Merge pull request #642 from ariard/2020-06-anchor-backend-refacto
[rust-lightning] / lightning / src / ln / onchaintx.rs
diff --git a/lightning/src/ln/onchaintx.rs b/lightning/src/ln/onchaintx.rs
deleted file mode 100644 (file)
index 16bb646..0000000
+++ /dev/null
@@ -1,1073 +0,0 @@
-// This file is Copyright its original authors, visible in version control
-// history.
-//
-// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
-// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
-// You may not use this file except in accordance with one or both of these
-// licenses.
-
-//! The logic to build claims and bump in-flight transactions until confirmations.
-//!
-//! OnchainTxHandler objects are fully-part of ChannelMonitor and encapsulates all
-//! building, tracking, bumping and notifications functions.
-
-use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
-use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
-use bitcoin::blockdata::script::Script;
-
-use bitcoin::hash_types::Txid;
-
-use bitcoin::secp256k1::{Secp256k1, Signature};
-use bitcoin::secp256k1;
-
-use ln::msgs::DecodeError;
-use ln::PaymentPreimage;
-use ln::chan_utils;
-use ln::chan_utils::{TxCreationKeys, ChannelTransactionParameters, HolderCommitmentTransaction};
-use chain::chaininterface::{FeeEstimator, BroadcasterInterface, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT};
-use chain::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER, InputMaterial, ClaimRequest};
-use chain::keysinterface::{Sign, KeysInterface};
-use util::logger::Logger;
-use util::ser::{Readable, ReadableArgs, Writer, Writeable, VecWriter};
-use util::byte_utils;
-
-use std::collections::HashMap;
-use core::cmp;
-use core::ops::Deref;
-use core::mem::replace;
-
-const MAX_ALLOC_SIZE: usize = 64*1024;
-
-/// An entry for an [`OnchainEvent`], stating the block height when the event was observed and the
-/// transaction causing it.
-///
-/// Used to determine when the on-chain event can be considered safe from a chain reorganization.
-#[derive(PartialEq)]
-struct OnchainEventEntry {
-       txid: Txid,
-       height: u32,
-       event: OnchainEvent,
-}
-
-impl OnchainEventEntry {
-       fn confirmation_threshold(&self) -> u32 {
-               self.height + ANTI_REORG_DELAY - 1
-       }
-
-       fn has_reached_confirmation_threshold(&self, height: u32) -> bool {
-               height >= self.confirmation_threshold()
-       }
-}
-
-/// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
-/// once they mature to enough confirmations (ANTI_REORG_DELAY)
-#[derive(PartialEq)]
-enum OnchainEvent {
-       /// Outpoint under claim process by our own tx, once this one get enough confirmations, we remove it from
-       /// bump-txn candidate buffer.
-       Claim {
-               claim_request: Txid,
-       },
-       /// Claim tx aggregate multiple claimable outpoints. One of the outpoint may be claimed by a counterparty party tx.
-       /// In this case, we need to drop the outpoint and regenerate a new claim tx. By safety, we keep tracking
-       /// the outpoint to be sure to resurect it back to the claim tx if reorgs happen.
-       ContentiousOutpoint {
-               outpoint: BitcoinOutPoint,
-               input_material: InputMaterial,
-       }
-}
-
-/// Higher-level cache structure needed to re-generate bumped claim txn if needed
-#[derive(Clone, PartialEq)]
-pub struct ClaimTxBumpMaterial {
-       // At every block tick, used to check if pending claiming tx is taking too
-       // much time for confirmation and we need to bump it.
-       height_timer: Option<u32>,
-       // Tracked in case of reorg to wipe out now-superflous bump material
-       feerate_previous: u32,
-       // Soonest timelocks among set of outpoints claimed, used to compute
-       // a priority of not feerate
-       soonest_timelock: u32,
-       // Cache of script, pubkey, sig or key to solve claimable outputs scriptpubkey.
-       per_input_material: HashMap<BitcoinOutPoint, InputMaterial>,
-}
-
-impl Writeable for ClaimTxBumpMaterial  {
-       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
-               self.height_timer.write(writer)?;
-               writer.write_all(&byte_utils::be32_to_array(self.feerate_previous))?;
-               writer.write_all(&byte_utils::be32_to_array(self.soonest_timelock))?;
-               writer.write_all(&byte_utils::be64_to_array(self.per_input_material.len() as u64))?;
-               for (outp, tx_material) in self.per_input_material.iter() {
-                       outp.write(writer)?;
-                       tx_material.write(writer)?;
-               }
-               Ok(())
-       }
-}
-
-impl Readable for ClaimTxBumpMaterial {
-       fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
-               let height_timer = Readable::read(reader)?;
-               let feerate_previous = Readable::read(reader)?;
-               let soonest_timelock = Readable::read(reader)?;
-               let per_input_material_len: u64 = Readable::read(reader)?;
-               let mut per_input_material = HashMap::with_capacity(cmp::min(per_input_material_len as usize, MAX_ALLOC_SIZE / 128));
-               for _ in 0 ..per_input_material_len {
-                       let outpoint = Readable::read(reader)?;
-                       let input_material = Readable::read(reader)?;
-                       per_input_material.insert(outpoint, input_material);
-               }
-               Ok(Self { height_timer, feerate_previous, soonest_timelock, per_input_material })
-       }
-}
-
-#[derive(PartialEq, Clone, Copy)]
-pub(crate) enum InputDescriptors {
-       RevokedOfferedHTLC,
-       RevokedReceivedHTLC,
-       OfferedHTLC,
-       ReceivedHTLC,
-       RevokedOutput, // either a revoked to_holder output on commitment tx, a revoked HTLC-Timeout output or a revoked HTLC-Success output
-}
-
-impl Writeable for InputDescriptors {
-       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
-               match self {
-                       &InputDescriptors::RevokedOfferedHTLC => {
-                               writer.write_all(&[0; 1])?;
-                       },
-                       &InputDescriptors::RevokedReceivedHTLC => {
-                               writer.write_all(&[1; 1])?;
-                       },
-                       &InputDescriptors::OfferedHTLC => {
-                               writer.write_all(&[2; 1])?;
-                       },
-                       &InputDescriptors::ReceivedHTLC => {
-                               writer.write_all(&[3; 1])?;
-                       }
-                       &InputDescriptors::RevokedOutput => {
-                               writer.write_all(&[4; 1])?;
-                       }
-               }
-               Ok(())
-       }
-}
-
-impl Readable for InputDescriptors {
-       fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
-               let input_descriptor = match <u8 as Readable>::read(reader)? {
-                       0 => {
-                               InputDescriptors::RevokedOfferedHTLC
-                       },
-                       1 => {
