1 package org.ldk.structs;
3 import org.ldk.impl.bindings;
4 import org.ldk.enums.*;
6 import java.util.Arrays;
7 import javax.annotation.Nullable;
10 * The `Watch` trait defines behavior for watching on-chain activity pertaining to channels as
11 * blocks are connected and disconnected.
13 * Each channel is associated with a [`ChannelMonitor`]. Implementations of this trait are
14 * responsible for maintaining a set of monitors such that they can be updated accordingly as
15 * channel state changes and HTLCs are resolved. See method documentation for specific
18 * Implementations **must** ensure that updates are successfully applied and persisted upon method
19 * completion. If an update fails with a [`PermanentFailure`], then it must immediately shut down
20 * without taking any further action such as persisting the current state.
22 * If an implementation maintains multiple instances of a channel's monitor (e.g., by storing
23 * backup copies), then it must ensure that updates are applied across all instances. Otherwise, it
24 * could result in a revoked transaction being broadcast, allowing the counterparty to claim all
25 * funds in the channel. See [`ChannelMonitorUpdateErr`] for more details about how to handle
28 * [`PermanentFailure`]: ChannelMonitorUpdateErr::PermanentFailure
30 @SuppressWarnings("unchecked") // We correctly assign various generic arrays
31 public class Watch extends CommonBase {
32 final bindings.LDKWatch bindings_instance;
33 Watch(Object _dummy, long ptr) { super(ptr); bindings_instance = null; }
34 private Watch(bindings.LDKWatch arg) {
35 super(bindings.LDKWatch_new(arg));
36 this.ptrs_to.add(arg);
37 this.bindings_instance = arg;
39 @Override @SuppressWarnings("deprecation")
40 protected void finalize() throws Throwable {
41 if (ptr != 0) { bindings.Watch_free(ptr); } super.finalize();
44 public static interface WatchInterface {
46 * Watches a channel identified by `funding_txo` using `monitor`.
48 * Implementations are responsible for watching the chain for the funding transaction along
49 * with any spends of outputs returned by [`get_outputs_to_watch`]. In practice, this means
50 * calling [`block_connected`] and [`block_disconnected`] on the monitor.
52 * Note: this interface MUST error with `ChannelMonitorUpdateErr::PermanentFailure` if
53 * the given `funding_txo` has previously been registered via `watch_channel`.
55 * [`get_outputs_to_watch`]: channelmonitor::ChannelMonitor::get_outputs_to_watch
56 * [`block_connected`]: channelmonitor::ChannelMonitor::block_connected
57 * [`block_disconnected`]: channelmonitor::ChannelMonitor::block_disconnected
59 Result_NoneChannelMonitorUpdateErrZ watch_channel(OutPoint funding_txo, ChannelMonitor monitor);
61 * Updates a channel identified by `funding_txo` by applying `update` to its monitor.
63 * Implementations must call [`update_monitor`] with the given update. See
64 * [`ChannelMonitorUpdateErr`] for invariants around returning an error.
66 * [`update_monitor`]: channelmonitor::ChannelMonitor::update_monitor
68 Result_NoneChannelMonitorUpdateErrZ update_channel(OutPoint funding_txo, ChannelMonitorUpdate update);
70 * Returns any monitor events since the last call. Subsequent calls must only return new
73 * Note that after any block- or transaction-connection calls to a [`ChannelMonitor`], no
74 * further events may be returned here until the [`ChannelMonitor`] has been fully persisted
77 * For details on asynchronous [`ChannelMonitor`] updating and returning
78 * [`MonitorEvent::UpdateCompleted`] here, see [`ChannelMonitorUpdateErr::TemporaryFailure`].
