HADOOP-7238. Refactor the cat and text commands to conform to new FsCommand class. Contributed by Daryn Sharp

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1101199 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -127,6 +127,9 @@ Trunk (unreleased changes)
     HADOOP-7265. Keep track of relative paths in PathData.  (Daryn Sharp
     via szetszwo)
 
+    HADOOP-7238. Refactor the cat and text commands to conform to new FsCommand
+    class.  (Daryn Sharp via szetszwo)
+
   OPTIMIZATIONS
 
   BUG FIXES

src/java/org/apache/hadoop/fs/FsShell.java

@@ -28,7 +28,6 @@ import java.util.Arrays;
 import java.util.Date;
 import java.util.List;
 import java.util.TimeZone;
-import java.util.zip.GZIPInputStream;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -39,17 +38,9 @@ import org.apache.hadoop.fs.shell.Command;
 import org.apache.hadoop.fs.shell.CommandFactory;
 import org.apache.hadoop.fs.shell.CommandFormat;
 import org.apache.hadoop.fs.shell.FsCommand;
-import org.apache.hadoop.io.DataInputBuffer;
-import org.apache.hadoop.io.DataOutputBuffer;
 import org.apache.hadoop.io.IOUtils;
-import org.apache.hadoop.io.SequenceFile;
-import org.apache.hadoop.io.Writable;
-import org.apache.hadoop.io.WritableComparable;
-import org.apache.hadoop.io.compress.CompressionCodec;
-import org.apache.hadoop.io.compress.CompressionCodecFactory;
 import org.apache.hadoop.ipc.RPC;
 import org.apache.hadoop.ipc.RemoteException;
-import org.apache.hadoop.util.ReflectionUtils;
 import org.apache.hadoop.util.StringUtils;
 import org.apache.hadoop.util.Tool;
 import org.apache.hadoop.util.ToolRunner;
@@ -175,10 +166,10 @@ public class FsShell extends Configured implements Tool {
    * Otherwise, IOException is thrown.
    * @param argv : arguments
    * @param pos : Ignore everything before argv[pos]  
-   * @exception: IOException  
+   * @throws Exception 
    * @see org.apache.hadoop.fs.FileSystem.globStatus 
    */
-  void copyToLocal(String[]argv, int pos) throws IOException {
+  void copyToLocal(String[]argv, int pos) throws Exception {
     CommandFormat cf = new CommandFormat("copyToLocal", 2,2,"crc","ignoreCrc");
     
     String srcstr = null;
@@ -199,7 +190,12 @@ public class FsShell extends Configured implements Tool {
       if (copyCrc) {
         System.err.println("-crc option is not valid when destination is stdout.");
       }
-      cat(srcstr, verifyChecksum);
+      
+      List<String> catArgv = new ArrayList<String>();
+      catArgv.add("-cat");
+      if (cf.getOpt("ignoreCrc")) catArgv.add("-ignoreCrc");
+      catArgv.add(srcstr);      
+      run(catArgv.toArray(new String[0]));
     } else {
       File dst = new File(dststr);      
       Path srcpath = new Path(srcstr);
@@ -316,115 +312,6 @@ public class FsShell extends Configured implements Tool {
     System.err.println("Option '-moveToLocal' is not implemented yet.");
   }
     