-                               InputDescriptors::RevokedReceivedHTLC
-                       },
-                       2 => {
-                               InputDescriptors::OfferedHTLC
-                       },
-                       3 => {
-                               InputDescriptors::ReceivedHTLC
-                       },
-                       4 => {
-                               InputDescriptors::RevokedOutput
-                       }
-                       _ => return Err(DecodeError::InvalidValue),
-               };
-               Ok(input_descriptor)
-       }
-}
-
-macro_rules! subtract_high_prio_fee {
-       ($logger: ident, $fee_estimator: expr, $value: expr, $predicted_weight: expr, $used_feerate: expr) => {
-               {
-                       $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority).into();
-                       let mut fee = $used_feerate as u64 * $predicted_weight / 1000;
-                       if $value <= fee {
-                               $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal).into();
-                               fee = $used_feerate as u64 * $predicted_weight / 1000;
-                               if $value <= fee.into() {
-                                       $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background).into();
-                                       fee = $used_feerate as u64 * $predicted_weight / 1000;
-                                       if $value <= fee {
-                                               log_error!($logger, "Failed to generate an on-chain punishment tx as even low priority fee ({} sat) was more than the entire claim balance ({} sat)",
-                                                       fee, $value);
-                                               false
-                                       } else {
-                                               log_warn!($logger, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
-                                                       $value);
-                                               $value -= fee;
-                                               true
-                                       }
-                               } else {
-                                       log_warn!($logger, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
-                                               $value);
-                                       $value -= fee;
-                                       true
-                               }
-                       } else {
-                               $value -= fee;
-                               true
-                       }
-               }
-       }
-}
-
-impl Readable for Option<Vec<Option<(usize, Signature)>>> {
-       fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
-               match Readable::read(reader)? {
-                       0u8 => Ok(None),
-                       1u8 => {
-                               let vlen: u64 = Readable::read(reader)?;
-                               let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::core::mem::size_of::<Option<(usize, Signature)>>()));
-                               for _ in 0..vlen {
-                                       ret.push(match Readable::read(reader)? {
-                                               0u8 => None,
-                                               1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
-                                               _ => return Err(DecodeError::InvalidValue)
-                                       });
-                               }
-                               Ok(Some(ret))
-                       },
-                       _ => Err(DecodeError::InvalidValue),
-               }
-       }
-}
-
-impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
-       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
-               match self {
-                       &Some(ref vec) => {
-                               1u8.write(writer)?;
-                               (vec.len() as u64).write(writer)?;
-                               for opt in vec.iter() {
-                                       match opt {
-                                               &Some((ref idx, ref sig)) => {
-                                                       1u8.write(writer)?;
-                                                       (*idx as u64).write(writer)?;
-                                                       sig.write(writer)?;
-                                               },
-                                               &None => 0u8.write(writer)?,
-                                       }
-                               }
-                       },
-                       &None => 0u8.write(writer)?,
-               }
-               Ok(())
-       }
-}
-
-
-/// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
-/// do RBF bumping if possible.
-pub struct OnchainTxHandler<ChannelSigner: Sign> {
-       destination_script: Script,
-       holder_commitment: HolderCommitmentTransaction,
-       // holder_htlc_sigs and prev_holder_htlc_sigs are in the order as they appear in the commitment
-       // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
-       // the set of HTLCs in the HolderCommitmentTransaction.
-       holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
-       prev_holder_commitment: Option<HolderCommitmentTransaction>,
-       prev_holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
-
-       signer: ChannelSigner,
-       pub(crate) channel_transaction_parameters: ChannelTransactionParameters,
-
-       // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
-       // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
-       // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
-       // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
-       // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
-       // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
-       // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
-       // we need to regenerate new claim request with reduced set of still-claimable outpoints.
-       // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
-       // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
-       // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
-       #[cfg(test)] // Used in functional_test to verify sanitization
-       pub pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
-       #[cfg(not(test))]
-       pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
-
-       // Used to link outpoints claimed in a connected block to a pending claim request.
-       // Key is outpoint than monitor parsing has detected we have keys/scripts to claim
-       // Value is (pending claim request identifier, confirmation_block), identifier
-       // is txid of the initial claiming transaction and is immutable until outpoint is
-       // post-anti-reorg-delay solved, confirmaiton_block is used to erase entry if
-       // block with output gets disconnected.
