--- /dev/null
+package org.ldk.structs;
+
+import org.ldk.impl.bindings;
+import org.ldk.enums.*;
+import org.ldk.util.*;
+import java.util.Arrays;
+import java.lang.ref.Reference;
+import javax.annotation.Nullable;
+
+
+/**
+ * Implements [`Persist`] in a way that writes and reads both [`ChannelMonitor`]s and
+ * [`ChannelMonitorUpdate`]s.
+ *
+ * # Overview
+ *
+ * The main benefit this provides over the [`KVStore`]'s [`Persist`] implementation is decreased
+ * I/O bandwidth and storage churn, at the expense of more IOPS (including listing, reading, and
+ * deleting) and complexity. This is because it writes channel monitor differential updates,
+ * whereas the other (default) implementation rewrites the entire monitor on each update. For
+ * routing nodes, updates can happen many times per second to a channel, and monitors can be tens
+ * of megabytes (or more). Updates can be as small as a few hundred bytes.
+ *
+ * Note that monitors written with `MonitorUpdatingPersister` are _not_ backward-compatible with
+ * the default [`KVStore`]'s [`Persist`] implementation. They have a prepended byte sequence,
+ * [`MONITOR_UPDATING_PERSISTER_PREPEND_SENTINEL`], applied to prevent deserialization with other
+ * persisters. This is because monitors written by this struct _may_ have unapplied updates. In
+ * order to downgrade, you must ensure that all updates are applied to the monitor, and remove the
+ * sentinel bytes.
+ *
+ * # Storing monitors
+ *
+ * Monitors are stored by implementing the [`Persist`] trait, which has two functions:
+ *
+ * - [`Persist::persist_new_channel`], which persists whole [`ChannelMonitor`]s.
+ * - [`Persist::update_persisted_channel`], which persists only a [`ChannelMonitorUpdate`]
+ *
+ * Whole [`ChannelMonitor`]s are stored in the [`CHANNEL_MONITOR_PERSISTENCE_PRIMARY_NAMESPACE`],
+ * using the familiar encoding of an [`OutPoint`] (for example, `[SOME-64-CHAR-HEX-STRING]_1`).
+ *
+ * Each [`ChannelMonitorUpdate`] is stored in a dynamic secondary namespace, as follows:
+ *
+ * - primary namespace: [`CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE`]
+ * - secondary namespace: [the monitor's encoded outpoint name]
+ *
+ * Under that secondary namespace, each update is stored with a number string, like `21`, which
+ * represents its `update_id` value.
+ *
+ * For example, consider this channel, named for its transaction ID and index, or [`OutPoint`]:
+ *
+ * - Transaction ID: `deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef`
+ * - Index: `1`
+ *
+ * Full channel monitors would be stored at a single key:
+ *
+ * `[CHANNEL_MONITOR_PERSISTENCE_PRIMARY_NAMESPACE]/deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef_1`
+ *
+ * Updates would be stored as follows (with `/` delimiting primary_namespace/secondary_namespace/key):
+ *
+ * ```text
+ * [CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE]/deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef_1/1
+ * [CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE]/deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef_1/2
+ * [CHANNEL_MONITOR_UPDATE_PERSISTENCE_PRIMARY_NAMESPACE]/deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef_1/3
+ * ```
+ * ... and so on.
+ *
+ * # Reading channel state from storage
+ *
+ * Channel state can be reconstructed by calling
+ * [`MonitorUpdatingPersister::read_all_channel_monitors_with_updates`]. Alternatively, users can
+ * list channel monitors themselves and load channels individually using
+ * [`MonitorUpdatingPersister::read_channel_monitor_with_updates`].
+ *
+ * ## EXTREMELY IMPORTANT
+ *
+ * It is extremely important that your [`KVStore::read`] implementation uses the
+ * [`io::ErrorKind::NotFound`] variant correctly: that is, when a file is not found, and _only_ in
+ * that circumstance (not when there is really a permissions error, for example). This is because
+ * neither channel monitor reading function lists updates. Instead, either reads the monitor, and
+ * using its stored `update_id`, synthesizes update storage keys, and tries them in sequence until
+ * one is not found. All _other_ errors will be bubbled up in the function's [`Result`].
