svn merge -c 1455883 from branch-1 for HDFS-4597. Backport WebHDFS concat.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.2@1455884 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -61,6 +61,8 @@ Release 1.2.0 - unreleased
     HDFS-4256 Backport concatenation of files into a single file to branch-1
     (sanjay Radia)
 
+    HDFS-4597. Backport WebHDFS concat.  (szetszwo)
+
   IMPROVEMENTS
 
     HDFS-3515. Port HDFS-1457 to branch-1. (eli)

src/core/org/apache/hadoop/fs/FileSystem.java

@@ -669,6 +669,17 @@ public abstract class FileSystem extends Configured implements Closeable {
    */
   public abstract FSDataOutputStream append(Path f, int bufferSize,
       Progressable progress) throws IOException;
+
+  /**
+   * Concat existing files together.
+   * @param trg the path to the target destination.
+   * @param psrcs the paths to the sources to use for the concatenation.
+   * @throws IOException
+   */
+  public void concat(final Path trg, final Path [] srcs) throws IOException {
+    throw new UnsupportedOperationException("Not implemented by the " + 
+        getClass().getSimpleName() + " FileSystem implementation");
+  }
   
   /**
    * Get replication.

src/core/org/apache/hadoop/fs/FilterFileSystem.java

@@ -114,7 +114,11 @@ public class FilterFileSystem extends FileSystem {
     return fs.append(f, bufferSize, progress);
   }
 
-  /** {@inheritDoc} */
+  @Override
+  public void concat(Path f, Path[] psrcs) throws IOException {
+    fs.concat(f, psrcs);
+  }
+
   @Override
   public FSDataOutputStream create(Path f, FsPermission permission,
       boolean overwrite, int bufferSize, short replication, long blockSize,

src/docs/src/documentation/content/xdocs/site.xml

@@ -166,6 +166,7 @@ See http://forrest.apache.org/docs/linking.html for more info.
                 <setTimes href="#setTimes(org.apache.hadoop.fs.Path,%20long,%20long)" />
 
                 <append href="#append(org.apache.hadoop.fs.Path,%20int,%20org.apache.hadoop.util.Progressable)" />
+                <concat href="#concat(org.apache.hadoop.fs.Path,%20org.apache.hadoop.fs.Path[])" />
                 <delete href="#delete(org.apache.hadoop.fs.Path,%20boolean)" />
               </filesystem>
             </fs>

src/docs/src/documentation/content/xdocs/webhdfs.xml

@@ -104,6 +104,9 @@
     <li><a href="#APPEND"><code>APPEND</code></a>
         (see <a href="ext:api/org/apache/hadoop/fs/filesystem/append">FileSystem.append</a>)
     </li>
+    <li><a href="#CONCAT"><code>CONCAT</code></a>
+        (see <a href="ext:api/org/apache/hadoop/fs/filesystem/concat">FileSystem.concat</a>)
+    </li>
   </ul></li>
   <li>HTTP DELETE
   <ul>
@@ -310,6 +313,28 @@ Content-Length: 0
   <a href="ext:api/org/apache/hadoop/fs/filesystem/append">FileSystem.append</a>
 </p>
       </section>
+<!-- ***************************************************************************** -->
+      <section id="CONCAT">
+        <title>Concatenate Files</title>
+<ul>
+  <li>Submit a HTTP POST request.
+    <source>
+        curl -i -X POST "http://&lt;HOST&gt;:&lt;PORT&gt;/webhdfs/v1/&lt;PATH&gt;?op=CONCAT&amp;sources=&lt;PATHS&gt;"
+    </source>
+The client receives a response with zero content length:
+    <source>
+HTTP/1.1 200 OK
+Content-Length: 0
+    </source>
+  </li>
+</ul>
+<p>
+  See also:
+  <a href="#sources"><code>sources</code></a>,
+  <a href="ext:api/org/apache/hadoop/fs/filesystem/concat">FileSystem.concat</a>
+</p>
+      </section>
+
 <!-- ***************************************************************************** -->
       <section id="OPEN">
         <title>Open and Read a File</title>
@@ -1534,6 +1559,22 @@ var fileStatusProperties =
   <a href="#SETREPLICATION"><code>SETREPLICATION</code></a>
 </p>
       </section>
+<!-- ***************************************************************************** -->
+      <section id="sources">
+        <title>Sources</title>
+<table>
+  <tr><td>Name</td><td><code>sources</code></td></tr>
+  <tr><td>Description</td><td>A list of source paths.</td></tr>
+  <tr><td>Type</td><td>String</td></tr>
+  <tr><td>Default Value</td><td>&lt;empty&gt;</td></tr>
+  <tr><td>Valid Values</td><td>A list of comma seperated absolute FileSystem paths without scheme and authority.</td></tr>
+  <tr><td>Syntax</td><td>Any string.</td></tr>
+</table>
+<p>
+  See also:
+  <a href="#CONCAT"><code>CONCAT</code></a>,
+</p>
+      </section>
 <!-- ***************************************************************************** -->
       <section id="token">
         <title>Token</title>

