feat(primitives): add and use foldhash as default hasher

Cargo.toml

@@ -77,6 +77,7 @@ sha3 = { version = "0.10.8", default-features = false }
 # maps
 hashbrown = { version = "0.15", default-features = false }
 indexmap = { version = "2.5", default-features = false }
+foldhash = { version = "0.1", default-features = false }
 rustc-hash = { version = "2.0", default-features = false }
 
 # misc

crates/primitives/Cargo.toml

@@ -73,6 +73,7 @@ hashbrown = { workspace = true, optional = true, features = [
     "inline-more",
 ] }
 indexmap = { workspace = true, optional = true }
+foldhash = { workspace = true, optional = true }
 rustc-hash = { workspace = true, optional = true }
 
 # arbitrary
@@ -94,12 +95,13 @@ criterion.workspace = true
 serde_json.workspace = true
 
 [features]
-default = ["std", "map-fxhash"]
+default = ["std", "map-foldhash"]
 std = [
     "bytes/std",
     "hex/std",
     "ruint/std",
     "alloy-rlp?/std",
+    "foldhash?/std",
     "indexmap?/std",
     "k256?/std",
     "keccak-asm?/std",
@@ -124,6 +126,7 @@ tiny-keccak = []
 map = ["dep:hashbrown"]
 map-hashbrown = ["map"]
 map-indexmap = ["map", "dep:indexmap"]
+map-foldhash = ["map", "dep:foldhash"]
 map-fxhash = ["map", "dep:rustc-hash"]
 
 getrandom = ["dep:getrandom"]

crates/primitives/src/map/fixed.rs

@@ -196,6 +196,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg_attr(miri, ignore = "foldhash queries time (orlp/foldhash#4)")]
     fn fb_hasher() {
         // Just by running it once we test that it compiles and that debug assertions are correct.
         ruint::const_for!(N in [ 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
@@ -206,6 +207,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg_attr(miri, ignore = "foldhash queries time (orlp/foldhash#4)")]
     fn map() {
         let mut map = AddressHashMap::<bool>::default();
         map.insert(Address::ZERO, true);

crates/primitives/src/map/mod.rs

@@ -20,6 +20,10 @@
 //! resistance should enable the "rand" feature so that the hasher is initialized using a random
 //! seed.
 //!
+//! Note that using the types provided in this module may require using different APIs than the
+//! standard library as they might not be generic over the hasher state, such as using
+//! `HashMap::default()` instead of `HashMap::new()`.
+//!
 //! [fb]: crate::FixedBytes
 //! [`Selector`]: crate::Selector
 //! [`Address`]: crate::Address
@@ -53,7 +57,7 @@ pub type HashMap<K, V, S = DefaultHashBuilder> = imp::HashMap<K, V, S>;
 /// See [`HashSet`](imp::HashSet) for more information.
 pub type HashSet<V, S = DefaultHashBuilder> = imp::HashSet<V, S>;
 
-// Faster hasher.
+// Faster hashers.
 cfg_if! {
     if #[cfg(feature = "map-fxhash")] {
         #[doc(no_inline)]
@@ -111,7 +115,9 @@ cfg_if! {
 
 // Default hasher.
 cfg_if! {
-    if #[cfg(feature = "map-fxhash")] {
+    if #[cfg(feature = "map-foldhash")] {
+        type DefaultHashBuilderInner = foldhash::fast::RandomState;
+    } else if #[cfg(feature = "map-fxhash")] {
         type DefaultHashBuilderInner = FxBuildHasher;
     } else if #[cfg(any(feature = "map-hashbrown", not(feature = "std")))] {
         type DefaultHashBuilderInner = hashbrown::DefaultHashBuilder;
@@ -150,6 +156,7 @@ mod tests {
     use super::*;
 
     #[test]
+    #[cfg_attr(miri, ignore = "foldhash queries time (orlp/foldhash#4)")]
     fn default_hasher_builder_traits() {
         let hash_builder = <DefaultHashBuilder as Default>::default();
         let _hash_builder2 = <DefaultHashBuilder as Clone>::clone(&hash_builder);

tests/core-sol/src/lib.rs

@@ -65,6 +65,7 @@ sol! {
 }
 
 #[test]
+#[cfg_attr(miri, ignore = "foldhash queries time (orlp/foldhash#4)")]
 fn do_stuff() {
     let mut set = alloy_core::primitives::map::HashSet::<MyStruct>::default();
     set.insert(Default::default());