Add tools/ddbg_service.

tools/ddbg_service/lib/debugger.dart

Index: tools/ddbg_service/lib/debugger.dart
diff --git a/tools/ddbg_service/lib/debugger.dart b/tools/ddbg_service/lib/debugger.dart
new file mode 100644
index 0000000000000000000000000000000000000000..ea28e03d15bb496e1ae327d2ccf0578525eda1ae
--- /dev/null
+++ b/tools/ddbg_service/lib/debugger.dart
@@ -0,0 +1,443 @@
+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library debugger;
+
+import "dart:async";
+import "dart:io";
+
+import "package:ddbg/commando.dart";
+import "package:observatory/service_io.dart";
+
+class Debugger {
+  Commando _cmdo;
+  var _cmdoSubscription;
+
+  VM _vm;
+  VM get vm => _vm;
+  set vm(VM vm) {
+    if (_vm == vm) {
+      // Do nothing.
+      return;
+    }
+    if (_vm != null) {
+      _vm.disconnect();
+    }
+    if (vm != null) {
+      vm.onConnect.then(_vmConnected);
+      vm.onDisconnect.then(_vmDisconnected);
+      vm.errors.stream.listen(_onServiceError);
+      vm.exceptions.stream.listen(_onServiceException);
+      vm.events.stream.listen(_onServiceEvent);
+    }
+    _vm = vm;
+  }
+
+  _vmConnected(VM vm) {
+    _cmdo.hide();
+    print('Connected to vm');

[Cutch, 2014/09/16 17:33:37]

Should these messages go through some abstraction instead of using print
directly?

[turnidge, 2014/09/16 17:52:34]

Done.

+    _cmdo.show();
+  }
+
+  _vmDisconnected(VM vm) {
+    _cmdo.hide();
+    print('Disconnected from vm');
+    _cmdo.show();
+  }
+
+  _onServiceError(ServiceError error) {
+    _cmdo.hide();
+    print('error $error');
+    _cmdo.show();
+  }
+
+  _onServiceException(ServiceException exception) {
+    _cmdo.hide();
+    print('${exception.message}');
+    _cmdo.show();
+  }
+
+  _onServiceEvent(ServiceEvent event) {
+    switch (event.eventType) {
+      case 'GC':
+        // Ignore GC events for now.
+        break;
+      default:
+        _cmdo.hide();
+        print('event $event');
+        _cmdo.show();
+        break;
+    }
+  }
+
+  VM _isolate;
+  VM get isolate => _isolate;
+  set isolate(Isolate isolate) {
+    _isolate = isolate;
+    _cmdo.hide();
+    print('Current isolate is now isolate ${getIsolateIndex(_isolate)}');
+    _cmdo.show();
+  }
+
+  Map _isolateIndexMap = new Map();
+  int _nextIsolateIndex = 0;
+  int getIsolateIndex(Isolate isolate) {
+    var index = _isolateIndexMap[isolate.id];
+    if (index == null) {
+      index = _nextIsolateIndex++;
+      _isolateIndexMap[isolate.id] = index;
+    }
+    return index;
+  }
+
+  void onUncaughtError(error, StackTrace trace) {
+    if (error is ServiceException ||
+        error is ServiceError) {
+      // These are handled elsewhere.  Ignore.
+      return;
+    }
+    print('\n--------\nExiting due to unexpected error:\n'
+          '  $error\n$trace\n');
+    quit();
+  }
+
+  Debugger() {
+    _cmdo = new Commando(completer: completeCommand);
+    _cmdoSubscription = _cmdo.commands.listen(_processCommand,
+                                             onError: _cmdoError,
+                                             onDone: _cmdoDone);
+  }
+
+  Future _closeCmdo() {
+    var sub = _cmdoSubscription;
+    _cmdoSubscription = null;
+    _cmdo = null;
+
+    var future = sub.cancel();
+    if (future != null) {
+      return future;
+    } else {
+      return new Future.value();
+    }
+  }
+
+  Future quit() {
+    return Future.wait([_closeCmdo()]).then((_) {
+        exit(0);
+      });
+  }
+
+  void _cmdoError(self, parent, zone, error, StackTrace trace) {
+    print('\n--------\nExiting due to unexpected error:\n'
+          '  $error\n$trace\n');
+    quit();
+  }
+
+  void _cmdoDone() {
+    quit();
+  }
+
+  void _processCommand(String cmdLine) {
+    void huh() {
+      print("'$cmdLine' not understood, try 'help' for help.");
+    }
+
+    _cmdo.hide();
+    cmdLine = cmdLine.trim();
+    var args = cmdLine.split(' ');
+    if (args.length == 0) {
+      return;
+    }
+    var command = args[0];
+    var matches = matchCommand(command, true);
+    if (matches.length == 0) {
+      huh();
+      _cmdo.show();
+    } else if (matches.length == 1) {
+      matches[0].run(this, args).then((_) {
+          _cmdo.show();
+        });
+    } else {
+      var matchNames = matches.map((handler) => handler.name);
+      print("Ambigous command '$command' : ${matchNames.toList()}");
+      _cmdo.show();
+    }
+  }
+
+}
+
+// Every debugger command extends this base class.
+abstract class Command {
+  String get name;
+  String get helpShort;
+  void printHelp(List<String> args);
+  Future run(Debugger debugger, List<String> args);
+}
+
+class AttachCommand extends Command {
+  final name = 'attach';
+  final helpShort = 'Attach to a running Dart VM';
+  void printHelp(List<String> args) {
+    print("""