src/hdfs/org/apache/hadoop/hdfs/DistributedFileSystem.java

@@ -220,14 +220,14 @@ public class DistributedFileSystem extends FileSystem {
   }
 
   /**
-   * THIS IS DFS only operations, it is not part of FileSystem
-   * move blocks from srcs to trg
-   * and delete srcs afterwards
-   * all blocks should be the same size
+   * Move blocks from srcs to trg and delete srcs afterwards.
+   * The file block sizes must be the same.
+   *
    * @param trg existing file to append to
    * @param psrcs list of files (same block size, same replication)
    * @throws IOException
    */
+  @Override
   public void concat(Path trg, Path [] psrcs) throws IOException {
     String [] srcs = new String [psrcs.length];
     for(int i=0; i<psrcs.length; i++) {

src/hdfs/org/apache/hadoop/hdfs/server/namenode/web/resources/NamenodeWebHdfsMethods.java

@@ -63,6 +63,7 @@ import org.apache.hadoop.hdfs.web.WebHdfsFileSystem;
 import org.apache.hadoop.hdfs.web.resources.AccessTimeParam;
 import org.apache.hadoop.hdfs.web.resources.BlockSizeParam;
 import org.apache.hadoop.hdfs.web.resources.BufferSizeParam;
+import org.apache.hadoop.hdfs.web.resources.ConcatSourcesParam;
 import org.apache.hadoop.hdfs.web.resources.DelegationParam;
 import org.apache.hadoop.hdfs.web.resources.DeleteOpParam;
 import org.apache.hadoop.hdfs.web.resources.DestinationParam;
@@ -401,10 +402,12 @@ public class NamenodeWebHdfsMethods {
           final DoAsParam doAsUser,
       @QueryParam(PostOpParam.NAME) @DefaultValue(PostOpParam.DEFAULT)
           final PostOpParam op,
+      @QueryParam(ConcatSourcesParam.NAME) @DefaultValue(ConcatSourcesParam.DEFAULT)
+          final ConcatSourcesParam concatSrcs,
       @QueryParam(BufferSizeParam.NAME) @DefaultValue(BufferSizeParam.DEFAULT)
           final BufferSizeParam bufferSize
       ) throws IOException, InterruptedException {
-    return post(ugi, delegation, username, doAsUser, ROOT, op, bufferSize);
+    return post(ugi, delegation, username, doAsUser, ROOT, op, concatSrcs, bufferSize);
   }
 
   /** Handle HTTP POST request. */
@@ -423,11 +426,13 @@ public class NamenodeWebHdfsMethods {
       @PathParam(UriFsPathParam.NAME) final UriFsPathParam path,
       @QueryParam(PostOpParam.NAME) @DefaultValue(PostOpParam.DEFAULT)
           final PostOpParam op,
+      @QueryParam(ConcatSourcesParam.NAME) @DefaultValue(ConcatSourcesParam.DEFAULT)
+          final ConcatSourcesParam concatSrcs,
       @QueryParam(BufferSizeParam.NAME) @DefaultValue(BufferSizeParam.DEFAULT)
           final BufferSizeParam bufferSize
       ) throws IOException, InterruptedException {
 
