/*
- dispatcher.cc -- implement Dispatcher
+ This file is part of LilyPond, the GNU music typesetter.
- source file of the GNU LilyPond music typesetter
+ Copyright (C) 2005--2014 Erik Sandberg <mandolaerik@gmail.com>
- (c) 2005-2006 Erik Sandberg <mandolaerik@gmail.com>
+ LilyPond is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ LilyPond is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with LilyPond. If not, see <http://www.gnu.org/licenses/>.
*/
#include "dispatcher.hh"
#include "warn.hh"
IMPLEMENT_SMOBS (Dispatcher);
-IMPLEMENT_TYPE_P (Dispatcher, "dispatcher");
+IMPLEMENT_TYPE_P (Dispatcher, "ly:dispatcher?");
IMPLEMENT_DEFAULT_EQUAL_P (Dispatcher);
Dispatcher::~Dispatcher ()
}
int
-Dispatcher::print_smob (SCM s, SCM p, scm_print_state*)
+Dispatcher::print_smob (SCM s, SCM p, scm_print_state *)
{
Dispatcher *me = (Dispatcher *) SCM_CELL_WORD_1 (s);
scm_puts ("#<Dispatcher ", p);
- scm_write (scm_vector_to_list (me->listeners_), p);
+ scm_write (scm_call_1 (ly_lily_module_constant ("hash-table->alist"),
+ me->listeners_), p);
scm_puts (">", p);
return 1;
}
This is done by keeping a priority queue of listener lists,
and iteratively send the event to the lowest-priority listener.
- An event is never sent twice to listeners with equal priority.
+ The only case where listeners with equal priority may exist is when
+ two dispatchers are connected for more than one event type. In that
+ case, the respective listeners all have the same priority, making
+ sure that any event is only dispatched at most once for that
+ combination of dispatchers, even if it matches more than one event
+ type.
*/
IMPLEMENT_LISTENER (Dispatcher, dispatch);
void
Dispatcher::dispatch (SCM sev)
{
Stream_event *ev = unsmob_stream_event (sev);
- SCM class_symbol = ev->get_property ("class");
- if (!scm_symbol_p (class_symbol))
- {
- warning (_f ("Event class should be a symbol"));
- return;
- }
-
- SCM class_list = scm_call_1 (ly_lily_module_constant ("ly:make-event-class"), class_symbol);
+ SCM class_list = ev->get_property ("class");
if (!scm_is_pair (class_list))
{
- ev->origin ()->warning (_f ("Unknown event class %s", ly_symbol2string (class_symbol).c_str ()));
+ ev->origin ()->warning (_ ("Event class should be a list"));
return;
}
+
+#if 0
bool sent = false;
+#endif
int num_classes = scm_ilength (class_list);
/*
listener list, and the lowest priority element is repeatedly
extracted and called.
- The priority queue is implemented as a bubble-sorted C
+ The priority queue is implemented as an insertion-sorted C
array. Using the stack instead of native Scheme datastructures
avoids overheads for memory allocation. The queue is usually small
(around 2 elements), so the quadratic sorting time is not a
The first step is to collect all listener lists and to initially
insert them in the priority queue.
*/
- struct { int prio; SCM list; } lists[num_classes+1];
+ struct { int prio; SCM list; } lists[num_classes + 1];
int i = 0;
- for (SCM cl = class_list; scm_is_pair(cl); cl = scm_cdr (cl))
+ for (SCM cl = class_list; scm_is_pair (cl); cl = scm_cdr (cl))
{
SCM list = scm_hashq_ref (listeners_, scm_car (cl), SCM_EOL);
- if (!scm_is_pair(list))
- num_classes--;
+ if (!scm_is_pair (list))
+ num_classes--;
else
- {
- // bubblesort.
+ {
+ // insertion sort.
int prio = scm_to_int (scm_caar (list));
- int j;
- for (j = i; j > 0 && lists[j-1].prio > prio; j--)
- lists[j] = lists[j-1];
- lists[j].prio = prio;
- lists[j].list = list;
- i++;
+ int j;
+ for (j = i; j > 0 && lists[j - 1].prio > prio; j--)
+ lists[j] = lists[j - 1];
+ lists[j].prio = prio;
+ lists[j].list = list;
+ i++;
}
}
lists[num_classes].prio = INT_MAX;
assert (lists[0].prio > last_priority);
last_priority = lists[0].prio;
- Listener *l = unsmob_listener (scm_cdar (lists[0].list));
+ Listener *l = Listener::unsmob (scm_cdar (lists[0].list));
l->listen (ev->self_scm ());
+#if 0
sent = true;
+#endif
}
// go to the next listener; bubble-sort the class list.
SCM next = scm_cdr (lists[0].list);
- if (!scm_is_pair(next))
+ if (!scm_is_pair (next))
num_classes--;
- int prio = (scm_is_pair(next)) ? scm_to_int (scm_caar (next)) : INT_MAX;
- for (i = 0; prio > lists[i+1].prio; i++)
- lists[i] = lists[i+1];
+ int prio = (scm_is_pair (next)) ? scm_to_int (scm_caar (next)) : INT_MAX;
+ for (i = 0; prio > lists[i + 1].prio; i++)
+ lists[i] = lists[i + 1];
lists[i].prio = prio;
lists[i].list = next;
}
-/* TODO: Uncomment.
