Replace the generic `parse_int_be` with a macro called twice

[rust-lightning] / lightning-invoice / src / de.rs

diff --git a/lightning-invoice/src/de.rs b/lightning-invoice/src/de.rs
index b055639124584f6e00366b65c0f7b14f5a21524d..9284999b1884474a51a82a7637ce237fbf7fae65 100644 (file)
--- a/lightning-invoice/src/de.rs
+++ b/lightning-invoice/src/de.rs
@@ -18,8 +18,6 @@ use lightning::ln::PaymentSecret;
 use lightning::routing::gossip::RoutingFees;
 use lightning::routing::router::{RouteHint, RouteHintHop};
 
-use num_traits::{CheckedAdd, CheckedMul};
-
 use secp256k1::ecdsa::{RecoveryId, RecoverableSignature};
 use secp256k1::PublicKey;
 
@@ -356,7 +354,7 @@ impl FromBase32 for PositiveTimestamp {
                if b32.len() != 7 {
                        return Err(Bolt11ParseError::InvalidSliceLength("PositiveTimestamp::from_base32()".into()));
                }
-               let timestamp: u64 = parse_int_be(b32, 32)
+               let timestamp: u64 = parse_u64_be(b32)
                        .expect("7*5bit < 64bit, no overflow possible");
                match PositiveTimestamp::from_unix_timestamp(timestamp) {
                        Ok(t) => Ok(t),
@@ -382,16 +380,17 @@ impl FromBase32 for Bolt11InvoiceSignature {
        }
 }
 
-pub(crate) fn parse_int_be<T, U>(digits: &[U], base: T) -> Option<T>
-       where T: CheckedAdd + CheckedMul + From<u8> + Default,
-             U: Into<u8> + Copy
-{
-       digits.iter().fold(Some(Default::default()), |acc, b|
-               acc
-                       .and_then(|x| x.checked_mul(&base))
-                       .and_then(|x| x.checked_add(&(Into::<u8>::into(*b)).into()))
-       )
-}
+macro_rules! define_parse_int_be { ($name: ident, $ty: ty) => {
+       fn $name(digits: &[u5]) -> Option<$ty> {
+               digits.iter().fold(Some(Default::default()), |acc, b|
+                       acc
+                               .and_then(|x| x.checked_mul(32))
+                               .and_then(|x| x.checked_add((Into::<u8>::into(*b)).into()))
+               )
+       }
+} }
+define_parse_int_be!(parse_u16_be, u16);
+define_parse_int_be!(parse_u64_be, u64);
 
 fn parse_tagged_parts(data: &[u5]) -> Result<Vec<RawTaggedField>, Bolt11ParseError> {
        let mut parts = Vec::<RawTaggedField>::new();
@@ -404,7 +403,7 @@ fn parse_tagged_parts(data: &[u5]) -> Result<Vec<RawTaggedField>, Bolt11ParseErr
 
                // Ignore tag at data[0], it will be handled in the TaggedField parsers and
                // parse the length to find the end of the tagged field's data
-               let len = parse_int_be(&data[1..3], 32).expect("can't overflow");
+               let len = parse_u16_be(&data[1..3]).expect("can't overflow") as usize;
                let last_element = 3 + len;
 
                if data.len() < last_element {
@@ -517,7 +516,7 @@ impl FromBase32 for ExpiryTime {
        type Err = Bolt11ParseError;
 
        fn from_base32(field_data: &[u5]) -> Result<ExpiryTime, Bolt11ParseError> {
-               match parse_int_be::<u64, u5>(field_data, 32)
+               match parse_u64_be(field_data)
                        .map(ExpiryTime::from_seconds)
                {
                        Some(t) => Ok(t),
@@ -530,7 +529,7 @@ impl FromBase32 for MinFinalCltvExpiryDelta {
        type Err = Bolt11ParseError;
 
        fn from_base32(field_data: &[u5]) -> Result<MinFinalCltvExpiryDelta, Bolt11ParseError> {
-               let expiry = parse_int_be::<u64, u5>(field_data, 32);
+               let expiry = parse_u64_be(field_data);
                if let Some(expiry) = expiry {
                        Ok(MinFinalCltvExpiryDelta(expiry))
                } else {
@@ -761,12 +760,16 @@ mod test {
 
        #[test]
        fn test_parse_int_from_bytes_be() {
-               use crate::de::parse_int_be;
-
-               assert_eq!(parse_int_be::<u32, u8>(&[1, 2, 3, 4], 256), Some(16909060));
-               assert_eq!(parse_int_be::<u32, u8>(&[1, 3], 32), Some(35));
-               assert_eq!(parse_int_be::<u32, u8>(&[255, 255, 255, 255], 256), Some(4294967295));
-               assert_eq!(parse_int_be::<u32, u8>(&[1, 0, 0, 0, 0], 256), None);
+               use crate::de::parse_u16_be;
+
+               assert_eq!(parse_u16_be(&[
+                               u5::try_from_u8(1).unwrap(), u5::try_from_u8(2).unwrap(),
+                               u5::try_from_u8(3).unwrap(), u5::try_from_u8(4).unwrap()]
+                       ), Some(34916));
+               assert_eq!(parse_u16_be(&[
+                               u5::try_from_u8(2).unwrap(), u5::try_from_u8(0).unwrap(),
+                               u5::try_from_u8(0).unwrap(), u5::try_from_u8(0).unwrap()]
+                       ), None);
        }
 
        #[test]