Implement Storage for PrefixedStorage and ReadonlyPrefixedStorage

Author: webmaster128

CHANGELOG.md

@@ -11,6 +11,9 @@ and this project adheres to
 - cosmwasm-std: Implement `Sub` and `SubAssign` for `Uint128`
 - cosmwasm-std: Implement custom events for contract execution results
 - cosmwasm-std: Add `CosmosMsg::Gov` for voting on governance proposals.
+- cosmwasm-storage: Implement `Storage` for `PrefixedStorage` and
+  `ReadonlyPrefixedStorage`. NOTE: Calling `set` or `remove` on
+  `ReadonlyPrefixedStorage` will panic!
 
 ### Removed
 

packages/storage/src/prefixed_storage.rs

@@ -41,23 +41,25 @@ impl<'a> PrefixedStorage<'a> {
             prefix: to_length_prefixed_nested(namespaces),
         }
     }
+}
 
-    pub fn get(&self, key: &[u8]) -> Option<Vec<u8>> {
+impl<'a> Storage for PrefixedStorage<'a> {
+    fn get(&self, key: &[u8]) -> Option<Vec<u8>> {
         get_with_prefix(self.storage, &self.prefix, key)
     }
 
-    pub fn set(&mut self, key: &[u8], value: &[u8]) {
+    fn set(&mut self, key: &[u8], value: &[u8]) {
         set_with_prefix(self.storage, &self.prefix, key, value);
     }
 
-    pub fn remove(&mut self, key: &[u8]) {
+    fn remove(&mut self, key: &[u8]) {
         remove_with_prefix(self.storage, &self.prefix, key);
     }
 
     #[cfg(feature = "iterator")]
     /// range allows iteration over a set of keys, either forwards or backwards
     /// uses standard rust range notation, and eg db.range(b"foo"..b"bar") also works reverse
-    pub fn range<'b>(
+    fn range<'b>(
         &'b self,
         start: Option<&[u8]>,
         end: Option<&[u8]>,
@@ -88,14 +90,24 @@ impl<'a> ReadonlyPrefixedStorage<'a> {
             prefix: to_length_prefixed_nested(namespaces),
         }
     }
+}
 
-    pub fn get(&self, key: &[u8]) -> Option<Vec<u8>> {
+impl<'a> Storage for ReadonlyPrefixedStorage<'a> {
+    fn get(&self, key: &[u8]) -> Option<Vec<u8>> {
         get_with_prefix(self.storage, &self.prefix, key)
     }
 
+    fn set(&mut self, _key: &[u8], _value: &[u8]) {
+        unimplemented!();
+    }
+
+    fn remove(&mut self, _key: &[u8]) {
+        unimplemented!();
+    }
+
     #[cfg(feature = "iterator")]
     /// range allows iteration over a set of keys, either forwards or backwards
-    pub fn range<'b>(
+    fn range<'b>(
         &'b self,
         start: Option<&[u8]>,
         end: Option<&[u8]>,