Apache Portable Runtime Utility Library
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
Modules | Macros | Functions | Variables
Hook Functions
APR Utility Functions

Modules

 Hook probe capability
 Optional Hook Functions

Macros

#define APR_IMPLEMENT_HOOK_GET_PROTO(ns, link, name)   link##_DECLARE(apr_array_header_t *) ns##_hook_get_##name(void)
#define APR_DECLARE_EXTERNAL_HOOK(ns, link, ret, name, args)
#define APR_HOOK_STRUCT(members)   static struct { members } _hooks;
#define APR_HOOK_LINK(name)   apr_array_header_t *link_##name;
#define APR_IMPLEMENT_EXTERNAL_HOOK_BASE(ns, link, name)
#define APR_IMPLEMENT_EXTERNAL_HOOK_VOID(ns, link, name, args_decl, args_use)
#define APR_IMPLEMENT_EXTERNAL_HOOK_RUN_ALL(ns, link, ret, name, args_decl, args_use, ok, decline)
#define APR_IMPLEMENT_EXTERNAL_HOOK_RUN_FIRST(ns, link, ret, name, args_decl, args_use, decline)
#define APR_HOOK_REALLY_FIRST   (-10)
#define APR_HOOK_FIRST   0
#define APR_HOOK_MIDDLE   10
#define APR_HOOK_LAST   20
#define APR_HOOK_REALLY_LAST   30

Functions

void apr_hook_sort_register (const char *szHookName, apr_array_header_t **aHooks)
void apr_hook_sort_all (void)
void apr_hook_debug_show (const char *szName, const char *const *aszPre, const char *const *aszSucc)
void apr_hook_deregister_all (void)

Variables

apr_pool_t * apr_hook_global_pool
int apr_hook_debug_enabled
const char * apr_hook_debug_current

Detailed Description

Macro Definition Documentation

#define APR_DECLARE_EXTERNAL_HOOK (   ns,
  link,
  ret,
  name,
  args 
)
Value:
typedef ret ns##_HOOK_##name##_t args; \
link##_DECLARE(void) ns##_hook_##name(ns##_HOOK_##name##_t *pf, \
const char * const *aszPre, \
const char * const *aszSucc, int nOrder); \
link##_DECLARE(ret) ns##_run_##name args; \
APR_IMPLEMENT_HOOK_GET_PROTO(ns,link,name); \
typedef struct ns##_LINK_##name##_t \
{ \
ns##_HOOK_##name##_t *pFunc; \
const char *szName; \
const char * const *aszPredecessors; \
const char * const *aszSuccessors; \
int nOrder; \
} ns##_LINK_##name##_t;

macro to declare the hook correctly

#define APR_HOOK_FIRST   0

run this hook first

#define APR_HOOK_LAST   20

run this hook after every other hook which is defined

#define APR_HOOK_LINK (   name)    apr_array_header_t *link_##name;

macro to link the hook structure

#define APR_HOOK_MIDDLE   10

run this hook somewhere

#define APR_HOOK_REALLY_FIRST   (-10)

run this hook first, before ANYTHING

#define APR_HOOK_REALLY_LAST   30

run this hook last, after EVERYTHING

#define APR_HOOK_STRUCT (   members)    static struct { members } _hooks;

macro to declare the hook structure

#define APR_IMPLEMENT_EXTERNAL_HOOK_BASE (   ns,
  link,
  name 
)
Value:
link##_DECLARE(void) ns##_hook_##name(ns##_HOOK_##name##_t *pf,const char * const *aszPre, \
const char * const *aszSucc,int nOrder) \
{ \
ns##_LINK_##name##_t *pHook; \
if(!_hooks.link_##name) \
{ \
_hooks.link_##name=apr_array_make(apr_hook_global_pool,1,sizeof(ns##_LINK_##name##_t)); \
apr_hook_sort_register(#name,&_hooks.link_##name); \
} \
pHook=apr_array_push(_hooks.link_##name); \
pHook->pFunc=pf; \
pHook->aszPredecessors=aszPre; \
pHook->aszSuccessors=aszSucc; \
pHook->nOrder=nOrder; \
pHook->szName=apr_hook_debug_current; \
if(apr_hook_debug_enabled) \
apr_hook_debug_show(#name,aszPre,aszSucc); \
} \
APR_IMPLEMENT_HOOK_GET_PROTO(ns,link,name) \
{ \
return _hooks.link_##name; \
}

macro to implement the hook

#define APR_IMPLEMENT_EXTERNAL_HOOK_RUN_ALL (   ns,
  link,
  ret,
  name,
  args_decl,
  args_use,
  ok,
  decline 
)
Value:
link##_DECLARE(ret) ns##_run_##name args_decl \
{ \
ns##_LINK_##name##_t *pHook; \
int n; \
ret rv = ok; \
APR_HOOK_INT_DCL_UD; \
\
APR_HOOK_PROBE_ENTRY(ud, ns, name, args_use); \
\
if(_hooks.link_##name) \
{ \
pHook=(ns##_LINK_##name##_t *)_hooks.link_##name->elts; \
for(n=0 ; n < _hooks.link_##name->nelts ; ++n) \
{ \
APR_HOOK_PROBE_INVOKE(ud, ns, name, (char *)pHook[n].szName, args_use); \
rv=pHook[n].pFunc args_use; \
APR_HOOK_PROBE_COMPLETE(ud, ns, name, (char *)pHook[n].szName, rv, args_use); \
if(rv != ok && rv != decline) \
break; \
rv = ok; \
} \
} \
\
APR_HOOK_PROBE_RETURN(ud, ns, name, rv, args_use); \
\
return rv; \
}