[Cutch, 2014/09/16 17:33:37]

Typically, Dart code uses ' over "

[turnidge, 2014/09/16 17:52:34]

Done.

+----- attach -----
+
+Attach to the Dart VM running at the indicated host:port. If no
+host:port is provided, attach to the VM running on the default port.
+
+Usage:
+  attach
+  attach <host:port>
+""");
+  }
+
+  Future run(Debugger debugger, List<String> args) {
+    if (args.length > 2) {
+      print('$name expects 0 or 1 arguments');
+      return new Future.value();
+    }
+    String hostPort = 'localhost:8181';
+    if (args.length > 1) {
+      hostPort = args[1];
+    }
+
+    debugger.vm = new WebSocketVM(new WebSocketVMTarget('ws://${hostPort}/ws'));
+    return debugger.vm.load().then((vm) {
+        if (debugger.isolate == null) {
+          for (var isolate in vm.isolates) {
+            if (isolate.name == 'root') {
+              debugger.isolate = isolate;
+            }
+          }
+        }
+      });
+  }
+}
+
+class DetachCommand extends Command {
+  final name = 'detach';
+  final helpShort = 'Detach from a running Dart VM';
+  void printHelp(List<String> args) {
+    print("""
+----- detach -----
+
+Detach from the Dart VM.
+
+Usage:
+  detach
+""");
+  }
+
+  Future run(Debugger debugger, List<String> args) {
+    if (args.length > 1) {
+      print('$name expects no arguments');
+      return new Future.value();
+    }
+    if (debugger.vm == null) {
+      print('No VM is attached');
+    } else {
+      debugger.vm = null;
+    }
+    return new Future.value();
+  }
+}
+
+class HelpCommand extends Command {
+  final name = 'help';
+  final helpShort = 'Show a list of debugger commands';
+  void printHelp(List<String> args) {
+    print("""
+----- help -----
+
+Show a list of debugger commands or get more information about a
+particular command.
+
+Usage:
+  help
+  help <command>
+""");
+  }
+
+  Future run(Debugger debugger, List<String> args) {
+    if (args.length <= 1) {
+      print("\nDebugger commands:\n");
+      for (var command in commandList) {
+        print('  ${command.name.padRight(11)} ${command.helpShort}');
+      }
+      print("For more information about a particular command, type:\n\n"
+            "  help <command>\n");
+
+      print("Commands may be abbreviated: e.g. type 'h' for 'help.\n");
+    } else {
+      var commandName = args[1];
+      var matches = matchCommand(commandName, true);
+      if (matches.length == 0) {
+        print("Command '$commandName' not recognized.  "
+              "Try 'help' for a list of commands.");
+      } else {
+        for (var command in matches) {
+          command.printHelp(args);
+        }
+      }
+    }
+
+    return new Future.value();
+  }
+}
+
+class IsolateCommand extends Command {
+  final name = 'isolate';
+  final helpShort = 'Isolate control';
+  void printHelp(List<String> args) {
+    print("""
+----- isolate -----
+
+List all isolates.
+
+Usage:
+  isolate
+  isolate list
+
+Set current isolate.
+
+Usage:
+  isolate <id>
+""");
+  }
+
+  Future run(Debugger debugger, List<String> args) {
+    if (args.length == 1 ||
+        (args.length == 2 && args[1] == 'list')) {
+      return _listIsolates(debugger);
+    } else if (args.length == 2) {
+      print('UNIMPLEMENTED');
+      return new Future.value();
+    } else {
+      if (args.length > 1) {
+        print('Unrecognized isolate command');
+        printHelp([]);
+        return new Future.value();
+      }
+    }
+  }
+    
+  Future _listIsolates(Debugger debugger) {
