Port SplitIndexStore to Dart.

pkg/analysis_server/test/index/split_store_test.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 test.index.split.store;
+
+import 'dart:async';
+import 'dart:collection';
+
+import 'package:analysis_server/src/index/split_store.dart';
+import 'package:analyzer/src/generated/element.dart';
+import 'package:analyzer/src/generated/engine.dart';
+import 'package:analyzer/src/generated/index.dart';
+import 'package:analyzer/src/generated/source.dart';
+import 'package:typed_mock/typed_mock.dart';
+import 'package:unittest/unittest.dart';
+
+import '../reflective_tests.dart';
+
+
+main() {
+  groupSep = ' | ';
+  group('ContextCodec', () {
+    runReflectiveTests(_ContextCodecTest);
+  });
+  group('ElementCodec', () {
+    runReflectiveTests(_ElementCodecTest);
+  });
+  group('FileNodeManager', () {
+    runReflectiveTests(_FileNodeManagerTest);
+  });
+  group('IndexNode', () {
+    runReflectiveTests(_IndexNodeTest);
+  });
+  group('IntToIntSetMap', () {
+    runReflectiveTests(_IntToIntSetMapTest);
+  });
+  group('LocationData', () {
+    runReflectiveTests(_LocationDataTest);
+  });
+  group('RelationKeyData', () {
+    runReflectiveTests(_RelationKeyDataTest);
+  });
+  group('RelationshipCodec', () {
+    runReflectiveTests(_RelationshipCodecTest);
+  });
+  group('SplitIndexStore', () {
+    runReflectiveTests(_SplitIndexStoreTest);
+  });
+  group('StringCodec', () {
+    runReflectiveTests(_StringCodecTest);
+  });
+}
+
+
+void _assertHasLocation(List<Location> locations, Element element, int offset,
+    int length) {
+  for (Location location in locations) {
+    if ((element == null || location.element == element) && location.offset ==
+        offset && location.length == length) {
+      return;
+    }
+  }
+  fail('Expected to find Location'
+      '(element=$element, offset=$offset, length=$length)');
+}
+
+
+@ReflectiveTestCase()
+class _ContextCodecTest {
+  ContextCodec codec = new ContextCodec();
+
+  void test_all() {
+    AnalysisContext contextA = new _MockAnalysisContext('contextA');
+    AnalysisContext contextB = new _MockAnalysisContext('contextB');
+    int idA = codec.encode(contextA);
+    int idB = codec.encode(contextB);
+    expect(codec.decode(idA), contextA);
+    expect(codec.decode(idB), contextB);
+  }
+}
+
+
+@ReflectiveTestCase()
+class _ElementCodecTest {
+  ElementCodec codec;
+  AnalysisContext context = new _MockAnalysisContext('context');
+  StringCodec stringCodec = new StringCodec();
+
+  void setUp() {
+    codec = new ElementCodec(stringCodec);
+  }
+
+  void test_localLocalVariable() {
+    {
+      Element element = new _MockElement();
+      ElementLocation location = new ElementLocationImpl.con3(["main", "foo@1",
+          "bar@2"]);
+      when(context.getElement(location)).thenReturn(element);
+      when(element.location).thenReturn(location);
+      int id = codec.encode(element);
+      expect(codec.decode(context, id), element);
+    }
+    {
+      Element element = new _MockElement();
+      ElementLocation location = new ElementLocationImpl.con3(["main", "foo@10",
+          "bar@20"]);
+      when(context.getElement(location)).thenReturn(element);
+      when(element.location).thenReturn(location);
+      int id = codec.encode(element);
+      expect(codec.decode(context, id), element);
+    }
+    // check strings, "foo" as a single string, no "foo@1" or "foo@10"
+    expect(stringCodec.nameToIndex, hasLength(3));
+    expect(stringCodec.nameToIndex, containsPair('main', 0));
+    expect(stringCodec.nameToIndex, containsPair('foo', 1));
+    expect(stringCodec.nameToIndex, containsPair('bar', 2));
+  }
+
+  void test_localVariable() {
+    {
+      Element element = new _MockElement();
+      ElementLocation location = new ElementLocationImpl.con3(["main",
+          "foo@42"]);
+      when(context.getElement(location)).thenReturn(element);
+      when(element.location).thenReturn(location);
+      int id = codec.encode(element);
+      expect(codec.decode(context, id), element);
+    }
+    {
+      Element element = new _MockElement();
+      ElementLocation location = new ElementLocationImpl.con3(["main",
+          "foo@4200"]);
+      when(context.getElement(location)).thenReturn(element);
+      when(element.location).thenReturn(location);
+      int id = codec.encode(element);
+      expect(codec.decode(context, id), element);
+    }
+    // check strings, "foo" as a single string, no "foo@42" or "foo@4200"
+    expect(stringCodec.nameToIndex, hasLength(2));
+    expect(stringCodec.nameToIndex, containsPair('main', 0));
+    expect(stringCodec.nameToIndex, containsPair('foo', 1));
+  }
+
+  void test_notLocal() {
+    Element element = new _MockElement();
+    ElementLocation location = new ElementLocationImpl.con3(["foo", "bar"]);
+    when(element.location).thenReturn(location);
+    when(context.getElement(location)).thenReturn(element);
+    int id = codec.encode(element);
+    expect(codec.encode(element), id);
+    expect(codec.decode(context, id), element);
+    // check strings
+    expect(stringCodec.nameToIndex, hasLength(2));
+    expect(stringCodec.nameToIndex, containsPair('foo', 0));
+    expect(stringCodec.nameToIndex, containsPair('bar', 1));
+  }
+}
+
+
+@ReflectiveTestCase()
+class _FileNodeManagerTest {
+  AnalysisContext context = new _MockAnalysisContext('context');
+  ContextCodec contextCodec = new _MockContextCodec();
+  int contextId = 13;
+  ElementCodec elementCodec = new _MockElementCodec();
+  FileManager fileManager = new _MockFileManager();
+  _MockLogger logger = new _MockLogger();
+  int nextElementId = 0;
+  FileNodeManager nodeManager;
