1 package org.ldk.structs;
3 import org.ldk.impl.bindings;
4 import org.ldk.enums.*;
6 import java.util.Arrays;
7 import java.lang.ref.Reference;
8 import javax.annotation.Nullable;
12 * [`Score`] implementation using channel success probability distributions.
14 * Channels are tracked with upper and lower liquidity bounds - when an HTLC fails at a channel,
15 * we learn that the upper-bound on the available liquidity is lower than the amount of the HTLC.
16 * When a payment is forwarded through a channel (but fails later in the route), we learn the
17 * lower-bound on the channel's available liquidity must be at least the value of the HTLC.
19 * These bounds are then used to determine a success probability using the formula from
20 * Optimally Reliable & Cheap Payment Flows on the Lightning Network* by Rene Pickhardt
21 * and Stefan Richter [[1]] (i.e. `(upper_bound - payment_amount) / (upper_bound - lower_bound)`).
23 * This probability is combined with the [`liquidity_penalty_multiplier_msat`] and
24 * [`liquidity_penalty_amount_multiplier_msat`] parameters to calculate a concrete penalty in
25 * milli-satoshis. The penalties, when added across all hops, have the property of being linear in
26 * terms of the entire path's success probability. This allows the router to directly compare
27 * penalties for different paths. See the documentation of those parameters for the exact formulas.
29 * The liquidity bounds are decayed by halving them every [`liquidity_offset_half_life`].
31 * Further, we track the history of our upper and lower liquidity bounds for each channel,
32 * allowing us to assign a second penalty (using [`historical_liquidity_penalty_multiplier_msat`]
33 * and [`historical_liquidity_penalty_amount_multiplier_msat`]) based on the same probability
34 * formula, but using the history of a channel rather than our latest estimates for the liquidity
39 * Mixing the `no-std` feature between serialization and deserialization results in undefined
42 * [1]: https://arxiv.org/abs/2107.05322
43 * [`liquidity_penalty_multiplier_msat`]: ProbabilisticScoringFeeParameters::liquidity_penalty_multiplier_msat
44 * [`liquidity_penalty_amount_multiplier_msat`]: ProbabilisticScoringFeeParameters::liquidity_penalty_amount_multiplier_msat
45 * [`liquidity_offset_half_life`]: ProbabilisticScoringDecayParameters::liquidity_offset_half_life
46 * [`historical_liquidity_penalty_multiplier_msat`]: ProbabilisticScoringFeeParameters::historical_liquidity_penalty_multiplier_msat
47 * [`historical_liquidity_penalty_amount_multiplier_msat`]: ProbabilisticScoringFeeParameters::historical_liquidity_penalty_amount_multiplier_msat
49 @SuppressWarnings("unchecked") // We correctly assign various generic arrays
50 public class ProbabilisticScorer extends CommonBase {
51 ProbabilisticScorer(Object _dummy, long ptr) { super(ptr); }
52 @Override @SuppressWarnings("deprecation")
53 protected void finalize() throws Throwable {
55 if (ptr != 0) { bindings.ProbabilisticScorer_free(ptr); }
59 * Creates a new scorer using the given scoring parameters for sending payments from a node
60 * through a network graph.
62 public static ProbabilisticScorer of(org.ldk.structs.ProbabilisticScoringDecayParameters decay_params, org.ldk.structs.NetworkGraph network_graph, org.ldk.structs.Logger logger) {
63 long ret = bindings.ProbabilisticScorer_new(decay_params == null ? 0 : decay_params.ptr, network_graph == null ? 0 : network_graph.ptr, logger.ptr);
64 Reference.reachabilityFence(decay_params);
65 Reference.reachabilityFence(network_graph);
66 Reference.reachabilityFence(logger);
67 if (ret >= 0 && ret <= 4096) { return null; }
68 org.ldk.structs.ProbabilisticScorer ret_hu_conv = null; if (ret < 0 || ret > 4096) { ret_hu_conv = new org.ldk.structs.ProbabilisticScorer(null, ret); }
69 if (ret_hu_conv != null) { ret_hu_conv.ptrs_to.add(ret_hu_conv); };
70 if (ret_hu_conv != null) { ret_hu_conv.ptrs_to.add(decay_params); };
71 if (ret_hu_conv != null) { ret_hu_conv.ptrs_to.add(network_graph); };
72 if (ret_hu_conv != null) { ret_hu_conv.ptrs_to.add(logger); };
77 * Dump the contents of this scorer into the configured logger.
79 * Note that this writes roughly one line per channel for which we have a liquidity estimate,
80 * which may be a substantial amount of log output.
82 public void debug_log_liquidity_stats() {
83 bindings.ProbabilisticScorer_debug_log_liquidity_stats(this.ptr);
84 Reference.reachabilityFence(this);
88 * Query the estimated minimum and maximum liquidity available for sending a payment over the
89 * channel with `scid` towards the given `target` node.
