* `Persist` defines behavior for persisting channel monitors: this could mean
* writing once to disk, and/or uploading to one or more backup services.
*
- * Note that for every new monitor, you **must** persist the new `ChannelMonitor`
- * to disk/backups. And, on every update, you **must** persist either the
- * `ChannelMonitorUpdate` or the updated monitor itself. Otherwise, there is risk
- * of situations such as revoking a transaction, then crashing before this
- * revocation can be persisted, then unintentionally broadcasting a revoked
- * transaction and losing money. This is a risk because previous channel states
- * are toxic, so it's important that whatever channel state is persisted is
- * kept up-to-date.
+ * Each method can return three possible values:
+ * If persistence (including any relevant `fsync()` calls) happens immediately, the
+ * implementation should return `Ok(())`, indicating normal channel operation should continue.
+ * If persistence happens asynchronously, implementations should first ensure the
+ * [`ChannelMonitor`] or [`ChannelMonitorUpdate`] are written durably to disk, and then return
+ * `Err(ChannelMonitorUpdateErr::TemporaryFailure)` while the update continues in the
+ * background. Once the update completes, [`ChainMonitor::channel_monitor_updated`] should be
+ * called with the corresponding [`MonitorUpdateId`].
+ *
+ * Note that unlike the direct [`chain::Watch`] interface,
+ * [`ChainMonitor::channel_monitor_updated`] must be called once for *each* update which occurs.
+ *
+ * If persistence fails for some reason, implementations should return
+ * `Err(ChannelMonitorUpdateErr::PermanentFailure)`, in which case the channel will likely be
+ * closed without broadcasting the latest state. See
+ * [`ChannelMonitorUpdateErr::PermanentFailure`] for more details.
*/
@SuppressWarnings("unchecked") // We correctly assign various generic arrays
public class Persist extends CommonBase {
public static interface PersistInterface {
/**
- * Persist a new channel's data. The data can be stored any way you want, but
- * the identifier provided by Rust-Lightning is the channel's outpoint (and
- * it is up to you to maintain a correct mapping between the outpoint and the
- * stored channel data). Note that you **must** persist every new monitor to
- * disk. See the `Persist` trait documentation for more details.
+ * Persist a new channel's data in response to a [`chain::Watch::watch_channel`] call. This is
+ * called by [`ChannelManager`] for new channels, or may be called directly, e.g. on startup.
+ *
+ * The data can be stored any way you want, but the identifier provided by LDK is the
+ * channel's outpoint (and it is up to you to maintain a correct mapping between the outpoint
+ * and the stored channel data). Note that you **must** persist every new monitor to disk.
+ *
+ * The `update_id` is used to identify this call to [`ChainMonitor::channel_monitor_updated`],
+ * if you return [`ChannelMonitorUpdateErr::TemporaryFailure`].
*
* See [`Writeable::write`] on [`ChannelMonitor`] for writing out a `ChannelMonitor`
* and [`ChannelMonitorUpdateErr`] for requirements when returning errors.
*
+ * [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
* [`Writeable::write`]: crate::util::ser::Writeable::write
*/
- Result_NoneChannelMonitorUpdateErrZ persist_new_channel(OutPoint id, ChannelMonitor data);
+ Result_NoneChannelMonitorUpdateErrZ persist_new_channel(OutPoint channel_id, ChannelMonitor data, MonitorUpdateId update_id);
/**
- * Update one channel's data. The provided `ChannelMonitor` has already
- * applied the given update.
+ * Update one channel's data. The provided [`ChannelMonitor`] has already applied the given
+ * update.
+ *
+ * Note that on every update, you **must** persist either the [`ChannelMonitorUpdate`] or the
+ * updated monitor itself to disk/backups. See the [`Persist`] trait documentation for more
+ * details.
*
- * Note that on every update, you **must** persist either the
- * `ChannelMonitorUpdate` or the updated monitor itself to disk/backups. See
- * the `Persist` trait documentation for more details.
+ * During blockchain synchronization operations, this may be called with no
+ * [`ChannelMonitorUpdate`], in which case the full [`ChannelMonitor`] needs to be persisted.
+ * Note that after the full [`ChannelMonitor`] is persisted any previous
+ * [`ChannelMonitorUpdate`]s which were persisted should be discarded - they can no longer be
+ * applied to the persisted [`ChannelMonitor`] as they were already applied.
*
* If an implementer chooses to persist the updates only, they need to make
* sure that all the updates are applied to the `ChannelMonitors` *before
* them in batches. The size of each monitor grows `O(number of state updates)`
* whereas updates are small and `O(1)`.
*
+ * The `update_id` is used to identify this call to [`ChainMonitor::channel_monitor_updated`],
+ * if you return [`ChannelMonitorUpdateErr::TemporaryFailure`].
