6 namespace org { namespace ldk { namespace structs {
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 [`InProgress`].
26 * [`InProgress`]: ChannelMonitorUpdateStatus::InProgress
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 public class Filter : CommonBase {
31 internal readonly bindings.LDKFilter bindings_instance;
32 internal Filter(object _dummy, long ptr) : base(ptr) { bindings_instance = null; }
33 private Filter(bindings.LDKFilter arg) : base(bindings.LDKFilter_new(arg)) {
34 this.ptrs_to.AddLast(arg);
35 this.bindings_instance = arg;
38 if (ptr != 0) { bindings.Filter_free(ptr); }
41 public interface FilterInterface {
43 * Registers interest in a transaction with `txid` and having an output with `script_pubkey` as
44 * a spending condition.
46 void register_tx(byte[] _txid, byte[] _script_pubkey);
48 * Registers interest in spends of a transaction output.
50 * Note that this method might be called during processing of a new block. You therefore need
51 * to ensure that also dependent output spents within an already connected block are correctly
52 * handled, e.g., by re-scanning the block in question whenever new outputs have been
53 * registered mid-processing.
55 void register_output(WatchedOutput _output);
57 private class LDKFilterHolder { internal Filter held; }
58 private class LDKFilterImpl : bindings.LDKFilter {
59 internal LDKFilterImpl(FilterInterface arg, LDKFilterHolder impl_holder) { this.arg = arg; this.impl_holder = impl_holder; }
60 private FilterInterface arg;
61 private LDKFilterHolder impl_holder;
62 public void register_tx(byte[] _txid, byte[] _script_pubkey) {
63 arg.register_tx(_txid, _script_pubkey);
66 public void register_output(long _output) {
67 org.ldk.structs.WatchedOutput _output_hu_conv = null; if (_output < 0 || _output > 4096) { _output_hu_conv = new org.ldk.structs.WatchedOutput(null, _output); }
68 if (_output_hu_conv != null) { _output_hu_conv.ptrs_to.AddLast(this); };
69 arg.register_output(_output_hu_conv);
73 public static Filter new_impl(FilterInterface arg) {
74 LDKFilterHolder impl_holder = new LDKFilterHolder();
75 impl_holder.held = new Filter(new LDKFilterImpl(arg, impl_holder));
76 return impl_holder.held;
79 * Registers interest in a transaction with `txid` and having an output with `script_pubkey` as
80 * a spending condition.
82 public void register_tx(byte[] txid, byte[] script_pubkey) {
83 bindings.Filter_register_tx(this.ptr, InternalUtils.check_arr_len(txid, 32), script_pubkey);
86 GC.KeepAlive(script_pubkey);
90 * Registers interest in spends of a transaction output.
92 * Note that this method might be called during processing of a new block. You therefore need
93 * to ensure that also dependent output spents within an already connected block are correctly
94 * handled, e.g., by re-scanning the block in question whenever new outputs have been
95 * registered mid-processing.
97 public void register_output(org.ldk.structs.WatchedOutput output) {
98 bindings.Filter_register_output(this.ptr, output == null ? 0 : output.ptr);
100 GC.KeepAlive(output);
101 if (this != null) { this.ptrs_to.AddLast(output); };