chore: impl EmptyDB traits manually

bluealloy · Sep 6, 2023 · cc7fd5e · cc7fd5e
1 parent db02975
commit cc7fd5e
Showing 1 changed file with 32 additions and 14 deletions.
diff --git a/crates/revm/src/db/emptydb.rs b/crates/revm/src/db/emptydb.rs
@@ -1,4 +1,4 @@
-use core::{convert::Infallible, marker::PhantomData};
+use core::{convert::Infallible, fmt, marker::PhantomData};
 use revm_interpreter::primitives::{
     db::{Database, DatabaseRef},
     AccountInfo, Bytecode, B160, B256, U256,
@@ -10,21 +10,40 @@ pub type EmptyDB = EmptyDBTyped<Infallible>;
 /// An empty database that always returns default values when queried.
 ///
 /// This is generic over a type which is used as the database error type.
-#[derive(Debug, Clone)]
 pub struct EmptyDBTyped<E> {
     _phantom: PhantomData<E>,
 }
 
-// Don't derive it because it doesn't need `E: Default`.
+// Don't derive traits, because the type parameter is unused.
+impl<E> Clone for EmptyDBTyped<E> {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+
+impl<E> Copy for EmptyDBTyped<E> {}
+
 impl<E> Default for EmptyDBTyped<E> {
-    #[inline(always)]
     fn default() -> Self {
         Self::new()
     }
 }
 
+impl<E> fmt::Debug for EmptyDBTyped<E> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("EmptyDB").finish_non_exhaustive()
+    }
+}
+
+impl<E> PartialEq for EmptyDBTyped<E> {
+    fn eq(&self, _: &Self) -> bool {
+        true
+    }
+}
+
+impl<E> Eq for EmptyDBTyped<E> {}
+
 impl<E> EmptyDBTyped<E> {
-    #[inline(always)]
     pub fn new() -> Self {
         Self {
             _phantom: PhantomData,
@@ -33,7 +52,6 @@ impl<E> EmptyDBTyped<E> {
 
     #[doc(hidden)]
     #[deprecated = "use `new` instead"]
-    #[inline(always)]
     pub fn new_keccak_block_hash() -> Self {
         Self::new()
     }
@@ -42,22 +60,22 @@ impl<E> EmptyDBTyped<E> {
 impl<E> Database for EmptyDBTyped<E> {
     type Error = E;
 
-    #[inline(always)]
+    #[inline]
     fn basic(&mut self, address: B160) -> Result<Option<AccountInfo>, Self::Error> {
         <Self as DatabaseRef>::basic(self, address)
     }
 
-    #[inline(always)]
+    #[inline]
     fn code_by_hash(&mut self, code_hash: B256) -> Result<Bytecode, Self::Error> {
         <Self as DatabaseRef>::code_by_hash(self, code_hash)
     }
 
-    #[inline(always)]
+    #[inline]
     fn storage(&mut self, address: B160, index: U256) -> Result<U256, Self::Error> {
         <Self as DatabaseRef>::storage(self, address, index)
     }
 
-    #[inline(always)]
+    #[inline]
     fn block_hash(&mut self, number: U256) -> Result<B256, Self::Error> {
         <Self as DatabaseRef>::block_hash(self, number)
     }
@@ -66,22 +84,22 @@ impl<E> Database for EmptyDBTyped<E> {
 impl<E> DatabaseRef for EmptyDBTyped<E> {
     type Error = E;
 
-    #[inline(always)]
+    #[inline]
     fn basic(&self, _address: B160) -> Result<Option<AccountInfo>, Self::Error> {
         Ok(None)
     }
 
-    #[inline(always)]
+    #[inline]
     fn code_by_hash(&self, _code_hash: B256) -> Result<Bytecode, Self::Error> {
         Ok(Bytecode::new())
     }
 
-    #[inline(always)]
+    #[inline]
     fn storage(&self, _address: B160, _index: U256) -> Result<U256, Self::Error> {
         Ok(U256::default())
     }
 
-    #[inline(always)]
+    #[inline]
     fn block_hash(&self, number: U256) -> Result<B256, Self::Error> {
         Ok(number.to_be_bytes().into())
     }