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Posted to common-commits@hadoop.apache.org by sz...@apache.org on 2011/04/07 23:59:38 UTC
svn commit: r1090039 - in /hadoop/common/trunk: ./
src/java/org/apache/hadoop/fs/ src/java/org/apache/hadoop/fs/shell/
src/test/core/org/apache/hadoop/fs/shell/
Author: szetszwo
Date: Thu Apr 7 21:59:37 2011
New Revision: 1090039
URL: http://svn.apache.org/viewvc?rev=1090039&view=rev
Log:
HADOOP-7202. Improve shell Command base class. Contributed by Daryn Sharp
Added:
hadoop/common/trunk/src/java/org/apache/hadoop/fs/shell/FsCommand.java
hadoop/common/trunk/src/java/org/apache/hadoop/fs/shell/PathData.java
hadoop/common/trunk/src/test/core/org/apache/hadoop/fs/shell/
hadoop/common/trunk/src/test/core/org/apache/hadoop/fs/shell/TestPathData.java
Modified:
hadoop/common/trunk/CHANGES.txt
hadoop/common/trunk/src/java/org/apache/hadoop/fs/FsShell.java
hadoop/common/trunk/src/java/org/apache/hadoop/fs/shell/Command.java
hadoop/common/trunk/src/java/org/apache/hadoop/fs/shell/Count.java
Modified: hadoop/common/trunk/CHANGES.txt
URL: http://svn.apache.org/viewvc/hadoop/common/trunk/CHANGES.txt?rev=1090039&r1=1090038&r2=1090039&view=diff
==============================================================================
--- hadoop/common/trunk/CHANGES.txt (original)
+++ hadoop/common/trunk/CHANGES.txt Thu Apr 7 21:59:37 2011
@@ -82,6 +82,8 @@ Trunk (unreleased changes)
HADOOP-7180. Better support on CommandFormat on the API and exceptions.
(Daryn Sharp via szetszwo)
+ HADOOP-7202. Improve shell Command base class. (Daryn Sharp via szetszwo)
+
OPTIMIZATIONS
BUG FIXES
Modified: hadoop/common/trunk/src/java/org/apache/hadoop/fs/FsShell.java
URL: http://svn.apache.org/viewvc/hadoop/common/trunk/src/java/org/apache/hadoop/fs/FsShell.java?rev=1090039&r1=1090038&r2=1090039&view=diff
==============================================================================
--- hadoop/common/trunk/src/java/org/apache/hadoop/fs/FsShell.java (original)
+++ hadoop/common/trunk/src/java/org/apache/hadoop/fs/FsShell.java Thu Apr 7 21:59:37 2011
@@ -23,7 +23,12 @@ import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.text.SimpleDateFormat;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Date;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.TimeZone;
import java.util.zip.GZIPInputStream;
import org.apache.commons.logging.Log;
@@ -44,9 +49,9 @@ import org.apache.hadoop.io.compress.Com
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;
-import org.apache.hadoop.util.StringUtils;
/** Provide command line access to a FileSystem. */
@InterfaceAudience.Private
@@ -370,7 +375,7 @@ public class FsShell extends Configured
private class TextRecordInputStream extends InputStream {
SequenceFile.Reader r;
- WritableComparable key;
+ WritableComparable<?> key;
Writable val;
DataInputBuffer inbuf;
@@ -1691,8 +1696,6 @@ public class FsShell extends Configured
delete(argv[i], true, rmSkipTrash);
} else if ("-df".equals(cmd)) {
df(argv[i]);
- } else if (Count.matches(cmd)) {
- new Count(argv, i, getConf()).runAll();
} else if ("-ls".equals(cmd)) {
exitCode = ls(argv[i], false);
} else if ("-lsr".equals(cmd)) {
@@ -1759,7 +1762,7 @@ public class FsShell extends Configured
} else if ("-df".equals(cmd) ) {
System.err.println("Usage: java FsShell" +
" [" + cmd + " [<path>]]");
- } else if (Count.matches(cmd)) {
+ } else if ("-count".equals(cmd)) {
System.err.println(prefix + " [" + Count.USAGE + "]");
} else if ("-rm".equals(cmd) || "-rmr".equals(cmd)) {
System.err.println("Usage: java FsShell [" + cmd +
@@ -1948,8 +1951,14 @@ public class FsShell extends Configured
du(argv, i);
} else if ("-dus".equals(cmd)) {
dus(argv, i);
- } else if (Count.matches(cmd)) {
- exitCode = new Count(argv, i, getConf()).runAll();
+ } else if ("-count".equals(cmd)) {
+ // TODO: next two lines are a temporary crutch until this entire
+ // block is overhauled
+ LinkedList<String> args = new LinkedList<String>(Arrays.asList(argv));
+ String cmdName = args.removeFirst();
+ Count runner = ReflectionUtils.newInstance(Count.class, getConf());
+ runner.setCommandName(cmdName); // TODO: will change with factory
+ exitCode = runner.run(args);
} else if ("-mkdir".equals(cmd)) {
exitCode = doall(cmd, argv, i);
