remove unused DartCompletionCache

pkg/analysis_server/lib/src/services/completion/dart_completion_cache.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.cache;
-
-import 'dart:async';
-import 'dart:collection';
-
-import 'package:analysis_server/src/protocol_server.dart'
-    hide Element, ElementKind;
-import 'package:analysis_server/src/services/completion/completion_manager.dart';
-import 'package:analysis_server/src/services/completion/dart_completion_manager.dart';
-import 'package:analysis_server/src/services/completion/suggestion_builder.dart';
-import 'package:analysis_server/src/services/search/search_engine.dart';
-import 'package:analyzer/dart/element/element.dart';
-import 'package:analyzer/dart/element/type.dart';
-import 'package:analyzer/src/generated/ast.dart';
-import 'package:analyzer/src/generated/engine.dart';
-import 'package:analyzer/src/generated/resolver.dart';
-import 'package:analyzer/src/generated/source.dart';
-import 'package:analyzer/src/task/dart.dart';
-
-/**
- * The `DartCompletionCache` contains cached information from a prior code
- * completion operation.
- */
-class DartCompletionCache extends CompletionCache {
-  /**
-   * A hash of the import directives
-   * or `null` if nothing has been cached.
-   */
-  String _importKey;
-
-  /**
-   * Type suggestions based upon imports,
-   * or `null` if nothing has been cached.
-   */
-  List<CompletionSuggestion> importedTypeSuggestions;
-
-  /**
-   * Suggestions for methods and functions that have void return type,
-   * or `null` if nothing has been cached.
-   */
-  List<CompletionSuggestion> importedVoidReturnSuggestions;
-
-  /**
-   * Other suggestions based upon imports,
-   * or `null` if nothing has been cached.
-   */
-  List<CompletionSuggestion> otherImportedSuggestions;
-
-  /**
-   * Suggestions for constructors
-   * or `null` if nothing has been cached.
-   */
-  List<CompletionSuggestion> importedConstructorSuggestions;
-
-  /**
-   * A collection of all imported completions
-   * or `null` if nothing has been cached.
-   */
-  HashSet<String> _importedCompletions;
-
-  /**
-   * A map of simple identifier to imported class element
-   * or `null` if nothing has been cached.
-   */
-  Map<String, ClassElement> importedClassMap;
-
-  /**
-   * The [ClassElement] for Object.
-   */
-  ClassElement _objectClassElement;
-
-  DartCompletionCache(AnalysisContext context, Source source)
-      : super(context, source);
-
-  /**
-   * Return a hash of the import directives for the cached import info
-   * or `null` if nothing has been cached.
-   */
-  String get importKey => _importKey;
-
-  /**
-   * Return the [ClassElement] for Object.
-   */
-  ClassElement get objectClassElement {
-    if (_objectClassElement == null) {
-      Source coreUri = context.sourceFactory.forUri('dart:core');
-      LibraryElement coreLib = context.getResult(coreUri, LIBRARY_ELEMENT8);
-      _objectClassElement = coreLib.getType('Object');
-    }
-    return _objectClassElement;
-  }
-
-  /**
-   * Given a resolved compilation unit, compute suggestions based upon the
-   * imports and other dart files (e.g. "part" files) in the library containing
-   * the given compilation unit. The returned future completes when the cache
-   * is populated.
-   *
-   * If [shouldWaitForLowPrioritySuggestions] is `true` then the returned
-   * future will complete when the cache is fully populated. If `false`,
-   * the returned future will complete sooner, but the cache will not include
-   * the lower priority suggestions added as a result of a global search.
-   * In this case, those lower priority suggestions will be added later
-   * when the index has been updated and the global search completes.
