Merge pull request #3610 from greymistcube/fix/state-store-commit

🐛 Fixed `IStateStore.Commit()`
planetarium · Jan 18, 2024 · ccef9c5 · ccef9c5
2 parents b4bde80 + 82760cb
commit ccef9c5
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Showing 6 changed files with 30 additions and 6 deletions.
diff --git a/CHANGES.md b/CHANGES.md
@@ -6,6 +6,9 @@ Version 3.9.5
 
 To be released.
 
+ -  (Libplanet.Store) Changed `IStateStore.Commit()` to return an `ITrie`
+    with either its `Root` as `null` or a `HashNode`.  [[#3610]]
+
 
 Version 3.9.4
 -------------

diff --git a/Libplanet.Store/IStateStore.cs b/Libplanet.Store/IStateStore.cs
@@ -3,6 +3,7 @@
 using System.Security.Cryptography;
 using Libplanet.Common;
 using Libplanet.Store.Trie;
+using Libplanet.Store.Trie.Nodes;
 
 namespace Libplanet.Store
 {
@@ -34,7 +35,9 @@ public interface IStateStore : IDisposable
         /// <see cref="ITrie.Hash"/>.
         /// </summary>
         /// <param name="trie">The <see cref="ITrie"/> to commit.</param>
-        /// <returns>The committed <see cref="ITrie"/>.</returns>
+        /// <returns>The committed <see cref="ITrie"/>.  The committed <see cref="ITrie"/>'s
+        /// <see cref="ITrie.Root"/> is guaranteed to be either <see langword="null"/>
+        /// or a <see cref="HashNode"/>.</returns>
         /// <remarks>
         /// Given <paramref name="trie"/> must have originated from the same instance
         /// (or with an instance with the same reference to an <see cref="IKeyValueStore"/>).

diff --git a/Libplanet.Store/Trie/MerkleTrie.Diff.cs b/Libplanet.Store/Trie/MerkleTrie.Diff.cs
@@ -61,7 +61,7 @@ public partial class MerkleTrie : ITrie
                                     }
 
                                 case ShortNode shortNode:
-                                    queue.Enqueue((shortNode.Value!, path.AddRange(shortNode.Key)));
+                                    queue.Enqueue((shortNode.Value, path.AddRange(shortNode.Key)));
                                     continue;
 
                                 case FullNode fullNode:
@@ -104,7 +104,7 @@ int i in Enumerable.Range(0, FullNode.ChildrenCount - 1))
                             continue;
 
                         case ShortNode shortNode:
-                            queue.Enqueue((shortNode.Value!, path.AddRange(shortNode.Key)));
+                            queue.Enqueue((shortNode.Value, path.AddRange(shortNode.Key)));
                             continue;
 
                         case FullNode fullNode:

diff --git a/Libplanet.Store/Trie/MerkleTrie.Insert.cs b/Libplanet.Store/Trie/MerkleTrie.Insert.cs
@@ -94,7 +94,7 @@ private INode InsertToShortNode(ShortNode shortNode, in PathCursor cursor, Value
                     ? fullNode.SetChild(
                         newChildIndex,
                         new ShortNode(newShortNodeKey, shortNode.Value))
-                    : fullNode.SetChild(newChildIndex, shortNode.Value!);
+                    : fullNode.SetChild(newChildIndex, shortNode.Value);
 
                 // Handles value node.
                 // Assumes next cursor nibble (including non-remaining case)

diff --git a/Libplanet.Store/TrieStateStore.Commit.cs b/Libplanet.Store/TrieStateStore.Commit.cs
@@ -36,9 +36,10 @@ public ITrie Commit(ITrie trie)
                 {
                     IValue bencoded = newRoot.ToBencodex();
                     byte[] serialized = _codec.Encode(bencoded);
-                    byte[] hash = SHA256.Create().ComputeHash(serialized);
+                    HashDigest<SHA256> hashDigest = HashDigest<SHA256>.DeriveFrom(serialized);
 
-                    writeBatch.Add(new KeyBytes(hash), serialized);
+                    writeBatch.Add(new KeyBytes(hashDigest.ByteArray), serialized);
+                    newRoot = new HashNode(hashDigest);
                 }
 
                 writeBatch.Flush();

diff --git a/Libplanet.Tests/Store/TrieStateStoreCommitTest.cs b/Libplanet.Tests/Store/TrieStateStoreCommitTest.cs
@@ -1,9 +1,11 @@
+using System;
 using System.Linq;
 using System.Security.Cryptography;
 using Bencodex.Types;
 using Libplanet.Common;
 using Libplanet.Store;
 using Libplanet.Store.Trie;
+using Libplanet.Store.Trie.Nodes;
 using Xunit;
 
 namespace Libplanet.Tests.Store
@@ -20,6 +22,7 @@ public void CommitEmptyDoesNotWrite()
 
             Assert.Null(emptyTrie.Root);
             Assert.True(stateStore.GetStateRoot(emptyRootHash).Recorded);
+            Assert.Null(stateStore.GetStateRoot(emptyRootHash).Root);
             Assert.False(keyValueStore.Exists(new KeyBytes(emptyRootHash.ByteArray)));
 
             emptyTrie = stateStore.Commit(emptyTrie);
@@ -57,5 +60,19 @@ public void Commit()
             Assert.Equal(new Text("2c73"), trie.Get(new KeyBytes(new byte[] { 0x2c, 0x73 })));
             Assert.Equal(new Text("234f"), trie.Get(new KeyBytes(new byte[] { 0x23, 0x4f })));
         }
+
+        [Fact]
+        public void CommittedNonEmptyTrieRootIsHashNode()
+        {
+            IKeyValueStore keyValueStore = new MemoryKeyValueStore();
+            IStateStore stateStore = new TrieStateStore(keyValueStore);
+            ITrie trie = stateStore.GetStateRoot(null);
+            trie = trie.Set(new KeyBytes(Array.Empty<byte>()), new Integer(1));
+            trie = stateStore.Commit(trie);
+            HashNode root = Assert.IsType<HashNode>(trie.Root);
+            trie = stateStore.GetStateRoot(trie.Hash);
+            Assert.IsType<HashNode>(trie.Root);
+            Assert.Equal(root, trie.Root);
+        }
     }
 }