Add logging to the incremental resolver.

pkg/analysis_server/lib/driver.dart

 // 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 driver;
 
 import 'dart:async';
 import 'dart:io';
 
 import 'package:analysis_server/http_server.dart';
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/socket_server.dart';
 import 'package:analysis_server/stdio_server.dart';
+import 'package:analyzer/src/generated/incremental_logger.dart';
 import 'package:analyzer/src/generated/java_io.dart';
 import 'package:analyzer/src/generated/sdk.dart';
 import 'package:analyzer/src/generated/sdk_io.dart';
 import 'package:args/args.dart';
 
+
+/**
+ * Initializes incremental logger.
+ *
+ * Supports following formats of [spec]:
+ *
+ *     "console" - log to the console;
+ *     "file:/some/file/name" - log to the file, overwritten on start.
+ */
+void _initIncrementalLogger(String spec) {
+  logger = new NullLogger();
+  if (spec == null) {
+    return;
+  }
+  // create logger
+  if (spec == 'console') {
+    logger = new StringSinkLogger(console.log);
+  }
+  if (spec.startsWith('file:')) {
+    String fileName = spec.substring('file:'.length);
+    File file = new File(fileName);
+    IOSink sink = file.openWrite();
+    logger = new StringSinkLogger(sink);
+  }
+}
+
+
 /**
  * The [Driver] class represents a single running instance of the analysis
  * server application.  It is responsible for parsing command line options
  * and starting the HTTP and/or stdio servers.
  */
 class Driver {
   /**
    * The name of the application that is used to start a server.
    */
   static const BINARY_NAME = "server";
 
   /**
    * The name of the option used to enable incremental resolution.
    */
   static const String ENABLE_INCREMENTAL_RESOLUTION =
       "enable-incremental-resolution";
 
   /**
+   * The name of the option used to describe the incremental resolution logger.
+   */
+  static const String INCREMENTAL_RESOLUTION_LOG = "incremental-resolution-log";
+
+  /**
    * The name of the option used to enable instrumentation.
    */
   static const String ENABLE_INSTRUMENTATION_OPTION = "enable-instrumentation";
 
   /**
    * The name of the option used to print usage information.
    */
   static const String HELP_OPTION = "help";
 
   /**
    * The name of the option used to specify the log file to which
    * instrumentation data is to be written.
    */
   static const String INSTRUMENTATION_LOG_FILE_OPTION =
       "instrumentation-log-file";
 
   /**
    * The name of the option used to specify if [print] should print to the
    * console instead of being intercepted.
    */
-  static const String INTERNAL_PRINT_TO_CONSOLE =
-      "internal-print-to-console";
+  static const String INTERNAL_PRINT_TO_CONSOLE = "internal-print-to-console";
 
   /**
    * The name of the option used to specify the port to which the server will
    * connect.
    */
   static const String PORT_OPTION = "port";
 
   /**
    * The path to the SDK.
    * TODO(paulberry): get rid of this once the 'analysis.updateSdks' request is
@@ skipping 27 matching lines @@
         ENABLE_INSTRUMENTATION_OPTION,
         help: "enable sending instrumentation information to a server",
         defaultsTo: false,
         negatable: false);
     parser.addFlag(
         HELP_OPTION,
         help: "print this help message without starting a server",
         defaultsTo: false,
         negatable: false);
     parser.addOption(
+        INCREMENTAL_RESOLUTION_LOG,
+        help: "the description of the incremental resolotion log");
+    parser.addOption(
         INSTRUMENTATION_LOG_FILE_OPTION,
         help: "[path] the file to which instrumentation data will be logged");
     parser.addFlag(
         INTERNAL_PRINT_TO_CONSOLE,
         help: "enable sending `print` output to the console",
         defaultsTo: false,
         negatable: false);
     parser.addOption(
         PORT_OPTION,
         help: "[port] the port on which the server will listen");
@@ skipping 32 matching lines @@
         _printUsage(parser);
         exitCode = 1;
         return;
       }
     }
 
     AnalysisServerOptions analysisServerOptions = new AnalysisServerOptions();
     analysisServerOptions.enableIncrementalResolution =
         results[ENABLE_INCREMENTAL_RESOLUTION];
 
+    _initIncrementalLogger(results[INCREMENTAL_RESOLUTION_LOG]);
+
     DartSdk defaultSdk;
     if (results[SDK_OPTION] != null) {
       defaultSdk = new DirectoryBasedDartSdk(new JavaFile(results[SDK_OPTION]));
     } else {
       // No path to the SDK provided; use DirectoryBasedDartSdk.defaultSdk,
       // which will make a guess.
       defaultSdk = DirectoryBasedDartSdk.defaultSdk;
     }
 
     socketServer = new SocketServer(analysisServerOptions, defaultSdk);
@@ skipping 40 matching lines @@
   /**
    * Print information about how to use the server.
    */
   void _printUsage(ArgParser parser) {
     print('Usage: $BINARY_NAME [flags]');
     print('');
     print('Supported flags are:');
     print(parser.usage);
   }
 }