-  /**
-   * Fetch all files that match the file pattern <i>srcf</i> and display
-   * their content on stdout. 
-   * @param srcf: a file pattern specifying source files
-   * @exception: IOException
-   * @see org.apache.hadoop.fs.FileSystem.globStatus 
-   */
-  void cat(String src, boolean verifyChecksum) throws IOException {
-    //cat behavior in Linux
-    //  [~/1207]$ ls ?.txt
-    //  x.txt  z.txt
-    //  [~/1207]$ cat x.txt y.txt z.txt
-    //  xxx
-    //  cat: y.txt: No such file or directory
-    //  zzz
-
-    Path srcPattern = new Path(src);
-    new DelayedExceptionThrowing() {
-      @Override
-      void process(Path p, FileSystem srcFs) throws IOException {
-        printToStdout(srcFs.open(p));
-      }
-    }.globAndProcess(srcPattern, getSrcFileSystem(srcPattern, verifyChecksum));
-  }
-
-  private class TextRecordInputStream extends InputStream {
-    SequenceFile.Reader r;
-    WritableComparable<?> key;
-    Writable val;
-
-    DataInputBuffer inbuf;
-    DataOutputBuffer outbuf;
-
-    public TextRecordInputStream(FileStatus f) throws IOException {
-      final Path fpath = f.getPath();
-      final Configuration lconf = getConf();
-      r = new SequenceFile.Reader(lconf, 
-                                  SequenceFile.Reader.file(fpath));
-      key = ReflectionUtils.newInstance(
-          r.getKeyClass().asSubclass(WritableComparable.class), lconf);
-      val = ReflectionUtils.newInstance(
-          r.getValueClass().asSubclass(Writable.class), lconf);
-      inbuf = new DataInputBuffer();
-      outbuf = new DataOutputBuffer();
-    }
-
-    public int read() throws IOException {
-      int ret;
-      if (null == inbuf || -1 == (ret = inbuf.read())) {
-        if (!r.next(key, val)) {
-          return -1;
-        }
-        byte[] tmp = key.toString().getBytes();
-        outbuf.write(tmp, 0, tmp.length);
-        outbuf.write('\t');
-        tmp = val.toString().getBytes();
-        outbuf.write(tmp, 0, tmp.length);
-        outbuf.write('\n');
-        inbuf.reset(outbuf.getData(), outbuf.getLength());
-        outbuf.reset();
-        ret = inbuf.read();
-      }
-      return ret;
-    }
-
-    public void close() throws IOException {
-      r.close();
-      super.close();
-    }
-  }
-
-  private InputStream forMagic(Path p, FileSystem srcFs) throws IOException {
-    FSDataInputStream i = srcFs.open(p);
-
-    // check codecs
-    CompressionCodecFactory cf = new CompressionCodecFactory(getConf());
-    CompressionCodec codec = cf.getCodec(p);
-    if (codec != null) {
-      return codec.createInputStream(i);
-    }
-
-    switch(i.readShort()) {
-      case 0x1f8b: // RFC 1952
-        i.seek(0);
-        return new GZIPInputStream(i);
-      case 0x5345: // 'S' 'E'
-        if (i.readByte() == 'Q') {
-          i.close();
-          return new TextRecordInputStream(srcFs.getFileStatus(p));
-        }
-        break;
-    }
-    i.seek(0);
-    return i;
-  }
-
-  void text(String srcf) throws IOException {
-    Path srcPattern = new Path(srcf);
-    new DelayedExceptionThrowing() {
-      @Override
-      void process(Path p, FileSystem srcFs) throws IOException {
-        if (srcFs.isDirectory(p)) {
-          throw new IOException("Source must be a file.");
-        }
-        printToStdout(forMagic(p, srcFs));
-      }
-    }.globAndProcess(srcPattern, srcPattern.getFileSystem(getConf()));
-  }
-    
    /**
    * Show the size of a partition in the filesystem that contains
    * the specified <i>path</i>.
@@ -953,11 +840,9 @@ public class FsShell extends Configured implements Tool {
       "[-rmr [-skipTrash] <src>] [-put <localsrc> ... <dst>] [-copyFromLocal <localsrc> ... <dst>]\n\t" +
       "[-moveFromLocal <localsrc> ... <dst>] [" + 
       GET_SHORT_USAGE + "\n\t" +
-      "[-cat <src>]\n\t" +
       "[" + COPYTOLOCAL_SHORT_USAGE + "] [-moveToLocal <src> <localdst>]\n\t" +
       "[-report]\n\t" +
-      "[-touchz <path>] [-test -[ezd] <path>] [-stat [format] <path>]\n\t" +
+      "[-touchz <path>] [-test -[ezd] <path>] [-stat [format] <path>]";
-      "[-text <path>]";
 
     String conf ="-conf <configuration file>:  Specify an application configuration file.";
  
