public void Pop(Server server)
{
System.Diagnostics.Debug.Assert(_logLength > 0);
var lastIndex = _logIndices[--_logLength];
//roll back add
if (lastIndex.Type == LogIndexType.AddServer)
{
System.Diagnostics.Debug.Assert(_configLocked);
var id = GetIPEndPoint(GetData(lastIndex));
_configLocked = false;
if (!server.ID.Equals(id))
server.RemoveClientFromLog(id);
Console.WriteLine("{0}x: Rolling back add server {1} and unlocking config", server.Name, id);
saveSuperBlock();
}
else if (lastIndex.Type == LogIndexType.RemoveServer)
{
System.Diagnostics.Debug.Assert(_configLocked);
var id = GetIPEndPoint(GetData(lastIndex));
_configLocked = false;
if (!server.ID.Equals(id))
server.AddClientFromLog(id);
Console.WriteLine("{0}x: Rolling back remove server {1} and unlocking config", server.Name, id);
saveSuperBlock();
}
//_logLength--;
}
//public bool WriteChunk(Server server, byte[] )
public bool Push(Server server, LogEntry data)
{
//we couldn't take this entry because we are still waiting for another
//to finish
if (_configLocked)
{
return false;
}
//if (data.Data == null && data.Index.ChunkSize > 0)
//{
// Console.WriteLine("{0}: Data length is 0 and data chunksize is {1}", server.Name, data.Index.ChunkSize);
// return false;
//}
//if (data.Data != null && data.Data.Length != data.Index.ChunkSize)
//{
// Console.WriteLine("{0}: Data length is {1} and data chunksize is {2}", server.Name, data.Data.Length, data.Index.ChunkSize);
// return false;
//}
// we must first write the data to the dat file
// in case of crash in between log data and log entry
// this will orphan the data and on startup will reclaim the space
// stream length is in UNSIGN but seek is SIGN?
// seek before we commit the data so we are at the right position
_logIndexWriter.Seek((int)(SUPER_BLOCK_SIZE + _logLength * LogIndex.LOG_RECORD_SIZE), SeekOrigin.Begin);
// make sure we have enough capacity
ensureLogIndices(_logLength + 1);
//write to log data file
_logDataFile.Seek(DataPosition, SeekOrigin.Begin);
_logDataFile.Write(data.Data, 0, (int)data.Index.ChunkSize);
//update log entries
_logIndices[_logLength] = data.Index;
//flush data
_logDataFile.Flush();
//write data
_logIndexWriter.Write(data.Index.Term);
_logIndexWriter.Write((uint)data.Index.Type);
_logIndexWriter.Write(data.Index.ChunkOffset);
_logIndexWriter.Write(data.Index.ChunkSize);
_logIndexWriter.Write(data.Index.Flag1);
_logIndexWriter.Write(data.Index.Flag2);
_logIndexWriter.Write(data.Index.Flag3);
_logIndexWriter.Write(data.Index.Flag4);
_logIndexWriter.Flush();
//inc log index
_logLength++;
//add server before commit
if (data.Index.Type == LogIndexType.AddServer)
{
var id = GetIPEndPoint(data.Data);
if (!server.ID.Equals(id))
server.AddClientFromLog(id);
//System.Diagnostics.Debug.Assert(_configLocked == false);
Console.WriteLine("{0}: Adding server {1} and locking config", server.Name, id);
_configLocked = true;
saveSuperBlock();
}
else if (data.Index.Type == LogIndexType.RemoveServer)
{
var id = GetIPEndPoint(data.Data);
if (!server.ID.Equals(id))
server.RemoveClientFromLog(id);
//System.Diagnostics.Debug.Assert(_configLocked == false);
Console.WriteLine("{0}: Removing server {1} and locking config", server.Name, id);
_configLocked = true;
saveSuperBlock();
}
//this can happen on log rollbacks
//System.Diagnostics.Debug.Assert(_logDataFile.Length == DataPosition);
return true;
}