public override void Handle(IEvent[] messages, long endSequence)
{
_logger.LogDebug($"回溯事件:{messages.Length}");
//过滤回溯时间，因为存在重建，所以可能重复消费
messages = messages.Where(a => a.UTCTimestamp > _subscribeEvent.UTCTimestamp).ToArray();
if (!messages.Any())
{
return;
}
var dict = messages.GroupBy(a => a.AggregateRootTypeName).ToDictionary(a => a.Key, a => a.ToList());
List <IAggregateRoot> aggregateRoots = new List <IAggregateRoot>();
List <IAggregateRoot> removeRoots = new List <IAggregateRoot>();
List <IAggregateRoot> addRoots = new List <IAggregateRoot>();
//获取
foreach (var item in dict)
{
Type entityType;
if (!_cacheEntitys.TryGetValue(item.Key, out entityType))
{
throw new Exception($"无法找到类型{item.Key}的聚合根");
}
//这里可以先从缓存获取，如果没有全部找到，再从数据库拿没有取到的。
var createIds = item.Value.Where(a => a.Operation == EventOperation.Created).Select(a => a.AggregateRootId).ToArray();
var ids = item.Value.Select(a => a.AggregateRootId).Except(createIds).ToArray();
List <IAggregateRoot> roots = new List <IAggregateRoot>();
foreach (var id in ids)
{
var key = GetKey(entityType, id);
var root = _snapshootCache.Get(entityType, id);
if (root == null)
{
continue;
}
roots.Add(root);
}
var storeIds = ids.Except(roots.Select(a => a.Id)).ToArray();
if (storeIds.Length > 0)
{
var snapshootStore = _snapshootStoreFactory.Create(entityType);
var storeRoots = snapshootStore.Get(storeIds);
roots.AddRange(storeRoots);
}
aggregateRoots.AddRange(roots);
}
//重建
foreach (var item in messages)
{
_logger.LogDebug($"执行快照事件：{item.Id} - {item.Operation} - {item.AggregateRootTypeName} - {item.AggregateRootId}");
IAggregateRoot root = aggregateRoots.FirstOrDefault(a => a.Id == item.AggregateRootId && a.GetType().Name.Equals(item.AggregateRootTypeName));
if (item.Operation == EventOperation.Created)
{
Type entityType;
if (!_cacheEntitys.TryGetValue(item.AggregateRootTypeName, out entityType))
{
//throw new Exception($"无法找到类型{item.AggregateRootTypeName}的聚合根");
_logger.LogError($"无法找到类型{item.AggregateRootTypeName}的聚合根");
continue;
}
root = Activator.CreateInstance(entityType, true) as IAggregateRoot;
aggregateRoots.Add(root);
addRoots.Add(root);
}
else if (item.Operation == EventOperation.Removed)
{
removeRoots.Add(root);
}
if (root == null)
{
_logger.LogError($"回溯快照的时候没有找到聚合根：[{item.Id}] - [{item.AggregateRootId} - {item.AggregateRootTypeName}]");
continue;
}
_eventRebuildHandler.Handle(root, item);
}
var rootDict = aggregateRoots.GroupBy(a => a.GetType()).ToDictionary(a => a.Key, a => a.ToList());
foreach (var item in rootDict)
{
var snapshootStore = _snapshootStoreFactory.Create(item.Key);
var addeds = item.Value.Intersect(addRoots).ToArray();
var removed = item.Value.Intersect(removeRoots).ToArray();
var updated = item.Value.Except(addeds).Except(removed).ToArray();
//存储快照
TryActionStore(list => snapshootStore.Add(list), addeds);
TryActionStore(list => snapshootStore.Remove(list), removed);
TryActionStore(list => snapshootStore.Update(list), updated);
}
//存储缓存
SetCache(aggregateRoots.Except(removeRoots));
RemoveCache(removeRoots);
//记录快照消费者处理的的最后的事件
var evt = messages.LastOrDefault();
if (evt != null)
{
_subscribeEvent.AggregateRootId = evt.AggregateRootId;
_subscribeEvent.AggregateRootTypeName = evt.AggregateRootTypeName;
_subscribeEvent.EventId = evt.Id;
_subscribeEvent.UTCTimestamp = evt.UTCTimestamp;
_subscribeEventStore.Save(_subscribeEvent);
_eventHandleSubject.Update(_subscribeEvent);
}
}
private List <IAggregateRoot> Get(Type rootType, Guid[] ids)
{
return(_snapshootStoreFactory.Create(rootType).Get(ids));
}
