_ Git - rust-lightning/blob - lightning/src/ln/package.rs

   1 //! Utilities for computing witnesses weight and feerate computation for onchain operation
   2
   3 use ln::msgs::DecodeError;
   4 use util::ser::{Readable, Writer, Writeable};
   5
   6 #[derive(PartialEq, Clone, Copy)]
   7 pub(crate) enum InputDescriptors {
   8         RevokedOfferedHTLC,
   9         RevokedReceivedHTLC,
  10         OfferedHTLC,
  11         ReceivedHTLC,
  12         RevokedOutput, // either a revoked to_holder output on commitment tx, a revoked HTLC-Timeout output or a revoked HTLC-Success output
  13 }
  14
  15 impl Writeable for InputDescriptors {
  16         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
  17                 match self {
  18                         &InputDescriptors::RevokedOfferedHTLC => {
  19                                 writer.write_all(&[0; 1])?;
  20                         },
  21                         &InputDescriptors::RevokedReceivedHTLC => {
  22                                 writer.write_all(&[1; 1])?;
  23                         },
  24                         &InputDescriptors::OfferedHTLC => {
  25                                 writer.write_all(&[2; 1])?;
  26                         },
  27                         &InputDescriptors::ReceivedHTLC => {
  28                                 writer.write_all(&[3; 1])?;
  29                         }
  30                         &InputDescriptors::RevokedOutput => {
  31                                 writer.write_all(&[4; 1])?;
  32                         }
  33                 }
  34                 Ok(())
  35         }
  36 }
  37
  38 impl Readable for InputDescriptors {
  39         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
  40                 let input_descriptor = match <u8 as Readable>::read(reader)? {
  41                         0 => {
  42                                 InputDescriptors::RevokedOfferedHTLC
  43                         },
  44                         1 => {
  45                                 InputDescriptors::RevokedReceivedHTLC
  46                         },
  47                         2 => {
  48                                 InputDescriptors::OfferedHTLC
  49                         },
  50                         3 => {
  51                                 InputDescriptors::ReceivedHTLC
  52                         },
  53                         4 => {
  54                                 InputDescriptors::RevokedOutput
  55                         }
  56                         _ => return Err(DecodeError::InvalidValue),
  57                 };
  58                 Ok(input_descriptor)
  59         }
  60 }
  61
  62 pub(crate) fn get_witnesses_weight(inputs: &[InputDescriptors]) -> usize {
  63         let mut tx_weight = 2; // count segwit flags
  64         for inp in inputs {
  65                 // We use expected weight (and not actual) as signatures and time lock delays may vary
  66                 tx_weight +=  match inp {
  67                         // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
  68                         &InputDescriptors::RevokedOfferedHTLC => {
  69                                 1 + 1 + 73 + 1 + 33 + 1 + 133
  70                         },
  71                         // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
  72                         &InputDescriptors::RevokedReceivedHTLC => {
  73                                 1 + 1 + 73 + 1 + 33 + 1 + 139
  74                         },
  75                         // number_of_witness_elements + sig_length + counterpartyhtlc_sig  + preimage_length + preimage + witness_script_length + witness_script
  76                         &InputDescriptors::OfferedHTLC => {
  77                                 1 + 1 + 73 + 1 + 32 + 1 + 133
  78                         },
  79                         // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
  80                         &InputDescriptors::ReceivedHTLC => {
  81                                 1 + 1 + 73 + 1 + 1 + 1 + 139
  82                         },
  83                         // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
  84                         &InputDescriptors::RevokedOutput => {
  85                                 1 + 1 + 73 + 1 + 1 + 1 + 77
  86                         },
  87                 };
  88         }
  89         tx_weight
  90 }