+  RelationshipCodec relationshipCodec;
+  StringCodec stringCodec = new StringCodec();
+
+  void setUp() {
+    relationshipCodec = new RelationshipCodec(stringCodec);
+    nodeManager = new FileNodeManager(fileManager, logger, stringCodec,
+        contextCodec, elementCodec, relationshipCodec);
+    when(contextCodec.encode(context)).thenReturn(contextId);
+    when(contextCodec.decode(contextId)).thenReturn(context);
+  }
+
+  void test_clear() {
+    nodeManager.clear();
+    verify(fileManager.clear()).once();
+  }
+
+  void test_getLocationCount_empty() {
+    expect(nodeManager.locationCount, 0);
+  }
+
+  void test_getNode_contextNull() {
+    String name = "42.index";
+    // record bytes
+    List<int> bytes;
+    when(fileManager.write(name, anyObject)).thenInvoke((name, bs) {
+      bytes = bs;
+    });
+    // put Node
+    Future putFuture;
+    {
+      IndexNode node = new IndexNode(context, elementCodec, relationshipCodec);
+      putFuture = nodeManager.putNode(name, node);
+    }
+    // do in the "put" Future
+    putFuture.then((_) {
+      // force "null" context
+      when(contextCodec.decode(contextId)).thenReturn(null);
+      // prepare input bytes
+      when(fileManager.read(name)).thenReturn(new Future.value(bytes));
+      // get Node
+      return nodeManager.getNode(name).then((IndexNode node) {
+        expect(node, isNull);
+        // no exceptions
+        verifyZeroInteractions(logger);
+      });
+    });
+  }
+
+  test_getNode_invalidVersion() {
+    String name = "42.index";
+    // prepare a stream with an invalid version
+    when(fileManager.read(name)).thenReturn(new Future.value([0x01, 0x02, 0x03,
+        0x04]));
+    // do in Future
+    return nodeManager.getNode(name).then((IndexNode node) {
+      // no IndexNode
+      expect(node, isNull);
+      // failed
+      verify(logger.logError2(anyObject, anyObject)).once();
+    });
+  }
+
+  test_getNode_streamException() {
+    String name = "42.index";
+    Exception exception = new Exception();
+    when(fileManager.read(name)).thenReturn(new Future(() {
+      return throw exception;
+    }));
+    // do in Future
+    return nodeManager.getNode(name).then((IndexNode node) {
+      expect(node, isNull);
+      // failed
+      verify(logger.logError2(anyString, exception)).once();
+    });
+  }
+
+  test_getNode_streamNull() {
+    String name = "42.index";
+    when(fileManager.read(name)).thenReturn(new Future.value(null));
+    // do in Future
+    return nodeManager.getNode(name).then((IndexNode node) {
+      expect(node, isNull);
+      // OK
+      verifyZeroInteractions(logger);
+    });
+  }
+
+  void test_newNode() {
+    IndexNode node = nodeManager.newNode(context);
+    expect(node.context, context);
+    expect(node.locationCount, 0);
+  }
+
+  test_putNode_getNode() {
+    String name = "42.index";
+    // record bytes
+    List<int> bytes;
+    when(fileManager.write(name, anyObject)).thenInvoke((name, bs) {
+      bytes = bs;
+    });
+    // prepare elements
+    Element elementA = _mockElement();
+    Element elementB = _mockElement();
+    Element elementC = _mockElement();
+    Relationship relationship = Relationship.getRelationship("my-relationship");
+    // put Node
+    Future putFuture;
+    {
+      // prepare relations
+      int elementIdA = 0;
+      int elementIdB = 1;
+      int elementIdC = 2;
+      int relationshipId = relationshipCodec.encode(relationship);
+      RelationKeyData key = new RelationKeyData.forData(elementIdA,
+          relationshipId);
+      List<LocationData> locations = [new LocationData.forData(elementIdB, 1,
+          10), new LocationData.forData(elementIdC, 2, 20)];
+      Map<RelationKeyData, List<LocationData>> relations = {
+        key: locations
+      };
+      // prepare Node
+      IndexNode node = new _MockIndexNode();
+      when(node.context).thenReturn(context);
+      when(node.relations).thenReturn(relations);
+      when(node.locationCount).thenReturn(2);
+      // put Node
+      putFuture = nodeManager.putNode(name, node);
+    }
+    // do in the Future
+    putFuture.then((_) {
+      // has locations
+      expect(nodeManager.locationCount, 2);
+      // prepare input bytes
+      when(fileManager.read(name)).thenReturn(new Future.value(bytes));
+      // get Node
+      return nodeManager.getNode(name).then((IndexNode node) {
+        expect(2, node.locationCount);
+        {
+          List<Location> locations = node.getRelationships(elementA,
+              relationship);
+          expect(locations, hasLength(2));
+          _assertHasLocation(locations, elementB, 1, 10);
+          _assertHasLocation(locations, elementC, 2, 20);
+        }
+      });
+    });
+  }
+
+  test_putNode_streamException() {
+    String name = "42.index";
+    Exception exception = new Exception();
+    when(fileManager.write(name, anyObject)).thenReturn(new Future(() {
+      return throw exception;
+    }));
+    // prepare IndexNode
+    IndexNode node = new _MockIndexNode();
+    when(node.context).thenReturn(context);
+    when(node.locationCount).thenReturn(0);
+    when(node.relations).thenReturn({});
+    // try to put
+    return nodeManager.putNode(name, node).then((_) {
+      // failed
+      verify(logger.logError2(anyString, anyObject)).once();
+    });
+  }
+
+  void test_removeNode() {
+    String name = "42.index";
+    nodeManager.removeNode(name);
+    verify(fileManager.delete(name)).once();
+  }
+
+  Element _mockElement() {
+    int elementId = nextElementId++;
+    Element element = new _MockElement();
+    when(elementCodec.encode(element)).thenReturn(elementId);
