HADOOP-7202. Improve shell Command base class. Contributed by Daryn Sharp

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1090039 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Tsz-wo Sze 2011-04-07 21:59:37 +00:00
parent 5bfd361ca7
commit a65753ddac
7 changed files with 582 additions and 61 deletions

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@ -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

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@ -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.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;
import org.apache.hadoop.util.StringUtils;
/** Provide command line access to a FileSystem. */
@InterfaceAudience.Private
@ -370,7 +375,7 @@ public class FsShell extends Configured implements Tool {
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 implements Tool {
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 implements Tool {
} 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 implements Tool {
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)) {

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@ -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 Configured {
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);
}
}

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@ -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);
}
}

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@ -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");
}
}

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@ -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();
}
}

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@ -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());
}
}