org.eclipse.linuxtools.lttng2.ui/src/org/eclipse/linuxtools/internal/lttng2/ui/views/control/remote/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.lttng2.ui.views.control.remote;
  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.lttng2.ui.views.control.messages.Messages;
  31 import org.eclipse.rse.services.shells.HostShellProcessAdapter;
  32 import org.eclipse.rse.services.shells.IHostShell;
  33 import org.eclipse.rse.services.shells.IShellService;
  34
  35 /**
  36  * <p>
  37  * Implementation of remote command execution using RSE's shell service.
  38  * </p>
  39  *
  40  * @author Patrick Tasse
  41  * @author Bernd Hufmann
  42  */
  43 public class CommandShell implements ICommandShell {
  44
  45     // ------------------------------------------------------------------------
  46     // Constants
  47     // ------------------------------------------------------------------------
  48
  49     // string to be echo'ed when running command in shell, used to indicate that the command has finished running
  50     public final static String DONE_MARKUP_STRING = "--RSE:donedonedone:--"; //$NON-NLS-1$
  51
  52     //command delimiter for shell
  53     public final static String CMD_DELIMITER = "\n"; //$NON-NLS-1$
  54
  55     public final static String SHELL_ECHO_CMD = " echo "; //$NON-NLS-1$
  56
  57     private final static int DEFAULT_TIMEOUT_VALUE = 15000; // in milliseconds
  58
  59     // ------------------------------------------------------------------------
  60     // Attributes
  61     // ------------------------------------------------------------------------
  62     private IRemoteSystemProxy fProxy = null;
  63     private IHostShell fHostShell = null;
  64     private BufferedReader fBufferReader = null;
  65     private ExecutorService fExecutor = Executors.newFixedThreadPool(1);
  66     private boolean fIsConnected = false;
  67
  68     // ------------------------------------------------------------------------
  69     // Constructors
  70     // ------------------------------------------------------------------------
  71     public CommandShell(IRemoteSystemProxy proxy) {
  72         fProxy = proxy;
  73     }
  74
  75     // ------------------------------------------------------------------------
  76     // Operations
  77     // ------------------------------------------------------------------------
  78     /*
  79      * (non-Javadoc)
  80      * @see org.eclipse.linuxtools.internal.lttng2.ui.views.control.service.ICommandShell#connect()
  81      */
  82     @Override
  83     public void connect() throws ExecutionException {
  84         IShellService shellService = fProxy.getShellService();
  85         Process p = null;
  86         try {
  87             fHostShell = shellService.launchShell("", new String[0], new NullProgressMonitor()); //$NON-NLS-1$
  88             p = new HostShellProcessAdapter(fHostShell);
  89         } catch (Exception e) {
  90             throw new ExecutionException(Messages.TraceControl_CommandShellError, e);
  91         }
  92         fBufferReader = new BufferedReader(new InputStreamReader(p.getInputStream()));
  93         fIsConnected = true;
  94
  95         // Flush Login messages
  96         executeCommand(" ", new NullProgressMonitor(), false); //$NON-NLS-1$
  97     }
  98
  99     /*
 100      * (non-Javadoc)
 101      * @see org.eclipse.linuxtools.internal.lttng2.ui.views.control.service.ICommandShell#disconnect()
 102      */
 103     @Override
 104     public void disconnect() {
 105         fIsConnected = false;
 106         try {
 107             fBufferReader.close();
 108         } catch (IOException e) {
 109             // ignore
 110         }
 111     }
 112
 113     /*
 114      * (non-Javadoc)
 115      * @see org.eclipse.linuxtools.internal.lttng2.ui.views.control.service.ICommandShell#executeCommand(java.lang.String, org.eclipse.core.runtime.IProgressMonitor)
 116      */
 117     @Override
 118     public ICommandResult executeCommand(String command, IProgressMonitor monitor) throws ExecutionException {
 119         return executeCommand(command, monitor, true);
 120     }
 121
 122     /*
 123      * (non-Javadoc)
 124      * @see org.eclipse.linuxtools.internal.lttng2.ui.views.control.service.ICommandShell#executeCommand(java.lang.String, org.eclipse.core.runtime.IProgressMonitor, boolean)
 125      */
 126     @Override
 127     public ICommandResult executeCommand(final String command, final IProgressMonitor monitor, final boolean checkReturnValue) throws ExecutionException {
 128         if (fIsConnected) {
