_ Git - ldk-java/blob - src/main/java/org/ldk/structs/EventsProvider.java

   1 package org.ldk.structs;
   2
   3 import org.ldk.impl.bindings;
   4 import org.ldk.enums.*;
   5 import org.ldk.util.*;
   6 import java.util.Arrays;
   7 import java.lang.ref.Reference;
   8 import javax.annotation.Nullable;
   9
  10 /**
  11  * A trait indicating an object may generate events.
  12  *
  13  * Events are processed by passing an [`EventHandler`] to [`process_pending_events`].
  14  *
  15  * # Requirements
  16  *
  17  * When using this trait, [`process_pending_events`] will call [`handle_event`] for each pending
  18  * event since the last invocation.
  19  *
  20  * In order to ensure no [`Event`]s are lost, implementors of this trait will persist [`Event`]s
  21  * and replay any unhandled events on startup. An [`Event`] is considered handled when
  22  * [`process_pending_events`] returns, thus handlers MUST fully handle [`Event`]s and persist any
  23  * relevant changes to disk *before* returning.
  24  *
  25  * Further, because an application may crash between an [`Event`] being handled and the
  26  * implementor of this trait being re-serialized, [`Event`] handling must be idempotent - in
  27  * effect, [`Event`]s may be replayed.
  28  *
  29  * Note, handlers may call back into the provider and thus deadlocking must be avoided. Be sure to
  30  * consult the provider's documentation on the implication of processing events and how a handler
  31  * may safely use the provider (e.g., see [`ChannelManager::process_pending_events`] and
  32  * [`ChainMonitor::process_pending_events`]).
  33  *
  34  * (C-not implementable) As there is likely no reason for a user to implement this trait on their
  35  * own type(s).
  36  *
  37  * [`process_pending_events`]: Self::process_pending_events
  38  * [`handle_event`]: EventHandler::handle_event
  39  * [`ChannelManager::process_pending_events`]: crate::ln::channelmanager::ChannelManager#method.process_pending_events
  40  * [`ChainMonitor::process_pending_events`]: crate::chain::chainmonitor::ChainMonitor#method.process_pending_events
  41  */
  42 @SuppressWarnings("unchecked") // We correctly assign various generic arrays
  43 public class EventsProvider extends CommonBase {
  44         final bindings.LDKEventsProvider bindings_instance;
  45         EventsProvider(Object _dummy, long ptr) { super(ptr); bindings_instance = null; }
  46         private EventsProvider(bindings.LDKEventsProvider arg) {
  47                 super(bindings.LDKEventsProvider_new(arg));
  48                 this.ptrs_to.add(arg);
  49                 this.bindings_instance = arg;
  50         }
  51         @Override @SuppressWarnings("deprecation")
  52         protected void finalize() throws Throwable {
  53                 if (ptr != 0) { bindings.EventsProvider_free(ptr); } super.finalize();
  54         }
  55
  56         public static interface EventsProviderInterface {
  57                 /**
  58                  * Processes any events generated since the last call using the given event handler.
  59                  *
  60                  * See the trait-level documentation for requirements.
  61                  */
  62                 void process_pending_events(EventHandler handler);
  63         }
  64         private static class LDKEventsProviderHolder { EventsProvider held; }
  65         public static EventsProvider new_impl(EventsProviderInterface arg) {
  66                 final LDKEventsProviderHolder impl_holder = new LDKEventsProviderHolder();
  67                 impl_holder.held = new EventsProvider(new bindings.LDKEventsProvider() {
  68                         @Override public void process_pending_events(long handler) {
  69                                 EventHandler ret_hu_conv = new EventHandler(null, handler);
  70                                 if (ret_hu_conv != null) { ret_hu_conv.ptrs_to.add(this); };
  71                                 arg.process_pending_events(ret_hu_conv);
  72                                 Reference.reachabilityFence(arg);
  73                         }
  74                 });
  75                 return impl_holder.held;
  76         }
  77         /**
  78          * Processes any events generated since the last call using the given event handler.
  79          *
  80          * See the trait-level documentation for requirements.
  81          */
  82         public void process_pending_events(EventHandler handler) {
  83                 bindings.EventsProvider_process_pending_events(this.ptr, handler == null ? 0 : handler.ptr);
  84                 Reference.reachabilityFence(this);
  85                 Reference.reachabilityFence(handler);
  86                 if (this != null) { this.ptrs_to.add(handler); };
  87         }
  88
  89 }