org.eclipse.linuxtools.lttng.ui/src/org/eclipse/linuxtools/internal/lttng/ui/views/control/service/CommandShell.java

   1 /**********************************************************************
   2  * Copyright (c) 2012 Ericsson
   3  *
   4  * All rights reserved. This program and the accompanying materials are
   5  * made available under the terms of the Eclipse Public License v1.0 which
   6  * accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *   Patrick Tasse - Initial API and implementation
  11  *   Bernd Hufmann - Updated using Executor Framework
  12  **********************************************************************/
  13 package org.eclipse.linuxtools.internal.lttng.ui.views.control.service;
  14
  15 import java.io.BufferedReader;
  16 import java.io.IOException;
  17 import java.io.InputStreamReader;
  18 import java.util.ArrayList;
  19 import java.util.concurrent.Callable;
  20 import java.util.concurrent.CancellationException;
  21 import java.util.concurrent.ExecutorService;
  22 import java.util.concurrent.Executors;
  23 import java.util.concurrent.FutureTask;
  24 import java.util.concurrent.TimeUnit;
  25 import java.util.concurrent.TimeoutException;
  26
  27 import org.eclipse.core.commands.ExecutionException;
  28 import org.eclipse.core.runtime.IProgressMonitor;
  29 import org.eclipse.core.runtime.NullProgressMonitor;
  30 import org.eclipse.linuxtools.internal.lttng.ui.views.control.Messages;
  31 import org.eclipse.linuxtools.internal.lttng.ui.views.control.remote.IRemoteSystemProxy;
  32 import org.eclipse.rse.services.shells.HostShellProcessAdapter;
  33 import org.eclipse.rse.services.shells.IHostShell;
  34 import org.eclipse.rse.services.shells.IShellService;
  35
  36 /**
  37  * <b><u>CommandShell</u></b>
  38  * <p>
  39  * Implementation of remote command execution using RSE's shell service.
  40  * </p>
  41  */
  42 public class CommandShell implements ICommandShell {
  43
  44     // ------------------------------------------------------------------------
  45     // Constants
  46     // ------------------------------------------------------------------------
  47
  48     // string to be echo'ed when running command in shell, used to indicate that the command has finished running
  49     public final static String DONE_MARKUP_STRING = "--RSE:donedonedone:--"; //$NON-NLS-1$
  50
  51     //command delimiter for shell
  52     public final static String CMD_DELIMITER = "\n"; //$NON-NLS-1$
  53
  54     public final static String SHELL_ECHO_CMD = " echo "; //$NON-NLS-1$
  55
  56     private final static int DEFAULT_TIMEOUT_VALUE = 15000; // in milliseconds
  57
  58     // ------------------------------------------------------------------------
  59     // Attributes
  60     // ------------------------------------------------------------------------
  61     private IRemoteSystemProxy fProxy = null;
  62     private IHostShell fHostShell = null;
  63     private BufferedReader fBufferReader = null;
  64     private ExecutorService fExecutor = Executors.newFixedThreadPool(1);
  65     private boolean fIsConnected = false;
  66
  67     // ------------------------------------------------------------------------
  68     // Constructors
  69     // ------------------------------------------------------------------------
  70     public CommandShell(IRemoteSystemProxy proxy) {
  71         fProxy = proxy;
  72     }
  73
  74     // ------------------------------------------------------------------------
  75     // Operations
  76     // ------------------------------------------------------------------------
  77     /*
  78      * (non-Javadoc)
  79      * @see org.eclipse.linuxtools.internal.lttng.ui.views.control.service.ICommandShell#connect()
  80      */
  81     @Override
  82     public void connect() throws ExecutionException {
  83         IShellService shellService = fProxy.getShellService();
  84         Process p = null;
  85         try {
  86             fHostShell = shellService.launchShell("", new String[0], new NullProgressMonitor()); //$NON-NLS-1$
  87             p = new HostShellProcessAdapter(fHostShell);
  88         } catch (Exception e) {
  89             throw new ExecutionException(Messages.TraceControl_CommandShellError, e);
  90         }
  91         fBufferReader = new BufferedReader(new InputStreamReader(p.getInputStream()));
  92         fIsConnected = true;
  93
  94         // Flush Login messages
  95         executeCommand(" ", new NullProgressMonitor(), false); //$NON-NLS-1$
  96     }
  97
  98     /*
  99      * (non-Javadoc)
 100      * @see org.eclipse.linuxtools.internal.lttng.ui.views.control.service.ICommandShell#disconnect()
 101      */
 102     @Override
 103     public void disconnect() {
 104         fIsConnected = false;
 105         try {
 106             fBufferReader.close();
 107         } catch (IOException e) {
 108             // ignore
 109         }
 110     }
 111
 112     /*
 113      * (non-Javadoc)
 114      * @see org.eclipse.linuxtools.internal.lttng.ui.views.control.service.ICommandShell#executeCommand(java.lang.String, org.eclipse.core.runtime.IProgressMonitor)
 115      */
 116     @Override
