Initial memory use status page

pkg/analysis_server/lib/src/status/memory_use.dart

+// Copyright (c) 2016, 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 analysis_server.src.status.memory_use;
+
+import 'dart:collection';
+
+import 'package:analysis_server/src/analysis_server.dart';
+import 'package:analyzer/dart/ast/ast.dart';
+import 'package:analyzer/dart/ast/visitor.dart';
+import 'package:analyzer/dart/element/element.dart';
+import 'package:analyzer/dart/element/visitor.dart';
+import 'package:analyzer/src/context/cache.dart';
+import 'package:analyzer/src/context/context.dart' show AnalysisContextImpl;
+import 'package:analyzer/src/dart/element/element.dart';
+import 'package:analyzer/src/generated/engine.dart';
+import 'package:analyzer/src/generated/sdk.dart';
+import 'package:analyzer/task/dart.dart';
+import 'package:analyzer/task/model.dart';
+
+/**
+ * A visitor that will count the number of instances of each type of AST node.
+ */
+class AstNodeCounter extends UnifyingAstVisitor<Null> {
+  /**
+   * A table mapping the types of the AST nodes to the number of instances
+   * visited.
+   */
+  final Map<Type, int> nodeCounts;
+
+  /**
+   * Initialize a newly created counter to increment the counts in the given map
+   * of [nodeCounts].
+   */
+  AstNodeCounter(this.nodeCounts);
+
+  @override
+  visitNode(AstNode node) {
+    Type type = node.runtimeType;
+    int count = nodeCounts[type] ?? 0;
+    nodeCounts[type] = count + 1;
+    super.visitNode(node);
+  }
+}
+
+/**
+ * A visitor that will count the number of instances of each type of element.
+ */
+class ElementCounter extends GeneralizingElementVisitor<Null> {
+  /**
+   * A table mapping the types of the elements to the number of instances
+   * visited.
+   */
+  final Map<Type, int> elementCounts;
+
+  /**
+   * A table mapping the types of the AST nodes to the number of instances
+   * visited.
+   */
+  final Map<Type, int> nodeCounts;
+
+  /**
+   * Initialize a newly created counter to increment the counts in the given map
+   * of [elementCounts].
+   */
+  ElementCounter(this.elementCounts, this.nodeCounts);
+
+  @override
+  visitConstructorElement(ConstructorElement element) {
+    if (element is ConstructorElementImpl) {
+      List<ConstructorInitializer> initializers = element.constantInitializers;
+      if (initializers != null) {
+        initializers.forEach((ConstructorInitializer initializer) {
+          _countNodes(initializer);
+        });
+      }
+    }
+    visitElement(element);
+  }
+
+  @override
+  visitElement(Element element) {
+    Type type = element.runtimeType;
+    int count = elementCounts[type] ?? 0;
+    elementCounts[type] = count + 1;
+    element.metadata.forEach((ElementAnnotation annotation) {
+      if (annotation is ElementAnnotationImpl) {
+        _countNodes(annotation.annotationAst);
+      }
+    });
+    super.visitElement(element);
+  }
+
+  visitFieldElement(FieldElement element) {
+    if (element is ConstVariableElement) {
+      _countInitializer(element as ConstVariableElement);
+    }
+    visitElement(element);
+  }
+
+  visitLocalVariableElement(LocalVariableElement element) {
+    if (element is ConstVariableElement) {
+      _countInitializer(element as ConstVariableElement);
+    }
+    visitElement(element);
+  }
+
+  visitParameterElement(ParameterElement element) {
+    if (element is ConstVariableElement) {
+      _countInitializer(element as ConstVariableElement);
+    }
+    visitElement(element);
+  }
+
+  visitTopLevelVariableElement(TopLevelVariableElement element) {
+    if (element is ConstVariableElement) {
+      _countInitializer(element as ConstVariableElement);
+    }
+    visitElement(element);
+  }
+
+  void _countInitializer(ConstVariableElement element) {
+    _countNodes(element.constantInitializer);
+  }
+
+  void _countNodes(AstNode node) {
+    if (node != null) {
+      node.accept(new AstNodeCounter(nodeCounts));
+    }
+  }
+}
+
+/**
+ * A set used when the number of instances of some type is too large to be kept.
+ */
+class InfiniteSet implements Set {
+  /**
+   * The unique instance of this class.
+   */
+  static final InfiniteSet instance = new InfiniteSet();
+
+  @override
+  int get length => -1;
+
+  @override
+  dynamic noSuchMethod(Invocation invocation) {
+    throw new UnsupportedError('Do not use instances of InfiniteSet');
+  }
+}
+
+/**
+ * Computes memory usage data by traversing the data structures reachable from
+ * an analysis server.
+ */
+class MemoryUseData {
+  /**
+   * The maximum size of an instance set.
+   */
+  static const int maxInstanceSetSize = 1000000;
+
+  /**
+   * A table mapping classes to instances of the class.
+   */
+  Map<Type, Set> instances = new HashMap<Type, Set>();
+
+  /**
+   * A set of all the library specific units, using equality rather than
+   * identity in order to determine whether re-using equal instances would save
+   * significant space.
+   */
+  Set<LibrarySpecificUnit> uniqueLSUs = new HashSet<LibrarySpecificUnit>();
+
+  /**
+   * A set of all the targeted results, using equality rather than identity in
+   * order to determine whether re-using equal instances would save significant
+   * space.
+   */
+  Set<TargetedResult> uniqueTargetedResults = new HashSet<TargetedResult>();
+
+  /**
+   * A table mapping the types of AST nodes to the number of instances being
+   * held directly (as values in the cache).
+   */
+  Map<Type, int> directNodeCounts = new HashMap<Type, int>();
+
+  /**
+   * A table mapping the types of AST nodes to the number of instances being
+   * held indirectly (such as nodes reachable from element models).
+   */
+  Map<Type, int> indirectNodeCounts = new HashMap<Type, int>();
+
+  /**
+   * A table mapping the types of the elements to the number of instances being
+   * held directly (as values in the cache).
+   */
+  final Map<Type, int> elementCounts = new HashMap<Type, int>();
+
+  /**
+   * Initialize a newly created instance.
+   */
+  MemoryUseData();
+
+  /**
+   * Traverse an analysis [server] to compute memory usage data.
+   */
+  void processAnalysisServer(AnalysisServer server) {
+    _recordInstance(server);
+    Iterable<AnalysisContext> contexts = server.analysisContexts;
+    for (AnalysisContextImpl context in contexts) {
+      _processAnalysisContext(context);
+    }
+    DartSdkManager manager = server.sdkManager;
+    List<SdkDescription> descriptors = manager.sdkDescriptors;
+    for (SdkDescription descriptor in descriptors) {
+      _processAnalysisContext(manager.getSdk(descriptor, () => null).context);
+    }
+  }
+
+  void _processAnalysisContext(AnalysisContextImpl context) {
+    _recordInstance(context);
+    _recordInstance(context.analysisCache);
+    Map<AnalysisTarget, CacheEntry> map =
+        context.privateAnalysisCachePartition.entryMap;
+    map.forEach((AnalysisTarget target, CacheEntry entry) {
+      _processAnalysisTarget(target);
+      _processCacheEntry(entry);
+    });
+  }
+
+  void _processAnalysisTarget(AnalysisTarget target) {
+    _recordInstance(target);
+  }
+
+  void _processCacheEntry(CacheEntry entry) {
+    _recordInstance(entry);
+    List<ResultDescriptor> descriptors = entry.nonInvalidResults;
+    for (ResultDescriptor descriptor in descriptors) {
+      _recordInstance(descriptor);
+      _processResultData(entry.getResultDataOrNull(descriptor));
+    }
+  }
+
+  void _processResultData(ResultData resultData) {
+    _recordInstance(resultData);
+    if (resultData != null) {