-       #[cfg(test)] // Used in functional_test to verify sanitization
-       pub claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
-       #[cfg(not(test))]
-       claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
-
-       onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
-
-       latest_height: u32,
-
-       secp_ctx: Secp256k1<secp256k1::All>,
-}
-
-const SERIALIZATION_VERSION: u8 = 1;
-const MIN_SERIALIZATION_VERSION: u8 = 1;
-
-impl<ChannelSigner: Sign> OnchainTxHandler<ChannelSigner> {
-       pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
-               write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
-
-               self.destination_script.write(writer)?;
-               self.holder_commitment.write(writer)?;
-               self.holder_htlc_sigs.write(writer)?;
-               self.prev_holder_commitment.write(writer)?;
-               self.prev_holder_htlc_sigs.write(writer)?;
-
-               self.channel_transaction_parameters.write(writer)?;
-
-               let mut key_data = VecWriter(Vec::new());
-               self.signer.write(&mut key_data)?;
-               assert!(key_data.0.len() < core::usize::MAX);
-               assert!(key_data.0.len() < core::u32::MAX as usize);
-               (key_data.0.len() as u32).write(writer)?;
-               writer.write_all(&key_data.0[..])?;
-
-               writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
-               for (ref ancestor_claim_txid, claim_tx_data) in self.pending_claim_requests.iter() {
-                       ancestor_claim_txid.write(writer)?;
-                       claim_tx_data.write(writer)?;
-               }
-
-               writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
-               for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
-                       outp.write(writer)?;
-                       claim_and_height.0.write(writer)?;
-                       claim_and_height.1.write(writer)?;
-               }
-
-               writer.write_all(&byte_utils::be64_to_array(self.onchain_events_awaiting_threshold_conf.len() as u64))?;
-               for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
-                       entry.txid.write(writer)?;
-                       writer.write_all(&byte_utils::be32_to_array(entry.height))?;
-                       match entry.event {
-                               OnchainEvent::Claim { ref claim_request } => {
-                                       writer.write_all(&[0; 1])?;
-                                       claim_request.write(writer)?;
-                               },
-                               OnchainEvent::ContentiousOutpoint { ref outpoint, ref input_material } => {
-                                       writer.write_all(&[1; 1])?;
-                                       outpoint.write(writer)?;
-                                       input_material.write(writer)?;
-                               }
-                       }
-               }
-               self.latest_height.write(writer)?;
-
-               write_tlv_fields!(writer, {}, {});
-               Ok(())
-       }
-}
-
-impl<'a, K: KeysInterface> ReadableArgs<&'a K> for OnchainTxHandler<K::Signer> {
-       fn read<R: ::std::io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
-               let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
-
-               let destination_script = Readable::read(reader)?;
-
-               let holder_commitment = Readable::read(reader)?;
-               let holder_htlc_sigs = Readable::read(reader)?;
-               let prev_holder_commitment = Readable::read(reader)?;
-               let prev_holder_htlc_sigs = Readable::read(reader)?;
-
-               let channel_parameters = Readable::read(reader)?;
-
-               let keys_len: u32 = Readable::read(reader)?;
-               let mut keys_data = Vec::with_capacity(cmp::min(keys_len as usize, MAX_ALLOC_SIZE));
-               while keys_data.len() != keys_len as usize {
-                       // Read 1KB at a time to avoid accidentally allocating 4GB on corrupted channel keys
-                       let mut data = [0; 1024];
-                       let read_slice = &mut data[0..cmp::min(1024, keys_len as usize - keys_data.len())];
-                       reader.read_exact(read_slice)?;
-                       keys_data.extend_from_slice(read_slice);
-               }
-               let signer = keys_manager.read_chan_signer(&keys_data)?;
-
-               let pending_claim_requests_len: u64 = Readable::read(reader)?;
-               let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
-               for _ in 0..pending_claim_requests_len {
-                       pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
-               }
-
-               let claimable_outpoints_len: u64 = Readable::read(reader)?;
-               let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
-               for _ in 0..claimable_outpoints_len {
-                       let outpoint = Readable::read(reader)?;
-                       let ancestor_claim_txid = Readable::read(reader)?;
-                       let height = Readable::read(reader)?;
-                       claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
-               }
-               let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
-               let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
-               for _ in 0..waiting_threshold_conf_len {
-                       let txid = Readable::read(reader)?;
-                       let height = Readable::read(reader)?;
-                       let event = match <u8 as Readable>::read(reader)? {
-                               0 => {
-                                       let claim_request = Readable::read(reader)?;
-                                       OnchainEvent::Claim {
-                                               claim_request
-                                       }
-                               },
-                               1 => {
-                                       let outpoint = Readable::read(reader)?;
-                                       let input_material = Readable::read(reader)?;
-                                       OnchainEvent::ContentiousOutpoint {
-                                               outpoint,
-                                               input_material
-                                       }
-                               }
-                               _ => return Err(DecodeError::InvalidValue),
-                       };
-                       onchain_events_awaiting_threshold_conf.push(OnchainEventEntry { txid, height, event });
-               }
-               let latest_height = Readable::read(reader)?;
-
-               read_tlv_fields!(reader, {}, {});
-
-               let mut secp_ctx = Secp256k1::new();
-               secp_ctx.seeded_randomize(&keys_manager.get_secure_random_bytes());
-
-               Ok(OnchainTxHandler {
-                       destination_script,
-                       holder_commitment,
-                       holder_htlc_sigs,
-                       prev_holder_commitment,
-                       prev_holder_htlc_sigs,
-                       signer,
-                       channel_transaction_parameters: channel_parameters,
-                       claimable_outpoints,
-                       pending_claim_requests,
-                       onchain_events_awaiting_threshold_conf,
-                       latest_height,
-                       secp_ctx,
-               })
-       }
-}
-
-impl<ChannelSigner: Sign> OnchainTxHandler<ChannelSigner> {
-       pub(crate) fn new(destination_script: Script, signer: ChannelSigner, channel_parameters: ChannelTransactionParameters, holder_commitment: HolderCommitmentTransaction, secp_ctx: Secp256k1<secp256k1::All>) -> Self {
-               OnchainTxHandler {
-                       destination_script,
-                       holder_commitment,
-                       holder_htlc_sigs: None,
-                       prev_holder_commitment: None,
-                       prev_holder_htlc_sigs: None,
-                       signer,
-                       channel_transaction_parameters: channel_parameters,
-                       pending_claim_requests: HashMap::new(),
-                       claimable_outpoints: HashMap::new(),
-                       onchain_events_awaiting_threshold_conf: Vec::new(),
-                       latest_height: 0,
-
-                       secp_ctx,
-               }
-       }
-
-       pub(crate) fn get_witnesses_weight(inputs: &[InputDescriptors]) -> usize {
-               let mut tx_weight = 2; // count segwit flags
-               for inp in inputs {
-                       // We use expected weight (and not actual) as signatures and time lock delays may vary
-                       tx_weight +=  match inp {
-                               // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
-                               &InputDescriptors::RevokedOfferedHTLC => {
-                                       1 + 1 + 73 + 1 + 33 + 1 + 133
-                               },
-                               // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
-                               &InputDescriptors::RevokedReceivedHTLC => {
-                                       1 + 1 + 73 + 1 + 33 + 1 + 139
-                               },
-                               // number_of_witness_elements + sig_length + counterpartyhtlc_sig  + preimage_length + preimage + witness_script_length + witness_script
-                               &InputDescriptors::OfferedHTLC => {
-                                       1 + 1 + 73 + 1 + 32 + 1 + 133
-                               },
-                               // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
-                               &InputDescriptors::ReceivedHTLC => {
-                                       1 + 1 + 73 + 1 + 1 + 1 + 139
-                               },
-                               // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
-                               &InputDescriptors::RevokedOutput => {
-                                       1 + 1 + 73 + 1 + 1 + 1 + 77
-                               },
-                       };
-               }
-               tx_weight
-       }
-
-       /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
-       /// output detection, we generate a first version of a claim tx and associate to it a height timer. A height timer is an absolute block
-       /// height than once reached we should generate a new bumped "version" of the claim tx to be sure than we safely claim outputs before
-       /// than our counterparty can do it too. If timelock expires soon, height timer is going to be scale down in consequence to increase
-       /// frequency of the bump and so increase our bets of success.
