Move split_store.dart to the store/ folder and extract collections/codecs.

pkg/analysis_server/lib/src/index/store/codec.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 index.store.codec;
+
+import 'dart:collection';
+
+import 'package:analysis_server/src/index/store/collection.dart';
+import 'package:analyzer/src/generated/element.dart';
+import 'package:analyzer/src/generated/engine.dart';
+import 'package:analyzer/src/generated/index.dart';
+
+
+/**
+ * A helper that encodes/decodes [AnalysisContext]s from/to integers.
+ */
+class ContextCodec {
+  /**
+   * A table mapping contexts to their unique indices.
+   */
+  Map<AnalysisContext, int> _contextToIndex = new HashMap<AnalysisContext, int>(
+      );
+
+  /**
+   * A table mapping indices to the corresponding contexts.
+   */
+  Map<int, AnalysisContext> _indexToContext = new HashMap<int, AnalysisContext>(
+      );
+
+  /**
+   * The next id to assign.
+   */
+  int _nextId = 0;
+
+  /**
+   * Returns the [AnalysisContext] that corresponds to the given index.
+   */
+  AnalysisContext decode(int index) => _indexToContext[index];
+
+  /**
+   * Returns an unique index for the given [AnalysisContext].
+   */
+  int encode(AnalysisContext context) {
+    int index = _contextToIndex[context];
+    if (index == null) {
+      index = _nextId++;
+      _contextToIndex[context] = index;
+      _indexToContext[index] = context;
+    }
+    return index;
+  }
+
+  /**
+   * Removes the given [context].
+   */
+  void remove(AnalysisContext context) {
+    int id = _contextToIndex.remove(context);
+    if (id != null) {
+      _indexToContext.remove(id);
+    }
+  }
+}
+
+
+/**
+ * A helper that encodes/decodes [Element]s to/from integers.
+ */
+class ElementCodec {
+  /**
+   * A list that works as a mapping of integers to element encodings (in form of integer arrays).
+   */
+  List<List<int>> _indexToPath = [];
+
+  /**
+   * A table mapping element locations (in form of integer arrays) into a single integer.
+   */
+  IntArrayToIntMap _pathToIndex = new IntArrayToIntMap();
+
+  final StringCodec _stringCodec;
+
+  ElementCodec(this._stringCodec);
+
+  /**
+   * Returns an [Element] that corresponds to the given location.
+   *
+   * @param context the [AnalysisContext] to find [Element] in
+   * @param index an integer corresponding to the [Element]
+   * @return the [Element] or `null`
+   */
+  Element decode(AnalysisContext context, int index) {
+    List<int> path = _indexToPath[index];
+    List<String> components = _getLocationComponents(path);
+    ElementLocation location = new ElementLocationImpl.con3(components);
+    return context.getElement(location);
+  }
+
+  /**
+   * Returns a unique integer that corresponds to the given [Element].
+   */
+  int encode(Element element) {
+    List<int> path = _getLocationPath(element);
+    int index = _pathToIndex[path];
+    if (index == null) {
+      index = _indexToPath.length;
+      _pathToIndex[path] = index;
+      _indexToPath.add(path);
+    }
+    return index;
+  }
+
+  List<String> _getLocationComponents(List<int> path) {
+    int length = path.length;
+    List<String> components = new List<String>();
+    for (int i = 0; i < length; i++) {
+      int componentId = path[i];
+      String component = _stringCodec.decode(componentId);
+      if (i < length - 1 && path[i + 1] < 0) {
+        component += '@${(-path[i + 1])}';
+        i++;
+      }
+      components.add(component);
+    }
+    return components;
+  }
+
+  List<int> _getLocationPath(Element element) {
+    List<String> components = element.location.components;
+    int length = components.length;
+    if (_hasLocalOffset(components)) {
+      List<int> path = new List<int>();
+      for (String component in components) {
+        int atOffset = component.indexOf('@');
+        if (atOffset == -1) {
+          path.add(_stringCodec.encode(component));
+        } else {
+          String preAtString = component.substring(0, atOffset);
+          String atString = component.substring(atOffset + 1);
+          path.add(_stringCodec.encode(preAtString));
+          path.add(-1 * int.parse(atString));
+        }
+      }
+      return path;
+    } else {
+      List<int> path = new List<int>.filled(length, 0);
+      for (int i = 0; i < length; i++) {
+        String component = components[i];
+        path[i] = _stringCodec.encode(component);
+      }
+      return path;
+    }
+  }
+
+  bool _hasLocalOffset(List<String> components) {
+    for (String component in components) {
+      if (component.indexOf('@') != -1) {
+        return true;
+      }
+    }
+    return false;
+  }
+}
+
+
+/**
+ * A helper that encodes/decodes [Relationship]s to/from integers.
+ */
+class RelationshipCodec {
+  final StringCodec _stringCodec;
+
+  RelationshipCodec(this._stringCodec);
+
+  Relationship decode(int idIndex) {
+    String id = _stringCodec.decode(idIndex);
+    return Relationship.getRelationship(id);
+  }
+
+  int encode(Relationship relationship) {
+    String id = relationship.identifier;
+    return _stringCodec.encode(id);
+  }
+}
+
+
+/**
+ * A helper that encodes/decodes [String]s from/to integers.
+ */
+class StringCodec {
+  /**
+   * A table mapping names to their unique indices.
+   */
+  final Map<String, int> nameToIndex = {};
+
+  /**
+   * A table mapping indices to the corresponding strings.
+   */
+  List<String> _indexToName = [];
+
+  /**
+   * Returns the [String] that corresponds to the given index.
+   */
+  String decode(int index) => _indexToName[index];
+
+  /**
+   * Returns an unique index for the given [String].
+   */
+  int encode(String name) {
+    int index = nameToIndex[name];
+    if (index == null) {
+      index = _indexToName.length;
+      nameToIndex[name] = index;
+      _indexToName.add(name);
+    }
+    return index;
+  }
+}