From 44cf6928da3462fb87e018019bfe1ee4c2085bd4 Mon Sep 17 00:00:00 2001 From: Elias Rohrer Date: Fri, 12 Apr 2024 10:19:05 +0200 Subject: [PATCH] Move `{REQUIRED,OPTIONAL}_FEATURES` masks to module-level consts .. which allows to DRY up their usage in several places. --- lightning/src/ln/features.rs | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/lightning/src/ln/features.rs b/lightning/src/ln/features.rs index 6b4834edf..8de57c2b9 100644 --- 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 Features { } 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 Features { // 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 Features { // 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 Readable for WithoutLength> { } pub(crate) fn unset_features_mask_at_position(other: &Features, 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 } -- 2.39.5