Move Index and IndexStore implementations into Engine.

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;
-  }
-}