1 package org.ldk.structs;
3 import org.ldk.impl.bindings;
4 import org.ldk.enums.*;
6 import java.util.Arrays;
9 * The `Watch` trait defines behavior for watching on-chain activity pertaining to channels as
10 * blocks are connected and disconnected.
12 * Each channel is associated with a [`ChannelMonitor`]. Implementations of this trait are
13 * responsible for maintaining a set of monitors such that they can be updated accordingly as
14 * channel state changes and HTLCs are resolved. See method documentation for specific
17 * Implementations **must** ensure that updates are successfully applied and persisted upon method
18 * completion. If an update fails with a [`PermanentFailure`], then it must immediately shut down
19 * without taking any further action such as persisting the current state.
21 * If an implementation maintains multiple instances of a channel's monitor (e.g., by storing
22 * backup copies), then it must ensure that updates are applied across all instances. Otherwise, it
23 * could result in a revoked transaction being broadcast, allowing the counterparty to claim all
24 * funds in the channel. See [`ChannelMonitorUpdateErr`] for more details about how to handle
27 * [`ChannelMonitor`]: channelmonitor::ChannelMonitor
28 * [`ChannelMonitorUpdateErr`]: channelmonitor::ChannelMonitorUpdateErr
29 * [`PermanentFailure`]: channelmonitor::ChannelMonitorUpdateErr::PermanentFailure
31 @SuppressWarnings("unchecked") // We correctly assign various generic arrays
32 public class Watch extends CommonBase {
33 final bindings.LDKWatch bindings_instance;
34 Watch(Object _dummy, long ptr) { super(ptr); bindings_instance = null; }
35 private Watch(bindings.LDKWatch arg) {
36 super(bindings.LDKWatch_new(arg));
37 this.ptrs_to.add(arg);
38 this.bindings_instance = arg;
40 @Override @SuppressWarnings("deprecation")
41 protected void finalize() throws Throwable {
42 if (ptr != 0) { bindings.Watch_free(ptr); } super.finalize();
45 public static interface WatchInterface {
47 * Watches a channel identified by `funding_txo` using `monitor`.
49 * Implementations are responsible for watching the chain for the funding transaction along
50 * with any spends of outputs returned by [`get_outputs_to_watch`]. In practice, this means
51 * calling [`block_connected`] and [`block_disconnected`] on the monitor.
53 * [`get_outputs_to_watch`]: channelmonitor::ChannelMonitor::get_outputs_to_watch
54 * [`block_connected`]: channelmonitor::ChannelMonitor::block_connected
55 * [`block_disconnected`]: channelmonitor::ChannelMonitor::block_disconnected
57 Result_NoneChannelMonitorUpdateErrZ watch_channel(OutPoint funding_txo, ChannelMonitor monitor);
59 * Updates a channel identified by `funding_txo` by applying `update` to its monitor.
61 * Implementations must call [`update_monitor`] with the given update. See
62 * [`ChannelMonitorUpdateErr`] for invariants around returning an error.
