Optional Hook Functions

Defines
#define	APR_OPTIONAL_HOOK(ns, name, pfn, aszPre, aszSucc, nOrder)
#define	APR_IMPLEMENT_OPTIONAL_HOOK_RUN_ALL(ns, link, ret, name, args_decl, args_use, ok, decline)
Functions
void	apr_optional_hook_add (const char *szName, void(*pfn)(void), const char *const *aszPre, const char *const *aszSucc, int nOrder)
apr_array_header_t *	apr_optional_hook_get (const char *szName)

---

Define Documentation

#define APR_IMPLEMENT_OPTIONAL_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; \
    apr_array_header_t *pHookArray=apr_optional_hook_get(#name); \
\
    if(!pHookArray) \
        return ok; \
\
    pHook=(ns##_LINK_##name##_t *)pHookArray->elts; \
    for(n=0 ; n < pHookArray->nelts ; ++n) \
        { \
        rv=(pHook[n].pFunc)args_use; \
\
        if(rv != ok && rv != decline) \
            return rv; \
        } \
    return ok; \
    }

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

Parameters:

ns	The namespace prefix of the hook functions
link	The linkage declaration prefix of the hook
ret	The type of the return value of the hook
ret	The type of the return value of the hook
name	The name of the hook
args_decl	The declaration of the arguments for the hook
args_use	The names for the arguments for the hook
ok	Success value
decline	Decline value

#define APR_OPTIONAL_HOOK	(		ns,
			name,
			pfn,
			aszPre,
			aszSucc,
			nOrder
	)

Value:

do { \
  ns##_HOOK_##name##_t *apu__hook = pfn; \
  apr_optional_hook_add(#name,(void (*)(void))apu__hook,aszPre, aszSucc, nOrder); \
} while (0)

Hook to an optional hook.

Parameters:

ns	The namespace prefix of the hook functions
name	The name of the hook
pfn	A pointer to a function that will be called
aszPre	a NULL-terminated array of strings that name modules whose hooks should precede this one
aszSucc	a NULL-terminated array of strings that name modules whose hooks should succeed this one
nOrder	an integer determining order before honouring aszPre and aszSucc (for example HOOK_MIDDLE)

---

Function Documentation

void apr_optional_hook_add	(	const char *	szName,
		void(*)(void)	pfn,
		const char *const *	aszPre,
		const char *const *	aszSucc,
		int	nOrder
	)

Function to implemnt the APR_OPTIONAL_HOOK Macro