@@ -1025,14 +910,6 @@ public class FsShell extends Configured implements Tool {
       "\t\tto the local name.  <src> is kept.  When copying mutiple, \n" +
       "\t\tfiles, the destination must be a directory. \n";
 
-    String cat = "-cat <src>: \tFetch all files that match the file pattern <src> \n" +
-      "\t\tand display their content on stdout.\n";
-
-    
-    String text = "-text <src>: \tTakes a source file and outputs the file in text format.\n" +
-      "\t\tThe allowed formats are zip and TextRecordInputStream.\n";
-         
-    
     String copyToLocal = COPYTOLOCAL_SHORT_USAGE
                          + ":  Identical to the -get command.\n";
 
@@ -1091,16 +968,12 @@ public class FsShell extends Configured implements Tool {
       System.out.println(copyToLocal);
     } else if ("moveToLocal".equals(cmd)) {
       System.out.println(moveToLocal);
-    } else if ("cat".equals(cmd)) {
-      System.out.println(cat);
     } else if ("get".equals(cmd)) {
       System.out.println(get);
     } else if ("touchz".equals(cmd)) {
       System.out.println(touchz);
     } else if ("test".equals(cmd)) {
       System.out.println(test);
-    } else if ("text".equals(cmd)) {
-      System.out.println(text);
     } else if ("stat".equals(cmd)) {
       System.out.println(stat);
     } else if ("help".equals(cmd)) {
@@ -1125,12 +998,10 @@ public class FsShell extends Configured implements Tool {
       System.out.println(copyFromLocal);
       System.out.println(moveFromLocal);
       System.out.println(get);
-      System.out.println(cat);
       System.out.println(copyToLocal);
       System.out.println(moveToLocal);
       System.out.println(touchz);
       System.out.println(test);
-      System.out.println(text);
       System.out.println(stat);
 
       for (String thisCmdName : commandFactory.getNames()) {
@@ -1181,9 +1052,7 @@ public class FsShell extends Configured implements Tool {
         //
         // issue the command to the fs
         //
-        if ("-cat".equals(cmd)) {
+        if ("-rm".equals(cmd)) {
-          cat(argv[i], true);
-        } else if ("-rm".equals(cmd)) {
           delete(argv[i], false, rmSkipTrash);
         } else if ("-rmr".equals(cmd)) {
           delete(argv[i], true, rmSkipTrash);
@@ -1191,8 +1060,6 @@ public class FsShell extends Configured implements Tool {
           df(argv[i]);
         } else if ("-touchz".equals(cmd)) {
           touchz(argv[i]);
-        } else if ("-text".equals(cmd)) {
-          text(argv[i]);
         }
       } catch (RemoteException e) {
         LOG.debug("Error", e);
@@ -1247,8 +1114,7 @@ public class FsShell extends Configured implements Tool {
       System.err.println("Usage: java FsShell" + 
                          " [-D <[property=value>]");
     } else if ("-du".equals(cmd) || "-dus".equals(cmd) ||
-               "-touchz".equals(cmd) ||
+               "-touchz".equals(cmd)) {
-               "-text".equals(cmd)) {
       System.err.println("Usage: java FsShell" + 
                          " [" + cmd + " <path>]");
     } else if ("-df".equals(cmd) ) {
@@ -1271,9 +1137,6 @@ public class FsShell extends Configured implements Tool {
     } else if ("-moveToLocal".equals(cmd)) {
       System.err.println("Usage: java FsShell" + 
                          " [" + cmd + " [-crc] <src> <localdst>]");
-    } else if ("-cat".equals(cmd)) {
-      System.err.println("Usage: java FsShell" + 
-                         " [" + cmd + " <src>]");
     } else if ("-test".equals(cmd)) {
       System.err.println("Usage: java FsShell" +
                          " [-test -[ezd] <path>]");
@@ -1294,8 +1157,6 @@ public class FsShell extends Configured implements Tool {
       System.err.println("           [-copyFromLocal <localsrc> ... <dst>]");
       System.err.println("           [-moveFromLocal <localsrc> ... <dst>]");
       System.err.println("           [" + GET_SHORT_USAGE + "]");
-      System.err.println("           [-cat <src>]");
-      System.err.println("           [-text <src>]");
       System.err.println("           [" + COPYTOLOCAL_SHORT_USAGE + "]");
       System.err.println("           [-moveToLocal [-crc] <src> <localdst>]");
       System.err.println("           [-touchz <path>]");
@@ -1350,9 +1211,7 @@ public class FsShell extends Configured implements Tool {
         return exitCode;
       }
     } else if ("-rm".equals(cmd) || "-rmr".equals(cmd) ||
-               "-cat".equals(cmd) ||
+               "-touchz".equals(cmd) || "-stat".equals(cmd)) {
-               "-touchz".equals(cmd) || "-stat".equals(cmd) ||
-               "-text".equals(cmd)) {
       if (argv.length < 2) {
         printUsage(cmd);
         return exitCode;
@@ -1399,10 +1258,6 @@ public class FsShell extends Configured implements Tool {
         moveFromLocal(srcs, argv[i++]);
       } else if ("-get".equals(cmd) || "-copyToLocal".equals(cmd)) {
         copyToLocal(argv, i);
-      } else if ("-cat".equals(cmd)) {
-        exitCode = doall(cmd, argv, i);
-      } else if ("-text".equals(cmd)) {
-        exitCode = doall(cmd, argv, i);
       } else if ("-moveToLocal".equals(cmd)) {
         moveToLocal(argv[i++], new Path(argv[i++]));
       } else if ("-mv".equals(cmd)) {