} else if ("-touchz".equals(cmd)) {
Modified: hadoop/common/trunk/src/java/org/apache/hadoop/fs/shell/Command.java
URL: http://svn.apache.org/viewvc/hadoop/common/trunk/src/java/org/apache/hadoop/fs/shell/Command.java?rev=1090039&r1=1090038&r2=1090039&view=diff
==============================================================================
--- hadoop/common/trunk/src/java/org/apache/hadoop/fs/shell/Command.java (original)
+++ hadoop/common/trunk/src/java/org/apache/hadoop/fs/shell/Command.java Thu Apr 7 21:59:37 2011
@@ -17,29 +17,67 @@
*/
package org.apache.hadoop.fs.shell;
-import java.io.*;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.PrintStream;
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
-import org.apache.hadoop.ipc.RemoteException;
+import org.apache.hadoop.util.StringUtils;
/**
* An abstract class for the execution of a file system command
*/
+@InterfaceAudience.Private
+@InterfaceStability.Evolving
+
abstract public class Command extends Configured {
protected String[] args;
+ protected String name;
+ protected int exitCode = 0;
+ protected int numErrors = 0;
+ protected boolean recursive = false;
+ protected ArrayList<Exception> exceptions = new ArrayList<Exception>();
+
+ private static final Log LOG = LogFactory.getLog(Command.class);
+
+ /** allows stdout to be captured if necessary */
+ public PrintStream out = System.out;
+ /** allows stderr to be captured if necessary */
+ public PrintStream err = System.err;
+
+ /** Constructor */
+ protected Command() {
+ out = System.out;
+ err = System.err;
+ }
/** Constructor */
protected Command(Configuration conf) {
super(conf);
}
- /** Return the command's name excluding the leading character - */
+ /** @return the command's name excluding the leading character - */
abstract public String getCommandName();
+ /**
+ * Name the command
+ * @param cmdName as invoked
+ */
+ public void setCommandName(String cmdName) {
+ name = cmdName;
+ }
+
/**
* Execute the command on the input path
*
@@ -57,30 +95,272 @@ abstract public class Command extends Co
int exitCode = 0;
for (String src : args) {
try {
- Path srcPath = new Path(src);
- FileSystem fs = srcPath.getFileSystem(getConf());
- FileStatus[] statuses = fs.globStatus(srcPath);
- if (statuses == null) {
- System.err.println("Can not find listing for " + src);
- exitCode = -1;
- } else {
- for(FileStatus s : statuses) {
- run(s.getPath());
- }
+ List<PathData> srcs = expandGlob(src);
+ for(PathData s : srcs) {
+ run(s.path);
}
- } catch (RemoteException re) {
- exitCode = -1;
- String content = re.getLocalizedMessage();
- int eol = content.indexOf('\n');
- if (eol>=0) {
- content = content.substring(0, eol);
- }
- System.err.println(getCommandName() + ": " + content);
} catch (IOException e) {
exitCode = -1;
- System.err.println(getCommandName() + ": " + e.getLocalizedMessage());
+ displayError(e);
}
}
return exitCode;
}
+
+ /**
+ * Invokes the command handler. The default behavior is to process options,
+ * expand arguments, and then process each argument.
+ * <pre>
+ * run
+ * \-> {@link #processOptions(LinkedList)}
+ * \-> {@link #expandArguments(LinkedList)} -> {@link #expandArgument(String)}*
+ * \-> {@link #processArguments(LinkedList)}
+ * \-> {@link #processArgument(PathData)}*
+ * \-> {@link #processPathArgument(PathData)}
+ * \-> {@link #processPaths(PathData, PathData...)}
+ * \-> {@link #processPath(PathData)}*
+ * \-> {@link #processNonexistentPathArgument(PathData)}
+ * </pre>
+ * Most commands will chose to implement just
+ * {@link #processOptions(LinkedList)} and {@link #processPath(PathData)}
+ *
+ * @param args the list of command line arguments
+ * @return the exit code for the command
+ * @throws IllegalArgumentException if called with invalid arguments
+ */
+ public int run(LinkedList<String> args) {
+ try {
+ processOptions(args);
+ processArguments(expandArguments(args));
+ } catch (IOException e) {
+ displayError(e);
+ }
+
+ return (numErrors == 0) ? exitCode : 1;
+ }
+
+ /**
+ * Must be implemented by commands to process the command line flags and
+ * check the bounds of the remaining arguments. If an
+ * IllegalArgumentException is thrown, the FsShell object will print the
+ * short usage of the command.