-    init(ugi, delegation, username, doAsUser, path, op, bufferSize);
+    init(ugi, delegation, username, doAsUser, path, op, concatSrcs, bufferSize);
 
     return ugi.doAs(new PrivilegedExceptionAction<Response>() {
       @Override
@@ -445,6 +450,11 @@ public class NamenodeWebHdfsMethods {
           fullpath, op.getValue(), -1L, -1L, bufferSize);
       return Response.temporaryRedirect(uri).type(MediaType.APPLICATION_OCTET_STREAM).build();
     }
+    case CONCAT:
+    {
+      namenode.concat(fullpath, concatSrcs.getAbsolutePaths());
+      return Response.ok().build();
+    }
     default:
       throw new UnsupportedOperationException(op + " is not supported");
     }

src/hdfs/org/apache/hadoop/hdfs/web/WebHdfsFileSystem.java

@@ -61,6 +61,7 @@ import org.apache.hadoop.hdfs.server.namenode.SafeModeException;
 import org.apache.hadoop.hdfs.web.resources.AccessTimeParam;
 import org.apache.hadoop.hdfs.web.resources.BlockSizeParam;
 import org.apache.hadoop.hdfs.web.resources.BufferSizeParam;
+import org.apache.hadoop.hdfs.web.resources.ConcatSourcesParam;
 import org.apache.hadoop.hdfs.web.resources.DeleteOpParam;
 import org.apache.hadoop.hdfs.web.resources.DestinationParam;
 import org.apache.hadoop.hdfs.web.resources.GetOpParam;
@@ -672,6 +673,15 @@ public class WebHdfsFileSystem extends FileSystem
     };
   }
 
+  @Override
+  public void concat(final Path trg, final Path [] srcs) throws IOException {
+    statistics.incrementWriteOps(1);
+    final HttpOpParam.Op op = PostOpParam.Op.CONCAT;
+
+    ConcatSourcesParam param = new ConcatSourcesParam(srcs);
+    run(op, trg, param);
+  }
+
   @Override
   public FSDataOutputStream create(final Path f, final FsPermission permission,
       final boolean overwrite, final int bufferSize, final short replication,

src/hdfs/org/apache/hadoop/hdfs/web/resources/ConcatSourcesParam.java

@@ -0,0 +1,65 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hadoop.hdfs.web.resources;
+
+import org.apache.hadoop.fs.Path;
+
+/** The concat source paths parameter. */
+public class ConcatSourcesParam extends StringParam {
+  /** Parameter name. */
+  public static final String NAME = "sources";
+
+  public static final String DEFAULT = "";
+
+  private static final Domain DOMAIN = new Domain(NAME, null);
+
+  private static String paths2String(Path[] paths) {
+    if (paths == null || paths.length == 0) {
+      return "";
+    }
+    final StringBuilder b = new StringBuilder(paths[0].toUri().getPath());
+    for(int i = 1; i < paths.length; i++) {
+      b.append(',').append(paths[i].toUri().getPath());
+    }
+    return b.toString();
+  }
+
+  /**
+   * Constructor.
+   * @param str a string representation of the parameter value.
+   */
+  public ConcatSourcesParam(String str) {
+    super(DOMAIN, str);
+  }
+
+  public ConcatSourcesParam(Path[] paths) {
+    this(paths2String(paths));
+  }
+
+  @Override
+  public String getName() {
+    return NAME;
+  }
+
+  /** @return the absolute path. */
+  public final String[] getAbsolutePaths() {
+    final String[] paths = getValue().split(",");
+    return paths;
+  }
+}

src/hdfs/org/apache/hadoop/hdfs/web/resources/PostOpParam.java

@@ -23,13 +23,17 @@ import java.net.HttpURLConnection;
 public class PostOpParam extends HttpOpParam<PostOpParam.Op> {
   /** Post operations. */
   public static enum Op implements HttpOpParam.Op {
-    APPEND(HttpURLConnection.HTTP_OK),
+    APPEND(true, HttpURLConnection.HTTP_OK),
 