+    when(elementCodec.decode(context, elementId)).thenReturn(element);
+    return element;
+  }
+}
+
+
+@ReflectiveTestCase()
+class _IndexNodeTest {
+  AnalysisContext context = new _MockAnalysisContext('context');
+  ElementCodec elementCodec = new _MockElementCodec();
+  int nextElementId = 0;
+  IndexNode node;
+  RelationshipCodec relationshipCodec;
+  StringCodec stringCodec = new StringCodec();
+
+  void setUp() {
+    relationshipCodec = new RelationshipCodec(stringCodec);
+    node = new IndexNode(context, elementCodec, relationshipCodec);
+  }
+
+  void test_getContext() {
+    expect(node.context, context);
+  }
+
+  void test_recordRelationship() {
+    Element elementA = _mockElement();
+    Element elementB = _mockElement();
+    Element elementC = _mockElement();
+    Relationship relationship = Relationship.getRelationship("my-relationship");
+    Location locationA = new Location(elementB, 1, 2);
+    Location locationB = new Location(elementC, 10, 20);
+    // empty initially
+    expect(node.locationCount, 0);
+    // record
+    node.recordRelationship(elementA, relationship, locationA);
+    expect(node.locationCount, 1);
+    node.recordRelationship(elementA, relationship, locationB);
+    expect(node.locationCount, 2);
+    // get relations
+    expect(node.getRelationships(elementB, relationship), isEmpty);
+    {
+      List<Location> locations = node.getRelationships(elementA, relationship);
+      expect(locations, hasLength(2));
+      _assertHasLocation(locations, null, 1, 2);
+      _assertHasLocation(locations, null, 10, 20);
+    }
+    // verify relations map
+    {
+      Map<RelationKeyData, List<LocationData>> relations = node.relations;
+      expect(relations, hasLength(1));
+      List<LocationData> locations = relations.values.first;
+      expect(locations, hasLength(2));
+    }
+  }
+
+  void test_setRelations() {
+    Element elementA = _mockElement();
+    Element elementB = _mockElement();
+    Element elementC = _mockElement();
+    Relationship relationship = Relationship.getRelationship("my-relationship");
+    // record
+    {
+      int elementIdA = 0;
+      int elementIdB = 1;
+      int elementIdC = 2;
+      int relationshipId = relationshipCodec.encode(relationship);
+      RelationKeyData key = new RelationKeyData.forData(elementIdA,
+          relationshipId);
+      List<LocationData> locations = [new LocationData.forData(elementIdB, 1,
+          10), new LocationData.forData(elementIdC, 2, 20)];
+      node.relations = {
+        key: locations
+      };
+    }
+    // request
+    List<Location> locations = node.getRelationships(elementA, relationship);
+    expect(locations, hasLength(2));
+    _assertHasLocation(locations, elementB, 1, 10);
+    _assertHasLocation(locations, elementC, 2, 20);
+  }
+
+  Element _mockElement() {
+    int elementId = nextElementId++;
+    Element element = new _MockElement();
+    when(elementCodec.encode(element)).thenReturn(elementId);
+    when(elementCodec.decode(context, elementId)).thenReturn(element);
+    return element;
+  }
+}
+
+
+@ReflectiveTestCase()
+class _IntToIntSetMapTest {
+  IntToIntSetMap map = new IntToIntSetMap(32, 0.75);
+
+  void test_clear() {
+    map.add(1, 10);
+    map.add(2, 20);
+    expect(map.length, 2);
+    map.clear();
+    expect(map.length, 0);
+  }
+
+  void test_get() {
+    map.add(1, 10);
+    map.add(1, 11);
+    map.add(1, 12);
+    map.add(2, 20);
+    map.add(2, 21);
+    expect(map.get(1), unorderedEquals([10, 11, 12]));
+    expect(map.get(2), unorderedEquals([20, 21]));
+  }
+
+  void test_get_no() {
+    expect(map.get(3), []);
+  }
+
+  void test_length() {
+    expect(map.length, 0);
+    map.add(1, 10);
+    expect(map.length, 1);
+    map.add(1, 11);
+    expect(map.length, 2);
+    map.add(1, 12);
+    expect(map.length, 3);
+    map.add(2, 20);
+    expect(map.length, 4);
+    map.add(2, 21);
+    expect(map.length, 5);
+  }
+}
+
+
+@ReflectiveTestCase()
+class _LocationDataTest {
+  AnalysisContext context = new _MockAnalysisContext('context');
+  ElementCodec elementCodec = new _MockElementCodec();
+  StringCodec stringCodec = new StringCodec();
+
+  void test_newForData() {
+    Element element = new _MockElement();
+    when(elementCodec.decode(context, 0)).thenReturn(element);
+    LocationData locationData = new LocationData.forData(0, 1, 2);
+    Location location = locationData.getLocation(context, elementCodec);
+    expect(location.element, element);
+    expect(location.offset, 1);
+    expect(location.length, 2);
+  }
+
+  void test_newForObject() {
+    // prepare Element
+    Element element = new _MockElement();
+    when(elementCodec.encode(element)).thenReturn(42);
+    when(elementCodec.decode(context, 42)).thenReturn(element);
+    // create
+    Location location = new Location(element, 1, 2);
+    LocationData locationData = new LocationData.forObject(elementCodec,
+        location);
+    // touch 'hashCode'
+    locationData.hashCode;
+    // ==
+    expect(locationData == new LocationData.forData(42, 1, 2), isTrue);
+    // getLocation()
+    {
+      Location newLocation = locationData.getLocation(context, elementCodec);
+      expect(location.element, element);
+      expect(location.offset, 1);
+      expect(location.length, 2);
+    }
+    // no Element - no Location
+    {
+      when(elementCodec.decode(context, 42)).thenReturn(null);
+      Location newLocation = locationData.getLocation(context, elementCodec);
+      expect(newLocation, isNull);
+    }
+  }
+}
+
+
+/**
+ * [Location] has no [==] and [hashCode], so to compare locations by value we
+ * need to wrap them into such object.
