Filter invalid jar reference counts in snapshots

Author: Caideyipi

iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/executable/ReferenceCountedJarMetaKeeper.java

@@ -98,12 +98,23 @@ public synchronized void deserializeJarNameToMd5(final InputStream inputStream)
 
   public synchronized void serializeJarNameToMd5AndReferenceCount(final OutputStream outputStream)
       throws IOException {
-    ReadWriteIOUtils.write(jarNameToMd5Map.size(), outputStream);
-    for (final Map.Entry<String, String> entry : jarNameToMd5Map.entrySet()) {
+    int size = 0;
+    for (final Map.Entry<String, Integer> entry : jarNameToReferenceCountMap.entrySet()) {
+      if (entry.getValue() > 0 && jarNameToMd5Map.containsKey(entry.getKey())) {
+        size++;
+      }
+    }
+
+    ReadWriteIOUtils.write(size, outputStream);
+    for (final Map.Entry<String, Integer> entry : jarNameToReferenceCountMap.entrySet()) {
       final String jarName = entry.getKey();
+      final int referenceCount = entry.getValue();
+      if (referenceCount <= 0 || !jarNameToMd5Map.containsKey(jarName)) {
+        continue;
+      }
       ReadWriteIOUtils.write(jarName, outputStream);
-      ReadWriteIOUtils.write(entry.getValue(), outputStream);
-      ReadWriteIOUtils.write(jarNameToReferenceCountMap.getOrDefault(jarName, 0), outputStream);
+      ReadWriteIOUtils.write(jarNameToMd5Map.get(jarName), outputStream);
+      ReadWriteIOUtils.write(referenceCount, outputStream);
     }
   }
 
@@ -114,8 +125,12 @@ public synchronized void deserializeJarNameToMd5AndReferenceCount(final InputStr
     final int jarSize = ReadWriteIOUtils.readInt(inputStream);
     for (int i = 0; i < jarSize; i++) {
       final String jarName = ReadWriteIOUtils.readString(inputStream);
-      jarNameToMd5Map.put(jarName, ReadWriteIOUtils.readString(inputStream));
-      jarNameToReferenceCountMap.put(jarName, ReadWriteIOUtils.readInt(inputStream));
+      final String md5 = ReadWriteIOUtils.readString(inputStream);
+      final int referenceCount = ReadWriteIOUtils.readInt(inputStream);
+      if (referenceCount > 0) {
+        jarNameToMd5Map.put(jarName, md5);
+        jarNameToReferenceCountMap.put(jarName, referenceCount);
+      }
     }
   }
 }

iotdb-core/node-commons/src/test/java/org/apache/iotdb/commons/executable/ReferenceCountedJarMetaKeeperTest.java

@@ -19,6 +19,7 @@
 
 package org.apache.iotdb.commons.executable;
 
+import org.apache.tsfile.utils.ReadWriteIOUtils;
 import org.junit.Assert;
 import org.junit.Test;
 
@@ -83,6 +84,22 @@ public void testJarNameToMd5AndReferenceCountSnapshot() throws IOException {
     Assert.assertFalse(loaded.containsJar(JAR_NAME));
   }
 
+  @Test
+  public void testDeserializeJarNameToMd5AndReferenceCountSkipsZeroReferenceCount()
+      throws IOException {
+    final ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+    ReadWriteIOUtils.write(1, outputStream);
+    ReadWriteIOUtils.write(JAR_NAME, outputStream);
+    ReadWriteIOUtils.write(MD5, outputStream);
+    ReadWriteIOUtils.write(0, outputStream);
+
+    final ReferenceCountedJarMetaKeeper loaded = new ReferenceCountedJarMetaKeeper();
+    loaded.deserializeJarNameToMd5AndReferenceCount(
+        new ByteArrayInputStream(outputStream.toByteArray()));
+
+    Assert.assertFalse(loaded.containsJar(JAR_NAME));
+  }
+
   private ByteArrayOutputStream serializeJarNameToMd5(final ReferenceCountedJarMetaKeeper keeper)
       throws IOException {
     final ByteArrayOutputStream outputStream = new ByteArrayOutputStream();