-    NULL(HttpURLConnection.HTTP_NOT_IMPLEMENTED);
+    CONCAT(false, HttpURLConnection.HTTP_OK),
 
+    NULL(false, HttpURLConnection.HTTP_NOT_IMPLEMENTED);
+
+    final boolean doOutputAndRedirect;
     final int expectedHttpResponseCode;
 
-    Op(final int expectedHttpResponseCode) {
+    Op(final boolean doOutputAndRedirect, final int expectedHttpResponseCode) {
+      this.doOutputAndRedirect = doOutputAndRedirect;
       this.expectedHttpResponseCode = expectedHttpResponseCode;
     }
 
@@ -40,12 +44,12 @@ public class PostOpParam extends HttpOpParam<PostOpParam.Op> {
 
     @Override
     public boolean getDoOutput() {
-      return true;
+      return doOutputAndRedirect;
     }
 
     @Override
     public boolean getRedirect() {
-      return true;
+      return doOutputAndRedirect;
     }
 
     @Override

src/test/org/apache/hadoop/hdfs/web/TestFSMainOperationsWebHdfs.java

@@ -28,10 +28,12 @@ import java.security.PrivilegedExceptionAction;
 import org.apache.commons.logging.impl.Log4JLogger;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FSMainOperationsBaseTest;
+import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.hdfs.DFSTestUtil;
 import org.apache.hadoop.hdfs.MiniDFSCluster;
 import org.apache.hadoop.hdfs.server.datanode.web.resources.DatanodeWebHdfsMethods;
 import org.apache.hadoop.hdfs.web.resources.ExceptionHandler;
@@ -56,6 +58,7 @@ public class TestFSMainOperationsWebHdfs extends FSMainOperationsBaseTest {
   public static void setupCluster() {
     final Configuration conf = new Configuration();
     conf.setBoolean(DFSConfigKeys.DFS_WEBHDFS_ENABLED_KEY, true);
+    conf.setLong(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, 1024);
     try {
       cluster = new MiniDFSCluster(conf, 2, true, null);
       cluster.waitActive();
@@ -97,6 +100,30 @@ public class TestFSMainOperationsWebHdfs extends FSMainOperationsBaseTest {
     return defaultWorkingDirectory;
   }
 
+  @Test
+  public void testConcat() throws Exception {
+    Path[] paths = {new Path("/test/hadoop/file1"),
+                    new Path("/test/hadoop/file2"),
+                    new Path("/test/hadoop/file3")};
+
+    DFSTestUtil.createFile(fSys, paths[0], 1024, (short) 3, 0);
+    DFSTestUtil.createFile(fSys, paths[1], 1024, (short) 3, 0);
+    DFSTestUtil.createFile(fSys, paths[2], 1024, (short) 3, 0);
+
+    Path catPath = new Path("/test/hadoop/catFile");
+    DFSTestUtil.createFile(fSys, catPath, 1024, (short) 3, 0);
+    Assert.assertTrue(exists(fSys, catPath));
+
+    fSys.concat(catPath, paths);
+
+    Assert.assertFalse(exists(fSys, paths[0]));
+    Assert.assertFalse(exists(fSys, paths[1]));
+    Assert.assertFalse(exists(fSys, paths[2]));
+
+    FileStatus fileStatus = fSys.getFileStatus(catPath);
+    Assert.assertEquals(1024*4, fileStatus.getLen());
+  }
+
   //copied from trunk.
   @Test
   public void testMkdirsFailsForSubdirectoryOfExistingFile() throws Exception {