Line data    Source code

       1             : #region Copyright
       2             : // // -----------------------------------------------------------------------
       3             : // // <copyright company="Chinchilla Software Limited">
       4             : // //   Copyright Chinchilla Software Limited. All rights reserved.
       5             : // // </copyright>
       6             : // // -----------------------------------------------------------------------
       7             : #endregion
       8             : 
       9             : using System;
      10             : using System.Collections.Generic;
      11             : using Cqrs.Domain.Exceptions;
      12             : using Cqrs.Events;
      13             : 
      14             : namespace Cqrs.Domain
      15             : {
      16             :         /// <summary>
      17             :         /// Provides a basic container to control when <see cref="IEvent{TAuthenticationToken}">events</see> are store in an <see cref="IEventStore{TAuthenticationToken}"/> and then published on an <see cref="IEventPublisher{TAuthenticationToken}"/>.
      18             :         /// </summary>
      19             :         /// <remarks>
      20             :         /// This shouldn't normally be used as a singleton.
      21             :         /// </remarks>
      22             :         public class SagaUnitOfWork<TAuthenticationToken> : ISagaUnitOfWork<TAuthenticationToken>
      23           1 :         {
      24             :                 private ISagaRepository<TAuthenticationToken> Repository { get; set; }
      25             : 
      26             :                 private Dictionary<Guid, ISagaDescriptor<TAuthenticationToken>> TrackedSagas { get; set; }
      27             : 
      28             :                 /// <summary>
      29             :                 /// Instantiates a new instance of <see cref="SagaUnitOfWork{TAuthenticationToken}"/>
      30             :                 /// </summary>
      31           1 :                 public SagaUnitOfWork(ISagaRepository<TAuthenticationToken> repository)
      32             :                 {
      33             :                         if(repository == null)
      34             :                                 throw new ArgumentNullException("repository");
      35             : 
      36             :                         Repository = repository;
      37             :                         TrackedSagas = new Dictionary<Guid, ISagaDescriptor<TAuthenticationToken>>();
      38             :                 }
      39             : 
      40             :                 /// <summary>
      41             :                 /// Add an item into the <see cref="IUnitOfWork{TAuthenticationToken}"/> ready to be committed.
      42             :                 /// </summary>
      43           1 :                 public void Add<TSaga>(TSaga saga)
      44             :                         where TSaga : ISaga<TAuthenticationToken>
      45             :                 {
      46             :                         if (!IsTracked(saga.Id))
      47             :                         {
      48             :                                 var sagaDescriptor = new SagaDescriptor<TSaga, TAuthenticationToken>
      49             :                                 {
      50             :                                         Saga = saga,
      51             :                                         Version = saga.Version
      52             :                                 };
      53             :                                 TrackedSagas.Add(saga.Id, sagaDescriptor);
      54             :                         }
      55             :                         else if (((TrackedSagas[saga.Id]).Saga) != (ISaga<TAuthenticationToken>)saga)
      56             :                                 throw new ConcurrencyException(saga.Id);
      57             :                 }
      58             : 
      59             :                 /// <summary>
      60             :                 /// Get an item from the <see cref="IUnitOfWork{TAuthenticationToken}"/> if it has already been loaded or get it from the <see cref="ISagaRepository{TAuthenticationToken}"/>.
      61             :                 /// </summary>
      62           1 :                 public TSaga Get<TSaga>(Guid id, int? expectedVersion = null)
      63             :                         where TSaga : ISaga<TAuthenticationToken>
      64             :                 {
      65             :                         if(IsTracked(id))
      66             :                         {
      67             :                                 var trackedSaga = (TSaga)TrackedSagas[id].Saga;
      68             :                                 if (expectedVersion != null && trackedSaga.Version != expectedVersion)
      69             :                                         throw new ConcurrencyException(trackedSaga.Id);
      70             :                                 return trackedSaga;
      71             :                         }
      72             : 
      73             :                         var saga = Repository.Get<TSaga>(id);
      74             :                         if (expectedVersion != null && saga.Version != expectedVersion)
      75             :                                 throw new ConcurrencyException(id);
      76             :                         Add(saga);
      77             : 
      78             :                         return saga;
      79             :                 }
      80             : 
      81             :                 private bool IsTracked(Guid id)
      82             :                 {
      83             :                         return TrackedSagas.ContainsKey(id);
      84             :                 }
      85             : 
      86             :                 /// <summary>
      87             :                 /// Commit any changed <see cref="Saga{TAuthenticationToken}"/> added to this <see cref="IUnitOfWork{TAuthenticationToken}"/> via <see cref="Add{T}"/>
      88             :                 /// into the <see cref="ISagaRepository{TAuthenticationToken}"/>
      89             :                 /// </summary>
      90           1 :                 public void Commit()
      91             :                 {
      92             :                         foreach (ISagaDescriptor<TAuthenticationToken> descriptor in TrackedSagas.Values)
      93             :                         {
      94             :                                 Repository.Save(descriptor.Saga, descriptor.Version);
      95             :                         }
      96             :                         TrackedSagas.Clear();
      97             :                 }
      98             :         }
      99             : }