80 MonitorEvent[] release_pending_monitor_events();
82 private static class LDKWatchHolder { Watch held; }
83 public static Watch new_impl(WatchInterface arg) {
84 final LDKWatchHolder impl_holder = new LDKWatchHolder();
85 impl_holder.held = new Watch(new bindings.LDKWatch() {
86 @Override public long watch_channel(long funding_txo, long monitor) {
87 OutPoint funding_txo_hu_conv = null; if (funding_txo < 0 || funding_txo > 4096) { funding_txo_hu_conv = new OutPoint(null, funding_txo); }
88 funding_txo_hu_conv.ptrs_to.add(this);
89 ChannelMonitor monitor_hu_conv = null; if (monitor < 0 || monitor > 4096) { monitor_hu_conv = new ChannelMonitor(null, monitor); }
90 monitor_hu_conv.ptrs_to.add(this);
91 Result_NoneChannelMonitorUpdateErrZ ret = arg.watch_channel(funding_txo_hu_conv, monitor_hu_conv);
92 long result = ret == null ? 0 : ret.clone_ptr();
95 @Override public long update_channel(long funding_txo, long update) {
96 OutPoint funding_txo_hu_conv = null; if (funding_txo < 0 || funding_txo > 4096) { funding_txo_hu_conv = new OutPoint(null, funding_txo); }
97 funding_txo_hu_conv.ptrs_to.add(this);
98 ChannelMonitorUpdate update_hu_conv = null; if (update < 0 || update > 4096) { update_hu_conv = new ChannelMonitorUpdate(null, update); }
99 update_hu_conv.ptrs_to.add(this);
100 Result_NoneChannelMonitorUpdateErrZ ret = arg.update_channel(funding_txo_hu_conv, update_hu_conv);
101 long result = ret == null ? 0 : ret.clone_ptr();
104 @Override public long[] release_pending_monitor_events() {
105 MonitorEvent[] ret = arg.release_pending_monitor_events();
106 long[] result = ret != null ? Arrays.stream(ret).mapToLong(ret_conv_14 -> ret_conv_14 == null ? 0 : ret_conv_14.clone_ptr()).toArray() : null;
110 return impl_holder.held;
113 * Watches a channel identified by `funding_txo` using `monitor`.
115 * Implementations are responsible for watching the chain for the funding transaction along
116 * with any spends of outputs returned by [`get_outputs_to_watch`]. In practice, this means
117 * calling [`block_connected`] and [`block_disconnected`] on the monitor.
119 * Note: this interface MUST error with `ChannelMonitorUpdateErr::PermanentFailure` if
120 * the given `funding_txo` has previously been registered via `watch_channel`.
122 * [`get_outputs_to_watch`]: channelmonitor::ChannelMonitor::get_outputs_to_watch
123 * [`block_connected`]: channelmonitor::ChannelMonitor::block_connected
124 * [`block_disconnected`]: channelmonitor::ChannelMonitor::block_disconnected
126 public Result_NoneChannelMonitorUpdateErrZ watch_channel(OutPoint funding_txo, ChannelMonitor monitor) {
127 long ret = bindings.Watch_watch_channel(this.ptr, funding_txo == null ? 0 : funding_txo.ptr & ~1, monitor == null ? 0 : monitor.ptr & ~1);
128 if (ret >= 0 && ret <= 4096) { return null; }
129 Result_NoneChannelMonitorUpdateErrZ ret_hu_conv = Result_NoneChannelMonitorUpdateErrZ.constr_from_ptr(ret);
134 * Updates a channel identified by `funding_txo` by applying `update` to its monitor.
136 * Implementations must call [`update_monitor`] with the given update. See
137 * [`ChannelMonitorUpdateErr`] for invariants around returning an error.
139 * [`update_monitor`]: channelmonitor::ChannelMonitor::update_monitor
141 public Result_NoneChannelMonitorUpdateErrZ update_channel(OutPoint funding_txo, ChannelMonitorUpdate update) {
142 long ret = bindings.Watch_update_channel(this.ptr, funding_txo == null ? 0 : funding_txo.ptr & ~1, update == null ? 0 : update.ptr & ~1);
143 if (ret >= 0 && ret <= 4096) { return null; }
144 Result_NoneChannelMonitorUpdateErrZ ret_hu_conv = Result_NoneChannelMonitorUpdateErrZ.constr_from_ptr(ret);
149 * Returns any monitor events since the last call. Subsequent calls must only return new
152 * Note that after any block- or transaction-connection calls to a [`ChannelMonitor`], no
153 * further events may be returned here until the [`ChannelMonitor`] has been fully persisted
156 * For details on asynchronous [`ChannelMonitor`] updating and returning
157 * [`MonitorEvent::UpdateCompleted`] here, see [`ChannelMonitorUpdateErr::TemporaryFailure`].
159 public MonitorEvent[] release_pending_monitor_events() {
160 long[] ret = bindings.Watch_release_pending_monitor_events(this.ptr);
161 MonitorEvent[] ret_conv_14_arr = new MonitorEvent[ret.length];
162 for (int o = 0; o < ret.length; o++) {
163 long ret_conv_14 = ret[o];
164 MonitorEvent ret_conv_14_hu_conv = MonitorEvent.constr_from_ptr(ret_conv_14);
165 ret_conv_14_hu_conv.ptrs_to.add(this);
166 ret_conv_14_arr[o] = ret_conv_14_hu_conv;
168 return ret_conv_14_arr;