/**
* This handler deals with recycling shadow objects.
* Since shadow objects are so easily recyclable,
* we are going to call reload_object() on them,
* and keep them here until they're reused.
* <p>
* ob = clone_object("/std/shadows/object/identity_hold");<br>
* should become...<br>
* ob = SHADOW_H->get_shadow("/std/shadows/object/identity_hold");
* @author Sandoz, 02 Sept. 2002.
* @see shadow()
* @see query_shadowing()
* @see recycle_shadow()
* @see get_shadow()
* @see delete_shadows()
* @changed Changed recycle_shadow() to return 1 on success and
* optimized a few other things - Sandoz 26 Sept. 2002.
*/
class shadow_data {
object *obs;
int hits;
int misses;
}
private mapping shadows = ([ ]);
/**
* This method recycles the shadow object that calls this.
* It puts it in the recycled list, where it can be taken
* from again when needed.
* @param ob the shadow object to recycle
* @return 1 upon success, 0 upon failure
* @see shadow()
* @see query_shadowing()
* @see get_shadow()
* @see delete_shadows()
* @see query_hits()
*/
int recycle_shadow( object ob ) {
class shadow_data data;
if( query_shadowing(ob) && !ENV(ob) &&
classp( data = shadows[base_name(ob)] ) &&
sizeof( data->obs ) < data->misses ) {
reload_object(ob);
data->obs += ({ ob });
return 1;
}
return 0;
} /* recycle_shadow() */
/**
* This method clones a shadow, or gets a recycled shadow
* from the handler if there are any available.
* @param str the filename of the shadow to get
* @return the shadow object
* @see shadow()
* @see query_shadowing()
* @see delete_shadows()
* @see recycle_shadow()
* @see query_hits()
*/
object get_shadow( string str ) {
class shadow_data data;
object ob, *obs;
int i;
if( classp( data = shadows[str] ) && ( i = sizeof( obs = data->obs ) ) ) {
while( i-- ) {
if( ( ob = obs[i] ) && !query_shadowing(ob) ) {
data->obs = obs[0..i-1];
data->hits++;
return ob;
}
}
// We found nothing of use.
data->obs = ({ });
}
if( ob = clone_object(str) ) {
if( undefinedp( shadows[str] ) )
shadows[str] = new( class shadow_data, obs : ({ }) );
shadows[str]->misses++;
}
return ob;
} /* get_shadow() */
/**
* This method destructs all shadows with the specified filename and
* deletes them from the handler. This is useful when you have
* updated a shadow, and don't want to use the recycled (outdated) ones.
* @param file the filename of the shadows to delete
* @see shadow()
* @see query_shadowing()
* @see recycle_shadow()
* @see get_shadow()
* @see query_hits()
*/
void delete_shadows( string file ) {
if( classp(shadows[file]) ) {
shadows[file]->obs = filter( shadows[file]->obs,
(: $1 && !query_shadowing($1) :) );
map( shadows[file]->obs, (: destruct($1) :) );
shadows[file]->obs = ({ });
}
} /* delete_shadows() */
/**
* This method returns the whole recycled shadows mapping.
* @return the whole recycled shadows mapping
* @see shadow()
* @see query_shadowing()
* @see recycle_shadow()
* @see get_shadow()
* @see delete_shadows()
* @see query_hits()
*/
mapping query_shadows() { return copy(shadows); }
/**
* This method returns the number of missed calls to the
* get_shadow() function for the specified file.
* @param the filename to get the miss count for
* @return the number of misses
* @see shadow()
* @see query_shadowing()
* @see recycle_shadow()
* @see get_shadow()
* @see delete_shadows()
* @see query_hits()
*/
int query_misses( string file ) {
if( classp( shadows[file] ) )
return shadows[file]->misses;
return 0;
} /* query_misses() */
/**
* This method returns the number of hits for a specific recycled shadow.
* @param file the filename of the shadow to get the hits rate for
* @return the hits rate for the specified shadow
* @see shadow()
* @see query_shadowing()
* @see recycle_shadow()
* @see get_shadow()
* @see delete_shadows()
*/
int query_hits( string file ) {
if( classp( shadows[file] ) )
return shadows[file]->hits;
return 0;
} /* query_hits() */
/**
* This method returns the recycled shadows for a specific file.
* @param file the filename of the shadow to get the recycled shadows for
* @return the recycled shadows
* @see shadow()
* @see query_shadowing()
* @see recycle_shadow()
* @see get_shadow()
* @see delete_shadows()
*/
object *query_recycled( string file ) {
if( classp( shadows[file] ) )
return shadows[file]->obs;
return 0;
} /* query_recycled() */
/** @ignore yes */
void dest_me() {
map( shadows, (: map( $2->obs - ({ 0 }), (: destruct($1) :) ) :) );
destruct(TO);
} /* dest_me() */
/** @ignore yes */
mixed stats() {
string file;
class shadow_data data;
int hits, misses, total;
foreach( file, data in shadows ) {
hits += data->hits;
misses += data->misses;
total += sizeof( data->obs );
}
return ({
({"total hits", hits }),
({"total misses", misses }),
({"total recycled", total }),
});
} /* stats() */