src/java/org/apache/hadoop/fs/shell/Display.java

@@ -0,0 +1,192 @@
+/**
+ * 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.fs.shell;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.LinkedList;
+import java.util.zip.GZIPInputStream;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.io.DataInputBuffer;
+import org.apache.hadoop.io.DataOutputBuffer;
+import org.apache.hadoop.io.IOUtils;
+import org.apache.hadoop.io.SequenceFile;
+import org.apache.hadoop.io.Writable;
+import org.apache.hadoop.io.WritableComparable;
+import org.apache.hadoop.io.compress.CompressionCodec;
+import org.apache.hadoop.io.compress.CompressionCodecFactory;
+import org.apache.hadoop.util.ReflectionUtils;
+
+/**
+ * Display contents of files 
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Evolving
+
+class Display extends FsCommand {
+  public static void registerCommands(CommandFactory factory) {
+    factory.addClass(Cat.class, "-cat");
+    factory.addClass(Text.class, "-text");
+  }
+
+  @Override
+  protected String getFnfText(Path path) {
+    // TODO: this is a pretty inconsistent way to output the path...!!
+    //       but, it's backwards compatible
+    try {
+      FileSystem fs = path.getFileSystem(getConf());
+      path = fs.makeQualified(path);
+    } catch (IOException e) {
+      // shouldn't happen, so just use path as-is
+      displayWarning("can't fully qualify "+path);
+    }
+    return "File does not exist: " + path.toUri().getPath();
+  }
+
+  /**
+   * Displays file content to stdout
+   */
+  public static class Cat extends Display {
+    public static final String NAME = "cat";
+    public static final String USAGE = "[-ignoreCrc] <src> ...";
+    public static final String DESCRIPTION =
+      "Fetch all files that match the file pattern <src> \n" +
+      "and display their content on stdout.\n";
+
+    private boolean verifyChecksum = true;
+
+    @Override
+    protected void processOptions(LinkedList<String> args)
+    throws IOException {
+      CommandFormat cf = new CommandFormat(null, 1, Integer.MAX_VALUE, "ignoreCrc");
+      cf.parse(args);
+      verifyChecksum = !cf.getOpt("ignoreCrc");
+    }
+
+    @Override
+    protected void processPath(PathData item) throws IOException {
+      item.fs.setVerifyChecksum(verifyChecksum);
+      printToStdout(getInputStream(item));
+    }
+
+    private void printToStdout(InputStream in) throws IOException {
+      try {
+        IOUtils.copyBytes(in, out, getConf(), false);
+      } finally {
+        in.close();
+      }
+    }
+
+    protected InputStream getInputStream(PathData item) throws IOException {
+      return item.fs.open(item.path);
+    }
+  }
+  
+  /**
+   * Same behavior as "-cat", but handles zip and TextRecordInputStream
+   * encodings. 
+   */ 
+  public static class Text extends Cat {
+    public static final String NAME = "text";
+    public static final String SHORT_USAGE = Cat.USAGE;
+    public static final String DESCRIPTION =
+      "Takes a source file and outputs the file in text format.\n" +
+      "The allowed formats are zip and TextRecordInputStream.";
+    
+    @Override
