1 package org.ldk.structs;
3 import org.ldk.impl.bindings;
4 import org.ldk.enums.*;
6 import java.util.Arrays;
9 * The `Filter` trait defines behavior for indicating chain activity of interest pertaining to
12 * This is useful in order to have a [`Watch`] implementation convey to a chain source which
13 * transactions to be notified of. Notification may take the form of pre-filtering blocks or, in
14 * the case of [BIP 157]/[BIP 158], only fetching a block if the compact filter matches. If
15 * receiving full blocks from a chain source, any further filtering is unnecessary.
17 * After an output has been registered, subsequent block retrievals from the chain source must not
18 * exclude any transactions matching the new criteria nor any in-block descendants of such
21 * Note that use as part of a [`Watch`] implementation involves reentrancy. Therefore, the `Filter`
22 * should not block on I/O. Implementations should instead queue the newly monitored data to be
23 * processed later. Then, in order to block until the data has been processed, any `Watch`
24 * invocation that has called the `Filter` must return [`TemporaryFailure`].
26 * [`Watch`]: trait.Watch.html
27 * [`TemporaryFailure`]: channelmonitor/enum.ChannelMonitorUpdateErr.html#variant.TemporaryFailure
28 * [BIP 157]: https://github.com/bitcoin/bips/blob/master/bip-0157.mediawiki
29 * [BIP 158]: https://github.com/bitcoin/bips/blob/master/bip-0158.mediawiki
31 @SuppressWarnings("unchecked") // We correctly assign various generic arrays
32 public class Filter extends CommonBase {
33 final bindings.LDKFilter bindings_instance;
34 Filter(Object _dummy, long ptr) { super(ptr); bindings_instance = null; }
35 private Filter(bindings.LDKFilter arg) {
36 super(bindings.LDKFilter_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.Filter_free(ptr); } super.finalize();
45 public static interface FilterInterface {
47 * Registers interest in a transaction with `txid` and having an output with `script_pubkey` as
48 * a spending condition.
50 void register_tx(byte[] txid, byte[] script_pubkey);
52 * Registers interest in spends of a transaction output identified by `outpoint` having
53 * `script_pubkey` as the spending condition.
55 void register_output(OutPoint outpoint, byte[] script_pubkey);
57 private static class LDKFilterHolder { Filter held; }
58 public static Filter new_impl(FilterInterface arg) {
59 final LDKFilterHolder impl_holder = new LDKFilterHolder();
60 impl_holder.held = new Filter(new bindings.LDKFilter() {
61 @Override public void register_tx(byte[] txid, byte[] script_pubkey) {
62 arg.register_tx(txid, script_pubkey);
64 @Override public void register_output(long outpoint, byte[] script_pubkey) {
65 OutPoint outpoint_hu_conv = new OutPoint(null, outpoint);
66 arg.register_output(outpoint_hu_conv, script_pubkey);
69 return impl_holder.held;
72 * Registers interest in a transaction with `txid` and having an output with `script_pubkey` as
73 * a spending condition.
75 public void register_tx(byte[] txid, byte[] script_pubkey) {
76 bindings.Filter_register_tx(this.ptr, txid, script_pubkey);
80 * Registers interest in spends of a transaction output identified by `outpoint` having
81 * `script_pubkey` as the spending condition.
83 public void register_output(OutPoint outpoint, byte[] script_pubkey) {
84 bindings.Filter_register_output(this.ptr, outpoint == null ? 0 : outpoint.ptr & ~1, script_pubkey);
85 this.ptrs_to.add(outpoint);