source: branches/PersistenceOverhaul/HeuristicLab.Persistence/4.0/Transformers/StackTransformer.cs @ 15529

#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2012 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
 *
 * This file is part of HeuristicLab.
 *
 * HeuristicLab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HeuristicLab is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using System;
using System.Collections;
using System.Collections.Generic;
using HeuristicLab.Persistence.Data;

namespace HeuristicLab.Persistence {
  internal abstract class GenericStackTransformer<TSource, TTarget> : TransformerBase {
    public override bool CanTransformType(Type type) {
      return type == typeof(Stack<TSource>);
    }
    public override PersistenceData ToData(object o, PersistenceMapper mapper) {
      var data = new ArrayData<TTarget>(Id);
      mapper.Cache(o, data);
      data.TypeId = mapper.GetTypeId(o.GetType());

      var enumerable = (IEnumerable<TSource>)o;
      var componentIds = new List<TTarget>();
      foreach (var component in enumerable) {
        componentIds.Add(GetTarget(component, mapper));
      }
      componentIds.Reverse();
      data.Values = componentIds.ToArray();
      return data;
    }

    public override object ToObject(PersistenceData data, PersistenceMapper mapper) {
      var collection = (ArrayData<TTarget>)data;
      var type = mapper.GetType(collection.TypeId);

      var o = Activator.CreateInstance(type, true);
      mapper.Cache(data, o);
      dynamic stack = o;
      foreach (var component in collection.Values) {
        stack.Push(GetSource(component, mapper));
      }
      return o;
    }

    protected abstract TTarget GetTarget(TSource source, PersistenceMapper mapper);
    protected abstract TSource GetSource(TTarget target, PersistenceMapper mapper);
  }

  internal abstract class PrimitiveStackTransformer<T> : GenericStackTransformer<T, T> {
    protected override T GetTarget(T source, PersistenceMapper mapper) {
      return source;
    }
    protected override T GetSource(T target, PersistenceMapper mapper) {
      return target;
    }
  }

  [Transformer("305FE51F-CE6A-43A7-A0FC-CCFFC1378680", 405)]
  internal sealed class DoubleStackTransformer : PrimitiveStackTransformer<double> { }

  [Transformer("E84A21DF-BDAF-4A24-9EF6-934ACDB82423", 406)]
  internal sealed class StackTransformer : GenericStackTransformer<object, uint> {
    public override bool CanTransformType(Type type) {
      return type.IsGenericType && (type.GetGenericTypeDefinition() == typeof(Stack<>));
    }

    protected override uint GetTarget(object source, PersistenceMapper mapper) {
      return mapper.GetDataId(source);
    }
    protected override object GetSource(uint target, PersistenceMapper mapper) {
      return mapper.GetObject(target);
    }
  }
}