Implement a hook that runs until one of the functions returns something other than OK or DECLINE

Parameters
nsThe namespace prefix of the hook functions
linkThe linkage declaration prefix of the hook
retType to return
nameThe name of the hook
args_declThe declaration of the arguments for the hook
args_useThe names for the arguments for the hook
okSuccess value
declineDecline value
Note
The link prefix FOO corresponds to FOO_DECLARE() macros, which provide export linkage from the module that IMPLEMENTs the hook, and import linkage from external modules that link to the hook's module.
#define APR_IMPLEMENT_EXTERNAL_HOOK_RUN_FIRST (   ns,
  link,
  ret,
  name,
  args_decl,
  args_use,
  decline 
)
Value:
link##_DECLARE(ret) ns##_run_##name args_decl \
{ \
ns##_LINK_##name##_t *pHook; \
int n; \
ret rv = decline; \
APR_HOOK_INT_DCL_UD; \
\
APR_HOOK_PROBE_ENTRY(ud, ns, name, args_use); \
\
if(_hooks.link_##name) \
{ \
pHook=(ns##_LINK_##name##_t *)_hooks.link_##name->elts; \
for(n=0 ; n < _hooks.link_##name->nelts ; ++n) \
{ \
APR_HOOK_PROBE_INVOKE(ud, ns, name, (char *)pHook[n].szName, args_use); \
rv=pHook[n].pFunc args_use; \
APR_HOOK_PROBE_COMPLETE(ud, ns, name, (char *)pHook[n].szName, rv, args_use); \
\
if(rv != decline) \
break; \
} \
} \
\
APR_HOOK_PROBE_RETURN(ud, ns, name, rv, args_use); \
\
return rv; \
}

Implement a hook that runs until the first function returns something other than the value of decline

Parameters
nsThe namespace prefix of the hook functions
linkThe linkage declaration prefix of the hook
nameThe name of the hook
retType to return
args_declThe declaration of the arguments for the hook
args_useThe names for the arguments for the hook
declineDecline value
Note
The link prefix FOO corresponds to FOO_DECLARE() macros, which provide export linkage from the module that IMPLEMENTs the hook, and import linkage from external modules that link to the hook's module.
#define APR_IMPLEMENT_EXTERNAL_HOOK_VOID (   ns,
  link,
  name,
  args_decl,
  args_use 
)
Value:
link##_DECLARE(void) ns##_run_##name args_decl \
{ \
ns##_LINK_##name##_t *pHook; \
int n; \
APR_HOOK_INT_DCL_UD; \
\
APR_HOOK_PROBE_ENTRY(ud, ns, name, args_use); \
\
if(_hooks.link_##name) \
{ \
pHook=(ns##_LINK_##name##_t *)_hooks.link_##name->elts; \
for(n=0 ; n < _hooks.link_##name->nelts ; ++n) \
{ \
APR_HOOK_PROBE_INVOKE(ud, ns, name, (char *)pHook[n].szName, args_use); \
pHook[n].pFunc args_use; \
APR_HOOK_PROBE_COMPLETE(ud, ns, name, (char *)pHook[n].szName, 0, args_use); \
} \
} \
\
APR_HOOK_PROBE_RETURN(ud, ns, name, 0, args_use); \
\
}

Implement a hook that has no return code, and therefore runs all of the registered functions

Parameters
nsThe namespace prefix of the hook functions
linkThe linkage declaration prefix of the hook
nameThe name of the hook
args_declThe declaration of the arguments for the hook
args_useThe names for the arguments for the hook
Note
The link prefix FOO corresponds to FOO_DECLARE() macros, which provide export linkage from the module that IMPLEMENTs the hook, and import linkage from external modules that link to the hook's module.
#define APR_IMPLEMENT_HOOK_GET_PROTO (   ns,
  link,
  name 
)    link##_DECLARE(apr_array_header_t *) ns##_hook_get_##name(void)

macro to return the prototype of the hook function

Function Documentation

void apr_hook_debug_show ( const char *  szName,
const char *const *  aszPre,
const char *const *  aszSucc 
)

Print all of the information about the current hook. This is used for debugging purposes.

Parameters
szNameThe name of the hook
aszPreAll of the functions in the predecessor array
aszSuccAll of the functions in the successor array
void apr_hook_deregister_all ( void  )

Remove all currently registered functions.

void apr_hook_sort_all ( void  )

Sort all of the registerd functions for a given hook

void apr_hook_sort_register ( const char *  szHookName,
apr_array_header_t **  aHooks 
)

Register a hook function to be sorted

Parameters
szHookNameThe name of the Hook the function is registered for
aHooksThe array which stores all of the functions for this hook

Variable Documentation

const char* apr_hook_debug_current

The name of the module that is currently registering a function

int apr_hook_debug_enabled

A global variable to determine if debugging information about the hooks functions should be printed

apr_pool_t* apr_hook_global_pool

The global pool used to allocate any memory needed by the hooks.