+ * @param args the command line arguments
+ * @throws IOException
+ */
+ protected void processOptions(LinkedList<String> args) throws IOException {}
+
+ /**
+ * Expands a list of arguments into {@link PathData} objects. The default
+ * behavior is to call {@link #expandArgument(String)} on each element
+ * which by default globs the argument. The loop catches IOExceptions,
+ * increments the error count, and displays the exception.
+ * @param args strings to expand into {@link PathData} objects
+ * @return list of all {@link PathData} objects the arguments
+ * @throws IOException if anything goes wrong...
+ */
+ protected LinkedList<PathData> expandArguments(LinkedList<String> args)
+ throws IOException {
+ LinkedList<PathData> expandedArgs = new LinkedList<PathData>();
+ for (String arg : args) {
+ try {
+ expandedArgs.addAll(expandArgument(arg));
+ } catch (IOException e) { // other exceptions are probably nasty
+ displayError(e);
+ }
+ }
+ return expandedArgs;
+ }
+
+ /**
+ * Expand the given argument into a list of {@link PathData} objects.
+ * The default behavior is to expand globs. Commands may override to
+ * perform other expansions on an argument.
+ * @param arg string pattern to expand
+ * @return list of {@link PathData} objects
+ * @throws IOException if anything goes wrong...
+ */
+ protected List<PathData> expandArgument(String arg) throws IOException {
+ return expandGlob(arg);
+ }
+
+ /**
+ * Processes the command's list of expanded arguments.
+ * {@link #processArgument(PathData)} will be invoked with each item
+ * in the list. The loop catches IOExceptions, increments the error
+ * count, and displays the exception.
+ * @param args a list of {@link PathData} to process
+ * @throws IOException if anything goes wrong...
+ */
+ protected void processArguments(LinkedList<PathData> args)
+ throws IOException {
+ for (PathData arg : args) {
+ try {
+ processArgument(arg);
+ } catch (IOException e) {
+ displayError(e);
+ }
+ }
+ }
+
+ /**
+ * Processes a {@link PathData} item, calling
+ * {@link #processPathArgument(PathData)} or
+ * {@link #processNonexistentPathArgument(PathData)} on each item.
+ * @param arg {@link PathData} item to process
+ * @throws IOException if anything goes wrong...
+ */
+ protected void processArgument(PathData item) throws IOException {
+ if (item.exists) {
+ processPathArgument(item);
+ } else {
+ processNonexistentPathArgument(item);
+ }
+ }
+
+ /**
+ * This is the last chance to modify an argument before going into the
+ * (possibly) recursive {@link #processPaths(PathData, PathData...)}
+ * -> {@link #processPath(PathData)} loop. Ex. ls and du use this to
+ * expand out directories.
+ * @param item a {@link PathData} representing a path which exists
+ * @throws IOException if anything goes wrong...
+ */
+ protected void processPathArgument(PathData item) throws IOException {
+ // null indicates that the call is not via recursion, ie. there is
+ // no parent directory that was expanded
+ processPaths(null, item);
+ }
+
+ /**
+ * Provides a hook for handling paths that don't exist. By default it
+ * will throw an exception. Primarily overriden by commands that create
+ * paths such as mkdir or touch.
+ * @param item the {@link PathData} that doesn't exist
+ * @throws FileNotFoundException if arg is a path and it doesn't exist
+ * @throws IOException if anything else goes wrong...
+ */
+ protected void processNonexistentPathArgument(PathData item)
+ throws IOException {
+ // TODO: this should be more posix-like: ex. "No such file or directory"
+ throw new FileNotFoundException("Can not find listing for " + item);
+ }
+
+ /**
+ * Iterates over the given expanded paths and invokes
+ * {@link #processPath(PathData)} on each element. If "recursive" is true,
+ * will do a post-visit DFS on directories.