+    protected InputStream getInputStream(PathData item) throws IOException {
+      FSDataInputStream i = (FSDataInputStream)super.getInputStream(item);
+      
+      // check codecs
+      CompressionCodecFactory cf = new CompressionCodecFactory(getConf());
+      CompressionCodec codec = cf.getCodec(item.path);
+      if (codec != null) {
+        return codec.createInputStream(i);
+      }
+
+      switch(i.readShort()) {
+        case 0x1f8b: { // RFC 1952
+          i.seek(0);
+          return new GZIPInputStream(i);
+        }
+        case 0x5345: { // 'S' 'E'
+          if (i.readByte() == 'Q') {
+            i.close();
+            return new TextRecordInputStream(item.stat);
+          }
+          break;
+        }
+      }
+      i.seek(0);
+      return i;
+    }    
+  }
+
+  protected class TextRecordInputStream extends InputStream {
+    SequenceFile.Reader r;
+    WritableComparable<?> key;
+    Writable val;
+
+    DataInputBuffer inbuf;
+    DataOutputBuffer outbuf;
+
+    public TextRecordInputStream(FileStatus f) throws IOException {
+      final Path fpath = f.getPath();
+      final Configuration lconf = getConf();
+      r = new SequenceFile.Reader(lconf, 
+          SequenceFile.Reader.file(fpath));
+      key = ReflectionUtils.newInstance(
+          r.getKeyClass().asSubclass(WritableComparable.class), lconf);
+      val = ReflectionUtils.newInstance(
+          r.getValueClass().asSubclass(Writable.class), lconf);
+      inbuf = new DataInputBuffer();
+      outbuf = new DataOutputBuffer();
+    }
+
+    public int read() throws IOException {
+      int ret;
+      if (null == inbuf || -1 == (ret = inbuf.read())) {
+        if (!r.next(key, val)) {
+          return -1;
+        }
+        byte[] tmp = key.toString().getBytes();
+        outbuf.write(tmp, 0, tmp.length);
+        outbuf.write('\t');
+        tmp = val.toString().getBytes();
+        outbuf.write(tmp, 0, tmp.length);
+        outbuf.write('\n');
+        inbuf.reset(outbuf.getData(), outbuf.getLength());
+        outbuf.reset();
+        ret = inbuf.read();
+      }
+      return ret;
+    }
+
+    public void close() throws IOException {
+      r.close();
+      super.close();
+    }
+  }
+}

src/java/org/apache/hadoop/fs/shell/FsCommand.java

@@ -45,6 +45,7 @@ abstract public class FsCommand extends Command {
   public static void registerCommands(CommandFactory factory) {
     factory.registerCommands(Copy.class);
     factory.registerCommands(Count.class);
+    factory.registerCommands(Display.class);
     factory.registerCommands(FsShellPermissions.class);
     factory.registerCommands(Ls.class);
     factory.registerCommands(Mkdir.class);

src/test/core/org/apache/hadoop/cli/testConf.xml

@@ -454,7 +454,7 @@
       <comparators>
         <comparator>
           <type>RegexpComparator</type>
-          <expected-output>^-cat &lt;src&gt;:( |\t)*Fetch all files that match the file pattern &lt;src&gt;( )*</expected-output>
+          <expected-output>^-cat \[-ignoreCrc\] &lt;src&gt; \.\.\.:( |\t)*Fetch all files that match the file pattern &lt;src&gt;( )*</expected-output>
         </comparator>
         <comparator>
           <type>RegexpComparator</type>