From 4cafe3855c71648e52994a43465fd11b70e17b4f Mon Sep 17 00:00:00 2001
From: dengchao <2326884052@qq.com>
Date: Fri, 13 Sep 2024 16:07:31 +0800
Subject: [PATCH] move newDigest to MD5Hash

---
 .../src/main/java/org/apache/ratis/io/MD5Hash.java     |  8 +++++---
 .../apache/ratis/server/storage/SnapshotManager.java   | 10 +---------
 2 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/ratis-common/src/main/java/org/apache/ratis/io/MD5Hash.java b/ratis-common/src/main/java/org/apache/ratis/io/MD5Hash.java
index e60bef9652..0d19feb938 100644
--- a/ratis-common/src/main/java/org/apache/ratis/io/MD5Hash.java
+++ b/ratis-common/src/main/java/org/apache/ratis/io/MD5Hash.java
@@ -30,13 +30,15 @@ public class MD5Hash {
   public static final int MD5_LEN = 16;
 
   private static final ThreadLocal<MessageDigest> DIGESTER_FACTORY =
-      ThreadLocal.withInitial(() -> {
+      ThreadLocal.withInitial(MD5Hash::newDigester);
+
+  public static MessageDigest newDigester() {
     try {
       return MessageDigest.getInstance("MD5");
     } catch (NoSuchAlgorithmException e) {
-      throw new RuntimeException(e);
+      throw new IllegalStateException("Failed to create MessageDigest for MD5", e);
     }
-  });
+  }
 
   private byte[] digest;
 
diff --git a/ratis-server/src/main/java/org/apache/ratis/server/storage/SnapshotManager.java b/ratis-server/src/main/java/org/apache/ratis/server/storage/SnapshotManager.java
index 093eacf16b..4b6687b057 100644
--- a/ratis-server/src/main/java/org/apache/ratis/server/storage/SnapshotManager.java
+++ b/ratis-server/src/main/java/org/apache/ratis/server/storage/SnapshotManager.java
@@ -89,7 +89,7 @@ private FileChannel open(FileChunkProto chunk, File tmpSnapshotFile) throws IOEx
       }
       // create the temp snapshot file and put padding inside
       out = FileUtils.newFileChannel(tmpSnapshotFile, StandardOpenOption.WRITE, StandardOpenOption.CREATE);
-      renewMd5Digest();
+      digester = MD5Hash.newDigester();
     } else {
       if (!exists) {
         throw new FileNotFoundException("Chunk offset is non-zero but file is not found: " + tmpSnapshotFile
@@ -172,14 +172,6 @@ public void installSnapshot(InstallSnapshotRequestProto request, StateMachine st
     }
   }
 
-  private void renewMd5Digest() throws IOException {
-    try {
-      digester =  MessageDigest.getInstance("MD5");
-    } catch (NoSuchAlgorithmException e) {
-      throw new IOException("could not find MD5 digest algorithm");
-    }
-  }
-
   private static void rename(File tmpDir, File stateMachineDir) throws IOException {
     LOG.info("Installed snapshot, renaming temporary dir {} to {}", tmpDir, stateMachineDir);