+ * @param parent if called via a recurse, will be the parent dir, else null
+ * @param items a list of {@link PathData} objects to process
+ * @throws IOException if anything goes wrong...
+ */
+ protected void processPaths(PathData parent, PathData ... items)
+ throws IOException {
+ // TODO: this really should be iterative
+ for (PathData item : items) {
+ try {
+ processPath(item);
+ if (recursive && item.stat.isDirectory()) {
+ recursePath(item);
+ }
+ } catch (IOException e) {
+ displayError(e);
+ }
+ }
+ }
+
+ /**
+ * Hook for commands to implement an operation to be applied on each
+ * path for the command. Note implementation of this method is optional
+ * if earlier methods in the chain handle the operation.
+ * @param item a {@link PathData} object
+ * @throws RuntimeException if invoked but not implemented
+ * @throws IOException if anything else goes wrong in the user-implementation
+ */
+ protected void processPath(PathData item) throws IOException {
+ throw new RuntimeException("processPath() is not implemented");
+ }
+
+ /**
+ * Gets the directory listing for a path and invokes
+ * {@link #processPaths(PathData, PathData...)}
+ * @param item {@link PathData} for directory to recurse into
+ * @throws IOException if anything goes wrong...
+ */
+ protected void recursePath(PathData item) throws IOException {
+ processPaths(item, item.getDirectoryContents());
+ }
+
+ /**
+ * Expand the given path as a glob pattern. Non-existent paths do not
+ * throw an exception because creation commands like touch and mkdir need
+ * to create them. The "stat" field will be null if the path does not
+ * exist.
+ * @param pattern the glob to expand
+ * @return list of {@link PathData} objects
+ * @throws FileNotFoundException the path is a glob with no matches
+ * @throws IOException anything else goes wrong...
+ */
+ protected List<PathData> expandGlob(String pattern) throws IOException {
+ Path path = new Path(pattern);
+ FileSystem fs = path.getFileSystem(getConf());
+ FileStatus[] stats = fs.globStatus(path);
+
+ if (stats != null && stats.length == 0) { // glob failed to match
+ // TODO: this should be more posix-like: ex. "No such file or directory"
+ throw new FileNotFoundException("Can not find listing for " + pattern);
+ }
+
+ List<PathData> items = new LinkedList<PathData>();
+ if (stats == null) { // not a glob & file not found, so null stat block
+ items.add(new PathData(fs, path, null));
+ } else {
+ // convert all the stats to PathData objs
+ for (FileStatus stat : stats) {
+ items.add(new PathData(fs, stat));
+ }
+ }
+ return items;
+ }
+
+ /**
+ * Display an exception prefaced with the command name. Also increments
+ * the error count for the command which will result in a non-zero exit
+ * code.
+ * @param e exception to display
+ */
+ public void displayError(Exception e) {
+ // build up a list of exceptions that occurred
+ exceptions.add(e);
+
+ String errorMessage = e.getLocalizedMessage();
+ if (errorMessage == null) {
+ // this is an unexpected condition, so dump the whole exception since
+ // it's probably a nasty internal error where the backtrace would be
+ // useful
+ errorMessage = StringUtils.stringifyException(e);
+ LOG.debug(errorMessage);
+ } else {
+ errorMessage = errorMessage.split("\n", 2)[0];
+ }
+ displayError(errorMessage);
+ }
+
+ /**
+ * Display an error string prefaced with the command name. Also increments
+ * the error count for the command which will result in a non-zero exit
+ * code.
+ * @param message error message to display
+ */
+ public void displayError(String message) {
+ numErrors++;
+ displayWarning(message);
+ }
+
+ /**
+ * Display an warning string prefaced with the command name.
+ * @param message warning message to display
+ */
+ public void displayWarning(String message) {
+ err.println(getCommandName() + ": " + message);
+ }
}
Modified: hadoop/common/trunk/src/java/org/apache/hadoop/fs/shell/Count.java
URL: http://svn.apache.org/viewvc/hadoop/common/trunk/src/java/org/apache/hadoop/fs/shell/Count.java?rev=1090039&r1=1090038&r2=1090039&view=diff
==============================================================================
--- hadoop/common/trunk/src/java/org/apache/hadoop/fs/shell/Count.java (original)
+++ hadoop/common/trunk/src/java/org/apache/hadoop/fs/shell/Count.java Thu Apr 7 21:59:37 2011
@@ -17,17 +17,23 @@
*/
package org.apache.hadoop.fs.shell;
-import java.io.*;
-import java.util.List;
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.LinkedList;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.fs.FileSystem;
-import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.ContentSummary;
+import org.apache.hadoop.fs.FsShell;
/**
* Count the number of directories, files, bytes, quota, and remaining quota.
