Merging changes from trunk to pick HDFS-4124 changes.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-2802@1403306 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -155,6 +155,9 @@ Trunk (Unreleased)
     HDFS-4122. Cleanup HDFS logs and reduce the size of logged messages.
     (suresh)
 
+    HDFS-4124. Refactor INodeDirectory#getExistingPathINodes() to enable 
+    returningmore than INode array. (Jing Zhao via suresh)
+
   OPTIMIZATIONS
 
   BUG FIXES

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

@@ -59,6 +59,7 @@
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.BlockUCState;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.INodeFileSnapshot;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.INodeFileWithLink;
+import org.apache.hadoop.hdfs.server.namenode.INodeDirectory.INodesInPath;
 import org.apache.hadoop.hdfs.util.ByteArray;
 
 import com.google.common.base.Preconditions;
@@ -594,8 +595,9 @@ boolean unprotectedRenameTo(String src, String dst, long timestamp)
     }
     
     byte[][] dstComponents = INode.getPathComponents(dst);
-    INode[] dstInodes = new INode[dstComponents.length];
+    INodesInPath dstInodesInPath = rootDir.getExistingPathINodes(dstComponents,
-    rootDir.getExistingPathINodes(dstComponents, dstInodes, false);
+        dstComponents.length, false);
+    INode[] dstInodes = dstInodesInPath.getINodes();
     if (dstInodes[dstInodes.length-1] != null) {
       NameNode.stateChangeLog.warn("DIR* FSDirectory.unprotectedRenameTo: "
                                    +"failed to rename "+src+" to "+dst+ 
@@ -714,8 +716,9 @@ boolean unprotectedRenameTo(String src, String dst, long timestamp,
       throw new IOException(error);
     }
     final byte[][] dstComponents = INode.getPathComponents(dst);
-    final INode[] dstInodes = new INode[dstComponents.length];
+    INodesInPath dstInodesInPath = rootDir.getExistingPathINodes(dstComponents,
-    rootDir.getExistingPathINodes(dstComponents, dstInodes, false);
+        dstComponents.length, false);
+    final INode[] dstInodes = dstInodesInPath.getINodes();
     INode dstInode = dstInodes[dstInodes.length - 1];
     if (dstInodes.length == 1) {
       error = "rename destination cannot be the root";
@@ -1513,12 +1516,13 @@ boolean mkdirs(String src, PermissionStatus permissions,
     src = normalizePath(src);
     String[] names = INode.getPathNames(src);
     byte[][] components = INode.getPathComponents(names);
-    INode[] inodes = new INode[components.length];
+    final int lastInodeIndex = components.length - 1;
-    final int lastInodeIndex = inodes.length - 1;
 
     writeLock();
     try {
-      rootDir.getExistingPathINodes(components, inodes, false);
+      INodesInPath inodesInPath = rootDir.getExistingPathINodes(components,
+          components.length, false);
+      INode[] inodes = inodesInPath.getINodes();
 
       // find the index of the first null in inodes[]
       StringBuilder pathbuilder = new StringBuilder();
@@ -1588,16 +1592,14 @@ boolean mkdirs(String src, PermissionStatus permissions,
     return true;
   }
 
-  /**
-   */
   INode unprotectedMkdir(String src, PermissionStatus permissions,
                           long timestamp) throws QuotaExceededException,
                           UnresolvedLinkException {
     assert hasWriteLock();
     byte[][] components = INode.getPathComponents(src);
-    INode[] inodes = new INode[components.length];
+    INodesInPath inodesInPath = rootDir.getExistingPathINodes(components,
-
+        components.length, false);
-    rootDir.getExistingPathINodes(components, inodes, false);
+    INode[] inodes = inodesInPath.getINodes();
     unprotectedMkdir(inodes, inodes.length-1, components[inodes.length-1],
         permissions, timestamp);
     return inodes[inodes.length-1];
@@ -1626,10 +1628,11 @@ private <T extends INode> T addNode(String src, T child,
     byte[] path = components[components.length-1];
     child.setLocalName(path);
     cacheName(child);
-    INode[] inodes = new INode[components.length];
     writeLock();
     try {
-      rootDir.getExistingPathINodes(components, inodes, false);
+      INodesInPath inodesInPath = rootDir.getExistingPathINodes(components,
+          components.length, false);
+      INode[] inodes = inodesInPath.getINodes();
       return addChild(inodes, inodes.length-1, child, childDiskspace);
     } finally {
       writeUnlock();