+ */
+class _LocationEqualsWrapper {
+  final Location location;
+
+  _LocationEqualsWrapper(this.location);
+
+  @override
+  int get hashCode {
+    return 31 * (31 * location.element.hashCode + location.offset) +
+        location.length;
+  }
+
+  @override
+  bool operator ==(Object other) {
+    if (other is _LocationEqualsWrapper) {
+      return other.location.offset == location.offset && other.location.length
+          == location.length && other.location.element == location.element;
+    }
+    return false;
+  }
+}
+
+
+class _MemoryNodeManager implements NodeManager {
+  ContextCodec _contextCodec = new ContextCodec();
+  ElementCodec _elementCodec;
+  int _locationCount = 0;
+  final Map<String, int> _nodeLocationCounts = new HashMap<String, int>();
+
+  final Map<String, IndexNode> _nodes = new HashMap<String, IndexNode>();
+  RelationshipCodec _relationshipCodec;
+  StringCodec _stringCodec = new StringCodec();
+
+  _MemoryNodeManager() {
+    _elementCodec = new ElementCodec(_stringCodec);
+    _relationshipCodec = new RelationshipCodec(_stringCodec);
+  }
+
+  @override
+  ContextCodec get contextCodec {
+    return _contextCodec;
+  }
+
+  @override
+  ElementCodec get elementCodec {
+    return _elementCodec;
+  }
+
+  @override
+  int get locationCount {
+    return _locationCount;
+  }
+
+  @override
+  StringCodec get stringCodec {
+    return _stringCodec;
+  }
+
+  @override
+  void clear() {
+    _nodes.clear();
+  }
+
+  int getLocationCount(String name) {
+    int locationCount = _nodeLocationCounts[name];
+    return locationCount != null ? locationCount : 0;
+  }
+
+  @override
+  Future<IndexNode> getNode(String name) {
+    return new Future.value(_nodes[name]);
+  }
+
+  bool isEmpty() {
+    for (IndexNode node in _nodes.values) {
+      Map<RelationKeyData, List<LocationData>> relations = node.relations;
+      if (!relations.isEmpty) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  @override
+  IndexNode newNode(AnalysisContext context) {
+    return new IndexNode(context, elementCodec, _relationshipCodec);
+  }
+
+  @override
+  void putNode(String name, IndexNode node) {
+    // update location count
+    {
+      _locationCount -= getLocationCount(name);
+      int nodeLocationCount = node.locationCount;
+      _nodeLocationCounts[name] = nodeLocationCount;
+      _locationCount += nodeLocationCount;
+    }
+    // remember the node
+    _nodes[name] = node;
+  }
+
+  @override
+  void removeNode(String name) {
+    _nodes.remove(name);
+  }
+}
+
+
+class _MockAnalysisContext extends TypedMock implements AnalysisContext {
+  String _name;
+  _MockAnalysisContext(this._name);
+  noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+  String toString() => _name;
+}
+
+
+class _MockCompilationUnitElement extends TypedMock implements
+    CompilationUnitElement {
+  noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}
+
+
+class _MockContextCodec extends TypedMock implements ContextCodec {
+  noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}
+
+
+class _MockElement extends TypedMock implements Element {
+  String _name;
+  _MockElement([this._name = '<element>']);
+  noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+  String toString() => _name;
+}
+
+
+class _MockElementCodec extends TypedMock implements ElementCodec {
+  noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}
+
+
+class _MockFileManager extends TypedMock implements FileManager {
+  noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}
+
+
+class _MockHtmlElement extends TypedMock implements HtmlElement {
+  noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}
+
+
+class _MockIndexNode extends TypedMock implements IndexNode {
+  noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}
+
+
+class _MockInstrumentedAnalysisContextImpl extends TypedMock implements
+    InstrumentedAnalysisContextImpl {
+  noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}
+
+
+class _MockLibraryElement extends TypedMock implements LibraryElement {
+  noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}
+
+
+class _MockLocation extends TypedMock implements Location {
+  noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}
+
+
+class _MockLogger extends TypedMock implements Logger {
+  noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}
+
+
+class _MockRelationshipCodec extends TypedMock implements RelationshipCodec {
+  noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}
+
+
+class _MockSource extends TypedMock implements Source {
+  String _name;
+  _MockSource(this._name);
+  noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+  String toString() => _name;
+}
+
+
+@ReflectiveTestCase()
+class _RelationKeyDataTest {
+  AnalysisContext context = new _MockAnalysisContext('context');
+  ElementCodec elementCodec = new _MockElementCodec();
+  RelationshipCodec relationshipCodec = new _MockRelationshipCodec();
+  StringCodec stringCodec = new StringCodec();
+
+  void test_newFromData() {
+    RelationKeyData keyData = new RelationKeyData.forData(1, 2);
+    // equals
+    expect(keyData == this, isFalse);
+    expect(keyData == new RelationKeyData.forData(10, 20), isFalse);
+    expect(keyData == keyData, isTrue);
+    expect(keyData == new RelationKeyData.forData(1, 2), isTrue);
+  }
+
+  void test_newFromObjects() {
+    // prepare Element
+    Element element;
+    int elementId = 2;
+    {
+      element = new _MockElement();
+      ElementLocation location = new ElementLocationImpl.con3(["foo", "bar"]);
+      when(element.location).thenReturn(location);
