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 * [`TemporaryFailure`]: channelmonitor::ChannelMonitorUpdateErr::TemporaryFailure
27 * [BIP 157]: https://github.com/bitcoin/bips/blob/master/bip-0157.mediawiki
28 * [BIP 158]: https://github.com/bitcoin/bips/blob/master/bip-0158.mediawiki
30 @SuppressWarnings("unchecked") // We correctly assign various generic arrays
31 public class Filter extends CommonBase {
32 final bindings.LDKFilter bindings_instance;
33 Filter(Object _dummy, long ptr) { super(ptr); bindings_instance = null; }
34 private Filter(bindings.LDKFilter arg) {
35 super(bindings.LDKFilter_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.Filter_free(ptr); } super.finalize();
44 public static interface FilterInterface {
46 * Registers interest in a transaction with `txid` and having an output with `script_pubkey` as
47 * a spending condition.
49 void register_tx(byte[] txid, byte[] script_pubkey);
51 * Registers interest in spends of a transaction output.
53 * Optionally, when `output.block_hash` is set, should return any transaction spending the
54 * output that is found in the corresponding block along with its index.
56 * This return value is useful for Electrum clients in order to supply in-block descendant
57 * transactions which otherwise were not included. This is not necessary for other clients if
58 * such descendant transactions were already included (e.g., when a BIP 157 client provides the
61 Option_C2Tuple_usizeTransactionZZ register_output(WatchedOutput output);
63 private static class LDKFilterHolder { Filter held; }
64 public static Filter new_impl(FilterInterface arg) {
65 final LDKFilterHolder impl_holder = new LDKFilterHolder();
66 impl_holder.held = new Filter(new bindings.LDKFilter() {
67 @Override public void register_tx(byte[] txid, byte[] script_pubkey) {
68 arg.register_tx(txid, script_pubkey);
70 @Override public long register_output(long output) {
71 WatchedOutput output_hu_conv = new WatchedOutput(null, output);
72 output_hu_conv.ptrs_to.add(this);
73 Option_C2Tuple_usizeTransactionZZ ret = arg.register_output(output_hu_conv);
74 long result = ret.ptr;
78 return impl_holder.held;
81 * Registers interest in a transaction with `txid` and having an output with `script_pubkey` as
82 * a spending condition.
84 public void register_tx(byte[] txid, byte[] script_pubkey) {
85 bindings.Filter_register_tx(this.ptr, txid, script_pubkey);
89 * Registers interest in spends of a transaction output.
91 * Optionally, when `output.block_hash` is set, should return any transaction spending the
92 * output that is found in the corresponding block along with its index.
94 * This return value is useful for Electrum clients in order to supply in-block descendant
95 * transactions which otherwise were not included. This is not necessary for other clients if
96 * such descendant transactions were already included (e.g., when a BIP 157 client provides the
99 public Option_C2Tuple_usizeTransactionZZ register_output(WatchedOutput output) {
100 long ret = bindings.Filter_register_output(this.ptr, output == null ? 0 : output.ptr & ~1);
101 Option_C2Tuple_usizeTransactionZZ ret_hu_conv = Option_C2Tuple_usizeTransactionZZ.constr_from_ptr(ret);
102 ret_hu_conv.ptrs_to.add(this);
103 this.ptrs_to.add(output);