*/
-public class Count extends Command {
+@InterfaceAudience.Private
+@InterfaceStability.Evolving
+
+public class Count extends FsCommand {
public static final String NAME = "count";
public static final String USAGE = "-" + NAME + "[-q] <path>";
public static final String DESCRIPTION = CommandUtils.formatDescription(USAGE,
@@ -37,41 +43,42 @@ public class Count extends Command {
"QUOTA REMAINING_QUATA SPACE_QUOTA REMAINING_SPACE_QUOTA ",
" DIR_COUNT FILE_COUNT CONTENT_SIZE FILE_NAME");
- private boolean qOption;
+ private boolean showQuotas;
+ /** Constructor */
+ public Count() {
+ setCommandName(NAME);
+ }
+
/** Constructor
- *
+ * @deprecated invoke via {@link FsShell}
* @param cmd the count command
* @param pos the starting index of the arguments
+ * @param conf configuration
*/
+ @Deprecated
public Count(String[] cmd, int pos, Configuration conf) {
super(conf);
- CommandFormat c = new CommandFormat(NAME, 1, Integer.MAX_VALUE, "q");
- List<String> parameters = c.parse(cmd, pos);
- this.args = parameters.toArray(new String[parameters.size()]);
- if (this.args.length == 0) { // default path is the current working directory
- this.args = new String[] {"."};
- }
- this.qOption = c.getOpt("q") ? true: false;
- }
-
- /** Check if a command is the count command
- *
- * @param cmd A string representation of a command starting with "-"
- * @return true if this is a count command; false otherwise
- */
- public static boolean matches(String cmd) {
- return ("-" + NAME).equals(cmd);
+ setCommandName(NAME);
+ LinkedList<String> parameters = new LinkedList<String>(Arrays.asList(cmd));
+ parameters.subList(0, pos).clear();
+ processOptions(parameters);
+ this.args = parameters.toArray(new String[0]);
}
@Override
- public String getCommandName() {
- return NAME;
+ protected void processOptions(LinkedList<String> args) {
+ CommandFormat cf = new CommandFormat(NAME, 1, Integer.MAX_VALUE, "q");
+ cf.parse(args);
+ if (args.isEmpty()) { // default path is the current working directory
+ args.add(".");
+ }
+ showQuotas = cf.getOpt("q");
}
@Override
- protected void run(Path path) throws IOException {
- FileSystem fs = path.getFileSystem(getConf());
- System.out.println(fs.getContentSummary(path).toString(qOption) + path);
+ protected void processPath(PathData src) throws IOException {
+ ContentSummary summary = src.fs.getContentSummary(src.path);
+ out.println(summary.toString(showQuotas) + src.path);
}
}
Added: hadoop/common/trunk/src/java/org/apache/hadoop/fs/shell/FsCommand.java
URL: http://svn.apache.org/viewvc/hadoop/common/trunk/src/java/org/apache/hadoop/fs/shell/FsCommand.java?rev=1090039&view=auto
==============================================================================
--- hadoop/common/trunk/src/java/org/apache/hadoop/fs/shell/FsCommand.java (added)
+++ hadoop/common/trunk/src/java/org/apache/hadoop/fs/shell/FsCommand.java Thu Apr 7 21:59:37 2011
@@ -0,0 +1,53 @@
+/**
+ * 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 org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.Path;
+
+/**
+ * Base class for all "hadoop fs" commands
+ */
+
+@InterfaceAudience.Private
+@InterfaceStability.Evolving
+
+// this class may not look useful now, but it's a placeholder for future
+// functionality to act as a registry for fs commands. currently it's being
+// used to implement unnecessary abstract methods in the base class
+
+abstract public class FsCommand extends Command {
+ protected FsCommand() {}
+
+ protected FsCommand(Configuration conf) {
+ super(conf);
+ }
+
+ public String getCommandName() {
+ return name.startsWith("-") ? name.substring(1) : name;
+ }
+
+ protected void run(Path path) throws IOException {
+ throw new RuntimeException("not supposed to get here");
+ }
+}
Added: hadoop/common/trunk/src/java/org/apache/hadoop/fs/shell/PathData.java
URL: http://svn.apache.org/viewvc/hadoop/common/trunk/src/java/org/apache/hadoop/fs/shell/PathData.java?rev=1090039&view=auto
==============================================================================
--- hadoop/common/trunk/src/java/org/apache/hadoop/fs/shell/PathData.java (added)
+++ hadoop/common/trunk/src/java/org/apache/hadoop/fs/shell/PathData.java Thu Apr 7 21:59:37 2011
@@ -0,0 +1,123 @@
+/**
+ * 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.FileNotFoundException;
+import java.io.IOException;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+
+/**
+ * Encapsulates a Path (path), its FileStatus (stat), and its FileSystem (fs).
