP_OPTIONAL_HOOK(name,fn,pre,succ,order) \
        APR_OPTIONAL_HOOK(ap,name,fn,pre,succ,order)

#endif /* AP_HOOKS_H */