+#if 0
+ /* TODO: Uncomment. */
if (!sent)
warning (_f ("Junking event: %s", ly_symbol2string (class_symbol).c_str ()));
-*/
+#endif
+}
+
+bool
+Dispatcher::is_listened_class (SCM cl)
+{
+ for (; scm_is_pair (cl); cl = scm_cdr (cl))
+ {
+ SCM list = scm_hashq_ref (listeners_, scm_car (cl), SCM_EOL);
+ if (scm_is_pair (list))
+ return true;
+ }
+ return false;
+}
+
+static SCM
+accumulate_types (void * /* closure */,
+ SCM key,
+ SCM val,
+ SCM result)
+{
+ if (scm_is_pair (val))
+ return scm_cons (key, result);
+ return result;
+}
+
+SCM
+Dispatcher::listened_types ()
+{
+ return scm_internal_hash_fold ((scm_t_hash_fold_fn) &accumulate_types,
+ NULL, SCM_EOL, listeners_);
}
void
dispatch (ev->self_scm ());
}
+// add_listener will always assign a new priority for each call
void
Dispatcher::add_listener (Listener l, SCM ev_class)
{
Dispatcher::internal_add_listener (Listener l, SCM ev_class, int priority)
{
SCM list = scm_hashq_ref (listeners_, ev_class, SCM_EOL);
+ // if ev_class is not yet listened to, we go through our list of
+ // source dispatchers and register ourselves there with the priority
+ // we have reserved for this dispatcher. The priority system
+ // usually distributes events in the order events are registered.
+ // The reuse of a previous priority when registering another event
+ // for a dispatcher/dispatcher connection bypasses the normal
+ // ordering, but it is the mechanism by which duplicate broadcasts
+ // of the same event from one dispatcher to another are avoided.
if (!scm_is_pair (list))
{
- /* Tell all dispatchers that we listen to, that we want to hear ev_class
+ /* Tell all dispatchers that we listen to, that we want to hear ev_class
events */
- for (SCM disp = dispatchers_; scm_is_pair(disp); disp = scm_cdr (disp))
- {
- int priority = scm_to_int (scm_cdar (disp));
- Dispatcher *d = unsmob_dispatcher (scm_caar (disp));
- d->internal_add_listener (GET_LISTENER (dispatch), ev_class, priority);
- }
+ for (SCM disp = dispatchers_; scm_is_pair (disp); disp = scm_cdr (disp))
+ {
+ int priority = scm_to_int (scm_cdar (disp));
+ Dispatcher *d = Dispatcher::unsmob (scm_caar (disp));
+ d->internal_add_listener (GET_LISTENER (dispatch), ev_class, priority);
+ }
listen_classes_ = scm_cons (ev_class, listen_classes_);
}
- SCM entry = scm_cons (scm_int2num (priority), l.smobbed_copy ());
+ SCM entry = scm_cons (scm_from_int (priority), l.smobbed_copy ());
list = scm_merge (list, scm_list_1 (entry), ly_lily_module_constant ("car<"));
scm_hashq_set_x (listeners_, ev_class, list);
}
SCM dummy = scm_cons (SCM_EOL, list);
SCM e = dummy;
- while (scm_is_pair(scm_cdr (e)))
- if (*unsmob_listener (scm_cdadr (e)) == l && first)
+ while (scm_is_pair (scm_cdr (e)))
+ if (*Listener::unsmob (scm_cdadr (e)) == l && first)
{
- scm_set_cdr_x (e, scm_cddr(e));
- first = false;
- break;
+ scm_set_cdr_x (e, scm_cddr (e));
+ first = false;
+ break;
}
else
e = scm_cdr (e);
scm_hashq_set_x (listeners_, ev_class, list);
if (first)
- warning ("Attempting to remove nonexisting listener.");
+ warning (_ ("Attempting to remove nonexisting listener."));
else if (!scm_is_pair (list))
{
/* Unregister with all dispatchers. */
for (SCM disp = dispatchers_; scm_is_pair (disp); disp = scm_cdr (disp))
- {
- Dispatcher *d = unsmob_dispatcher (scm_caar (disp));
- d->remove_listener (GET_LISTENER (dispatch), ev_class);
- }
+ {
+ Dispatcher *d = Dispatcher::unsmob (scm_caar (disp));
+ d->remove_listener (GET_LISTENER (dispatch), ev_class);
+ }
listen_classes_ = scm_delq_x (ev_class, listen_classes_);
}
}
void
Dispatcher::register_as_listener (Dispatcher *disp)
{
+ // We are creating and remembering the priority _we_ have with the
+ // foreign dispatcher. All events are dispatched with the same
+ // priority. The result is that, for example, a single event class
+ // will only trigger an event listener once.
int priority = ++disp->priority_count_;
// Don't register twice to the same dispatcher.
if (scm_assq (disp->self_scm (), dispatchers_) != SCM_BOOL_F)
{
- warning ("Already listening to dispatcher, ignoring request");
+ warning (_ ("Already listening to dispatcher, ignoring request"));
return;
}
- dispatchers_ = scm_acons (disp->self_scm (), scm_int2num (priority), dispatchers_);
+ dispatchers_ = scm_acons (disp->self_scm (), scm_from_int (priority), dispatchers_);
Listener list = GET_LISTENER (dispatch);
for (SCM cl = listen_classes_; scm_is_pair (cl); cl = scm_cdr (cl))
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