-       fn get_height_timer(current_height: u32, timelock_expiration: u32) -> u32 {
-               if timelock_expiration <= current_height + 3 {
-                       return current_height + 1
-               } else if timelock_expiration - current_height <= 15 {
-                       return current_height + 3
-               }
-               current_height + 15
-       }
-
-       /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize coutnerparty onchain) lays on the assumption of claim transactions getting confirmed before timelock expiration
-       /// (CSV or CLTV following cases). In case of high-fee spikes, claim tx may stuck in the mempool, so you need to bump its feerate quickly using Replace-By-Fee or Child-Pay-For-Parent.
-       /// Panics if there are signing errors, because signing operations in reaction to on-chain events
-       /// are not expected to fail, and if they do, we may lose funds.
-       fn generate_claim_tx<F: Deref, L: Deref>(&mut self, height: u32, cached_claim_datas: &ClaimTxBumpMaterial, fee_estimator: &F, logger: &L) -> Option<(Option<u32>, u32, Transaction)>
-               where F::Target: FeeEstimator,
-                                       L::Target: Logger,
-       {
-               if cached_claim_datas.per_input_material.len() == 0 { return None } // But don't prune pending claiming request yet, we may have to resurrect HTLCs
-               let mut inputs = Vec::new();
-               for outp in cached_claim_datas.per_input_material.keys() {
-                       log_trace!(logger, "Outpoint {}:{}", outp.txid, outp.vout);
-                       inputs.push(TxIn {
-                               previous_output: *outp,
-                               script_sig: Script::new(),
-                               sequence: 0xfffffffd,
-                               witness: Vec::new(),
-                       });
-               }
-               let mut bumped_tx = Transaction {
-                       version: 2,
-                       lock_time: 0,
-                       input: inputs,
-                       output: vec![TxOut {
-                               script_pubkey: self.destination_script.clone(),
-                               value: 0
-                       }],
-               };
-
-               macro_rules! RBF_bump {
-                       ($amount: expr, $old_feerate: expr, $fee_estimator: expr, $predicted_weight: expr) => {
-                               {
-                                       let mut used_feerate: u32;
-                                       // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
-                                       let new_fee = if $old_feerate < $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) {
-                                               let mut value = $amount;
-                                               if subtract_high_prio_fee!(logger, $fee_estimator, value, $predicted_weight, used_feerate) {
-                                                       // Overflow check is done in subtract_high_prio_fee
-                                                       ($amount - value)
-                                               } else {
-                                                       log_trace!(logger, "Can't new-estimation bump new claiming tx, amount {} is too small", $amount);
-                                                       return None;
-                                               }
-                                       // ...else just increase the previous feerate by 25% (because that's a nice number)
-                                       } else {
-                                               let fee = $old_feerate as u64 * ($predicted_weight as u64) / 750;
-                                               if $amount <= fee {
-                                                       log_trace!(logger, "Can't 25% bump new claiming tx, amount {} is too small", $amount);
-                                                       return None;
-                                               }
-                                               fee
-                                       };
-
-                                       let previous_fee = $old_feerate as u64 * ($predicted_weight as u64) / 1000;
-                                       let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * ($predicted_weight as u64) / 1000;
-                                       // BIP 125 Opt-in Full Replace-by-Fee Signaling
-                                       //      * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
-                                       //      * 4. The replacement transaction must also pay for its own bandwidth at or above the rate set by the node's minimum relay fee setting.
