public long Read(long fromId, long count, List <ChatHistoryMessage> result)
{
if (count <= 0)
{
return(0);
}
if (SeekDataOffset(fromId) < 0)
{
return(0);
}
long i = 0;
for (; i < count; ++i)
{
byte[] msgSizeBytes = new byte[4];
int msgSizeLen = data.Read(msgSizeBytes, 0, msgSizeBytes.Length);
if (msgSizeLen == 0) // eof
{
break;
}
if (msgSizeBytes.Length != msgSizeLen)
{
throw new Exception("read size error");
}
int msgSize = BitConverter.ToInt32(msgSizeBytes, 0);
byte[] msgDataBytes = new byte[msgSize];
if (msgDataBytes.Length != data.Read(msgDataBytes, 0, msgDataBytes.Length))
{
throw new Exception("read data error");
}
global::Zeze.Serialize.ByteBuffer bb = global::Zeze.Serialize.ByteBuffer.Wrap(msgDataBytes);
ChatHistoryMessage msg = new ChatHistoryMessage();
msg.Decode(bb);
if (msg.Id != fromId + i)
{
throw new Exception("msgId error");
}
result.Add(msg);
}
return(i);
}
/// <summary>
/// 增加消息到聊天历史中。
/// </summary>
/// <param name="sender">发送者</param>
/// <param name="type">消息类型</param>
/// <param name="content">消息内容</param>
/// <returns></returns>
public long AddMessage(string sender, int type, byte[] content)
{
if (type < 0)
{
throw new ArgumentException("type is reserved: " + type);
}
lock (this)
{
ChatHistoryMessage msg = new ChatHistoryMessage
{
Tag = 0,
Id = LastId,
TimeTicks = DateTime.Now.Ticks,
Sender = sender,
Type = type,
Content = content
};
if (this.SeparateContentLength > 0 && content.Length > this.SeparateContentLength)
{
msg.Tag = ChatHistoryMessage.TagSeparate;
msg.SaveContentToFile(System.IO.Path.Combine(this.ContentHome, msg.Id.ToString()));
msg.Content = Array.Empty <byte>(); // 对于图片视频，这里可以考虑放一个缩小的提示性图片。
}
if (this.MaxSingleDataFileLength > 0 && _lastDataFile.DataFileLength > this.MaxSingleDataFileLength)
{
OpenOrCreateLastDataFile(LastId);
}
global::Zeze.Serialize.ByteBuffer bb = global::Zeze.Serialize.ByteBuffer.Allocate(msg.SizeHint());
bb.BeginWriteWithSize4(out var state);
msg.Encode(bb);
bb.EndWriteWithSize4(state);
_lastDataFile.WriteToTail(bb.Bytes, bb.ReadIndex, bb.Size);
return(LastId++); // 最后才真的增加，避免上面异常导致LastId已被增加。
}
}
public byte[] LoadContentFromFile(long id)
{
return(ChatHistoryMessage.LoadContentFromFile(System.IO.Path.Combine(this.ContentHome, id.ToString())));
}