-   */
-  Future<bool> computeImportInfo(CompilationUnit unit,
-      SearchEngine searchEngine, bool shouldWaitForLowPrioritySuggestions) {
-    importedTypeSuggestions = <CompletionSuggestion>[];
-    otherImportedSuggestions = <CompletionSuggestion>[];
-    importedConstructorSuggestions = <CompletionSuggestion>[];
-    importedVoidReturnSuggestions = <CompletionSuggestion>[];
-    importedClassMap = new Map<String, ClassElement>();
-    _importedCompletions = new HashSet<String>();
-
-    // Assert that the compilation unit is resolved
-    // and represents the expected source
-    assert(unit.element.source == source);
-
-    // Exclude elements from local library
-    // because they are provided by LocalReferenceContributor
-    Set<LibraryElement> excludedLibs = new Set<LibraryElement>();
-    excludedLibs.add(unit.element.enclosingElement);
-
-    // Determine the compilation unit defining the library containing
-    // this compilation unit
-    List<Source> libraries = context.getLibrariesContaining(source);
-    assert(libraries != null);
-    Source libSource = libraries.length > 0 ? libraries[0] : null;
-    Future<CompilationUnit> futureLibUnit = _computeLibUnit(libSource, unit);
-
-    // Include implicitly imported dart:core elements
-    _addDartCoreSuggestions();
-
-    // Include explicitly imported and part elements
-    Future futureImportsCached = futureLibUnit.then((CompilationUnit libUnit) {
-      _addImportedElemSuggestions(libSource, libUnit, excludedLibs);
-      // Don't wait for search of lower relevance results to complete.
-      // Set key indicating results are ready, and lower relevance results
-      // will be added to the cache when the search completes.
-      _importKey = _computeImportKey(unit);
-      return true;
-    });
-
-    // Add non-imported elements as low relevance
-    // after the imported element suggestions have been added
-    Future<bool> futureAllCached = futureImportsCached.then((_) {
-      return searchEngine
-          .searchTopLevelDeclarations('')
-          .then((List<SearchMatch> matches) {
-        _addNonImportedElementSuggestions(matches, excludedLibs);
-        return true;
-      });
-    });
-
-    return shouldWaitForLowPrioritySuggestions
-        ? futureAllCached
-        : futureImportsCached;
-  }
-
-  /**
-   * Return `true` if the import information is cached for the given
-   * compilation unit.
-   */
-  bool isImportInfoCached(CompilationUnit unit) =>
-      _importKey != null && _importKey == _computeImportKey(unit);
-
-  /**
-   * Add constructor suggestions for the given class.
-   */
-  void _addConstructorSuggestions(
-      ClassElement classElem, int relevance, Source importForSource) {
-    String className = classElem.name;
-    for (ConstructorElement constructor in classElem.constructors) {
-      if (!constructor.isPrivate) {
-        CompletionSuggestion suggestion = createSuggestion(constructor,
-            relevance: relevance, importForSource: importForSource);
-        if (suggestion != null) {
-          String name = suggestion.completion;
-          name = name.length > 0 ? '$className.$name' : className;
-          suggestion.completion = name;
-          suggestion.selectionOffset = suggestion.completion.length;
-          importedConstructorSuggestions.add(suggestion);
-        }
-      }
-    }
-  }
-
-  /**
-   * Add suggestions for implicitly imported elements in dart:core.
-   */
-  void _addDartCoreSuggestions() {
-    Source coreUri = context.sourceFactory.forUri('dart:core');
-    LibraryElement coreLib = context.getResult(coreUri, LIBRARY_ELEMENT8);
-    if (coreLib == null) {
-      // If the core library has not been analyzed yet, then we cannot add any
-      // suggestions from it.
-      return;
-    }
-    Namespace coreNamespace =
-        new NamespaceBuilder().createPublicNamespaceForLibrary(coreLib);
-    coreNamespace.definedNames.forEach((String name, Element elem) {
-      if (elem is ClassElement) {
-        importedClassMap[name] = elem;
-      }
-      _addSuggestion(elem, DART_RELEVANCE_DEFAULT);
-    });
-  }
-
-  /**
-   * Add suggestions for explicitly imported and part elements in the given
-   * library. Add libraries that should not have their elements suggested
-   * even as low priority to [excludedLibs].