-                                       let new_fee = if new_fee < previous_fee + min_relay_fee {
-                                               new_fee + previous_fee + min_relay_fee - new_fee
-                                       } else {
-                                               new_fee
-                                       };
-                                       Some((new_fee, new_fee * 1000 / ($predicted_weight as u64)))
-                               }
-                       }
-               }
-
-               // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
-               // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
-               let new_timer = Some(Self::get_height_timer(height, cached_claim_datas.soonest_timelock));
-               let mut inputs_witnesses_weight = 0;
-               let mut amt = 0;
-               let mut dynamic_fee = true;
-               for per_outp_material in cached_claim_datas.per_input_material.values() {
-                       match per_outp_material {
-                               &InputMaterial::Revoked { ref input_descriptor, ref amount, .. } => {
-                                       inputs_witnesses_weight += Self::get_witnesses_weight(&[*input_descriptor]);
-                                       amt += *amount;
-                               },
-                               &InputMaterial::CounterpartyHTLC { ref preimage, ref htlc, .. } => {
-                                       inputs_witnesses_weight += Self::get_witnesses_weight(if preimage.is_some() { &[InputDescriptors::OfferedHTLC] } else { &[InputDescriptors::ReceivedHTLC] });
-                                       amt += htlc.amount_msat / 1000;
-                               },
-                               &InputMaterial::HolderHTLC { .. } => {
-                                       dynamic_fee = false;
-                               },
-                               &InputMaterial::Funding { .. } => {
-                                       dynamic_fee = false;
-                               }
-                       }
-               }
-               if dynamic_fee {
-                       let predicted_weight = (bumped_tx.get_weight() + inputs_witnesses_weight) as u64;
-                       let mut new_feerate;
-                       // If old feerate is 0, first iteration of this claim, use normal fee calculation
-                       if cached_claim_datas.feerate_previous != 0 {
-                               if let Some((new_fee, feerate)) = RBF_bump!(amt, cached_claim_datas.feerate_previous, fee_estimator, predicted_weight) {
-                                       // If new computed fee is superior at the whole claimable amount burn all in fees
-                                       if new_fee as u64 > amt {
-                                               bumped_tx.output[0].value = 0;
-                                       } else {
-                                               bumped_tx.output[0].value = amt - new_fee as u64;
-                                       }
-                                       new_feerate = feerate;
-                               } else { return None; }
-                       } else {
-                               if subtract_high_prio_fee!(logger, fee_estimator, amt, predicted_weight, new_feerate) {
-                                       bumped_tx.output[0].value = amt;
-                               } else { return None; }
-                       }
-                       assert!(new_feerate != 0);
-
-                       for (i, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
-                               match per_outp_material {
-                                       &InputMaterial::Revoked { ref per_commitment_point, ref counterparty_delayed_payment_base_key, ref counterparty_htlc_base_key, ref per_commitment_key, ref input_descriptor, ref amount, ref htlc, ref on_counterparty_tx_csv } => {
-                                               if let Ok(tx_keys) = TxCreationKeys::derive_new(&self.secp_ctx, &per_commitment_point, counterparty_delayed_payment_base_key, counterparty_htlc_base_key, &self.signer.pubkeys().revocation_basepoint, &self.signer.pubkeys().htlc_basepoint) {
-
-                                                       let witness_script = if let Some(ref htlc) = *htlc {
-                                                               chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &tx_keys.broadcaster_htlc_key, &tx_keys.countersignatory_htlc_key, &tx_keys.revocation_key)
-                                                       } else {
-                                                               chan_utils::get_revokeable_redeemscript(&tx_keys.revocation_key, *on_counterparty_tx_csv, &tx_keys.broadcaster_delayed_payment_key)
-                                                       };
-
-                                                       let sig = if let Some(ref htlc) = *htlc {
-                                                               self.signer.sign_justice_revoked_htlc(&bumped_tx, i, *amount, &per_commitment_key, &htlc, &self.secp_ctx).expect("sign justice tx")
-                                                       } else {
-                                                               self.signer.sign_justice_revoked_output(&bumped_tx, i, *amount, &per_commitment_key, &self.secp_ctx).expect("sign justice tx")
-                                                       };
-                                                       bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
-                                                       bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
-                                                       if htlc.is_some() {
-                                                               bumped_tx.input[i].witness.push(tx_keys.revocation_key.clone().serialize().to_vec());
-                                                       } else {
-                                                               bumped_tx.input[i].witness.push(vec!(1));
-                                                       }
-                                                       bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
-
-                                                       log_trace!(logger, "Going to broadcast Penalty Transaction {} claiming revoked {} output {} from {} with new feerate {}...", bumped_tx.txid(), if *input_descriptor == InputDescriptors::RevokedOutput { "to_holder" } else if *input_descriptor == InputDescriptors::RevokedOfferedHTLC { "offered" } else if *input_descriptor == InputDescriptors::RevokedReceivedHTLC { "received" } else { "" }, outp.vout, outp.txid, new_feerate);
-                                               }
-                                       },
-                                       &InputMaterial::CounterpartyHTLC { ref per_commitment_point, ref counterparty_delayed_payment_base_key, ref counterparty_htlc_base_key, ref preimage, ref htlc } => {
-                                               if let Ok(tx_keys) = TxCreationKeys::derive_new(&self.secp_ctx, &per_commitment_point, counterparty_delayed_payment_base_key, counterparty_htlc_base_key, &self.signer.pubkeys().revocation_basepoint, &self.signer.pubkeys().htlc_basepoint) {
-                                                       let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &tx_keys.broadcaster_htlc_key, &tx_keys.countersignatory_htlc_key, &tx_keys.revocation_key);
-
-                                                       if !preimage.is_some() { bumped_tx.lock_time = htlc.cltv_expiry }; // Right now we don't aggregate time-locked transaction, if we do we should set lock_time before to avoid breaking hash computation
-                                                       let sig = self.signer.sign_counterparty_htlc_transaction(&bumped_tx, i, &htlc.amount_msat / 1000, &per_commitment_point, htlc, &self.secp_ctx).expect("sign counterparty HTLC tx");
-                                                       bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
-                                                       bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
-                                                       if let &Some(preimage) = preimage {
-                                                               bumped_tx.input[i].witness.push(preimage.0.to_vec());