 117     public ICommandResult executeCommand(String command, IProgressMonitor monitor) throws ExecutionException {
 118         return executeCommand(command, monitor, true);
 119     }
 120
 121     /*
 122      * (non-Javadoc)
 123      * @see org.eclipse.linuxtools.internal.lttng.ui.views.control.service.ICommandShell#executeCommand(java.lang.String, org.eclipse.core.runtime.IProgressMonitor, boolean)
 124      */
 125     @Override
 126     public ICommandResult executeCommand(final String command, final IProgressMonitor monitor, final boolean checkReturnValue) throws ExecutionException {
 127         if (fIsConnected) {
 128             FutureTask<CommandResult> future = new FutureTask<CommandResult>(new Callable<CommandResult>() {
 129                 @Override
 130                 public CommandResult call() throws IOException, CancellationException {
 131                     final ArrayList<String> result = new ArrayList<String>();
 132                     int returnValue = 0;
 133
 134                     synchronized (fHostShell) {
 135                         fHostShell.writeToShell(formatShellCommand(command));
 136                         String nextLine;
 137                         while ((nextLine = fBufferReader.readLine()) != null) {
 138
 139                             if (monitor.isCanceled()) {
 140                                 flushInput();
 141                                 throw new CancellationException();
 142                             }
 143
 144                             if (nextLine.contains(DONE_MARKUP_STRING) && nextLine.contains(SHELL_ECHO_CMD)) {
 145                                 break;
 146                             }
 147                         }
 148
 149                         while ((nextLine = fBufferReader.readLine()) != null) {
 150                             // check if job was cancelled
 151                             if (monitor.isCanceled()) {
 152                                 flushInput();
 153                                 throw new CancellationException();
 154                             }
 155
 156                             if (!nextLine.contains(DONE_MARKUP_STRING)) {
 157                                 result.add(nextLine);
 158                             } else {
 159                                 if (checkReturnValue) {
 160                                     returnValue = Integer.valueOf(nextLine.substring(DONE_MARKUP_STRING.length()+1));
 161                                 }
 162                                 break;
 163                             }
 164                         }
 165
 166                         flushInput();
 167                     }
 168                     return new CommandResult(returnValue, result.toArray(new String[result.size()]));
 169                 }
 170             });
 171
 172             fExecutor.execute(future);
 173
 174             try {
 175                 return future.get(DEFAULT_TIMEOUT_VALUE, TimeUnit.MILLISECONDS);
 176             } catch (java.util.concurrent.ExecutionException ex) {
 177                 throw new ExecutionException(Messages.TraceControl_ExecutionFailure, ex);
 178             } catch (InterruptedException ex) {
 179                 throw new ExecutionException(Messages.TraceControl_ExecutionCancelled, ex);
 180             } catch (TimeoutException ex) {
 181                 throw new ExecutionException(Messages.TraceControl_ExecutionTimeout, ex);
 182             }
 183         }
 184         throw new ExecutionException(Messages.TraceControl_ShellNotConnected, null);
 185     }
 186
 187     // ------------------------------------------------------------------------
 188     // Helper methods
 189     // ------------------------------------------------------------------------
 190     /**
 191      * Flushes the buffer reader
 192      * @throws IOException
 193      */
 194     private void flushInput() throws IOException {
 195         char[] cbuf = new char[1];
 196         while (fBufferReader.ready()) {
 197             if (fBufferReader.read(cbuf, 0, 1) == -1) {
 198                 break;
 199             }
 200         }
 201     }
 202
 203     /**
 204      * format the command to be sent into the shell command with the done markup string.
 205      * The done markup string is needed so we can tell that end of output has been reached.
 206      *
 207      * @param cmd
 208      * @return formatted command string
 209      */
 210     private String formatShellCommand(String cmd) {
 211         if (cmd == null || cmd.equals("")) //$NON-NLS-1$
 212             return cmd;
 213         StringBuffer formattedCommand = new StringBuffer();
 214         // Make a multi line command by using \ and \r. This is needed for matching
 215         // the DONE_MARKUP_STRING in echoed command when having a long command
 216         // (bigger than max SSH line)
 217         formattedCommand.append(cmd).append("\\\r;"); //$NON-NLS-1$
 218         formattedCommand.append(SHELL_ECHO_CMD).append(DONE_MARKUP_STRING);
 219         formattedCommand.append(" $?"); //$NON-NLS-1$
 220         formattedCommand.append(CMD_DELIMITER);
 221         return formattedCommand.toString();
 222     }
 223
 224 }