+      when(context.getElement(location)).thenReturn(element);
+      when(elementCodec.encode(element)).thenReturn(elementId);
+    }
+    // prepare relationship
+    Relationship relationship = Relationship.getRelationship("my-relationship");
+    int relationshipId = 1;
+    when(relationshipCodec.encode(relationship)).thenReturn(relationshipId);
+    // create RelationKeyData
+    RelationKeyData keyData = new RelationKeyData.forObject(elementCodec,
+        relationshipCodec, element, relationship);
+    // touch
+    keyData.hashCode;
+    // equals
+    expect(keyData == this, isFalse);
+    expect(keyData == new RelationKeyData.forData(10, 20), isFalse);
+    expect(keyData == keyData, isTrue);
+    expect(keyData == new RelationKeyData.forData(elementId, relationshipId),
+        isTrue);
+  }
+}
+
+
+@ReflectiveTestCase()
+class _RelationshipCodecTest {
+  RelationshipCodec codec;
+  StringCodec stringCodec = new StringCodec();
+
+  void setUp() {
+    codec = new RelationshipCodec(stringCodec);
+  }
+
+  void test_all() {
+    Relationship relationship = Relationship.getRelationship("my-relationship");
+    int id = codec.encode(relationship);
+    expect(codec.decode(id), relationship);
+  }
+}
+
+
+class _SingleSourceContainer implements SourceContainer {
+  final Source _source;
+  _SingleSourceContainer(this._source);
+  @override
+  bool contains(Source source) => source == _source;
+}
+
+
+@ReflectiveTestCase()
+class _SplitIndexStoreTest {
+  AnalysisContext contextA = new _MockAnalysisContext('contextA');
+
+  AnalysisContext contextB = new _MockAnalysisContext('contextB');
+
+  AnalysisContext contextC = new _MockAnalysisContext('contextC');
+
+  Element elementA = new _MockElement('elementA');
+  Element elementB = new _MockElement('elementB');
+
+  Element elementC = new _MockElement('elementC');
+  Element elementD = new _MockElement('elementD');
+  ElementLocation elementLocationA = new ElementLocationImpl.con3(
+      ["/home/user/sourceA.dart", "ClassA"]);
+  ElementLocation elementLocationB = new ElementLocationImpl.con3(
+      ["/home/user/sourceB.dart", "ClassB"]);
+  ElementLocation elementLocationC = new ElementLocationImpl.con3(
+      ["/home/user/sourceC.dart", "ClassC"]);
+  ElementLocation elementLocationD = new ElementLocationImpl.con3(
+      ["/home/user/sourceD.dart", "ClassD"]);
+  HtmlElement htmlElementA = new _MockHtmlElement();
+  HtmlElement htmlElementB = new _MockHtmlElement();
+  LibraryElement libraryElement = new _MockLibraryElement();
+  Source librarySource = new _MockSource('librarySource');
+  CompilationUnitElement libraryUnitElement = new _MockCompilationUnitElement();
+  _MemoryNodeManager nodeManager = new _MemoryNodeManager();
+  Relationship relationship = Relationship.getRelationship("test-relationship");
+  Source sourceA = new _MockSource('sourceA');
+  Source sourceB = new _MockSource('sourceB');
+  Source sourceC = new _MockSource('sourceC');
+  Source sourceD = new _MockSource('sourceD');
+  SplitIndexStore store;
+  CompilationUnitElement unitElementA = new _MockCompilationUnitElement();
+  CompilationUnitElement unitElementB = new _MockCompilationUnitElement();
+  CompilationUnitElement unitElementC = new _MockCompilationUnitElement();
+  CompilationUnitElement unitElementD = new _MockCompilationUnitElement();
+  void setUp() {
+    store = new SplitIndexStore(nodeManager);
+    when(contextA.isDisposed).thenReturn(false);
+    when(contextB.isDisposed).thenReturn(false);
+    when(contextC.isDisposed).thenReturn(false);
+    when(contextA.getElement(elementLocationA)).thenReturn(elementA);
+    when(contextA.getElement(elementLocationB)).thenReturn(elementB);
+    when(contextA.getElement(elementLocationC)).thenReturn(elementC);
+    when(contextA.getElement(elementLocationD)).thenReturn(elementD);
+    when(sourceA.fullName).thenReturn("/home/user/sourceA.dart");
+    when(sourceB.fullName).thenReturn("/home/user/sourceB.dart");
+    when(sourceC.fullName).thenReturn("/home/user/sourceC.dart");
+    when(sourceD.fullName).thenReturn("/home/user/sourceD.dart");
+    when(elementA.context).thenReturn(contextA);
+    when(elementB.context).thenReturn(contextA);
+    when(elementC.context).thenReturn(contextA);
+    when(elementD.context).thenReturn(contextA);
+    when(elementA.location).thenReturn(elementLocationA);
+    when(elementB.location).thenReturn(elementLocationB);
+    when(elementC.location).thenReturn(elementLocationC);
+    when(elementD.location).thenReturn(elementLocationD);
+    when(elementA.enclosingElement).thenReturn(unitElementA);
+    when(elementB.enclosingElement).thenReturn(unitElementB);
+    when(elementC.enclosingElement).thenReturn(unitElementC);
+    when(elementD.enclosingElement).thenReturn(unitElementD);
+    when(elementA.source).thenReturn(sourceA);
+    when(elementB.source).thenReturn(sourceB);
+    when(elementC.source).thenReturn(sourceC);
+    when(elementD.source).thenReturn(sourceD);
+    when(elementA.library).thenReturn(libraryElement);
+    when(elementB.library).thenReturn(libraryElement);
+    when(elementC.library).thenReturn(libraryElement);
+    when(elementD.library).thenReturn(libraryElement);
+    when(unitElementA.source).thenReturn(sourceA);
+    when(unitElementB.source).thenReturn(sourceB);
+    when(unitElementC.source).thenReturn(sourceC);
+    when(unitElementD.source).thenReturn(sourceD);
+    when(unitElementA.library).thenReturn(libraryElement);
+    when(unitElementB.library).thenReturn(libraryElement);