-   */
-  void _addImportedElemSuggestions(Source libSource, CompilationUnit libUnit,
-      Set<LibraryElement> excludedLibs) {
-    if (libUnit != null) {
-      libUnit.directives.forEach((Directive directive) {
-        if (directive is ImportDirective) {
-          ImportElement importElem = directive.element;
-          if (importElem != null && importElem.importedLibrary != null) {
-            if (directive.prefix == null) {
-              Namespace importNamespace = new NamespaceBuilder()
-                  .createImportNamespaceForDirective(importElem);
-              // Include top level elements
-              importNamespace.definedNames.forEach((String name, Element elem) {
-                if (elem is ClassElement) {
-                  importedClassMap[name] = elem;
-                }
-                _addSuggestion(elem, DART_RELEVANCE_DEFAULT);
-              });
-            } else {
-              // Exclude elements from prefixed imports
-              // because they are provided by PrefixedElementContributor
-              // Suggested by LibraryPrefixContributor
-              // _addLibraryPrefixSuggestion(importElem);
-              // excludedLibs.add(importElem.importedLibrary);
-            }
-          }
-        } else if (directive is PartDirective) {
-          // Suggested by LocalLibraryContributor
-          // CompilationUnitElement partElem = directive.element;
-          // if (partElem != null && partElem.source != source) {
-          //   partElem.accept(new _NonLocalElementCacheVisitor(this));
-          // }
-        }
-      });
-      if (libSource != source) {
-        // Suggested by LocalLibraryContributor
-        // libUnit.element.accept(new _NonLocalElementCacheVisitor(this));
-      }
-    }
-  }
-
-  /**
-   * Add suggestions for all top level elements in the context
-   * excluding those elemnents for which suggestions have already been added.
-   */
-  void _addNonImportedElementSuggestions(
-      List<SearchMatch> matches, Set<LibraryElement> excludedLibs) {
-    // Exclude internal Dart SDK libraries
-    for (var lib in context.sourceFactory.dartSdk.sdkLibraries) {
-      if (lib.isInternal) {
-        Source libUri = context.sourceFactory.forUri(lib.shortName);
-        if (libUri != null) {
-          LibraryElement libElem = context.getResult(libUri, LIBRARY_ELEMENT8);
-          if (libElem != null) {
-            excludedLibs.add(libElem);
-          }
-        }
-      }
-    }
-
-    AnalysisContext sdkContext = context.sourceFactory.dartSdk.context;
-    matches.forEach((SearchMatch match) {
-      if (match.kind == MatchKind.DECLARATION) {
-        Element element = match.element;
-        if ((element.context == context || element.context == sdkContext) &&
-            element.isPublic &&
-            !excludedLibs.contains(element.library) &&
-            !_importedCompletions.contains(element.displayName)) {
-          _addSuggestion(element, DART_RELEVANCE_LOW, importForSource: source);
-        }
-      }
-    });
-  }
-
-  /**
-   * Add a suggestion for the given element.
-   */
-  void _addSuggestion(Element element, int relevance,
-      {Source importForSource}) {
-    if (element is ExecutableElement) {
-      // Do not suggest operators or local functions
-      if (element.isOperator) {
-        return;
-      }
-      if (element is FunctionElement) {
-        if (element.enclosingElement is! CompilationUnitElement) {
-          return;
-        }
-      }
-    }
-
-    CompletionSuggestion suggestion = createSuggestion(element,
-        relevance: relevance, importForSource: importForSource);
-
-    if (suggestion != null) {
-      if (element is ExecutableElement) {
-        DartType returnType = element.returnType;
-        if (returnType != null && returnType.isVoid) {
-          importedVoidReturnSuggestions.add(suggestion);
-        } else {
-          otherImportedSuggestions.add(suggestion);
-        }
-      } else if (element is FunctionTypeAliasElement) {
-        importedTypeSuggestions.add(suggestion);
-      } else if (element is ClassElement) {
-        importedTypeSuggestions.add(suggestion);
-        _addConstructorSuggestions(element, relevance, importForSource);
-      } else {
-        otherImportedSuggestions.add(suggestion);
-      }
-      _importedCompletions.add(suggestion.completion);
-    }
-  }
-
-  /**
-   * Compute the hash of the imports for the given compilation unit.
-   */
-  String _computeImportKey(CompilationUnit unit) {
-    StringBuffer sb = new StringBuffer();
-    unit.directives.forEach((Directive directive) {
-      sb.write(directive.toSource());
-    });
-    return sb.toString();
-  }
-
-  /**
-   * Compute the library unit for the given library source,
-   * where the [unit] is the resolved compilation unit associated with [source].
-   */
-  Future<CompilationUnit> _computeLibUnit(
-      Source libSource, CompilationUnit unit) {
-    // If the sources are the same then we already have the library unit
-    if (libSource == source) {
-      return new Future.value(unit);
-    }
-    // If [source] is a part, then compute the library unit
-    if (libSource != null) {
-      return context.computeResolvedCompilationUnitAsync(libSource, libSource);
-    }
-    return new Future.value(null);
-  }
-}