Hook for overriding the ContextManager and some code clean-up (with more to follow)

pkg/analysis_server/lib/src/analysis_server.dart

Index: pkg/analysis_server/lib/src/analysis_server.dart
diff --git a/pkg/analysis_server/lib/src/analysis_server.dart b/pkg/analysis_server/lib/src/analysis_server.dart
index 7f135d2d547a4a576ed703e43f55a971b136ed26..60d721f9749aa4723adaaad1c4310cd3d1215131 100644
--- a/pkg/analysis_server/lib/src/analysis_server.dart
+++ b/pkg/analysis_server/lib/src/analysis_server.dart
@@ -108,10 +108,10 @@ class AnalysisServer {
   final ServerPlugin serverPlugin;
 
   /**
-   * [ContextManager] which handles the mapping from analysis roots
-   * to context directories.
+   * The [ContextManager] that handles the mapping from analysis roots to
+   * context directories.
    */
-  ServerContextManager contextDirectoryManager;
+  ServerContextManager contextManager;
 
   /**
    * A flag indicating whether the server is running.  When false, contexts
@@ -254,6 +254,9 @@ class AnalysisServer {
    * Initialize a newly created server to receive requests from and send
    * responses to the given [channel].
    *
+   * If a [contextManager] is provided, then the [packageResolverProvider] will
+   * be ignored.
+   *
    * If [rethrowExceptions] is true, then any exceptions thrown by analysis are
    * propagated up the call stack.  The default is true to allow analysis
    * exceptions to show up in unit tests, but it should be set to false when
@@ -263,20 +266,30 @@ class AnalysisServer {
       OptimizingPubPackageMapProvider packageMapProvider, Index _index,
       this.serverPlugin, AnalysisServerOptions analysisServerOptions,
       this.defaultSdk, this.instrumentationService,
-      {ResolverProvider packageResolverProvider: null,
+      {ContextManager contextManager: null,
+      ResolverProvider packageResolverProvider: null,
       this.rethrowExceptions: true})
       : index = _index,
         searchEngine = _index != null ? createSearchEngine(_index) : null {
     _performance = performanceDuringStartup;
     operationQueue = new ServerOperationQueue();
-    contextDirectoryManager = new ServerContextManager(this, resourceProvider,
-        packageResolverProvider, packageMapProvider, instrumentationService);
-    contextDirectoryManager.defaultOptions.incremental = true;
-    contextDirectoryManager.defaultOptions.incrementalApi =
-        analysisServerOptions.enableIncrementalResolutionApi;
-    contextDirectoryManager.defaultOptions.incrementalValidation =
-        analysisServerOptions.enableIncrementalResolutionValidation;
-    contextDirectoryManager.defaultOptions.generateImplicitErrors = false;
+    if (contextManager == null) {
+      contextManager = new ServerContextManager(this, resourceProvider,
+          packageResolverProvider, packageMapProvider, instrumentationService);
+      AnalysisOptionsImpl options =
+          (contextManager as ServerContextManager).defaultOptions;
+      options.incremental = true;
+      options.incrementalApi =
+          analysisServerOptions.enableIncrementalResolutionApi;
+      options.incrementalValidation =
+          analysisServerOptions.enableIncrementalResolutionValidation;
+      options.generateImplicitErrors = false;
+    } else if (contextManager is! ServerContextManager) {
+      // TODO(brianwilkerson) Remove this when the interface is complete.
+      throw new StateError(
+          'The contextManager must be an instance of ServerContextManager');
+    }
+    this.contextManager = contextManager;
     _noErrorNotification = analysisServerOptions.noErrorNotification;
     AnalysisEngine.instance.logger = new AnalysisLogger();
     _onAnalysisStartedController = new StreamController.broadcast();
@@ -321,7 +334,7 @@ class AnalysisServer {
    * The stream that is notified when contexts are added or removed.
    */
   Stream<ContextsChangedEvent> get onContextsChanged =>
-      contextDirectoryManager.onContextsChanged;
+      contextManager.onContextsChanged;
 
   /**
    * The stream that is notified when a single file has been analyzed.
@@ -374,7 +387,7 @@ class AnalysisServer {
    * analyzed.
    */
   void fileAnalyzed(ChangeNotice notice) {
-    if (contextDirectoryManager.isInAnalysisRoot(notice.source.fullName)) {
+    if (contextManager.isInAnalysisRoot(notice.source.fullName)) {
       _onFileAnalyzedController.add(notice);
     }
   }
@@ -465,14 +478,15 @@ class AnalysisServer {
     {
       AnalysisContext containingContext = getContainingContext(path);
       if (containingContext != null) {
-        Source source =
-            ContextManager.createSourceInContext(containingContext, file);
+        Source source = AbstractContextManager.createSourceInContext(
+            containingContext, file);
         return new ContextSourcePair(containingContext, source);
       }
     }
     // try to find a context that analysed the file
     for (AnalysisContext context in folderMap.values) {
-      Source source = ContextManager.createSourceInContext(context, file);
+      Source source =
+          AbstractContextManager.createSourceInContext(context, file);
       SourceKind kind = context.getKindOf(source);
       if (kind != SourceKind.UNKNOWN) {
         return new ContextSourcePair(context, source);
@@ -772,7 +786,7 @@ class AnalysisServer {
     }
     // Instruct the contextDirectoryManager to rebuild all contexts from
     // scratch.
-    contextDirectoryManager.refresh(roots);
+    contextManager.refresh(roots);
   }
 
