HDFS-6328. Clean up dead code in FSDirectory. Contributed by Haohui Mai.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1593755 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -346,6 +346,8 @@ Release 2.5.0 - UNRELEASED
     HDFS-6294. Use INode IDs to avoid conflicts when a file open for write is
     renamed. (cmccabe)
 
+    HDFS-6328. Clean up dead code in FSDirectory. (wheat9)
+
   OPTIMIZATIONS
 
     HDFS-6214. Webhdfs has poor throughput for files >2GB (daryn)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java

@@ -275,7 +275,7 @@ void waitForReady() {
         while (!ready) {
           try {
             cond.await(5000, TimeUnit.MILLISECONDS);
-          } catch (InterruptedException ie) {
+          } catch (InterruptedException ignored) {
           }
         }
       } finally {
@@ -722,9 +722,8 @@ boolean unprotectedRenameTo(String src, String dst, long timestamp)
       } else {
         withCount.getReferredINode().setLocalName(dstChildName);
         int dstSnapshotId = dstIIP.getLatestSnapshotId();
-        final INodeReference.DstReference ref = new INodeReference.DstReference(
+        toDst = new INodeReference.DstReference(
             dstParent.asDirectory(), withCount, dstSnapshotId);
-        toDst = ref;
       }
       
       added = addLastINodeNoQuotaCheck(dstIIP, toDst);
@@ -763,14 +762,12 @@ boolean unprotectedRenameTo(String src, String dst, long timestamp)
         } else if (!srcChildIsReference) { // src must be in snapshot
           // the withCount node will no longer be used thus no need to update
           // its reference number here
-          final INode originalChild = withCount.getReferredINode();
+          srcChild = withCount.getReferredINode();
-          srcChild = originalChild;
           srcChild.setLocalName(srcChildName);
         } else {
           withCount.removeReference(oldSrcChild.asReference());
-          final INodeReference originalRef = new INodeReference.DstReference(
+          srcChild = new INodeReference.DstReference(
               srcParent, withCount, srcRefDstSnapshot);
-          srcChild = originalRef;
           withCount.getReferredINode().setLocalName(srcChildName);
         }
         
@@ -813,7 +810,7 @@ boolean unprotectedRenameTo(String src, String dst, long timestamp,
         }
       }
     }
-    String error = null;
+    final String error;
     final INodesInPath srcIIP = getINodesInPath4Write(src, false);
     final INode srcInode = srcIIP.getLastINode();
     // validate source
@@ -980,9 +977,8 @@ boolean unprotectedRenameTo(String src, String dst, long timestamp,
       } else {
         withCount.getReferredINode().setLocalName(dstChildName);
         int dstSnapshotId = dstIIP.getLatestSnapshotId();
-        final INodeReference.DstReference ref = new INodeReference.DstReference(
+        toDst = new INodeReference.DstReference(
             dstIIP.getINode(-2).asDirectory(), withCount, dstSnapshotId);
-        toDst = ref;
       }
 
       // add src as dst to complete rename
@@ -1043,14 +1039,12 @@ boolean unprotectedRenameTo(String src, String dst, long timestamp,
         } else if (!srcChildIsReference) { // src must be in snapshot
           // the withCount node will no longer be used thus no need to update
           // its reference number here
-          final INode originalChild = withCount.getReferredINode();
+          srcChild = withCount.getReferredINode();
-          srcChild = originalChild;
           srcChild.setLocalName(srcChildName);
         } else {
           withCount.removeReference(oldSrcChild.asReference());
-          final INodeReference originalRef = new INodeReference.DstReference(
+          srcChild = new INodeReference.DstReference(
               srcParent, withCount, srcRefDstSnapshot);
-          srcChild = originalRef;
           withCount.getReferredINode().setLocalName(srcChildName);
         }
         
@@ -1162,20 +1156,6 @@ long getPreferredBlockSize(String path) throws UnresolvedLinkException,
     }
   }
 
