Move `{REQUIRED,OPTIONAL}_FEATURES` masks to module-level consts

.. which allows to DRY up their usage in several places.

diff --git a/lightning/src/ln/features.rs b/lightning/src/ln/features.rs
index 6b4834edf67efdec993aadacfee17376adb65237..8de57c2b975f1d6a53d801252ac65258ed5aa070 100644 (file)
--- a/lightning/src/ln/features.rs
+++ b/lightning/src/ln/features.rs
@@ -443,6 +443,9 @@ mod sealed {
                set_unknown_feature_required, supports_unknown_test_feature, requires_unknown_test_feature);
 }
 
+const ANY_REQUIRED_FEATURES_MASK: u8 = 0b01_01_01_01;
+const ANY_OPTIONAL_FEATURES_MASK: u8 = 0b10_10_10_10;
+
 /// Tracks the set of features which a node implements, templated by the context in which it
 /// appears.
 ///
@@ -616,8 +619,8 @@ impl ChannelTypeFeatures {
                // ChannelTypeFeatures must only contain required bits, so we OR the required forms of all
                // optional bits and then AND out the optional ones.
                for byte in ret.flags.iter_mut() {
-                       *byte |= (*byte & 0b10_10_10_10) >> 1;
-                       *byte &= 0b01_01_01_01;
+                       *byte |= (*byte & ANY_OPTIONAL_FEATURES_MASK) >> 1;
+                       *byte &= ANY_REQUIRED_FEATURES_MASK;
                }
                ret
        }
@@ -762,7 +765,7 @@ impl<T: sealed::Context> Features<T> {
        }
 
        pub(crate) fn supports_any_optional_bits(&self) -> bool {
-               self.flags.iter().any(|&byte| (byte & 0b10_10_10_10) != 0)
+               self.flags.iter().any(|&byte| (byte & ANY_OPTIONAL_FEATURES_MASK) != 0)
        }
 
        /// Returns true if this `Features` object contains required features unknown by `other`.
@@ -770,9 +773,8 @@ impl<T: sealed::Context> Features<T> {
                // Bitwise AND-ing with all even bits set except for known features will select required
                // unknown features.
                self.flags.iter().enumerate().any(|(i, &byte)| {
-                       const REQUIRED_FEATURES: u8 = 0b01_01_01_01;
                        let unknown_features = unset_features_mask_at_position(other, i);
-                       (byte & (REQUIRED_FEATURES & unknown_features)) != 0
+                       (byte & (ANY_REQUIRED_FEATURES_MASK & unknown_features)) != 0
                })
        }
 
@@ -802,13 +804,12 @@ impl<T: sealed::Context> Features<T> {
                // unknown features.
                let byte_count = T::KNOWN_FEATURE_MASK.len();
                self.flags.iter().enumerate().any(|(i, &byte)| {
-                       let required_features = 0b01_01_01_01;
                        let unknown_features = if i < byte_count {
                                !T::KNOWN_FEATURE_MASK[i]
                        } else {
                                0b11_11_11_11
                        };
-                       (byte & (required_features & unknown_features)) != 0
+                       (byte & (ANY_REQUIRED_FEATURES_MASK & unknown_features)) != 0
                })
        }
 
@@ -1030,13 +1031,11 @@ impl<T: sealed::Context> Readable for WithoutLength<Features<T>> {
 }
 
 pub(crate) fn unset_features_mask_at_position<T: sealed::Context>(other: &Features<T>, index: usize) -> u8 {
-       const REQUIRED_FEATURES: u8 = 0b01_01_01_01;
-       const OPTIONAL_FEATURES: u8 = 0b10_10_10_10;
        if index < other.flags.len() {
                // Form a mask similar to !T::KNOWN_FEATURE_MASK only for `other`
                !(other.flags[index]
-                       | ((other.flags[index] >> 1) & REQUIRED_FEATURES)
-                       | ((other.flags[index] << 1) & OPTIONAL_FEATURES))
+                       | ((other.flags[index] >> 1) & ANY_REQUIRED_FEATURES_MASK)
+                       | ((other.flags[index] << 1) & ANY_OPTIONAL_FEATURES_MASK))
        } else {
                0b11_11_11_11
        }