+ *
+ * # Pruning stale channel updates
+ *
+ * Stale updates are pruned when a full monitor is written. The old monitor is first read, and if
+ * that succeeds, updates in the range between the old and new monitors are deleted. The `lazy`
+ * flag is used on the [`KVStore::remove`] method, so there are no guarantees that the deletions
+ * will complete. However, stale updates are not a problem for data integrity, since updates are
+ * only read that are higher than the stored [`ChannelMonitor`]'s `update_id`.
+ *
+ * If you have many stale updates stored (such as after a crash with pending lazy deletes), and
+ * would like to get rid of them, consider using the
+ * [`MonitorUpdatingPersister::cleanup_stale_updates`] function.
+ */
+@SuppressWarnings("unchecked") // We correctly assign various generic arrays
+public class MonitorUpdatingPersister extends CommonBase {
+ MonitorUpdatingPersister(Object _dummy, long ptr) { super(ptr); }
+ @Override @SuppressWarnings("deprecation")
+ protected void finalize() throws Throwable {
+ super.finalize();
+ if (ptr != 0) { bindings.MonitorUpdatingPersister_free(ptr); }
+ }
+
+ /**
+ * Constructs a new [`MonitorUpdatingPersister`].
+ *
+ * The `maximum_pending_updates` parameter controls how many updates may be stored before a
+ * [`MonitorUpdatingPersister`] consolidates updates by writing a full monitor. Note that
+ * consolidation will frequently occur with fewer updates than what you set here; this number
+ * is merely the maximum that may be stored. When setting this value, consider that for higher
+ * values of `maximum_pending_updates`:
+ *
+ * - [`MonitorUpdatingPersister`] will tend to write more [`ChannelMonitorUpdate`]s than
+ * [`ChannelMonitor`]s, approaching one [`ChannelMonitor`] write for every
+ * `maximum_pending_updates` [`ChannelMonitorUpdate`]s.
+ * - [`MonitorUpdatingPersister`] will issue deletes differently. Lazy deletes will come in
+ * \"waves\" for each [`ChannelMonitor`] write. A larger `maximum_pending_updates` means bigger,
+ * less frequent \"waves.\"
+ * - [`MonitorUpdatingPersister`] will potentially have more listing to do if you need to run
+ * [`MonitorUpdatingPersister::cleanup_stale_updates`].
+ */
+ public static MonitorUpdatingPersister of(org.ldk.structs.KVStore kv_store, org.ldk.structs.Logger logger, long maximum_pending_updates, org.ldk.structs.EntropySource entropy_source, org.ldk.structs.SignerProvider signer_provider) {
+ long ret = bindings.MonitorUpdatingPersister_new(kv_store.ptr, logger.ptr, maximum_pending_updates, entropy_source.ptr, signer_provider.ptr);
+ Reference.reachabilityFence(kv_store);
+ Reference.reachabilityFence(logger);
+ Reference.reachabilityFence(maximum_pending_updates);
+ Reference.reachabilityFence(entropy_source);
+ Reference.reachabilityFence(signer_provider);
+ if (ret >= 0 && ret <= 4096) { return null; }
+ org.ldk.structs.MonitorUpdatingPersister ret_hu_conv = null; if (ret < 0 || ret > 4096) { ret_hu_conv = new org.ldk.structs.MonitorUpdatingPersister(null, ret); }
+ if (ret_hu_conv != null) { ret_hu_conv.ptrs_to.add(ret_hu_conv); };
+ if (ret_hu_conv != null) { ret_hu_conv.ptrs_to.add(kv_store); };
+ if (ret_hu_conv != null) { ret_hu_conv.ptrs_to.add(logger); };
+ if (ret_hu_conv != null) { ret_hu_conv.ptrs_to.add(entropy_source); };
+ if (ret_hu_conv != null) { ret_hu_conv.ptrs_to.add(signer_provider); };
+ return ret_hu_conv;
+ }
+
+ /**
+ * Reads all stored channel monitors, along with any stored updates for them.
+ *
+ * It is extremely important that your [`KVStore::read`] implementation uses the
+ * [`io::ErrorKind::NotFound`] variant correctly. For more information, please see the
+ * documentation for [`MonitorUpdatingPersister`].