-  boolean exists(String src) throws UnresolvedLinkException {
-    src = normalizePath(src);
-    readLock();
-    try {
-      INode inode = getNode(src, false);
-      if (inode == null) {
-         return false;
-      }
-      return !inode.isFile() || inode.asFile().getBlocks() != null;
-    } finally {
-      readUnlock();
-    }
-  }
-  
   void setPermission(String src, FsPermission permission)
       throws FileNotFoundException, UnresolvedLinkException,
       QuotaExceededException, SnapshotAccessControlException {
@@ -1669,21 +1649,6 @@ private INode getINode4DotSnapshot(String src) throws UnresolvedLinkException {
     return null;
   }
 
-  /**
-   * Get the blocks associated with the file.
-   */
-  Block[] getFileBlocks(String src) throws UnresolvedLinkException {
-    waitForReady();
-    readLock();
-    try {
-      final INode i = getNode(src, false);
-      return i != null && i.isFile()? i.asFile().getBlocks(): null;
-    } finally {
-      readUnlock();
-    }
-  }
-
-
   INodesInPath getExistingPathINodes(byte[][] components)
       throws UnresolvedLinkException {
     return INodesInPath.resolve(rootDir, components);
@@ -1745,12 +1710,8 @@ boolean isValidToCreate(String src) throws UnresolvedLinkException,
     String srcs = normalizePath(src);
     readLock();
     try {
-      if (srcs.startsWith("/") && !srcs.endsWith("/")
+      return srcs.startsWith("/") && !srcs.endsWith("/")
-          && getINode4Write(srcs, false) == null) {
+              && getINode4Write(srcs, false) == null;
-        return true;
-      } else {
-        return false;
-      }
     } finally {
       readUnlock();
     }
@@ -2003,7 +1964,7 @@ boolean mkdirs(String src, PermissionStatus permissions,
       
       // create directories beginning from the first null index
       for(; i < inodes.length; i++) {
-        pathbuilder.append(Path.SEPARATOR + names[i]);
+        pathbuilder.append(Path.SEPARATOR).append(names[i]);
         unprotectedMkdir(namesystem.allocateNewInodeId(), iip, i,
             components[i], (i < lastInodeIndex) ? parentPermissions
                 : permissions, null, now);
@@ -2132,7 +2093,7 @@ private void verifyQuotaForRename(INode[] src, INode[] dst)
       return;
     }
     int i = 0;
-    for(; src[i] == dst[i]; i++);
+    while(src[i] == dst[i]) { i++; }
     // src[i - 1] is the last common ancestor.
 
     final Quota.Counts delta = src[src.length - 1].computeQuotaUsage();
@@ -2293,7 +2254,7 @@ private boolean addChild(INodesInPath iip, int pos,
         counts.get(Quota.NAMESPACE), counts.get(Quota.DISKSPACE), checkQuota);
     boolean isRename = (child.getParent() != null);
     final INodeDirectory parent = inodes[pos-1].asDirectory();
-    boolean added = false;
+    boolean added;
     try {
       added = parent.addChild(child, true, iip.getLatestSnapshotId());
     } catch (QuotaExceededException e) {
@@ -2657,7 +2618,7 @@ private HdfsLocatedFileStatus createLocatedFileStatus(byte[] path,
       blocksize = fileNode.getPreferredBlockSize();
 
       final boolean inSnapshot = snapshot != Snapshot.CURRENT_STATE_ID; 
-      final boolean isUc = inSnapshot ? false : fileNode.isUnderConstruction();
+      final boolean isUc = !inSnapshot && fileNode.isUnderConstruction();
       final long fileSize = !inSnapshot && isUc ? 
           fileNode.computeFileSizeNotIncludingLastUcBlock() : size;
       loc = getFSNamesystem().getBlockManager().createLocatedBlocks(
@@ -3011,7 +2972,7 @@ static String resolvePath(String src, byte[][] pathComponents, FSDirectory fsd)
       return src;
     }
     final String inodeId = DFSUtil.bytes2String(pathComponents[3]);
-    long id = 0;
+    final long id;
     try {
       id = Long.parseLong(inodeId);
     } catch (NumberFormatException e) {