 129             FutureTask<CommandResult> future = new FutureTask<CommandResult>(new Callable<CommandResult>() {
 130                 @Override
 131                 public CommandResult call() throws IOException, CancellationException {
 132                     final ArrayList<String> result = new ArrayList<String>();
 133                     int returnValue = 0;
 134
 135                     synchronized (fHostShell) {
 136                         fHostShell.writeToShell(formatShellCommand(command));
 137                         String nextLine;
 138                         while ((nextLine = fBufferReader.readLine()) != null) {
 139
 140                             if (monitor.isCanceled()) {
 141                                 flushInput();
 142                                 throw new CancellationException();
 143                             }
 144
 145                             if (nextLine.contains(DONE_MARKUP_STRING) && nextLine.contains(SHELL_ECHO_CMD)) {
 146                                 break;
 147                             }
 148                         }
 149
 150                         while ((nextLine = fBufferReader.readLine()) != null) {
 151                             // check if job was cancelled
 152                             if (monitor.isCanceled()) {
 153                                 flushInput();
 154                                 throw new CancellationException();
 155                             }
 156
 157                             if (!nextLine.contains(DONE_MARKUP_STRING)) {
 158                                 result.add(nextLine);
 159                             } else {
 160                                 if (checkReturnValue) {
 161                                     returnValue = Integer.valueOf(nextLine.substring(DONE_MARKUP_STRING.length()+1));
 162                                 }
 163                                 break;
 164                             }
 165                         }
 166
 167                         flushInput();
 168                     }
 169                     return new CommandResult(returnValue, result.toArray(new String[result.size()]));
 170                 }
 171             });
 172
 173             fExecutor.execute(future);
 174
 175             try {
 176                 return future.get(DEFAULT_TIMEOUT_VALUE, TimeUnit.MILLISECONDS);
 177             } catch (java.util.concurrent.ExecutionException ex) {
 178                 throw new ExecutionException(Messages.TraceControl_ExecutionFailure, ex);
 179             } catch (InterruptedException ex) {
 180                 throw new ExecutionException(Messages.TraceControl_ExecutionCancelled, ex);
 181             } catch (TimeoutException ex) {
 182                 throw new ExecutionException(Messages.TraceControl_ExecutionTimeout, ex);
 183             }
 184         }
 185         throw new ExecutionException(Messages.TraceControl_ShellNotConnected, null);
 186     }
 187
 188     // ------------------------------------------------------------------------
 189     // Helper methods
 190     // ------------------------------------------------------------------------
 191     /**
 192      * Flushes the buffer reader
 193      * @throws IOException
 194      */
 195     private void flushInput() throws IOException {
 196         char[] cbuf = new char[1];
 197         while (fBufferReader.ready()) {
 198             if (fBufferReader.read(cbuf, 0, 1) == -1) {
 199                 break;
 200             }
 201         }
 202     }
 203
 204     /**
 205      * format the command to be sent into the shell command with the done markup string.
 206      * The done markup string is needed so we can tell that end of output has been reached.
 207      *
 208      * @param cmd
 209      * @return formatted command string
 210      */
 211     private String formatShellCommand(String cmd) {
 212         if (cmd == null || cmd.equals("")) //$NON-NLS-1$
 213             return cmd;
 214         StringBuffer formattedCommand = new StringBuffer();
 215         // Make a multi line command by using \ and \r. This is needed for matching
 216         // the DONE_MARKUP_STRING in echoed command when having a long command
 217         // (bigger than max SSH line)
 218         formattedCommand.append(cmd).append("\\\r;"); //$NON-NLS-1$
 219         formattedCommand.append(SHELL_ECHO_CMD).append(DONE_MARKUP_STRING);
 220         formattedCommand.append(" $?"); //$NON-NLS-1$
 221         formattedCommand.append(CMD_DELIMITER);
 222         return formattedCommand.toString();
 223     }
 224
 225 }