Remove the ExecutionDomainHandler

This also introduces the map in which individual handler generators are
stored and the code needed to use them.

Change-Id: Iba400ac2f943f6727dc89a9bba0a26a17396ae4e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/240560
Reviewed-by: Samuel Rawlins <srawlins@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>

Author: bwilkerson

pkg/analysis_server/lib/src/analysis_server.dart

@@ -8,8 +8,7 @@ import 'dart:io' as io;
 import 'dart:math' show max;
 
 import 'package:analysis_server/protocol/protocol.dart';
-import 'package:analysis_server/protocol/protocol_constants.dart'
-    show PROTOCOL_VERSION;
+import 'package:analysis_server/protocol/protocol_constants.dart';
 import 'package:analysis_server/protocol/protocol_generated.dart'
     hide AnalysisOptions;
 import 'package:analysis_server/src/analysis_server_abstract.dart';
@@ -20,14 +19,19 @@ import 'package:analysis_server/src/domain_analysis.dart';
 import 'package:analysis_server/src/domain_analytics.dart';
 import 'package:analysis_server/src/domain_completion.dart';
 import 'package:analysis_server/src/domain_diagnostic.dart';
-import 'package:analysis_server/src/domain_execution.dart';
 import 'package:analysis_server/src/domain_kythe.dart';
 import 'package:analysis_server/src/domain_server.dart';
 import 'package:analysis_server/src/domains/analysis/occurrences.dart';
 import 'package:analysis_server/src/domains/analysis/occurrences_dart.dart';
 import 'package:analysis_server/src/edit/edit_domain.dart';
 import 'package:analysis_server/src/flutter/flutter_domain.dart';
 import 'package:analysis_server/src/flutter/flutter_notifications.dart';
+import 'package:analysis_server/src/handler/legacy/execution_create_context.dart';
+import 'package:analysis_server/src/handler/legacy/execution_delete_context.dart';
+import 'package:analysis_server/src/handler/legacy/execution_get_suggestions.dart';
+import 'package:analysis_server/src/handler/legacy/execution_map_uri.dart';
+import 'package:analysis_server/src/handler/legacy/execution_set_subscriptions.dart';
+import 'package:analysis_server/src/handler/legacy/legacy_handler.dart';
 import 'package:analysis_server/src/operation/operation_analysis.dart';
 import 'package:analysis_server/src/plugin/notification_manager.dart';
 import 'package:analysis_server/src/protocol_server.dart' as server;
@@ -65,11 +69,30 @@ import 'package:telemetry/crash_reporting.dart';
 import 'package:telemetry/telemetry.dart' as telemetry;
 import 'package:watcher/watcher.dart';
 
+/// A function that can be executed to create a handler for a request.
+typedef HandlerGenerator = LegacyHandler Function(
+    AnalysisServer, Request, CancellationToken);
+
 typedef OptionUpdater = void Function(AnalysisOptionsImpl options);
 
 /// Instances of the class [AnalysisServer] implement a server that listens on a
 /// [CommunicationChannel] for analysis requests and process them.
 class AnalysisServer extends AbstractAnalysisServer {
+  /// A map from the name of a request to a function used to create a request
+  /// handler.
+  static final Map<String, HandlerGenerator> handlerGenerators = {
+    EXECUTION_REQUEST_CREATE_CONTEXT: (server, request, cancellationToken) =>
+        ExecutionCreateContextHandler(server, request, cancellationToken),
+    EXECUTION_REQUEST_DELETE_CONTEXT: (server, request, cancellationToken) =>
+        ExecutionDeleteContextHandler(server, request, cancellationToken),
+    EXECUTION_REQUEST_GET_SUGGESTIONS: (server, request, cancellationToken) =>
+        ExecutionGetSuggestionsHandler(server, request, cancellationToken),
+    EXECUTION_REQUEST_MAP_URI: (server, request, cancellationToken) =>
+        ExecutionMapUriHandler(server, request, cancellationToken),
+    EXECUTION_REQUEST_SET_SUBSCRIPTIONS: (server, request, cancellationToken) =>
+        ExecutionSetSubscriptionsHandler(server, request, cancellationToken),
+  };
+
   /// The channel from which requests are received and to which responses should
   /// be sent.
   final ServerCommunicationChannel channel;
@@ -225,7 +248,6 @@ class AnalysisServer extends AbstractAnalysisServer {
       EditDomainHandler(this),
       SearchDomainHandler(this),
       CompletionDomainHandler(this),
-      ExecutionDomainHandler(this, executionContext),
       DiagnosticDomainHandler(this),
       AnalyticsDomainHandler(this),
       KytheDomainHandler(this),
@@ -295,33 +317,54 @@ class AnalysisServer extends AbstractAnalysisServer {
     runZonedGuarded(() {
       var cancellationToken = CancelableToken();
       cancellationTokens[request.id] = cancellationToken;
-      var count = handlers.length;
-      for (var i = 0; i < count; i++) {
+      var generator = handlerGenerators[request.method];
+      if (generator != null) {
         try {
-          var response = handlers[i].handleRequest(request, cancellationToken);
-          if (response == Response.DELAYED_RESPONSE) {
-            return;
-          }
-          if (response != null) {
-            sendResponse(response);
-            return;
-          }
+          var handler = generator(this, request, cancellationToken);
+          handler.handle();
         } on InconsistentAnalysisException {
           sendResponse(Response.contentModified(request));
-          return;
         } on RequestFailure catch (exception) {
           sendResponse(exception.response);
-          return;
         } catch (exception, stackTrace) {
           var error =
               RequestError(RequestErrorCode.SERVER_ERROR, exception.toString());
           error.stackTrace = stackTrace.toString();
           var response = Response(request.id, error: error);
           sendResponse(response);
-          return;
         }
+      } else {
+        // TODO(brianwilkerson) When all the handlers are in [handlerGenerators]
+        //  remove local variable and for loop below.
+        var count = handlers.length;
+        for (var i = 0; i < count; i++) {
+          try {
+            var response =
+                handlers[i].handleRequest(request, cancellationToken);
+            if (response == Response.DELAYED_RESPONSE) {
+              return;
+            }
+            if (response != null) {
+              sendResponse(response);
+              return;
+            }
+          } on InconsistentAnalysisException {
+            sendResponse(Response.contentModified(request));
+            return;
+          } on RequestFailure catch (exception) {
+            sendResponse(exception.response);
+            return;
+          } catch (exception, stackTrace) {
+            var error = RequestError(
+                RequestErrorCode.SERVER_ERROR, exception.toString());
+            error.stackTrace = stackTrace.toString();
+            var response = Response(request.id, error: error);
+            sendResponse(response);
+            return;
+          }
+        }
+        sendResponse(Response.unknownRequest(request));
       }
-      sendResponse(Response.unknownRequest(request));
     }, (exception, stackTrace) {
       instrumentationService.logException(
         FatalException(