+    when(unitElementC.library).thenReturn(libraryElement);
+    when(unitElementD.library).thenReturn(libraryElement);
+    when(htmlElementA.source).thenReturn(sourceA);
+    when(htmlElementB.source).thenReturn(sourceB);
+    // library
+    when(libraryUnitElement.library).thenReturn(libraryElement);
+    when(libraryUnitElement.source).thenReturn(librarySource);
+    when(libraryElement.source).thenReturn(librarySource);
+    when(libraryElement.definingCompilationUnit).thenReturn(libraryUnitElement);
+  }
+  void test_aboutToIndexDart_disposedContext() {
+    when(contextA.isDisposed).thenReturn(true);
+    expect(store.aboutToIndexDart(contextA, unitElementA), isFalse);
+  }
+  void test_aboutToIndexDart_disposedContext_wrapped() {
+    when(contextA.isDisposed).thenReturn(true);
+    InstrumentedAnalysisContextImpl instrumentedContext =
+        new _MockInstrumentedAnalysisContextImpl();
+    when(instrumentedContext.basis).thenReturn(contextA);
+    expect(store.aboutToIndexDart(instrumentedContext, unitElementA), isFalse);
+  }
+
+  void test_aboutToIndexDart_library_first() {
+    when(libraryElement.parts).thenReturn(<CompilationUnitElement>[unitElementA,
+        unitElementB]);
+    {
+      store.aboutToIndexDart(contextA, libraryUnitElement);
+      store.doneIndex();
+    }
+    {
+      List<Location> locations = store.getRelationships(elementA, relationship);
+      assertLocations(locations, []);
+    }
+  }
+
+  test_aboutToIndexDart_library_secondWithoutOneUnit() {
+    Location locationA = mockLocation(elementA);
+    Location locationB = mockLocation(elementB);
+    {
+      store.aboutToIndexDart(contextA, unitElementA);
+      store.recordRelationship(elementA, relationship, locationA);
+      store.doneIndex();
+    }
+    {
+      store.aboutToIndexDart(contextA, unitElementB);
+      store.recordRelationship(elementA, relationship, locationB);
+      store.doneIndex();
+    }
+    // "A" and "B" locations
+    return store.getRelationshipsAsync(elementA, relationship).then(
+        (List<Location> locations) {
+      assertLocations(locations, [locationA, locationB]);
+    }).then((_) {
+      // apply "libraryUnitElement", only with "B"
+      when(libraryElement.parts).thenReturn([unitElementB]);
+      {
+        store.aboutToIndexDart(contextA, libraryUnitElement);
+        store.doneIndex();
+      }
+      return store.getRelationshipsAsync(elementA, relationship).then(
+          (List<Location> locations) {
+        assertLocations(locations, [locationB]);
+      });
+    });
+  }
+
+  void test_aboutToIndexDart_nullLibraryElement() {
+    when(unitElementA.library).thenReturn(null);
+    expect(store.aboutToIndexDart(contextA, unitElementA), isFalse);
+  }
+
+  void test_aboutToIndexDart_nullLibraryUnitElement() {
+    when(libraryElement.definingCompilationUnit).thenReturn(null);
+    expect(store.aboutToIndexDart(contextA, unitElementA), isFalse);
+  }
+
+  void test_aboutToIndexDart_nullUnitElement() {
+    expect(store.aboutToIndexDart(contextA, null), isFalse);
+  }
+
+  test_aboutToIndexHtml_() {
+    Location locationA = mockLocation(elementA);
+    Location locationB = mockLocation(elementB);
+    {
+      store.aboutToIndexHtml(contextA, htmlElementA);
+      store.recordRelationship(elementA, relationship, locationA);
+      store.doneIndex();
+    }
+    {
+      store.aboutToIndexHtml(contextA, htmlElementB);
+      store.recordRelationship(elementA, relationship, locationB);
+      store.doneIndex();
+    }
+    // "A" and "B" locations
+    return store.getRelationshipsAsync(elementA, relationship).then(
+        (List<Location> locations) {
+      assertLocations(locations, [locationA, locationB]);
+    });
+  }
+
+  void test_aboutToIndexHtml_disposedContext() {
+    when(contextA.isDisposed).thenReturn(true);
+    expect(store.aboutToIndexHtml(contextA, htmlElementA), isFalse);
+  }
+
+  void test_clear() {
+    Location locationA = mockLocation(elementA);
+    store.aboutToIndexDart(contextA, unitElementA);
+    store.recordRelationship(elementA, relationship, locationA);
+    store.doneIndex();
+    expect(nodeManager.isEmpty(), isFalse);
+    // clear
+    store.clear();
+    expect(nodeManager.isEmpty(), isTrue);
+  }
+
+  test_getRelationships_empty() {
+    return store.getRelationshipsAsync(elementA, relationship).then(
+        (List<Location> locations) {
+      expect(locations, isEmpty);
+    });
+  }
+
+  void test_getStatistics() {
+    // empty initially
+    {
+      String statistics = store.statistics;
+      expect(statistics, contains('0 locations'));
+      expect(statistics, contains('0 sources'));
+    }
+    // add 2 locations
+    Location locationA = mockLocation(elementA);
+    Location locationB = mockLocation(elementB);
+    {
+      store.aboutToIndexDart(contextA, unitElementA);
+      store.recordRelationship(elementA, relationship, locationA);
+      store.doneIndex();
+    }
+    {
+      store.aboutToIndexDart(contextA, unitElementB);
+      store.recordRelationship(elementA, relationship, locationB);
+      store.doneIndex();
+    }
+    {
+      String statistics = store.statistics;
+      expect(statistics, contains('2 locations'));
+      expect(statistics, contains('3 sources'));
+    }
+  }
+
+  void test_recordRelationship_nullElement() {
+    Location locationA = mockLocation(elementA);
+    store.recordRelationship(null, relationship, locationA);
+    store.doneIndex();
+    expect(nodeManager.isEmpty(), isTrue);
+  }
+
+  void test_recordRelationship_nullLocation() {