+ */
+ public Result_CVec_C2Tuple_ThirtyTwoBytesChannelMonitorZZIOErrorZ read_all_channel_monitors_with_updates(org.ldk.structs.BroadcasterInterface broadcaster, org.ldk.structs.FeeEstimator fee_estimator) {
+ long ret = bindings.MonitorUpdatingPersister_read_all_channel_monitors_with_updates(this.ptr, broadcaster.ptr, fee_estimator.ptr);
+ Reference.reachabilityFence(this);
+ Reference.reachabilityFence(broadcaster);
+ Reference.reachabilityFence(fee_estimator);
+ if (ret >= 0 && ret <= 4096) { return null; }
+ Result_CVec_C2Tuple_ThirtyTwoBytesChannelMonitorZZIOErrorZ ret_hu_conv = Result_CVec_C2Tuple_ThirtyTwoBytesChannelMonitorZZIOErrorZ.constr_from_ptr(ret);
+ if (this != null) { this.ptrs_to.add(broadcaster); };
+ if (this != null) { this.ptrs_to.add(fee_estimator); };
+ return ret_hu_conv;
+ }
+
+ /**
+ * Read a single channel monitor, along with any stored updates for it.
+ *
+ * It is extremely important that your [`KVStore::read`] implementation uses the
+ * [`io::ErrorKind::NotFound`] variant correctly. For more information, please see the
+ * documentation for [`MonitorUpdatingPersister`].
+ *
+ * For `monitor_key`, channel storage keys be the channel's transaction ID and index, or
+ * [`OutPoint`], with an underscore `_` between them. For example, given:
+ *
+ * - Transaction ID: `deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef`
+ * - Index: `1`
+ *
+ * The correct `monitor_key` would be:
+ * `deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef_1`
+ *
+ * Loading a large number of monitors will be faster if done in parallel. You can use this
+ * function to accomplish this. Take care to limit the number of parallel readers.
+ */
+ public Result_C2Tuple_ThirtyTwoBytesChannelMonitorZIOErrorZ read_channel_monitor_with_updates(org.ldk.structs.BroadcasterInterface broadcaster, org.ldk.structs.FeeEstimator fee_estimator, java.lang.String monitor_key) {
+ long ret = bindings.MonitorUpdatingPersister_read_channel_monitor_with_updates(this.ptr, broadcaster.ptr, fee_estimator.ptr, monitor_key);
+ Reference.reachabilityFence(this);
+ Reference.reachabilityFence(broadcaster);
+ Reference.reachabilityFence(fee_estimator);
+ Reference.reachabilityFence(monitor_key);
+ if (ret >= 0 && ret <= 4096) { return null; }
+ Result_C2Tuple_ThirtyTwoBytesChannelMonitorZIOErrorZ ret_hu_conv = Result_C2Tuple_ThirtyTwoBytesChannelMonitorZIOErrorZ.constr_from_ptr(ret);
+ if (this != null) { this.ptrs_to.add(broadcaster); };
+ if (this != null) { this.ptrs_to.add(fee_estimator); };
+ return ret_hu_conv;
+ }
+
+ /**
+ * Cleans up stale updates for all monitors.
+ *
+ * This function works by first listing all monitors, and then for each of them, listing all
+ * updates. The updates that have an `update_id` less than or equal to than the stored monitor
+ * are deleted. The deletion can either be lazy or non-lazy based on the `lazy` flag; this will
+ * be passed to [`KVStore::remove`].
+ */
+ public Result_NoneIOErrorZ cleanup_stale_updates(boolean lazy) {
+ long ret = bindings.MonitorUpdatingPersister_cleanup_stale_updates(this.ptr, lazy);
+ Reference.reachabilityFence(this);
+ Reference.reachabilityFence(lazy);
+ if (ret >= 0 && ret <= 4096) { return null; }
+ Result_NoneIOErrorZ ret_hu_conv = Result_NoneIOErrorZ.constr_from_ptr(ret);
+ return ret_hu_conv;
+ }
+
+ /**
+ * Constructs a new Persist which calls the relevant methods on this_arg.
+ * This copies the `inner` pointer in this_arg and thus the returned Persist must be freed before this_arg is
+ */
+ public Persist as_Persist() {
+ long ret = bindings.MonitorUpdatingPersister_as_Persist(this.ptr);
+ Reference.reachabilityFence(this);
+ if (ret >= 0 && ret <= 4096) { return null; }
+ Persist ret_hu_conv = new Persist(null, ret);
+ if (ret_hu_conv != null) { ret_hu_conv.ptrs_to.add(this); };
+ return ret_hu_conv;
+ }
+
+}
projects / ldk-java / blobdiff