91 public Option_C2Tuple_u64u64ZZ estimated_channel_liquidity_range(long scid, org.ldk.structs.NodeId target) {
92 long ret = bindings.ProbabilisticScorer_estimated_channel_liquidity_range(this.ptr, scid, target == null ? 0 : target.ptr);
93 Reference.reachabilityFence(this);
94 Reference.reachabilityFence(scid);
95 Reference.reachabilityFence(target);
96 if (ret >= 0 && ret <= 4096) { return null; }
97 org.ldk.structs.Option_C2Tuple_u64u64ZZ ret_hu_conv = org.ldk.structs.Option_C2Tuple_u64u64ZZ.constr_from_ptr(ret);
98 if (ret_hu_conv != null) { ret_hu_conv.ptrs_to.add(this); };
99 if (this != null) { this.ptrs_to.add(target); };
104 * Query the historical estimated minimum and maximum liquidity available for sending a
105 * payment over the channel with `scid` towards the given `target` node.
107 * Returns two sets of 8 buckets. The first set describes the octiles for lower-bound
108 * liquidity estimates, the second set describes the octiles for upper-bound liquidity
109 * estimates. Each bucket describes the relative frequency at which we've seen a liquidity
110 * bound in the octile relative to the channel's total capacity, on an arbitrary scale.
111 * Because the values are slowly decayed, more recent data points are weighted more heavily
112 * than older datapoints.
114 * When scoring, the estimated probability that an upper-/lower-bound lies in a given octile
115 * relative to the channel's total capacity is calculated by dividing that bucket's value with
116 * the total of all buckets for the given bound.
118 * For example, a value of `[0, 0, 0, 0, 0, 0, 32]` indicates that we believe the probability
119 * of a bound being in the top octile to be 100%, and have never (recently) seen it in any
120 * other octiles. A value of `[31, 0, 0, 0, 0, 0, 0, 32]` indicates we've seen the bound being
121 * both in the top and bottom octile, and roughly with similar (recent) frequency.
123 * Because the datapoints are decayed slowly over time, values will eventually return to
124 * `Some(([0; 8], [0; 8]))`.
126 public Option_C2Tuple_EightU16sEightU16sZZ historical_estimated_channel_liquidity_probabilities(long scid, org.ldk.structs.NodeId target) {
127 long ret = bindings.ProbabilisticScorer_historical_estimated_channel_liquidity_probabilities(this.ptr, scid, target == null ? 0 : target.ptr);
128 Reference.reachabilityFence(this);
129 Reference.reachabilityFence(scid);
130 Reference.reachabilityFence(target);
131 if (ret >= 0 && ret <= 4096) { return null; }
132 org.ldk.structs.Option_C2Tuple_EightU16sEightU16sZZ ret_hu_conv = org.ldk.structs.Option_C2Tuple_EightU16sEightU16sZZ.constr_from_ptr(ret);
133 if (ret_hu_conv != null) { ret_hu_conv.ptrs_to.add(this); };
134 if (this != null) { this.ptrs_to.add(target); };
139 * Constructs a new Score which calls the relevant methods on this_arg.
140 * This copies the `inner` pointer in this_arg and thus the returned Score must be freed before this_arg is
142 public Score as_Score() {
143 long ret = bindings.ProbabilisticScorer_as_Score(this.ptr);
144 Reference.reachabilityFence(this);
145 if (ret >= 0 && ret <= 4096) { return null; }
146 Score ret_hu_conv = new Score(null, ret);
147 if (ret_hu_conv != null) { ret_hu_conv.ptrs_to.add(this); };
152 * Serialize the ProbabilisticScorer object into a byte array which can be read by ProbabilisticScorer_read
154 public byte[] write() {
155 byte[] ret = bindings.ProbabilisticScorer_write(this.ptr);
156 Reference.reachabilityFence(this);
161 * Read a ProbabilisticScorer from a byte array, created by ProbabilisticScorer_write
163 public static Result_ProbabilisticScorerDecodeErrorZ read(byte[] ser, org.ldk.structs.ProbabilisticScoringDecayParameters arg_a, org.ldk.structs.NetworkGraph arg_b, org.ldk.structs.Logger arg_c) {
164 long ret = bindings.ProbabilisticScorer_read(ser, arg_a == null ? 0 : arg_a.ptr, arg_b == null ? 0 : arg_b.ptr, arg_c.ptr);
165 Reference.reachabilityFence(ser);
166 Reference.reachabilityFence(arg_a);
167 Reference.reachabilityFence(arg_b);
168 Reference.reachabilityFence(arg_c);
169 if (ret >= 0 && ret <= 4096) { return null; }
170 Result_ProbabilisticScorerDecodeErrorZ ret_hu_conv = Result_ProbabilisticScorerDecodeErrorZ.constr_from_ptr(ret);
171 if (ret_hu_conv != null) { ret_hu_conv.ptrs_to.add(arg_a); };
172 if (ret_hu_conv != null) { ret_hu_conv.ptrs_to.add(arg_b); };
173 if (ret_hu_conv != null) { ret_hu_conv.ptrs_to.add(arg_c); };