-                                                       } else {
-                                                               // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
-                                                               bumped_tx.input[i].witness.push(vec![]);
-                                                       }
-                                                       bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
-                                                       log_trace!(logger, "Going to broadcast Claim Transaction {} claiming counterparty {} htlc output {} from {} with new feerate {}...", bumped_tx.txid(), if preimage.is_some() { "offered" } else { "received" }, outp.vout, outp.txid, new_feerate);
-                                               }
-                                       },
-                                       _ => unreachable!()
-                               }
-                       }
-                       log_trace!(logger, "...with timer {}", new_timer.unwrap());
-                       assert!(predicted_weight >= bumped_tx.get_weight() as u64);
-                       return Some((new_timer, new_feerate as u32, bumped_tx))
-               } else {
-                       for (_, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
-                               match per_outp_material {
-                                       &InputMaterial::HolderHTLC { ref preimage, ref amount } => {
-                                               let htlc_tx = self.get_fully_signed_htlc_tx(outp, preimage);
-                                               if let Some(htlc_tx) = htlc_tx {
-                                                       let feerate = (amount - htlc_tx.output[0].value) * 1000 / htlc_tx.get_weight() as u64;
-                                                       // Timer set to $NEVER given we can't bump tx without anchor outputs
-                                                       log_trace!(logger, "Going to broadcast Holder HTLC-{} claiming HTLC output {} from {}...", if preimage.is_some() { "Success" } else { "Timeout" }, outp.vout, outp.txid);
-                                                       return Some((None, feerate as u32, htlc_tx));
-                                               }
-                                               return None;
-                                       },
-                                       &InputMaterial::Funding { ref funding_redeemscript } => {
-                                               let signed_tx = self.get_fully_signed_holder_tx(funding_redeemscript);
-                                               // Timer set to $NEVER given we can't bump tx without anchor outputs
-                                               log_trace!(logger, "Going to broadcast Holder Transaction {} claiming funding output {} from {}...", signed_tx.txid(), outp.vout, outp.txid);
-                                               return Some((None, self.holder_commitment.feerate_per_kw(), signed_tx));
-                                       }
-                                       _ => unreachable!()
-                               }
-                       }
-               }
-               None
-       }
-
-       /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
-       /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
-       /// Formerly this was named `block_connected`, but it is now also used for claiming an HTLC output
-       /// if we receive a preimage after force-close.
-       pub(crate) fn update_claims_view<B: Deref, F: Deref, L: Deref>(&mut self, txn_matched: &[&Transaction], claimable_outpoints: Vec<ClaimRequest>, latest_height: Option<u32>, broadcaster: &B, fee_estimator: &F, logger: &L)
-               where B::Target: BroadcasterInterface,
-                     F::Target: FeeEstimator,
-                                       L::Target: Logger,
-       {
-               let height = match latest_height {
-                       Some(h) => h,
-                       None => self.latest_height,
-               };
-               log_trace!(logger, "Updating claims view at height {} with {} matched transactions and {} claim requests", height, txn_matched.len(), claimable_outpoints.len());
-               let mut new_claims = Vec::new();
-               let mut aggregated_claim = HashMap::new();
-               let mut aggregated_soonest = ::core::u32::MAX;
-
-               // Try to aggregate outputs if their timelock expiration isn't imminent (absolute_timelock
-               // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
-               for req in claimable_outpoints {
-                       // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
-                       if let Some(_) = self.claimable_outpoints.get(&req.outpoint) { log_trace!(logger, "Bouncing off outpoint {}:{}, already registered its claiming request", req.outpoint.txid, req.outpoint.vout); } else {
-                               log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.absolute_timelock, height + CLTV_SHARED_CLAIM_BUFFER);
-                               if req.absolute_timelock <= height + CLTV_SHARED_CLAIM_BUFFER || !req.aggregable { // Don't aggregate if outpoint absolute timelock is soon or marked as non-aggregable
-                                       let mut single_input = HashMap::new();
-                                       single_input.insert(req.outpoint, req.witness_data);
-                                       new_claims.push((req.absolute_timelock, single_input));
-                               } else {
-                                       aggregated_claim.insert(req.outpoint, req.witness_data);
-                                       if req.absolute_timelock < aggregated_soonest {
-                                               aggregated_soonest = req.absolute_timelock;
-                                       }
-                               }
-                       }
-               }
-               new_claims.push((aggregated_soonest, aggregated_claim));
-
-               // Generate claim transactions and track them to bump if necessary at
-               // height timer expiration (i.e in how many blocks we're going to take action).
-               for (soonest_timelock, claim) in new_claims.drain(..) {
-                       let mut claim_material = ClaimTxBumpMaterial { height_timer: None, feerate_previous: 0, soonest_timelock, per_input_material: claim };
-                       if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
-                               claim_material.height_timer = new_timer;
-                               claim_material.feerate_previous = new_feerate;
-                               let txid = tx.txid();
-                               for k in claim_material.per_input_material.keys() {
-                                       log_trace!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
-                                       self.claimable_outpoints.insert(k.clone(), (txid, height));
-                               }
-                               self.pending_claim_requests.insert(txid, claim_material);
-                               log_info!(logger, "Broadcasting onchain {}", log_tx!(tx));
-                               broadcaster.broadcast_transaction(&tx);
-                       }
-               }
-
-               let mut bump_candidates = HashMap::new();
-               for tx in txn_matched {
-                       // Scan all input to verify is one of the outpoint spent is of interest for us
-                       let mut claimed_outputs_material = Vec::new();
-                       for inp in &tx.input {
-                               if let Some(first_claim_txid_height) = self.claimable_outpoints.get(&inp.previous_output) {
-                                       // If outpoint has claim request pending on it...
-                                       if let Some(claim_material) = self.pending_claim_requests.get_mut(&first_claim_txid_height.0) {
-                                               //... we need to verify equality between transaction outpoints and claim request
-                                               // outpoints to know if transaction is the original claim or a bumped one issued
-                                               // by us.