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

@@ -135,9 +135,9 @@ private INode getChildINode(byte[] name) {
    */
   private INode getNode(byte[][] components, boolean resolveLink
       ) throws UnresolvedLinkException {
-    INode[] inode  = new INode[1];
+    INodesInPath inodesInPath = getExistingPathINodes(components, 1,
-    getExistingPathINodes(components, inode, resolveLink);
+        resolveLink);
-    return inode[0];
+    return inodesInPath.inodes[0];
   }
 
   /**
@@ -185,27 +185,29 @@ INode getNode(String path, boolean resolveLink)
    * fill the array with [rootINode,c1,c2,null]
    * 
    * @param components array of path component name
-   * @param existing array to fill with existing INodes
+   * @param numOfINodes number of INodes to return
    * @param resolveLink indicates whether UnresolvedLinkException should
    *        be thrown when the path refers to a symbolic link.
-   * @return number of existing INodes in the path
+   * @return the specified number of existing INodes in the path
    */
-  int getExistingPathINodes(byte[][] components, INode[] existing, 
+  INodesInPath getExistingPathINodes(byte[][] components, int numOfINodes,
-      boolean resolveLink) throws UnresolvedLinkException {
+      boolean resolveLink)
+      throws UnresolvedLinkException {
     assert this.compareTo(components[0]) == 0 :
         "Incorrect name " + getLocalName() + " expected "
         + (components[0] == null? null: DFSUtil.bytes2String(components[0]));
 
+    INodesInPath existing = new INodesInPath(numOfINodes);
     INode curNode = this;
     int count = 0;
-    int index = existing.length - components.length;
+    int index = numOfINodes - components.length;
     if (index > 0) {
       index = 0;
     }
     while (count < components.length && curNode != null) {
       final boolean lastComp = (count == components.length - 1);      
       if (index >= 0) {
-        existing[index] = curNode;
+        existing.inodes[index] = curNode;
       }
       if (curNode.isLink() && (!lastComp || (lastComp && resolveLink))) {
         final String path = constructPath(components, 0, components.length);
@@ -230,7 +232,7 @@ int getExistingPathINodes(byte[][] components, INode[] existing,
       count++;
       index++;
     }
-    return count;
+    return existing;
   }
 
   /**
@@ -251,11 +253,9 @@ int getExistingPathINodes(byte[][] components, INode[] existing,
   INode[] getExistingPathINodes(String path, boolean resolveLink) 
     throws UnresolvedLinkException {
     byte[][] components = getPathComponents(path);
-    INode[] inodes = new INode[components.length];
+    INodesInPath inodes = this.getExistingPathINodes(components,
-
+        components.length, resolveLink);
-    this.getExistingPathINodes(components, inodes, resolveLink);
+    return inodes.inodes;
-    
-    return inodes;
   }
 
   /**
@@ -346,9 +346,8 @@ INodeDirectory getParent(byte[][] pathComponents
     if (pathComponents.length < 2)  // add root
       return null;
     // Gets the parent INode
-    INode[] inodes  = new INode[2];
+    INodesInPath inodes =  getExistingPathINodes(pathComponents, 2, false);
-    getExistingPathINodes(pathComponents, inodes, false);
+    INode inode = inodes.inodes[0];
-    INode inode = inodes[0];
     if (inode == null) {
       throw new FileNotFoundException("Parent path does not exist: "+
           DFSUtil.byteArray2String(pathComponents));
@@ -452,4 +451,22 @@ int collectSubtreeBlocksAndClear(List<Block> v) {
     children = null;
     return total;
   }
+  
+  /**
+   * Used by
+   * {@link INodeDirectory#getExistingPathINodes(byte[][], int, boolean)}.
+   * Containing INodes information resolved from a given path.
+   */
+  static class INodesInPath {
+    private INode[] inodes;
+    
+    public INodesInPath(int number) {
+      assert (number >= 0);
+      this.inodes = new INode[number];
+    }
+    
+    INode[] getINodes() {
+      return inodes;
+    }
+  }
 }