void WriteContinuation(int messageSize)
{
// First, allocate a new buffer:
string newName = Name + "." + ++m_BufferCount;
int newLength = Math.Max(messageSize * 10, MinimumBufferSize);
var newFile = new SafeMemoryMappedFile(MemoryMappedFile.CreateNew(newName, newLength, MemoryMappedFileAccess.ReadWrite));
Trace.WriteLine($"Allocated new buffer of {newLength} bytes");
// Write a message to the old buffer indicating the address of the new buffer:
WriteMessage(new byte[0]);
// Keep the old buffer alive until the reader has indicated that it's seen it:
m_OldBuffers.Add(Buffer);
// Make the new buffer current:
Buffer = newFile;
Length = newFile.Length;
Offset = StartingOffset;
// Release old buffers that have been read:
foreach (var buffer in m_OldBuffers.Take(m_OldBuffers.Count - 1).ToArray())
{
lock (buffer.NoDisposeWhileLocked)
{
if (!buffer.Disposed && buffer.Accessor.ReadBoolean(4))
{
m_OldBuffers.Remove(buffer);
buffer.Dispose();
Trace.WriteLine("Cleaned file");
}
}
}
}
protected MutexFreePipe(string name, bool createBuffer)
{
Name = name;
var mmFile = createBuffer
? MemoryMappedFile.CreateNew(String.Concat(name, INITIAL_FILE_EXT), MinimumBufferSize, MemoryMappedFileAccess.ReadWrite)
: MemoryMappedFile.OpenExisting(String.Concat(name, INITIAL_FILE_EXT));
Buffer = new SafeMemoryMappedFile(mmFile);
NewMessageSignal = new EventWaitHandle(false, EventResetMode.AutoReset, String.Concat(name, ".signal"));
Length = Buffer.Length;
Offset = StartingOffset;
}
unsafe byte[] GetNextMessage()
{
m_LastMessageProcessed++;
lock (NoDisposeWhileLocked)
{
if (Disposed)
{
return(null);
}
lock (Buffer.NoDisposeWhileLocked)
{
if (Buffer.Disposed)
{
return(null);
}
byte *offsetPointer = Buffer.Pointer + Offset;
var msgPointer = (int *)offsetPointer;
int msgLength = *msgPointer;
Offset += MessageHeaderLength;
offsetPointer += MessageHeaderLength;
if (msgLength == 0)
{
Buffer.Accessor.Write(4, true); // Signal that we no longer need file
Buffer.Dispose();
string newName = Name + "." + ++m_BufferCount;
Buffer = new SafeMemoryMappedFile(MemoryMappedFile.OpenExisting(newName));
Offset = StartingOffset;
return(new byte[0]);
}
Offset += msgLength;
//MMF.Accessor.ReadArray (Offset, msg, 0, msg.Length); // too slow
var msg = new byte[msgLength];
Marshal.Copy(new IntPtr(offsetPointer), msg, 0, msg.Length);
return(msg);
}
}
}