-                                               let mut set_equality = true;
-                                               if claim_material.per_input_material.len() != tx.input.len() {
-                                                       set_equality = false;
-                                               } else {
-                                                       for (claim_inp, tx_inp) in claim_material.per_input_material.keys().zip(tx.input.iter()) {
-                                                               if *claim_inp != tx_inp.previous_output {
-                                                                       set_equality = false;
-                                                               }
-                                                       }
-                                               }
-
-                                               macro_rules! clean_claim_request_after_safety_delay {
-                                                       () => {
-                                                               let entry = OnchainEventEntry {
-                                                                       txid: tx.txid(),
-                                                                       height,
-                                                                       event: OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() }
-                                                               };
-                                                               if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
-                                                                       self.onchain_events_awaiting_threshold_conf.push(entry);
-                                                               }
-                                                       }
-                                               }
-
-                                               // If this is our transaction (or our counterparty spent all the outputs
-                                               // before we could anyway with same inputs order than us), wait for
-                                               // ANTI_REORG_DELAY and clean the RBF tracking map.
-                                               if set_equality {
-                                                       clean_claim_request_after_safety_delay!();
-                                               } else { // If false, generate new claim request with update outpoint set
-                                                       let mut at_least_one_drop = false;
-                                                       for input in tx.input.iter() {
-                                                               if let Some(input_material) = claim_material.per_input_material.remove(&input.previous_output) {
-                                                                       claimed_outputs_material.push((input.previous_output, input_material));
-                                                                       at_least_one_drop = true;
-                                                               }
-                                                               // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
-                                                               if claim_material.per_input_material.is_empty() {
-                                                                       clean_claim_request_after_safety_delay!();
-                                                               }
-                                                       }
-                                                       //TODO: recompute soonest_timelock to avoid wasting a bit on fees
-                                                       if at_least_one_drop {
-                                                               bump_candidates.insert(first_claim_txid_height.0.clone(), claim_material.clone());
-                                                       }
-                                               }
-                                               break; //No need to iterate further, either tx is our or their
-                                       } else {
-                                               panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
-                                       }
-                               }
-                       }
-                       for (outpoint, input_material) in claimed_outputs_material.drain(..) {
-                               let entry = OnchainEventEntry {
-                                       txid: tx.txid(),
-                                       height,
-                                       event: OnchainEvent::ContentiousOutpoint { outpoint, input_material },
-                               };
-                               if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
-                                       self.onchain_events_awaiting_threshold_conf.push(entry);
-                               }
-                       }
-               }
-
-               // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
-               let onchain_events_awaiting_threshold_conf =
-                       self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
-               for entry in onchain_events_awaiting_threshold_conf {
-                       if entry.has_reached_confirmation_threshold(height) {
-                               match entry.event {
-                                       OnchainEvent::Claim { claim_request } => {
-                                               // We may remove a whole set of claim outpoints here, as these one may have
-                                               // been aggregated in a single tx and claimed so atomically
-                                               if let Some(bump_material) = self.pending_claim_requests.remove(&claim_request) {
-                                                       for outpoint in bump_material.per_input_material.keys() {
-                                                               self.claimable_outpoints.remove(&outpoint);
-                                                       }
-                                               }
-                                       },
-                                       OnchainEvent::ContentiousOutpoint { outpoint, .. } => {
-                                               self.claimable_outpoints.remove(&outpoint);
-                                       }
-                               }
-                       } else {
-                               self.onchain_events_awaiting_threshold_conf.push(entry);
-                       }
-               }
-
-               // Check if any pending claim request must be rescheduled
-               for (first_claim_txid, ref claim_data) in self.pending_claim_requests.iter() {
-                       if let Some(height_timer) = claim_data.height_timer {
-                               if height >= height_timer {
-                                       bump_candidates.insert(*first_claim_txid, (*claim_data).clone());
-                               }
-                       }
-               }
-
-               // Build, bump and rebroadcast tx accordingly
-               log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
-               for (first_claim_txid, claim_material) in bump_candidates.iter() {
-                       if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
-                               log_info!(logger, "Broadcasting onchain {}", log_tx!(bump_tx));
-                               broadcaster.broadcast_transaction(&bump_tx);
-                               if let Some(claim_material) = self.pending_claim_requests.get_mut(first_claim_txid) {
-                                       claim_material.height_timer = new_timer;
-                                       claim_material.feerate_previous = new_feerate;
-                               }
-                       }
-               }
-       }
-
-       pub(crate) fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
-               &mut self,
-               txid: &Txid,
-               broadcaster: B,
-               fee_estimator: F,
-               logger: L,
-       ) where
-               B::Target: BroadcasterInterface,
-               F::Target: FeeEstimator,
-               L::Target: Logger,
-       {
-               let mut height = None;
-               for entry in self.onchain_events_awaiting_threshold_conf.iter() {
-                       if entry.txid == *txid {
-                               height = Some(entry.height);
-                               break;
-                       }
-               }
-
-               if let Some(height) = height {
-                       self.block_disconnected(height, broadcaster, fee_estimator, logger);
-               }
-       }
-
-       pub(crate) fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: F, logger: L)
-               where B::Target: BroadcasterInterface,
-                     F::Target: FeeEstimator,
-                                       L::Target: Logger,
-       {
-               let mut bump_candidates = HashMap::new();
-               let onchain_events_awaiting_threshold_conf =
-                       self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
-               for entry in onchain_events_awaiting_threshold_conf {
-                       if entry.height >= height {
-                               //- our claim tx on a commitment tx output
-                               //- resurect outpoint back in its claimable set and regenerate tx
-                               match entry.event {
-                                       OnchainEvent::ContentiousOutpoint { outpoint, input_material } => {
-                                               if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&outpoint) {
-                                                       if let Some(claim_material) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) {
-                                                               claim_material.per_input_material.insert(outpoint, input_material);
-                                                               // Using a HashMap guarantee us than if we have multiple outpoints getting
-                                                               // resurrected only one bump claim tx is going to be broadcast
-                                                               bump_candidates.insert(ancestor_claimable_txid.clone(), claim_material.clone());
-                                                       }
-                                               }
-                                       },
-                                       _ => {},
-                               }
-                       } else {
-                               self.onchain_events_awaiting_threshold_conf.push(entry);
-                       }
-               }
-               for (_, claim_material) in bump_candidates.iter_mut() {
-                       if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &&*fee_estimator, &&*logger) {
-                               claim_material.height_timer = new_timer;
-                               claim_material.feerate_previous = new_feerate;
-                               log_info!(logger, "Broadcasting onchain {}", log_tx!(bump_tx));
-                               broadcaster.broadcast_transaction(&bump_tx);
-                       }
-               }
-               for (ancestor_claim_txid, claim_material) in bump_candidates.drain() {
-                       self.pending_claim_requests.insert(ancestor_claim_txid.0, claim_material);
-               }
-               //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
-               // right now if one of the outpoint get disconnected, just erase whole pending claim request.
