HBASE-14230 replace reflection in FSHlog with HdfsDataOutputStream#getCurrentBlockReplication()

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/wal/FSHLog.java

@@ -24,7 +24,6 @@ import java.io.IOException;
 import java.io.InterruptedIOException;
 import java.io.OutputStream;
 import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
 import java.net.URLEncoder;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -77,6 +76,8 @@ import org.apache.hadoop.hbase.wal.WALKey;
 import org.apache.hadoop.hbase.wal.WALPrettyPrinter;
 import org.apache.hadoop.hbase.wal.WALProvider.Writer;
 import org.apache.hadoop.hbase.wal.WALSplitter;
+import org.apache.hadoop.hdfs.DFSOutputStream;
+import org.apache.hadoop.hdfs.client.HdfsDataOutputStream;
 import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
 import org.apache.hadoop.util.StringUtils;
 import org.apache.htrace.NullScope;
@@ -275,9 +276,6 @@ public class FSHLog implements WAL {
   // Minimum tolerable replicas, if the actual value is lower than it, rollWriter will be triggered
   private final int minTolerableReplication;
 
-  // DFSOutputStream.getNumCurrentReplicas method instance gotten via reflection.
-  private final Method getNumCurrentReplicas;
-  private final Method getPipeLine; // refers to DFSOutputStream.getPipeLine
   private final int slowSyncNs;
 
   private final static Object [] NO_ARGS = new Object []{};
@@ -528,10 +526,6 @@ public class FSHLog implements WAL {
     this.slowSyncNs =
         1000000 * conf.getInt("hbase.regionserver.hlog.slowsync.ms",
           DEFAULT_SLOW_SYNC_TIME_MS);
-    // handle the reflection necessary to call getNumCurrentReplicas(). TODO: Replace with
-    // HdfsDataOutputStream#getCurrentBlockReplication() and go without reflection.
-    this.getNumCurrentReplicas = getGetNumCurrentReplicas(this.hdfs_out);
-    this.getPipeLine = getGetPipeline(this.hdfs_out);
 
     // This is the 'writer' -- a single threaded executor.  This single thread 'consumes' what is
     // put on the ring buffer.
@@ -1405,34 +1399,6 @@ public class FSHLog implements WAL {
     return len;
   }
 
-  /**
-   * Find the 'getNumCurrentReplicas' on the passed <code>os</code> stream.
-   * This is used for getting current replicas of a file being written.
-   * @return Method or null.
-   */
-  private Method getGetNumCurrentReplicas(final FSDataOutputStream os) {
-    // TODO: Remove all this and use the now publically available
-    // HdfsDataOutputStream#getCurrentBlockReplication()
-    Method m = null;
-    if (os != null) {
-      Class<? extends OutputStream> wrappedStreamClass = os.getWrappedStream().getClass();
-      try {
-        m = wrappedStreamClass.getDeclaredMethod("getNumCurrentReplicas", new Class<?>[] {});
-        m.setAccessible(true);
-      } catch (NoSuchMethodException e) {
-        LOG.info("FileSystem's output stream doesn't support getNumCurrentReplicas; " +
-         "HDFS-826 not available; fsOut=" + wrappedStreamClass.getName());
-      } catch (SecurityException e) {
-        LOG.info("No access to getNumCurrentReplicas on FileSystems's output stream; HDFS-826 " +
-          "not available; fsOut=" + wrappedStreamClass.getName(), e);
-        m = null; // could happen on setAccessible()
-      }
-    }
-    if (m != null) {
-      if (LOG.isTraceEnabled()) LOG.trace("Using getNumCurrentReplicas");
-    }
-    return m;
-  }
 
   /**
    * This method gets the datanode replication count for the current WAL.
@@ -1447,14 +1413,14 @@ public class FSHLog implements WAL {
    * @throws Exception
    */
   @VisibleForTesting
-  int getLogReplication()
-  throws IllegalArgumentException, IllegalAccessException, InvocationTargetException {
-    final OutputStream stream = getOutputStream();
-    if (this.getNumCurrentReplicas != null && stream != null) {
-      Object repl = this.getNumCurrentReplicas.invoke(stream, NO_ARGS);
-      if (repl instanceof Integer) {
-        return ((Integer)repl).intValue();
+  int getLogReplication() {
+    try {
+      //in standalone mode, it will return 0
+      if (this.hdfs_out instanceof HdfsDataOutputStream) {
+        return ((HdfsDataOutputStream) this.hdfs_out).getCurrentBlockReplication();
       }
+    } catch (IOException e) {
+      LOG.info("", e);
     }
     return 0;
   }
@@ -1988,49 +1954,15 @@ public class FSHLog implements WAL {
       System.exit(-1);
     }
   }
-  
-  /**
-   * Find the 'getPipeline' on the passed <code>os</code> stream.
-   * @return Method or null.
-   */
-  private Method getGetPipeline(final FSDataOutputStream os) {
-    Method m = null;
-    if (os != null) {
-      Class<? extends OutputStream> wrappedStreamClass = os.getWrappedStream()
-          .getClass();
-      try {
-        m = wrappedStreamClass.getDeclaredMethod("getPipeline",
-          new Class<?>[] {});
-        m.setAccessible(true);
-      } catch (NoSuchMethodException e) {
-        LOG.info("FileSystem's output stream doesn't support"
-            + " getPipeline; not available; fsOut="
-            + wrappedStreamClass.getName());
-      } catch (SecurityException e) {
-        LOG.info(
-          "Doesn't have access to getPipeline on "
-              + "FileSystems's output stream ; fsOut="
-              + wrappedStreamClass.getName(), e);
-        m = null; // could happen on setAccessible()
-      }
-    }
-    return m;
-  }
 
   /**
    * This method gets the pipeline for the current WAL.
    */
   @VisibleForTesting
   DatanodeInfo[] getPipeLine() {
-    if (this.getPipeLine != null && this.hdfs_out != null) {
-      Object repl;
-      try {
-        repl = this.getPipeLine.invoke(getOutputStream(), NO_ARGS);
-        if (repl instanceof DatanodeInfo[]) {
-          return ((DatanodeInfo[]) repl);
-        }
-      } catch (Exception e) {
-        LOG.info("Get pipeline failed", e);
+    if (this.hdfs_out != null) {
+      if (this.hdfs_out.getWrappedStream() instanceof DFSOutputStream) {
+        return ((DFSOutputStream) this.hdfs_out.getWrappedStream()).getPipeline();
       }
     }
     return new DatanodeInfo[0];