+ * The stat field will be null if the path does not exist.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Evolving
+
+public class PathData {
+ public final Path path;
+ public FileStatus stat;
+ public final FileSystem fs;
+ public boolean exists;
+
+ /**
+ * Creates an object to wrap the given parameters as fields.
+ * @param theFs the FileSystem
+ * @param thePath a Path
+ * @param theStat the FileStatus (may be null if the path doesn't exist)
+ */
+ public PathData(FileSystem theFs, Path thePath, FileStatus theStat) {
+ path = thePath;
+ stat = theStat;
+ fs = theFs;
+ exists = (stat != null);
+ }
+
+ /**
+ * Convenience ctor that looks up the file status for a path. If the path
+ * doesn't exist, then the status will be null
+ * @param fs the FileSystem for the path
+ * @param path the pathname to lookup
+ * @throws IOException if anything goes wrong
+ */
+ public PathData(FileSystem fs, Path path) throws IOException {
+ this(fs, path, getStat(fs, path));
+ }
+
+ // need a static method for the ctor above
+ private static FileStatus getStat(FileSystem fs, Path path)
+ throws IOException {
+ FileStatus status = null;
+ try {
+ status = fs.getFileStatus(path);
+ } catch (FileNotFoundException e) {} // ignore FNF
+ return status;
+ }
+
+ /**
+ * Convenience ctor that extracts the path from the given file status
+ * @param fs the FileSystem for the FileStatus
+ * @param stat the FileStatus
+ */
+ public PathData(FileSystem fs, FileStatus stat) {
+ this(fs, stat.getPath(), stat);
+ }
+
+ /**
+ * Updates the paths's file status
+ * @return the updated FileStatus
+ * @throws IOException if anything goes wrong...
+ */
+ public FileStatus refreshStatus() throws IOException {
+ stat = fs.getFileStatus(path);
+ return stat;
+ }
+
+ /**
+ * Returns a list of PathData objects of the items contained in the given
+ * directory.
+ * @return list of PathData objects for its children
+ * @throws IOException if anything else goes wrong...
+ */
+ public PathData[] getDirectoryContents() throws IOException {
+ if (!stat.isDirectory()) {
+ throw new IOException(path + ": Not a directory");
+ }
+
+ FileStatus[] stats = fs.listStatus(path);
+ PathData[] items = new PathData[stats.length];
+ for (int i=0; i < stats.length; i++) {
+ items[i] = new PathData(fs, stats[i]);
+ }
+ return items;
+ }
+
+ /**
+ * Returns the printable version of the path that is just the
+ * filesystem path instead of the full uri
+ * @return String of the path
+ */
+ public String toString() {
+ return path.toString();
+ }
+}
Added: hadoop/common/trunk/src/test/core/org/apache/hadoop/fs/shell/TestPathData.java
URL: http://svn.apache.org/viewvc/hadoop/common/trunk/src/test/core/org/apache/hadoop/fs/shell/TestPathData.java?rev=1090039&view=auto
==============================================================================
--- hadoop/common/trunk/src/test/core/org/apache/hadoop/fs/shell/TestPathData.java (added)
+++ hadoop/common/trunk/src/test/core/org/apache/hadoop/fs/shell/TestPathData.java Thu Apr 7 21:59:37 2011
@@ -0,0 +1,47 @@
+/**
+ * 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 org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class TestPathData {
+ protected static Configuration conf;
+ protected static FileSystem fs;
+ protected static Path dir;
+
+ @BeforeClass
+ public static void initialize() throws Exception {
+ conf = new Configuration();
+ fs = FileSystem.getLocal(conf);
+ dir = new Path("/tmp");
+ }
+
+ @Test
+ public void testWithPath() throws Exception {
+ PathData item = new PathData(fs, dir);
+ assertEquals(fs, item.fs);
+ assertEquals(dir, item.path);
+ assertTrue(item.stat != null);
+ assertTrue(item.stat.isDirectory());
+ }
+}