private EventStreamRecord ReadEventStreamRecord(byte[] recordBuffer)
{
var record = new EventStreamRecord();
record.ReadFrom(recordBuffer);
return(record);
}
public EventAppendResult AppendEventStreams(IEnumerable <IEventStream> eventStreams)
{
lock (_lockObj)
{
var eventStreamDict = GroupEventStreamByAggregateRoot(eventStreams);
var eventAppendResult = new EventAppendResult();
foreach (var entry in eventStreamDict)
{
var aggregateRootId = entry.Key;
var eventStreamList = entry.Value;
//检查当前聚合根的事件是否合法
if (!CheckAggregateEvents(aggregateRootId, eventStreamList, eventAppendResult, out AggregateLatestVersionData aggregateLatestVersionData))
{
continue;
}
//如果合法，则持久化事件到文件
foreach (var eventStream in eventStreamList)
{
var record = new EventStreamRecord
{
AggregateRootId = eventStream.AggregateRootId,
AggregateRootType = eventStream.AggregateRootType,
Version = eventStream.Version,
CommandId = eventStream.CommandId,
Timestamp = eventStream.Timestamp,
CommandCreateTimestamp = eventStream.CommandCreateTimestamp,
Events = eventStream.Events
};
if (aggregateLatestVersionData != null)
{
record.PreviousRecordLogPosition = aggregateLatestVersionData.LogPosition;
}
//写入事件到文件
_eventDataChunkWriter.Write(record);
//更新聚合根的内存缓存数据
RefreshMemoryCache(aggregateRootId, ref aggregateLatestVersionData, record);
//添加事件到事件队列，以便进行异步持久化事件索引和命令索引
_eventStreamRecordQueue.Enqueue(record);
}
eventAppendResult.SuccessAggregateRootIdList.Add(aggregateRootId);
}
return(eventAppendResult);
}
}
private void RefreshMemoryCache(string aggregateRootId, ref AggregateLatestVersionData aggregateLatestVersionData, EventStreamRecord record)
{
if (aggregateLatestVersionData != null)
{
var oldLastActiveTimestamp = aggregateLatestVersionData.LastActiveTimestamp;
aggregateLatestVersionData.Update(record.LogPosition, record.Version);
var newLastActiveTimestamp = aggregateLatestVersionData.LastActiveTimestamp;
_aggregateIndexCacheDict.UpdateTimeKeyDict(aggregateRootId, oldLastActiveTimestamp, newLastActiveTimestamp);
}
else
{
aggregateLatestVersionData = new AggregateLatestVersionData(record.LogPosition, record.Version);
_aggregateIndexCacheDict.AddOrUpdate(aggregateRootId, aggregateLatestVersionData);
}
_commandIndexCacheDict.AddOrUpdate(record.CommandId, new CommandIndexData(record.CommandCreateTimestamp));
}
public EventAppendResult AppendEventStream(IEventStream eventStream)
{
lock (_lockObj)
{
//判断命令是否重复
var commandCacheKey = BuildCommandCacheKey(eventStream.CommandCreateTimestamp);
if (_commandIndexDict.TryGetValue(commandCacheKey, out ConcurrentDictionary <string, byte> commandIndexDict))
{
if (commandIndexDict.ContainsKey(eventStream.CommandId))
{
return(EventAppendResult.DuplicateCommand);
}
}
//判断版本号是否冲突，使用内存中仅保留每个聚合根最新版本的字典来实现
if (_aggregateLatestVersionDict.TryGetValue(eventStream.AggregateRootId, out AggregateLatestVersionData aggregateLatestVersionData))
{
if (eventStream.Version != (aggregateLatestVersionData.Version + 1))
{
return(EventAppendResult.InvalidEventVersion);
}
}
else if (eventStream.Version != 1)
{
return(EventAppendResult.InvalidEventVersion);
}
//写入eventStream到文件
var record = new EventStreamRecord
{
AggregateRootId = eventStream.AggregateRootId,
AggregateRootType = eventStream.AggregateRootType,
Version = eventStream.Version,
CommandId = eventStream.CommandId,
Timestamp = eventStream.Timestamp,
CommandCreateTimestamp = eventStream.CommandCreateTimestamp,
Events = eventStream.Events
};
if (aggregateLatestVersionData != null)
{
record.PreviousRecordLogPosition = aggregateLatestVersionData.LogPosition;
}
_eventDataChunkWriter.Write(record);
//更新聚合根最新的事件版本
if (aggregateLatestVersionData != null)
{
aggregateLatestVersionData.Version = record.Version;
aggregateLatestVersionData.LogPosition = record.LogPosition;
}
else
{
aggregateLatestVersionData = new AggregateLatestVersionData
{
Version = record.Version,
LogPosition = record.LogPosition
};
_aggregateLatestVersionDict[eventStream.AggregateRootId] = aggregateLatestVersionData;
}
//添加命令索引到内存字典
_commandIndexDict
.GetOrAdd(commandCacheKey, k => new ConcurrentDictionary <string, byte>())
.TryAdd(eventStream.CommandId, 1);
//添加事件到事件队列，以便进行异步持久化事件索引和命令索引
_eventStreamRecordQueue.Enqueue(record);
return(EventAppendResult.Success);
}
}