-               let mut remove_request = Vec::new();
-               self.claimable_outpoints.retain(|_, ref v|
-                       if v.1 >= height {
-                       remove_request.push(v.0.clone());
-                       false
-                       } else { true });
-               for req in remove_request {
-                       self.pending_claim_requests.remove(&req);
-               }
-       }
-
-       pub(crate) fn get_relevant_txids(&self) -> Vec<Txid> {
-               let mut txids: Vec<Txid> = self.onchain_events_awaiting_threshold_conf
-                       .iter()
-                       .map(|entry| entry.txid)
-                       .collect();
-               txids.sort_unstable();
-               txids.dedup();
-               txids
-       }
-
-       pub(crate) fn provide_latest_holder_tx(&mut self, tx: HolderCommitmentTransaction) {
-               self.prev_holder_commitment = Some(replace(&mut self.holder_commitment, tx));
-               self.holder_htlc_sigs = None;
-       }
-
-       // Normally holder HTLCs are signed at the same time as the holder commitment tx.  However,
-       // in some configurations, the holder commitment tx has been signed and broadcast by a
-       // ChannelMonitor replica, so we handle that case here.
-       fn sign_latest_holder_htlcs(&mut self) {
-               if self.holder_htlc_sigs.is_none() {
-                       let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
-                       self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, sigs));
-               }
-       }
-
-       // Normally only the latest commitment tx and HTLCs need to be signed.  However, in some
-       // configurations we may have updated our holder commitment but a replica of the ChannelMonitor
-       // broadcast the previous one before we sync with it.  We handle that case here.
-       fn sign_prev_holder_htlcs(&mut self) {
-               if self.prev_holder_htlc_sigs.is_none() {
-                       if let Some(ref holder_commitment) = self.prev_holder_commitment {
-                               let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(holder_commitment, &self.secp_ctx).expect("sign previous holder commitment");
-                               self.prev_holder_htlc_sigs = Some(Self::extract_holder_sigs(holder_commitment, sigs));
-                       }
-               }
-       }
-
-       fn extract_holder_sigs(holder_commitment: &HolderCommitmentTransaction, sigs: Vec<Signature>) -> Vec<Option<(usize, Signature)>> {
-               let mut ret = Vec::new();
-               for (htlc_idx, (holder_sig, htlc)) in sigs.iter().zip(holder_commitment.htlcs().iter()).enumerate() {
-                       let tx_idx = htlc.transaction_output_index.unwrap();
-                       if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
-                       ret[tx_idx as usize] = Some((htlc_idx, holder_sig.clone()));
-               }
-               ret
-       }
-
-       //TODO: getting lastest holder transactions should be infallible and result in us "force-closing the channel", but we may
-       // have empty holder commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
-       // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
-       // to monitor before.
-       pub(crate) fn get_fully_signed_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
-               let (sig, htlc_sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("signing holder commitment");
-               self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
-               self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
-       }
-
-       #[cfg(any(test, feature="unsafe_revoked_tx_signing"))]
-       pub(crate) fn get_fully_signed_copy_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
-               let (sig, htlc_sigs) = self.signer.unsafe_sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
-               self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
-               self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
-       }
-
-       pub(crate) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
-               let mut htlc_tx = None;
-               let commitment_txid = self.holder_commitment.trust().txid();
-               // Check if the HTLC spends from the current holder commitment
-               if commitment_txid == outp.txid {
-                       self.sign_latest_holder_htlcs();
-                       if let &Some(ref htlc_sigs) = &self.holder_htlc_sigs {
-                               let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
-                               let trusted_tx = self.holder_commitment.trust();
-                               let counterparty_htlc_sig = self.holder_commitment.counterparty_htlc_sigs[*htlc_idx];
-                               htlc_tx = Some(trusted_tx
-                                       .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
-                       }
-               }
-               // If the HTLC doesn't spend the current holder commitment, check if it spends the previous one
-               if htlc_tx.is_none() && self.prev_holder_commitment.is_some() {
-                       let commitment_txid = self.prev_holder_commitment.as_ref().unwrap().trust().txid();
-                       if commitment_txid == outp.txid {
-                               self.sign_prev_holder_htlcs();
-                               if let &Some(ref htlc_sigs) = &self.prev_holder_htlc_sigs {
-                                       let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
-                                       let holder_commitment = self.prev_holder_commitment.as_ref().unwrap();
-                                       let trusted_tx = holder_commitment.trust();
-                                       let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[*htlc_idx];
-                                       htlc_tx = Some(trusted_tx
-                                               .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
-                               }
-                       }
-               }
-               htlc_tx
-       }
-
-       #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
-       pub(crate) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
-               let latest_had_sigs = self.holder_htlc_sigs.is_some();
-               let prev_had_sigs = self.prev_holder_htlc_sigs.is_some();
-               let ret = self.get_fully_signed_htlc_tx(outp, preimage);
-               if !latest_had_sigs {
-                       self.holder_htlc_sigs = None;
-               }
-               if !prev_had_sigs {
-                       self.prev_holder_htlc_sigs = None;
-               }
-               ret
-       }
-}