HDDS-12413. Move field declarations to start of class in hdds-container-service

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/HddsPolicyProvider.java

@@ -39,6 +39,13 @@ public final class HddsPolicyProvider extends PolicyProvider {
   private static final Supplier<HddsPolicyProvider> SUPPLIER =
       MemoizedSupplier.valueOf(HddsPolicyProvider::new);
 
+  private static final List<Service> DN_SERVICES =
+      Collections.singletonList(
+          new Service(
+              OZONE_SECURITY_RECONFIGURE_PROTOCOL_ACL,
+              ReconfigureProtocol.class)
+      );
+
   private HddsPolicyProvider() {
   }
 
@@ -48,12 +55,6 @@ public static HddsPolicyProvider getInstance() {
     return SUPPLIER.get();
   }
 
-  private static final List<Service> DN_SERVICES =
-      Collections.singletonList(
-          new Service(
-              OZONE_SECURITY_RECONFIGURE_PROTOCOL_ACL,
-              ReconfigureProtocol.class)
-      );
 
   @Override
   public Service[] getServices() {

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/common/helpers/CommandHandlerMetrics.java

@@ -35,32 +35,11 @@
  */
 @InterfaceAudience.Private
 public final class CommandHandlerMetrics implements MetricsSource {
-  enum CommandMetricsMetricsInfo implements MetricsInfo {
-    Command("The type of the SCM command"),
-    TotalRunTimeMs("The total runtime of the command handler in milliseconds"),
-    AvgRunTimeMs("Average run time of the command handler in milliseconds"),
-    QueueWaitingTaskCount("The number of queued tasks waiting for execution"),
-    InvocationCount("The number of times the command handler has been invoked"),
-    ThreadPoolActivePoolSize("The number of active threads in the thread pool"),
-    ThreadPoolMaxPoolSize("The maximum number of threads in the thread pool"),
-    CommandReceivedCount(
-        "The number of received SCM commands for each command type");
-
-    private final String desc;
-    CommandMetricsMetricsInfo(String desc) {
-      this.desc = desc;
-    }
+  public static final String SOURCE_NAME = CommandHandlerMetrics.class.getSimpleName();
 
-    @Override
-    public String description() {
-      return desc;
-    }
-  }
-
-  public static final String SOURCE_NAME =
-      CommandHandlerMetrics.class.getSimpleName();
   private final Map<Type, CommandHandler> handlerMap;
   private final Map<Type, AtomicInteger> commandCount;
+
   private CommandHandlerMetrics(Map<Type, CommandHandler> handlerMap) {
     this.handlerMap = handlerMap;
     this.commandCount = new HashMap<>();
@@ -121,4 +100,26 @@ public void unRegister() {
     MetricsSystem ms = DefaultMetricsSystem.instance();
     ms.unregisterSource(SOURCE_NAME);
   }
+
+  enum CommandMetricsMetricsInfo implements MetricsInfo {
+    Command("The type of the SCM command"),
+    TotalRunTimeMs("The total runtime of the command handler in milliseconds"),
+    AvgRunTimeMs("Average run time of the command handler in milliseconds"),
+    QueueWaitingTaskCount("The number of queued tasks waiting for execution"),
+    InvocationCount("The number of times the command handler has been invoked"),
+    ThreadPoolActivePoolSize("The number of active threads in the thread pool"),
+    ThreadPoolMaxPoolSize("The maximum number of threads in the thread pool"),
+    CommandReceivedCount(
+        "The number of received SCM commands for each command type");
+
+    private final String desc;
+    CommandMetricsMetricsInfo(String desc) {
+      this.desc = desc;
+    }
+
+    @Override
+    public String description() {
+      return desc;
+    }
+  }
 }

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/common/impl/OpenContainerBlockMap.java

@@ -40,6 +40,16 @@
  * marking the container as closed.
  */
 public class OpenContainerBlockMap {
+  /**
+   * TODO : We may construct the openBlockMap by reading the Block Layout
+   * for each block inside a container listing all chunk files and reading the
+   * sizes. This will help to recreate the openKeys Map once the DataNode
+   * restarts.
+   *
+   * For now, we will track all open blocks of a container in the blockMap.
+   */
+  private final ConcurrentMap<Long, BlockDataMap> containers = new ConcurrentHashMap<>();
+
   /**
    * Map: localId {@literal ->} BlockData.
    *
@@ -69,17 +79,6 @@ synchronized List<BlockData> getAll() {
     }
   }
 
-  /**
-   * TODO : We may construct the openBlockMap by reading the Block Layout
-   * for each block inside a container listing all chunk files and reading the
-   * sizes. This will help to recreate the openKeys Map once the DataNode
-   * restarts.
-   *
-   * For now, we will track all open blocks of a container in the blockMap.
-   */
-  private final ConcurrentMap<Long, BlockDataMap> containers =
-      new ConcurrentHashMap<>();
-
   /**
    * Removes the Container matching with specified containerId.
    * @param containerId containerId

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/common/interfaces/Container.java

@@ -39,24 +39,6 @@ public interface Container<CONTAINERDATA extends ContainerData> {
    * Encapsulates the result of a container scan.
    */
   class ScanResult {
-    /**
-     * Represents the reason a container scan failed and a container should
-     * be marked unhealthy.
-     */
-    public enum FailureType {
-      MISSING_CONTAINER_DIR,
-      MISSING_METADATA_DIR,
-      MISSING_CONTAINER_FILE,
-      MISSING_CHUNKS_DIR,
-      MISSING_CHUNK_FILE,
-      CORRUPT_CONTAINER_FILE,
-      CORRUPT_CHUNK,
-      INCONSISTENT_CHUNK_LENGTH,
-      INACCESSIBLE_DB,
-      WRITE_FAILURE,
-      DELETED_CONTAINER
-    }
-
     private final boolean healthy;
     private final File unhealthyFile;
     private final FailureType failureType;
@@ -94,6 +76,24 @@ public FailureType getFailureType() {
     public Throwable getException() {
       return exception;
     }
+
+    /**
+     * Represents the reason a container scan failed and a container should
+     * be marked unhealthy.
+     */
+    public enum FailureType {
+      MISSING_CONTAINER_DIR,
+      MISSING_METADATA_DIR,
+      MISSING_CONTAINER_FILE,
+      MISSING_CHUNKS_DIR,
+      MISSING_CHUNK_FILE,
+      CORRUPT_CONTAINER_FILE,
+      CORRUPT_CHUNK,
+      INCONSISTENT_CHUNK_LENGTH,
+      INACCESSIBLE_DB,
+      WRITE_FAILURE,
+      DELETED_CONTAINER
+    }
   }
 
   /**