Rework contribution sorter to use futures

pkg/analysis_server/lib/src/services/completion/dart_completion_manager.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 services.completion.dart;
 
 import 'dart:async';
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/provisional/completion/completion_core.dart'
     show AnalysisRequest, CompletionRequest;
 import 'package:analysis_server/src/provisional/completion/dart/completion_target.dart';
 import 'package:analysis_server/src/services/completion/arglist_contributor.dart';
 import 'package:analysis_server/src/services/completion/combinator_contributor.dart';
-import 'package:analysis_server/src/services/completion/common_usage_computer.dart';
 import 'package:analysis_server/src/services/completion/completion_manager.dart';
-import 'package:analysis_server/src/services/completion/contribution_sorter.dart';
+import 'package:analysis_server/src/services/completion/dart/common_usage_sorter.dart';
+import 'package:analysis_server/src/services/completion/dart/contribution_sorter.dart';
 import 'package:analysis_server/src/services/completion/dart_completion_cache.dart';
 import 'package:analysis_server/src/services/completion/imported_reference_contributor.dart';
 import 'package:analysis_server/src/services/completion/keyword_contributor.dart';
 import 'package:analysis_server/src/services/completion/local_reference_contributor.dart';
 import 'package:analysis_server/src/services/completion/optype.dart';
 import 'package:analysis_server/src/services/completion/prefixed_element_contributor.dart';
 import 'package:analysis_server/src/services/completion/uri_contributor.dart';
 import 'package:analysis_server/src/services/search/search_engine.dart';
-import 'package:analyzer/src/context/context.dart'
-    show AnalysisFutureHelper, AnalysisContextImpl;
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/engine.dart' hide AnalysisContextImpl;
 import 'package:analyzer/src/generated/scanner.dart';
 import 'package:analyzer/src/generated/source.dart';
 
 const int DART_RELEVANCE_COMMON_USAGE = 1200;
 const int DART_RELEVANCE_DEFAULT = 1000;
 const int DART_RELEVANCE_HIGH = 2000;
 const int DART_RELEVANCE_INHERITED_ACCESSOR = 1057;
 const int DART_RELEVANCE_INHERITED_FIELD = 1058;
@@ skipping 33 matching lines @@
 }
 
 /**
  * Manages code completion for a given Dart file completion request.
  */
 class DartCompletionManager extends CompletionManager {
   /**
    * The [defaultContributionSorter] is a long-lived object that isn't allowed
    * to maintain state between calls to [ContributionSorter#sort(...)].
    */
-  static ContributionSorter defaultContributionSorter =
-      new CommonUsageComputer();
+  static DartContributionSorter defaultContributionSorter =
+      new CommonUsageSorter();
 
   final SearchEngine searchEngine;
   final DartCompletionCache cache;
   List<DartCompletionContributor> contributors;
-  ContributionSorter contributionSorter;
+  DartContributionSorter contributionSorter;
 
   DartCompletionManager(
       AnalysisContext context, this.searchEngine, Source source, this.cache,
       [this.contributors, this.contributionSorter])
       : super(context, source) {
     if (contributors == null) {
       contributors = [
         // LocalReferenceContributor before ImportedReferenceContributor
         // because local suggestions take precedence
         // and can hide other suggestions with the same name
@@ skipping 74 matching lines @@
           }
         }
       }
 
       List<DartCompletionContributor> todo = new List.from(contributors);
       todo.removeWhere((DartCompletionContributor c) {
         return performance.logElapseTime('computeFast ${c.runtimeType}', () {
           return c.computeFast(request);
         });
       });
-      _processAnalysisRequest(request,
-          contributionSorter.sort(request, request.suggestions));
+      // TODO(danrubel) current sorter requires no additional analysis,
+      // but need to handle the returned future the same way that futures
+      // returned from contributors are handled once this method is refactored
+      // to be async.
+      /* await */ contributionSorter.sort(request, request.suggestions);
       // TODO (danrubel) if request is obsolete
       // (processAnalysisRequest returns false)
       // then send empty results
       if (todo.isEmpty) {
         sendResults(request, todo.isEmpty);
       }
       return todo;
     });
   }
 
@@ skipping 22 matching lines @@
         int count = todo.length;
         todo.forEach((DartCompletionContributor c) {
           String name = c.runtimeType.toString();
           String completeTag = 'computeFull $name complete';
           performance.logStartTime(completeTag);
           performance.logElapseTime('computeFull $name', () {
             c.computeFull(request).then((bool changed) {
               performance.logElapseTime(completeTag);
               bool last = --count == 0;
               if (changed || last) {
-                _processAnalysisRequest(request,
-                    contributionSorter.sort(request, request.suggestions));
+                // TODO(danrubel) current sorter requires no additional analysis,
+                // but need to handle the returned future the same way that futures
+                // returned from contributors are handled once this method is refactored
+                // to be async.
+                /* await */ contributionSorter.sort(request, request.suggestions);
                 // TODO (danrubel) if request is obsolete
                 // (processAnalysisRequest returns false)
                 // then send empty results
                 sendResults(request, last);
               }
             });
           });
         });
       });
     });
@@ skipping 40 matching lines @@
     Source libSource = libraries[0];
     assert(libSource != null);
     return context
         .computeResolvedCompilationUnitAsync(source, libSource)
         .catchError((_) {
       // This source file is not scheduled for analysis, so a resolved
       // compilation unit is never going to get computed.
       return null;
     }, test: (e) => e is AnalysisNotScheduledError);
   }
-
-  /**
-   * Process the analysis [analysis] and any subsequent requests.
-   * Return a [Future] that returns `true`
-   * once all analysis requests have been processed
-   * or `false` if the original completion request is obsolete
-   * and processing requests was terminated before finished.
-   */
-  Future<bool> _processAnalysisRequest(
-      CompletionRequest request, AnalysisRequest analysis) {
-    // Return if no additional analysis is necessary
-    if (analysis == null) {
-      return new Future.value(true);
-    }
-
-    // Check to see if the result is already cached
-    var cachedValue = context.getResult(analysis.target, analysis.descriptor);
-    if (cachedValue != null) {
-      return _processAnalysisRequest(
-          request, analysis.callback(request, cachedValue));
-    }
-
-    // TODO (danrubel) determine when completion request is obsolete
-    // and analysis should be terminated before requesting additional analysis
-
-    // Request additional analysis
-    return new AnalysisFutureHelper((context as AnalysisContextImpl),
-        analysis.target, analysis.descriptor).computeAsync().then((value) {
-      return _processAnalysisRequest(
-          request, analysis.callback(request, cachedValue));
-    });
-  }
 }
 
 /**
  * The context in which the completion is requested.
  */
 class DartCompletionRequest extends CompletionRequestImpl {
   /**
    * Cached information from a prior code completion operation.
    */
   final DartCompletionCache cache;
@@ skipping 116 matching lines @@
             parameterNames: suggestion.parameterNames,
             parameterTypes: suggestion.parameterTypes,
             requiredParameterCount: suggestion.requiredParameterCount,
             hasNamedParameters: suggestion.hasNamedParameters,
             returnType: suggestion.returnType,
             element: suggestion.element);
       }
     }
   }
 }