+ *
* See [`Writeable::write`] on [`ChannelMonitor`] for writing out a `ChannelMonitor`,
* [`Writeable::write`] on [`ChannelMonitorUpdate`] for writing out an update, and
* [`ChannelMonitorUpdateErr`] for requirements when returning errors.
*
* [`Writeable::write`]: crate::util::ser::Writeable::write
+ *
+ * Note that update (or a relevant inner pointer) may be NULL or all-0s to represent None
*/
- Result_NoneChannelMonitorUpdateErrZ update_persisted_channel(OutPoint id, ChannelMonitorUpdate update, ChannelMonitor data);
+ Result_NoneChannelMonitorUpdateErrZ update_persisted_channel(OutPoint channel_id, ChannelMonitorUpdate update, ChannelMonitor data, MonitorUpdateId update_id);
}
private static class LDKPersistHolder { Persist held; }
public static Persist new_impl(PersistInterface arg) {
final LDKPersistHolder impl_holder = new LDKPersistHolder();
impl_holder.held = new Persist(new bindings.LDKPersist() {
- @Override public long persist_new_channel(long id, long data) {
- OutPoint id_hu_conv = new OutPoint(null, id);
- id_hu_conv.ptrs_to.add(this);
- ChannelMonitor data_hu_conv = new ChannelMonitor(null, data);
- Result_NoneChannelMonitorUpdateErrZ ret = arg.persist_new_channel(id_hu_conv, data_hu_conv);
+ @Override public long persist_new_channel(long channel_id, long data, long update_id) {
+ OutPoint channel_id_hu_conv = null; if (channel_id < 0 || channel_id > 4096) { channel_id_hu_conv = new OutPoint(null, channel_id); }
+ channel_id_hu_conv.ptrs_to.add(this);
+ ChannelMonitor data_hu_conv = null; if (data < 0 || data > 4096) { data_hu_conv = new ChannelMonitor(null, data); }
+ MonitorUpdateId update_id_hu_conv = null; if (update_id < 0 || update_id > 4096) { update_id_hu_conv = new MonitorUpdateId(null, update_id); }
+ update_id_hu_conv.ptrs_to.add(this);
+ Result_NoneChannelMonitorUpdateErrZ ret = arg.persist_new_channel(channel_id_hu_conv, data_hu_conv, update_id_hu_conv);
long result = ret != null ? ret.ptr : 0;
return result;
}
- @Override public long update_persisted_channel(long id, long update, long data) {
- OutPoint id_hu_conv = new OutPoint(null, id);
- id_hu_conv.ptrs_to.add(this);
- ChannelMonitorUpdate update_hu_conv = new ChannelMonitorUpdate(null, update);
- ChannelMonitor data_hu_conv = new ChannelMonitor(null, data);
- Result_NoneChannelMonitorUpdateErrZ ret = arg.update_persisted_channel(id_hu_conv, update_hu_conv, data_hu_conv);
+ @Override public long update_persisted_channel(long channel_id, long update, long data, long update_id) {
+ OutPoint channel_id_hu_conv = null; if (channel_id < 0 || channel_id > 4096) { channel_id_hu_conv = new OutPoint(null, channel_id); }
+ channel_id_hu_conv.ptrs_to.add(this);
+ ChannelMonitorUpdate update_hu_conv = null; if (update < 0 || update > 4096) { update_hu_conv = new ChannelMonitorUpdate(null, update); }
+ ChannelMonitor data_hu_conv = null; if (data < 0 || data > 4096) { data_hu_conv = new ChannelMonitor(null, data); }
+ MonitorUpdateId update_id_hu_conv = null; if (update_id < 0 || update_id > 4096) { update_id_hu_conv = new MonitorUpdateId(null, update_id); }
+ update_id_hu_conv.ptrs_to.add(this);
+ Result_NoneChannelMonitorUpdateErrZ ret = arg.update_persisted_channel(channel_id_hu_conv, update_hu_conv, data_hu_conv, update_id_hu_conv);
long result = ret != null ? ret.ptr : 0;
return result;
}
return impl_holder.held;
}
/**
- * Persist a new channel's data. The data can be stored any way you want, but
- * the identifier provided by Rust-Lightning is the channel's outpoint (and
- * it is up to you to maintain a correct mapping between the outpoint and the
- * stored channel data). Note that you **must** persist every new monitor to
- * disk. See the `Persist` trait documentation for more details.
+ * Persist a new channel's data in response to a [`chain::Watch::watch_channel`] call. This is
+ * called by [`ChannelManager`] for new channels, or may be called directly, e.g. on startup.
+ *
+ * The data can be stored any way you want, but the identifier provided by LDK is the
+ * channel's outpoint (and it is up to you to maintain a correct mapping between the outpoint
+ * and the stored channel data). Note that you **must** persist every new monitor to disk.
