Implement iterator over nodes; refactor key-value iterator (#517)

Co-authored-by: Ron Kuris <[email protected]>

firewood/src/db.rs

@@ -320,14 +320,15 @@ impl<S: ShaleStore<Node> + Send + Sync> api::DbView for DbRev<S> {
 
 impl<S: ShaleStore<Node> + Send + Sync> DbRev<S> {
     pub fn stream(&self) -> merkle::MerkleKeyValueStream<'_, S, Bincode> {
-        self.merkle.iter(self.header.kv_root)
+        self.merkle.key_value_iter(self.header.kv_root)
     }
 
     pub fn stream_from(
         &self,
         start_key: Box<[u8]>,
     ) -> merkle::MerkleKeyValueStream<'_, S, Bincode> {
-        self.merkle.iter_from(self.header.kv_root, start_key)
+        self.merkle
+            .key_value_iter_from_key(self.header.kv_root, start_key)
     }
 
     fn flush_dirty(&mut self) -> Option<()> {

firewood/src/merkle.rs

@@ -1715,11 +1715,11 @@ impl<S: ShaleStore<Node> + Send + Sync, T> Merkle<S, T> {
         self.store.flush_dirty()
     }
 
-    pub(crate) fn iter(&self, root: DiskAddress) -> MerkleKeyValueStream<'_, S, T> {
+    pub(crate) fn key_value_iter(&self, root: DiskAddress) -> MerkleKeyValueStream<'_, S, T> {
         MerkleKeyValueStream::new(self, root)
     }
 
-    pub(crate) fn iter_from(
+    pub(crate) fn key_value_iter_from_key(
         &self,
         root: DiskAddress,
         key: Box<[u8]>,
@@ -1750,8 +1750,10 @@ impl<S: ShaleStore<Node> + Send + Sync, T> Merkle<S, T> {
 
         let mut stream = match first_key {
             // TODO: fix the call-site to force the caller to do the allocation
-            Some(key) => self.iter_from(root, key.as_ref().to_vec().into_boxed_slice()),
-            None => self.iter(root),
+            Some(key) => {
+                self.key_value_iter_from_key(root, key.as_ref().to_vec().into_boxed_slice())
+            }
+            None => self.key_value_iter(root),
         };
 
         // fetch the first key from the stream