+    if (debugger.vm == null) {
+      print('No VM is attached');
+      return new Future.value();
+    }
+    return debugger.vm.reload().then((vm) {
+        // Sort the isolates by their indices.
+        var isolates = vm.isolates.toList();
+        isolates.sort((iso1, iso2) {
+            return (debugger.getIsolateIndex(iso1) -
+                    debugger.getIsolateIndex(iso2));
+          });
+
+        StringBuffer sb = new StringBuffer();
+        print('  ID       NAME         STATE');
+        print('-----------------------------------------------');
+        for (var isolate in isolates) {
+          if (isolate == debugger.isolate) {
+            sb.write('* ');
+          } else {
+            sb.write('  ');
+          }
+          sb.write(debugger.getIsolateIndex(isolate).toString().padRight(8));
+          sb.write(' ');
+          sb.write(isolate.name.padRight(12));
+          sb.write(' ');
+          if (isolate.pauseEvent != null) {
+            switch (isolate.pauseEvent.eventType) {
+              case 'IsolateCreated':
+                sb.write('paused at isolate start');
+                break;
+              case 'IsolateShutdown':
+                sb.write('paused at isolate exit');
+                break;
+              case 'IsolateInterrupted':
+                sb.write('paused');
+                break;
+              case 'BreakpointReached':
+                sb.write('paused by breakpoint');
+                break;
+              case 'ExceptionThrown':
+                sb.write('paused by exception');
+                break;
+              default:
+                sb.write('paused by unknown cause');
+                break;
+            }
+          } else if (isolate.running) {
+            sb.write('running');
+          } else if (isolate.idle) {
+            sb.write('idle');
+          } else if (isolate.loading) {
+            // TODO(turnidge): This is weird in a command line debugger.
+            sb.write('(not available)');
+          }
+          sb.write('\n');
+        }
+        print(sb);
+      });
+    return new Future.value();
+  }
+}
+
+class QuitCommand extends Command {
+  final name = 'quit';
+  final helpShort = 'Quit the debugger.';
+  void printHelp(List<String> args) {
+    print("""
+----- quit -----
+
+Quit the debugger.
+
+Usage:
+  quit
+""");
+  }
+
+  Future run(Debugger debugger, List<String> args) {
+    if (args.length > 1) {
+      print("Unexpected arguments to $name command.");
+      return new Future.value();
+    }
+    return debugger.quit();
+  }
+}
+
+List<Command> commandList =
+    [ new AttachCommand(),
+      new DetachCommand(),
+      new HelpCommand(),
+      new IsolateCommand(),
+      new QuitCommand() ];
+
+List<Command> matchCommand(String commandName, bool exactMatchWins) {
+  var matches = [];
+  for (var command in commandList) {
+    if (command.name.startsWith(commandName)) {
+      if (exactMatchWins && command.name == commandName) {
+        // Exact match
+        return [command];
+      } else {
+        matches.add(command);
+      }
+    }
+  }
+  return matches;
+}
+
+List<String> completeCommand(List<String> commandParts) {
+  var completions = new List<String>();
+  if (commandParts.length == 1) {
+    String prefix = commandParts[0];
+    for (var command in commandList) {
+      if (command.name.startsWith(prefix)) {
+        completions.add(command.name);
+      }
+    }
+  }
+  return completions;
+}