+ *
+ * The `update_id` is used to identify this call to [`ChainMonitor::channel_monitor_updated`],
+ * if you return [`ChannelMonitorUpdateErr::TemporaryFailure`].
*
* See [`Writeable::write`] on [`ChannelMonitor`] for writing out a `ChannelMonitor`
* and [`ChannelMonitorUpdateErr`] for requirements when returning errors.
*
+ * [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
* [`Writeable::write`]: crate::util::ser::Writeable::write
*/
- public Result_NoneChannelMonitorUpdateErrZ persist_new_channel(OutPoint id, ChannelMonitor data) {
- long ret = bindings.Persist_persist_new_channel(this.ptr, id == null ? 0 : id.ptr & ~1, data == null ? 0 : data.ptr & ~1);
- if (ret >= 0 && ret < 1024) { return null; }
+ public Result_NoneChannelMonitorUpdateErrZ persist_new_channel(OutPoint channel_id, ChannelMonitor data, MonitorUpdateId update_id) {
+ long ret = bindings.Persist_persist_new_channel(this.ptr, channel_id == null ? 0 : channel_id.ptr & ~1, data == null ? 0 : data.ptr & ~1, update_id == null ? 0 : update_id.ptr & ~1);
+ if (ret >= 0 && ret <= 4096) { return null; }
Result_NoneChannelMonitorUpdateErrZ ret_hu_conv = Result_NoneChannelMonitorUpdateErrZ.constr_from_ptr(ret);
this.ptrs_to.add(data);
return ret_hu_conv;
}
/**
- * Update one channel's data. The provided `ChannelMonitor` has already
- * applied the given update.
+ * Update one channel's data. The provided [`ChannelMonitor`] has already applied the given
+ * update.
*
- * Note that on every update, you **must** persist either the
- * `ChannelMonitorUpdate` or the updated monitor itself to disk/backups. See
- * the `Persist` trait documentation for more details.
+ * Note that on every update, you **must** persist either the [`ChannelMonitorUpdate`] or the
+ * updated monitor itself to disk/backups. See the [`Persist`] trait documentation for more
+ * details.
+ *
+ * During blockchain synchronization operations, this may be called with no
+ * [`ChannelMonitorUpdate`], in which case the full [`ChannelMonitor`] needs to be persisted.
+ * Note that after the full [`ChannelMonitor`] is persisted any previous
+ * [`ChannelMonitorUpdate`]s which were persisted should be discarded - they can no longer be
+ * applied to the persisted [`ChannelMonitor`] as they were already applied.
*
* If an implementer chooses to persist the updates only, they need to make
* sure that all the updates are applied to the `ChannelMonitors` *before
* them in batches. The size of each monitor grows `O(number of state updates)`
* whereas updates are small and `O(1)`.
*
+ * The `update_id` is used to identify this call to [`ChainMonitor::channel_monitor_updated`],
+ * if you return [`ChannelMonitorUpdateErr::TemporaryFailure`].
+ *
* See [`Writeable::write`] on [`ChannelMonitor`] for writing out a `ChannelMonitor`,
* [`Writeable::write`] on [`ChannelMonitorUpdate`] for writing out an update, and
* [`ChannelMonitorUpdateErr`] for requirements when returning errors.
*
* [`Writeable::write`]: crate::util::ser::Writeable::write
+ *
+ * Note that update (or a relevant inner pointer) may be NULL or all-0s to represent None
*/
- public Result_NoneChannelMonitorUpdateErrZ update_persisted_channel(OutPoint id, ChannelMonitorUpdate update, ChannelMonitor data) {
- long ret = bindings.Persist_update_persisted_channel(this.ptr, id == null ? 0 : id.ptr & ~1, update == null ? 0 : update.ptr & ~1, data == null ? 0 : data.ptr & ~1);
- if (ret >= 0 && ret < 1024) { return null; }
+ public Result_NoneChannelMonitorUpdateErrZ update_persisted_channel(OutPoint channel_id, @Nullable ChannelMonitorUpdate update, ChannelMonitor data, MonitorUpdateId update_id) {
+ long ret = bindings.Persist_update_persisted_channel(this.ptr, channel_id == null ? 0 : channel_id.ptr & ~1, update == null ? 0 : update.ptr & ~1, data == null ? 0 : data.ptr & ~1, update_id == null ? 0 : update_id.ptr & ~1);
+ if (ret >= 0 && ret <= 4096) { return null; }
Result_NoneChannelMonitorUpdateErrZ ret_hu_conv = Result_NoneChannelMonitorUpdateErrZ.constr_from_ptr(ret);
this.ptrs_to.add(update);
this.ptrs_to.add(data);