ap_hooks.h revision 11e076839c8d5a82d55e710194d0daac51390dbd
/* 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 */