X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fdispatcher.cc;h=49536a0a8a36d7485bb1211522d22e34813591a8;hb=5bbfc22fce036b9b69df5e420de93e11da23c05e;hp=6a11654e233465ea6a59de9947b8c28aba33f3f4;hpb=848c75e664dce315df7671dd567e9c96abc23d5f;p=lilypond.git diff --git a/lily/dispatcher.cc b/lily/dispatcher.cc index 6a11654e23..49536a0a8a 100644 --- a/lily/dispatcher.cc +++ b/lily/dispatcher.cc @@ -1,7 +1,7 @@ /* This file is part of LilyPond, the GNU music typesetter. - Copyright (C) 2005--2011 Erik Sandberg + Copyright (C) 2005--2014 Erik Sandberg LilyPond is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -58,7 +58,8 @@ Dispatcher::print_smob (SCM s, SCM p, scm_print_state *) { Dispatcher *me = (Dispatcher *) SCM_CELL_WORD_1 (s); scm_puts ("#listeners_), p); + scm_write (scm_call_1 (ly_lily_module_constant ("hash-table->alist"), + me->listeners_), p); scm_puts (">", p); return 1; } @@ -70,25 +71,25 @@ Event dispatching: 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_is_symbol (class_symbol)) - { - warning (_ ("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 @@ -101,7 +102,7 @@ Dispatcher::dispatch (SCM sev) 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 @@ -120,7 +121,7 @@ Dispatcher::dispatch (SCM sev) 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--) @@ -148,7 +149,7 @@ Dispatcher::dispatch (SCM sev) 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; @@ -167,17 +168,48 @@ Dispatcher::dispatch (SCM sev) #if 0 /* TODO: Uncomment. */ - if (!sent) - warning (_f ("Junking event: %s", ly_symbol2string (class_symbol).c_str ())); + 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 Dispatcher::broadcast (Stream_event *ev) { dispatch (ev->self_scm ()); } +// add_listener will always assign a new priority for each call void Dispatcher::add_listener (Listener l, SCM ev_class) { @@ -188,6 +220,14 @@ inline void 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 @@ -195,7 +235,7 @@ Dispatcher::internal_add_listener (Listener l, SCM ev_class, int priority) 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)); + 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_); @@ -222,7 +262,7 @@ Dispatcher::remove_listener (Listener l, SCM ev_class) 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) + if (*Listener::unsmob (scm_cdadr (e)) == l && first) { scm_set_cdr_x (e, scm_cddr (e)); first = false; @@ -234,13 +274,13 @@ Dispatcher::remove_listener (Listener l, SCM ev_class) 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)); + Dispatcher *d = Dispatcher::unsmob (scm_caar (disp)); d->remove_listener (GET_LISTENER (dispatch), ev_class); } listen_classes_ = scm_delq_x (ev_class, listen_classes_); @@ -251,12 +291,16 @@ Dispatcher::remove_listener (Listener l, SCM ev_class) 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; }