pkg/analysis_server/lib/src/domain_execution.dart

@@ -8,23 +8,20 @@ import 'package:analysis_server/protocol/protocol.dart';
 import 'package:analysis_server/protocol/protocol_generated.dart';
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/handler/legacy/legacy_handler.dart';
-import 'package:analysis_server/src/services/execution/execution_context.dart';
 import 'package:analyzer/src/utilities/cancellation.dart';
 
 /// The handler for the `execution.createContext` request.
 class ExecutionCreateContextHandler extends LegacyHandler {
-  /// The context used by the execution domain handlers.
-  final ExecutionContext executionContext;
-
   /// Initialize a newly created handler to be able to service requests for the
   /// [server].
   ExecutionCreateContextHandler(AnalysisServer server, Request request,
-      CancellationToken cancellationToken, this.executionContext)
+      CancellationToken cancellationToken)
       : super(server, request, cancellationToken);
 
   @override
   Future<void> handle() async {
     var file = ExecutionCreateContextParams.fromRequest(request).contextRoot;
+    var executionContext = server.executionContext;
     var contextId = (executionContext.nextContextId++).toString();
     executionContext.contextMap[contextId] = file;
     sendResult(ExecutionCreateContextResult(contextId));

pkg/analysis_server/lib/src/handler/legacy/execution_create_context.dart

@@ -8,24 +8,20 @@ import 'package:analysis_server/protocol/protocol.dart';
 import 'package:analysis_server/protocol/protocol_generated.dart';
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/handler/legacy/legacy_handler.dart';
-import 'package:analysis_server/src/services/execution/execution_context.dart';
 import 'package:analyzer/src/utilities/cancellation.dart';
 
 /// The handler for the `execution.deleteContext` request.
 class ExecutionDeleteContextHandler extends LegacyHandler {
-  /// The context used by the execution domain handlers.
-  final ExecutionContext executionContext;
-
   /// Initialize a newly created handler to be able to service requests for the
   /// [server].
   ExecutionDeleteContextHandler(AnalysisServer server, Request request,
-      CancellationToken cancellationToken, this.executionContext)
+      CancellationToken cancellationToken)
       : super(server, request, cancellationToken);
 
   @override
   Future<void> handle() async {
     var contextId = ExecutionDeleteContextParams.fromRequest(request).id;
-    executionContext.contextMap.remove(contextId);
+    server.executionContext.contextMap.remove(contextId);
     sendResult(ExecutionDeleteContextResult());
   }
 }

pkg/analysis_server/lib/src/handler/legacy/execution_delete_context.dart

@@ -8,26 +8,22 @@ import 'package:analysis_server/protocol/protocol.dart';
 import 'package:analysis_server/protocol/protocol_generated.dart';
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/handler/legacy/legacy_handler.dart';
-import 'package:analysis_server/src/services/execution/execution_context.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/src/utilities/cancellation.dart';
 
 /// The handler for the `execution.mapUri` request.
 class ExecutionMapUriHandler extends LegacyHandler {
-  /// The context used by the execution domain handlers.
-  final ExecutionContext executionContext;
-
   /// Initialize a newly created handler to be able to service requests for the
   /// [server].
   ExecutionMapUriHandler(AnalysisServer server, Request request,
-      CancellationToken cancellationToken, this.executionContext)
+      CancellationToken cancellationToken)
       : super(server, request, cancellationToken);
 
   @override
   Future<void> handle() async {
     var params = ExecutionMapUriParams.fromRequest(request);
     var contextId = params.id;
-    var path = executionContext.contextMap[contextId];
+    var path = server.executionContext.contextMap[contextId];
     if (path == null) {
       sendResponse(Response.invalidParameter(request, 'id',
           'There is no execution context with an id of $contextId'));

pkg/analysis_server/lib/src/handler/legacy/execution_map_uri.dart

@@ -3,7 +3,6 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'package:analysis_server/protocol/protocol_generated.dart';
-import 'package:analysis_server/src/domain_execution.dart';
 import 'package:analysis_server/src/protocol_server.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
@@ -124,7 +123,6 @@ class ExecutionDomainTest extends AbstractAnalysisTest {
   Future<void> setUp() async {
     super.setUp();
     await createProject();
-    handler = ExecutionDomainHandler(server, server.executionContext);
     await _createExecutionContext(testFile);
   }