[scheglov, 2016/07/11 15:27:49]

_recordInstance throws if resultData is null.

[Brian Wilkerson, 2016/07/11 17:26:36]

I don't think that's true. It will invoke runtimeType, but that will succeed and
return `Null`.

+      _recordInstance(resultData.state);
+      _recordInstance(resultData.value, onFirstOccurrence: (Object object) {
+        if (object is AstNode) {
+          object.accept(new AstNodeCounter(directNodeCounts));
+        } else if (object is Element) {
+          object.accept(new ElementCounter(elementCounts, indirectNodeCounts));
+        }
+      });
+      resultData.dependedOnResults.forEach(_processTargetedResult);
+      resultData.dependentResults.forEach(_processTargetedResult);
+    }
+  }
+
+  void _processTargetedResult(TargetedResult result) {
+    _recordInstance(result);
+    uniqueTargetedResults.add(result);
+    _recordInstance(result.target);
+    _recordInstance(result.result);
+  }
+
+  /**
+   * Record the given [instance] that was found. If this is the first time that
+   * the instance has been found, execute the [onFirstOccurrence] function.
+   *
+   * Note that instances will not be recorded if there are more than
+   * [maxInstanceSetSize] instances of the same type, and that the
+   * [onFirstOccurrence] function will not be executed if the instance is not
+   * recorded.
+   */
+  void _recordInstance(Object instance,
+      {void onFirstOccurrence(Object object)}) {
+    Type type = instance.runtimeType;
+    Set instanceSet =
+        instances.putIfAbsent(type, () => new HashSet(equals: identical));

[scheglov, 2016/07/11 15:27:49]

Or just new HashSet.identity()

[Brian Wilkerson, 2016/07/11 17:26:36]

Done.

+    if (instanceSet != InfiniteSet.instance) {
+      if (instanceSet.add(instance) && onFirstOccurrence != null) {
+        onFirstOccurrence(instance);
+      }
+      if (instanceSet.length >= maxInstanceSetSize) {
+        instances[type] = InfiniteSet.instance;
+      }
+    }
+    if (instance is LibrarySpecificUnit) {
+      uniqueLSUs.add(instance);
+    }
+  }
+}