+    store.recordRelationship(elementA, relationship, null);
+    store.doneIndex();
+    expect(nodeManager.isEmpty(), isTrue);
+  }
+
+  test_recordRelationship_oneElement_twoNodes() {
+    Location locationA = mockLocation(elementA);
+    Location locationB = mockLocation(elementB);
+    {
+      store.aboutToIndexDart(contextA, unitElementA);
+      store.recordRelationship(elementA, relationship, locationA);
+      store.doneIndex();
+    }
+    {
+      store.aboutToIndexDart(contextA, unitElementB);
+      store.recordRelationship(elementA, relationship, locationB);
+      store.doneIndex();
+    }
+    return store.getRelationshipsAsync(elementA, relationship).then(
+        (List<Location> locations) {
+      assertLocations(locations, [locationA, locationB]);
+    });
+  }
+
+  test_recordRelationship_oneLocation() {
+    Location locationA = mockLocation(elementA);
+    store.aboutToIndexDart(contextA, unitElementA);
+    store.recordRelationship(elementA, relationship, locationA);
+    store.doneIndex();
+    return store.getRelationshipsAsync(elementA, relationship).then(
+        (List<Location> locations) {
+      assertLocations(locations, [locationA]);
+    });
+  }
+
+  test_recordRelationship_twoLocations() {
+    Location locationA = mockLocation(elementA);
+    Location locationB = mockLocation(elementA);
+    store.aboutToIndexDart(contextA, unitElementA);
+    store.recordRelationship(elementA, relationship, locationA);
+    store.recordRelationship(elementA, relationship, locationB);
+    store.doneIndex();
+    return store.getRelationshipsAsync(elementA, relationship).then(
+        (List<Location> locations) {
+      assertLocations(locations, [locationA, locationB]);
+    });
+  }
+
+  test_removeContext() {
+    Location locationA = mockLocation(elementA);
+    Location locationB = mockLocation(elementB);
+    {
+      store.aboutToIndexDart(contextA, unitElementA);
+      store.recordRelationship(elementA, relationship, locationA);
+      store.doneIndex();
+    }
+    {
+      store.aboutToIndexDart(contextA, unitElementB);
+      store.recordRelationship(elementA, relationship, locationB);
+      store.doneIndex();
+    }
+    // "A" and "B" locations
+    return store.getRelationshipsAsync(elementA, relationship).then(
+        (List<Location> locations) {
+      assertLocations(locations, [locationA, locationB]);
+    }).then((_) {
+      // remove "A" context
+      store.removeContext(contextA);
+      return store.getRelationshipsAsync(elementA, relationship).then(
+          (List<Location> locations) {
+        assertLocations(locations, []);
+      });
+    });
+  }
+
+  void test_removeContext_nullContext() {
+    store.removeContext(null);
+  }
+
+  test_removeSource_library() {
+    Location locationA = mockLocation(elementA);
+    Location locationB = mockLocation(elementB);
+    Location locationC = mockLocation(elementC);
+    {
+      store.aboutToIndexDart(contextA, unitElementA);
+      store.recordRelationship(elementA, relationship, locationA);
+      store.doneIndex();
+    }
+    {
+      store.aboutToIndexDart(contextA, unitElementB);
+      store.recordRelationship(elementA, relationship, locationB);
+      store.doneIndex();
+    }
+    {
+      store.aboutToIndexDart(contextA, unitElementC);
+      store.recordRelationship(elementA, relationship, locationC);
+      store.doneIndex();
+    }
+    // "A", "B" and "C" locations
+    return store.getRelationshipsAsync(elementA, relationship).then(
+        (List<Location> locations) {
+      assertLocations(locations, [locationA, locationB, locationC]);
+    }).then((_) {
+      // remove "librarySource"
+      store.removeSource(contextA, librarySource);
+      return store.getRelationshipsAsync(elementA, relationship).then(
+          (List<Location> locations) {
+        assertLocations(locations, []);
+      });
+    });
+  }
+
+  void test_removeSource_nullContext() {
+    store.removeSource(null, sourceA);
+  }
+
+  test_removeSource_unit() {
+    Location locationA = mockLocation(elementA);
+    Location locationB = mockLocation(elementB);
+    Location locationC = mockLocation(elementC);
+    {
+      store.aboutToIndexDart(contextA, unitElementA);
+      store.recordRelationship(elementA, relationship, locationA);
+      store.doneIndex();
+    }
+    {
+      store.aboutToIndexDart(contextA, unitElementB);
+      store.recordRelationship(elementA, relationship, locationB);
+      store.doneIndex();
+    }
+    {
+      store.aboutToIndexDart(contextA, unitElementC);
+      store.recordRelationship(elementA, relationship, locationC);
+      store.doneIndex();
+    }
+    // "A", "B" and "C" locations
+    return store.getRelationshipsAsync(elementA, relationship).then(
+        (List<Location> locations) {
+      assertLocations(locations, [locationA, locationB, locationC]);
+    }).then((_) {
+      // remove "A" source
+      store.removeSource(contextA, sourceA);
+      return store.getRelationshipsAsync(elementA, relationship).then(
+          (List<Location> locations) {
+        assertLocations(locations, [locationB, locationC]);
+      });
+    });
+  }
+
+  test_removeSources_library() {
+    Location locationA = mockLocation(elementA);
+    Location locationB = mockLocation(elementB);
+    {
+      store.aboutToIndexDart(contextA, unitElementA);
+      store.recordRelationship(elementA, relationship, locationA);
+      store.doneIndex();
+    }
+    {
+      store.aboutToIndexDart(contextA, unitElementB);
+      store.recordRelationship(elementA, relationship, locationB);
