/** Read all the messages in the queue */
public List <TaggedBlob> Read()
{
List <TaggedBlob> result = new List <TaggedBlob>();
// Wait until there's (probably) something new
this.sharedMemory.BufferChangedEvent.WaitOne();
if (this.sharedMemory.Mutex.WaitOneNoExcept())
{
try {
// Read the message count at the start of the buffer
this.sharedMemory.MemoryViewStream.Seek(0, SeekOrigin.Begin);
int messageCount = this.sharedMemory.Reader.ReadInt32();
// Read over that many messages
for (int i = 0; i < messageCount; i++)
{
result.Add(TaggedBlob.Read(this.sharedMemory.Reader));
}
// Update the message count
this.sharedMemory.MemoryViewStream.Seek(0, SeekOrigin.Begin);
this.sharedMemory.Writer.Write((int)0);
}
finally
{
this.sharedMemory.Mutex.ReleaseMutex();
}
}
return(result);
}
//---------------------------------------------------------------------
// Reading and writing
//---------------------------------------------------------------------
public static TaggedBlob Read(BinaryReader reader)
{
TaggedBlob result = new TaggedBlob();
result.Tag = reader.ReadInt32();
int cb = reader.ReadInt32();
result.Payload = reader.ReadBytes(cb);
return result;
}
//---------------------------------------------------------------------
// Reading and writing
//---------------------------------------------------------------------
public static TaggedBlob Read(BinaryReader reader)
{
TaggedBlob result = new TaggedBlob();
result.Tag = reader.ReadInt32();
int cb = reader.ReadInt32();
result.Payload = reader.ReadBytes(cb);
return(result);
}
public void Write(TaggedBlob blob, int msTimeout = -1)
{
if (this.sharedMemory.Mutex.WaitOneNoExcept(msTimeout))
{
try {
// Read the message count at the start of the buffer
this.sharedMemory.MemoryViewStream.Seek(0, SeekOrigin.Begin);
int messageCount = this.sharedMemory.Reader.ReadInt32();
// Skip over that many messages
for (int i = 0; i < messageCount; i++)
{
TaggedBlob.Read(this.sharedMemory.Reader);
}
// Write the next string. 'May hit the buffer end and throw exception, but
// that's ok; we'll just be ignoring this message
blob.Write(this.sharedMemory.Writer);
// Update the message count
this.sharedMemory.MemoryViewStream.Seek(0, SeekOrigin.Begin);
this.sharedMemory.Writer.Write(messageCount + 1);
// Let the reader know there's new stuff
this.sharedMemory.BufferChangedEvent.Set();
}
catch (Exception)
{
// Ignore write errors; they'll be at buffer end. The actual exeption we
// see is a NotSupportedException thrown by the stream when asked to extend
// it's length
}
finally
{
this.sharedMemory.Mutex.ReleaseMutex();
}
}
}
public void Write(TaggedBlob blob, int msTimeout=-1)
{
if (this.sharedMemory.Mutex.WaitOneNoExcept(msTimeout))
{
try {
// Read the message count at the start of the buffer
this.sharedMemory.MemoryViewStream.Seek(0, SeekOrigin.Begin);
int messageCount = this.sharedMemory.Reader.ReadInt32();
// Skip over that many messages
for (int i = 0; i < messageCount; i++)
{
TaggedBlob.Read(this.sharedMemory.Reader);
}
// Write the next string. 'May hit the buffer end and throw exception, but
// that's ok; we'll just be ignoring this message
blob.Write(this.sharedMemory.Writer);
// Update the message count
this.sharedMemory.MemoryViewStream.Seek(0, SeekOrigin.Begin);
this.sharedMemory.Writer.Write(messageCount + 1);
// Let the reader know there's new stuff
this.sharedMemory.BufferChangedEvent.Set();
}
catch (Exception)
{
// Ignore write errors; they'll be at buffer end. The actual exeption we
// see is a NotSupportedException thrown by the stream when asked to extend
// it's length
}
finally
{
this.sharedMemory.Mutex.ReleaseMutex();
}
}
}