Server options handling.

pkg/analysis_server/lib/src/server_options.dart

+// Copyright (c) 2015, 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.
+
+// This code was auto-generated, is not intended to be edited, and is subject to

[Brian Wilkerson, 2015/07/30 18:18:59]

?

[pquitslund, 2015/07/30 19:55:48]

Done.

+// significant change. Please see the README file for more information.
+
+library analysis_server.server_options;

[Brian Wilkerson, 2015/07/30 18:18:59]

Should be "analysis_server.src.server_options".

[pquitslund, 2015/07/30 19:55:47]

Done.

+
+import 'dart:io';
+
+import 'package:path/path.dart' as path;
+import 'package:yaml/yaml.dart';
+
+const _optionsFileName = 'dart_analysis_server.options';
+
+/// The shared options instance.
+ServerOptions _serverOptions;
+
+/// Server options.
+ServerOptions get serverOptions {
+  if (_serverOptions == null) {
+    _serverOptions = _loadOptions();
+  }
+  return _serverOptions;
+}
+
+File _findOptionsFile() {
+  String home;
+  Map<String, String> envVars = Platform.environment;
+  if (Platform.isMacOS || Platform.isLinux) {
+    home = envVars['HOME'];
+  } else if (Platform.isWindows) {
+    home = envVars['UserProfile'];
+  }
+
+  // Shouldn't happen but to be safe.

[Brian Wilkerson, 2015/07/30 18:18:59]

This can happen if either (a) the platform is not known or (b) if the
environment variable is not set.

Neither of those is common, but neither is impossible. We should update the
comment to include that information (or add a doc comment).

[pquitslund, 2015/07/30 19:55:48]

Done.

+  if (home == null) {
+    return null;
+  }
+
+  return new File(path.context.join(home, _optionsFileName));
+}
+
+ServerOptions _loadOptions() {
+  File optionsFile = _findOptionsFile();
+  try {
+    if (optionsFile.existsSync()) {

[Brian Wilkerson, 2015/07/30 18:18:59]

Add "optionsFile != null &&"

[pquitslund, 2015/07/30 19:55:47]

Done.

+      return new ServerOptions.fromFile(optionsFile);
+    }
+  } catch (e) {
+    return new ServerOptions._empty();
+  }

[scheglov, 2015/07/30 18:04:10]

If the options file does not exist, we will fall-through here.
Maybe more the return statement from the catch block here?

[pquitslund, 2015/07/30 19:55:47]

Ah, yes.  Good catch!

+}
+
+/// Describes options captured in an external options file.
+/// `ServerOptions` are described in a file `dart_analysis_server.options`
+/// located in the user's home directory. Options are defined in YAML and
+/// read once and cached. In order for changes to be picked up, server needs
+/// to be restarted.
+class ServerOptions {
+  final Map<String, dynamic> _options = <String, dynamic>{};

[Brian Wilkerson, 2015/07/30 18:18:59]

It probably doesn't matter much here, but we've adopted a style of always using
"new HashMap<...>()" rather than a literal map because it's more efficient.

[pquitslund, 2015/07/30 19:55:47]

NP.  Updated.

+
+  /// Load options from the given [contents].
+  ServerOptions.fromContents(String contents) {
+    _readOptions(contents);
+  }
+
+  /// Load options from the given [options] file.
+  factory ServerOptions.fromFile(File options) =>
+      new ServerOptions.fromContents(options.readAsStringSync());
+
+  /// Create an empty options object.
+  ServerOptions._empty();
+
+  /// Get the value for `key` from the options file.
+  dynamic operator [](String key) => _options[key];
+
+  /// Get a String value for this `key` or [defaultValue] if undefined
+  /// or not a String.
+  String getStringValue(String key, {String defaultValue: null}) {
+    var value = _options[key];
+    if (value is String) {
+      return value;
+    }
+    return defaultValue;
+  }
+
+  /// Test whether the given [booleanPropertyKey] is set to the value `true`.
+  /// For example:
+  ///     myDebugOption:true
+  ///     myDebugOption:TRUE  # Also true (case and trailing whitespace are ignored).
+  ///     myDebugOption2:false
+  ///     myDebugOption2:off  # Treated as `false`.
+  ///     myDebugOption2:on   # Also read as `false`.

[Brian Wilkerson, 2015/07/30 18:18:59]

nit: it would be more consistent if either all the keys were the same or all the
keys were unique.

[pquitslund, 2015/07/30 19:55:47]

Done.

+  bool isSet(String booleanPropertyKey) => _options[booleanPropertyKey] == true;
+
+  void _readOptions(String contents) {
+    var doc = loadYaml(contents);
+    if (doc is YamlMap) {
+      doc.forEach((k, v) {
+        if (k is String) {
+          _options[k] = v;
+        }
+      });
+    }
+  }
+}