64 * [`update_monitor`]: channelmonitor::ChannelMonitor::update_monitor
65 * [`ChannelMonitorUpdateErr`]: channelmonitor::ChannelMonitorUpdateErr
67 Result_NoneChannelMonitorUpdateErrZ update_channel(OutPoint funding_txo, ChannelMonitorUpdate update);
69 * Returns any monitor events since the last call. Subsequent calls must only return new
72 MonitorEvent[] release_pending_monitor_events();
74 private static class LDKWatchHolder { Watch held; }
75 public static Watch new_impl(WatchInterface arg) {
76 final LDKWatchHolder impl_holder = new LDKWatchHolder();
77 impl_holder.held = new Watch(new bindings.LDKWatch() {
78 @Override public long watch_channel(long funding_txo, long monitor) {
79 OutPoint funding_txo_hu_conv = new OutPoint(null, funding_txo);
80 funding_txo_hu_conv.ptrs_to.add(this);
81 ChannelMonitor monitor_hu_conv = new ChannelMonitor(null, monitor);
82 monitor_hu_conv.ptrs_to.add(this);
83 Result_NoneChannelMonitorUpdateErrZ ret = arg.watch_channel(funding_txo_hu_conv, monitor_hu_conv);
84 long result = ret != null ? ret.ptr : 0;
87 @Override public long update_channel(long funding_txo, long update) {
88 OutPoint funding_txo_hu_conv = new OutPoint(null, funding_txo);
89 funding_txo_hu_conv.ptrs_to.add(this);
90 ChannelMonitorUpdate update_hu_conv = new ChannelMonitorUpdate(null, update);
91 update_hu_conv.ptrs_to.add(this);
92 Result_NoneChannelMonitorUpdateErrZ ret = arg.update_channel(funding_txo_hu_conv, update_hu_conv);
93 long result = ret != null ? ret.ptr : 0;
96 @Override public long[] release_pending_monitor_events() {
97 MonitorEvent[] ret = arg.release_pending_monitor_events();
98 long[] result = Arrays.stream(ret).mapToLong(ret_conv_14 -> ret_conv_14.ptr).toArray();
99 /* TODO 2 MonitorEvent */;
103 return impl_holder.held;
106 * Watches a channel identified by `funding_txo` using `monitor`.
108 * Implementations are responsible for watching the chain for the funding transaction along
109 * with any spends of outputs returned by [`get_outputs_to_watch`]. In practice, this means
110 * calling [`block_connected`] and [`block_disconnected`] on the monitor.
112 * [`get_outputs_to_watch`]: channelmonitor::ChannelMonitor::get_outputs_to_watch
113 * [`block_connected`]: channelmonitor::ChannelMonitor::block_connected
114 * [`block_disconnected`]: channelmonitor::ChannelMonitor::block_disconnected
116 public Result_NoneChannelMonitorUpdateErrZ watch_channel(OutPoint funding_txo, ChannelMonitor monitor) {
117 long ret = bindings.Watch_watch_channel(this.ptr, funding_txo == null ? 0 : funding_txo.ptr & ~1, monitor == null ? 0 : monitor.ptr & ~1);
118 Result_NoneChannelMonitorUpdateErrZ ret_hu_conv = Result_NoneChannelMonitorUpdateErrZ.constr_from_ptr(ret);
119 this.ptrs_to.add(funding_txo);
120 this.ptrs_to.add(monitor);
125 * Updates a channel identified by `funding_txo` by applying `update` to its monitor.
127 * Implementations must call [`update_monitor`] with the given update. See
128 * [`ChannelMonitorUpdateErr`] for invariants around returning an error.
130 * [`update_monitor`]: channelmonitor::ChannelMonitor::update_monitor
131 * [`ChannelMonitorUpdateErr`]: channelmonitor::ChannelMonitorUpdateErr
133 public Result_NoneChannelMonitorUpdateErrZ update_channel(OutPoint funding_txo, ChannelMonitorUpdate update) {
134 long ret = bindings.Watch_update_channel(this.ptr, funding_txo == null ? 0 : funding_txo.ptr & ~1, update == null ? 0 : update.ptr & ~1);
135 Result_NoneChannelMonitorUpdateErrZ ret_hu_conv = Result_NoneChannelMonitorUpdateErrZ.constr_from_ptr(ret);
136 this.ptrs_to.add(funding_txo);
137 this.ptrs_to.add(update);
142 * Returns any monitor events since the last call. Subsequent calls must only return new
145 public MonitorEvent[] release_pending_monitor_events() {
146 long[] ret = bindings.Watch_release_pending_monitor_events(this.ptr);
147 MonitorEvent[] ret_conv_14_arr = new MonitorEvent[ret.length];
148 for (int o = 0; o < ret.length; o++) {
149 long ret_conv_14 = ret[o];
150 MonitorEvent ret_conv_14_hu_conv = MonitorEvent.constr_from_ptr(ret_conv_14);
151 ret_conv_14_hu_conv.ptrs_to.add(this);
152 ret_conv_14_arr[o] = ret_conv_14_hu_conv;
154 return ret_conv_14_arr;