+      store.doneIndex();
+    }
+    // "A" and "B" locations
+    return store.getRelationshipsAsync(elementA, relationship).then(
+        (List<Location> locations) {
+      assertLocations(locations, [locationA, locationB]);
+    }).then((_) {
+      // remove "librarySource"
+      store.removeSources(contextA, new _SingleSourceContainer(librarySource));
+      return store.getRelationshipsAsync(elementA, relationship).then(
+          (List<Location> locations) {
+        assertLocations(locations, []);
+      });
+    });
+  }
+
+  void test_removeSources_nullContext() {
+    store.removeSources(null, null);
+  }
+
+  test_removeSources_unit() {
+    Location locationA = mockLocation(elementA);
+    Location locationB = mockLocation(elementB);
+    Location locationC = mockLocation(elementC);
+    {
+      store.aboutToIndexDart(contextA, unitElementA);
+      store.recordRelationship(elementA, relationship, locationA);
+      store.doneIndex();
+    }
+    {
+      store.aboutToIndexDart(contextA, unitElementB);
+      store.recordRelationship(elementA, relationship, locationB);
+      store.doneIndex();
+    }
+    {
+      store.aboutToIndexDart(contextA, unitElementC);
+      store.recordRelationship(elementA, relationship, locationC);
+      store.doneIndex();
+    }
+    // "A", "B" and "C" locations
+    return store.getRelationshipsAsync(elementA, relationship).then(
+        (List<Location> locations) {
+      assertLocations(locations, [locationA, locationB, locationC]);
+    }).then((_) {
+      // remove "A" source
+      store.removeSources(contextA, new _SingleSourceContainer(sourceA));
+      store.removeSource(contextA, sourceA);
+      return store.getRelationshipsAsync(elementA, relationship).then(
+          (List<Location> locations) {
+        assertLocations(locations, [locationB, locationC]);
+      });
+    });
+  }
+
+  test_universe_aboutToIndex() {
+    when(contextA.getElement(elementLocationA)).thenReturn(elementA);
+    when(contextB.getElement(elementLocationB)).thenReturn(elementB);
+    Location locationA = mockLocation(elementA);
+    Location locationB = mockLocation(elementB);
+    {
+      store.aboutToIndexDart(contextA, unitElementA);
+      store.recordRelationship(UniverseElement.INSTANCE, relationship,
+          locationA);
+      store.doneIndex();
+    }
+    {
+      store.aboutToIndexDart(contextB, unitElementB);
+      store.recordRelationship(UniverseElement.INSTANCE, relationship,
+          locationB);
+      store.doneIndex();
+    }
+    // get relationships
+    return store.getRelationshipsAsync(UniverseElement.INSTANCE,
+        relationship).then((List<Location> locations) {
+      assertLocations(locations, [locationA, locationB]);
+    }).then((_) {
+      // re-index "unitElementA"
+      store.aboutToIndexDart(contextA, unitElementA);
+      store.doneIndex();
+      return store.getRelationshipsAsync(UniverseElement.INSTANCE,
+          relationship).then((List<Location> locations) {
+        assertLocations(locations, [locationB]);
+      });
+    });
+  }
+
+  test_universe_removeContext() {
+    when(contextA.getElement(elementLocationA)).thenReturn(elementA);
+    when(contextB.getElement(elementLocationB)).thenReturn(elementB);
+    Location locationA = mockLocation(elementA);
+    Location locationB = mockLocation(elementB);
+    {
+      store.aboutToIndexDart(contextA, unitElementA);
+      store.recordRelationship(UniverseElement.INSTANCE, relationship,
+          locationA);
+      store.doneIndex();
+    }
+    {
+      store.aboutToIndexDart(contextB, unitElementB);
+      store.recordRelationship(UniverseElement.INSTANCE, relationship,
+          locationB);
+      store.doneIndex();
+    }
+    return store.getRelationshipsAsync(UniverseElement.INSTANCE,
+        relationship).then((List<Location> locations) {
+      assertLocations(locations, [locationA, locationB]);
+    }).then((_) {
+      // remove "contextA"
+      store.removeContext(contextA);
+      return store.getRelationshipsAsync(UniverseElement.INSTANCE,
+          relationship).then((List<Location> locations) {
+        assertLocations(locations, [locationB]);
+      });
+    });
+  }
+
+  /**
+   * Asserts that the "actual" locations have all the "expected" locations and only them.
+   */
+  static void assertLocations(List<Location> actual, List<Location> expected) {
+    List<_LocationEqualsWrapper> actualWrappers = wrapLocations(actual);
+    List<_LocationEqualsWrapper> expectedWrappers = wrapLocations(expected);
+    expect(actualWrappers, unorderedEquals(expectedWrappers));
+  }
+
+  /**
+   * @return the new [Location] mock.
+   */
+  static Location mockLocation(Element element) {
+    Location location = new _MockLocation();
+    when(location.element).thenReturn(element);
+    when(location.offset).thenReturn(0);
+    when(location.length).thenReturn(0);
+    return location;
+  }
+
+  /**
+   * Wraps the given locations into [LocationEqualsWrapper].
+   */
+  static List<_LocationEqualsWrapper> wrapLocations(List<Location> locations) {
+    List<_LocationEqualsWrapper> wrappers = <_LocationEqualsWrapper>[];
+    for (Location location in locations) {
+      wrappers.add(new _LocationEqualsWrapper(location));
+    }
+    return wrappers;
+  }
+}
+
+
+@ReflectiveTestCase()
+class _StringCodecTest {
+  StringCodec codec = new StringCodec();
+
+  void test_all() {
+    int idA = codec.encode('aaa');
+    int idB = codec.encode('bbb');
+    expect(codec.decode(idA), 'aaa');
+    expect(codec.decode(idB), 'bbb');
+  }
+}