   /**
@@ -877,8 +891,7 @@ class AnalysisServer {
   void setAnalysisRoots(String requestId, List<String> includedPaths,
       List<String> excludedPaths, Map<String, String> packageRoots) {
     try {
-      contextDirectoryManager.setRoots(
-          includedPaths, excludedPaths, packageRoots);
+      contextManager.setRoots(includedPaths, excludedPaths, packageRoots);
     } on UnimplementedError catch (e) {
       throw new RequestFailure(
           new Response.unsupportedFeature(requestId, e.message));
@@ -962,7 +975,8 @@ class AnalysisServer {
             Uri uri = context.sourceFactory.restoreUri(source);
             if (uri.scheme != 'file') {
               preferredContext = context;
-              source = ContextManager.createSourceInContext(context, resource);
+              source = AbstractContextManager.createSourceInContext(
+                  context, resource);
               break;
             }
           }
@@ -1009,8 +1023,7 @@ class AnalysisServer {
    * absolute path.
    */
   bool shouldSendErrorsNotificationFor(String file) {
-    return !_noErrorNotification &&
-        contextDirectoryManager.isInAnalysisRoot(file);
+    return !_noErrorNotification && contextManager.isInAnalysisRoot(file);
   }
 
   void shutdown() {
@@ -1157,11 +1170,13 @@ class AnalysisServer {
         optionUpdater(options);
       });
       context.analysisOptions = options;
+      // TODO(brianwilkerson) As far as I can tell, this doesn't cause analysis

[Paul Berry, 2015/07/09 21:45:57]

Ouch.  I believe you are right.

+      // to be scheduled for this context.
     });
     //
     // Update the defaults used to create new contexts.
     //
-    AnalysisOptionsImpl options = contextDirectoryManager.defaultOptions;
+    AnalysisOptionsImpl options = contextManager.defaultOptions;
     optionUpdaters.forEach((OptionUpdater optionUpdater) {
       optionUpdater(options);
     });
@@ -1175,8 +1190,7 @@ class AnalysisServer {
     Set<AnalysisContext> contexts = new HashSet<AnalysisContext>();
     resources.forEach((Resource resource) {
       if (resource is Folder) {
-        contexts
-            .addAll(contextDirectoryManager.contextsInAnalysisRoot(resource));
+        contexts.addAll(contextManager.contextsInAnalysisRoot(resource));
       }
     });
     return contexts;
@@ -1243,13 +1257,9 @@ class AnalysisServerOptions {
 }
 
 /**
- * A [ContextsChangedEvent] indicate what contexts were added or removed.
- *
- * No context should be added to the event more than once. It does not make
- * sense, for example, for a context to be both added and removed.
+ * An implementation of a [ContextsChangedEvent].
  */
-class ContextsChangedEvent {
-
+class ContextsChangedEventImpl implements ContextsChangedEvent {

[Paul Berry, 2015/07/09 21:45:57]

I don't follow the benefit of making an interface/implementation distinction for
this class.  Usually the benefit would be to allow the implementation to be part
of the public API while the implementation remains private.  But since the
plug-in will have to provide an implementation of onContextsChanged, which
returns a stream of ContextsChangedEvent, that means that the plug-in will have
to be able to create concrete instantiations of ContextsChangedEvent.  So both
the implementation and the interface will have to be part of the public API in
order for someone to write a context manager plug-in.

[Brian Wilkerson, 2015/07/13 17:18:50]

I agree. Done.

   /**
    * The contexts that were added to the server.
    */
@@ -1265,7 +1275,7 @@ class ContextsChangedEvent {
    */
   final List<AnalysisContext> removed;
 
-  ContextsChangedEvent({this.added: AnalysisContext.EMPTY_LIST,
+  ContextsChangedEventImpl({this.added: AnalysisContext.EMPTY_LIST,
       this.changed: AnalysisContext.EMPTY_LIST,
       this.removed: AnalysisContext.EMPTY_LIST});
 }
@@ -1300,7 +1310,7 @@ class PriorityChangeEvent {
   PriorityChangeEvent(this.firstSource);
 }
 
-class ServerContextManager extends ContextManager {
+class ServerContextManager extends AbstractContextManager {
   final AnalysisServer analysisServer;
 
   /**
@@ -1338,7 +1348,7 @@ class ServerContextManager extends ContextManager {
     context.sourceFactory = _createSourceFactory(packageUriResolver);
     context.analysisOptions = new AnalysisOptionsImpl.from(defaultOptions);
     _onContextsChangedController
-        .add(new ContextsChangedEvent(added: [context]));
+        .add(new ContextsChangedEventImpl(added: [context]));
     analysisServer.schedulePerformAnalysisOperation(context);
     return context;
   }
@@ -1382,7 +1392,7 @@ class ServerContextManager extends ContextManager {
     }
     analysisServer.operationQueue.contextRemoved(context);
     _onContextsChangedController
-        .add(new ContextsChangedEvent(removed: [context]));
+        .add(new ContextsChangedEventImpl(removed: [context]));
     analysisServer.sendContextAnalysisDoneNotifications(
         context, AnalysisDoneReason.CONTEXT_REMOVED);
     context.dispose();
@@ -1412,7 +1422,7 @@ class ServerContextManager extends ContextManager {
     AnalysisContext context = analysisServer.folderMap[contextFolder];
     context.sourceFactory = _createSourceFactory(packageUriResolver);
     _onContextsChangedController
-        .add(new ContextsChangedEvent(changed: [context]));
+        .add(new ContextsChangedEventImpl(changed: [context]));
     analysisServer.schedulePerformAnalysisOperation(context);
   }