public void Consume(long offset, out GruppoMessage message)
{
if (_guard.EnterExecute())
{
try
{
using (var index = _fileSystem.OpenIndexReader())
using (var messageReader = _fileSystem.OpenMessageFileReader(offset))
{
index.BaseStream.Seek((offset) * sizeof(Int64), SeekOrigin.Begin);
long beginOffset = index.ReadInt64();
messageReader.BaseStream.Seek(beginOffset, SeekOrigin.Begin);
message = ReadMessage(messageReader, offset, true);
}
}
finally
{
_guard.ExitExecute();
}
}
else
{
message = null;
}
}
public void Peek(long offset, out GruppoMessage message)
{
if (_guard.EnterExecute())
{
try
{
using (var index = _fileSystem.OpenIndexReader())
using (var messageReader = _fileSystem.OpenMessageFileReader(offset))
{
long position = offset * sizeof(long);
if (position > index.BaseStream.Length)
{
message = null;
return;
}
index.BaseStream.Position = position;
long messagePosition = index.ReadInt64();
messageReader.BaseStream.Position = messagePosition;
message = ReadMessage(messageReader, offset, false);
}
}
finally
{
_guard.ExitExecute();
}
}
else
{
message = null;
}
}
public void Consume(string groupName, out GruppoMessage message)
{
if (_guard.EnterExecute())
{
try
{
Group group;
lock (_groupConsumers)
{
if (!_groupConsumers.TryGetValue(groupName, out group))
{
group = CreateGroup(groupName);
_groupConsumers.Add(groupName, group);
}
}
lock (group)
{
// is there a message to read?
if (group.IndexReader.BaseStream.Position < group.IndexReader.BaseStream.Length)
{
// advance the index reader -- this is an atomic way of knowing if we have finished reading a message
// writing the index takes one step, writing the message takes several steps and we shouldn't try to read
// a message until it's completely written. The index is the last thing written so wait on it.
long messagePosition = group.IndexReader.ReadInt64();
// if the offset is zero then a new message file has been reached get it
if (messagePosition == 0)
{
group.MessageReader.Dispose();
group.MessageReader = _fileSystem.OpenMessageFileReader(group.Offset);
}
// read the message
message = ReadMessage(group.MessageReader, group.Offset, true);
group.Offset++;
// write group index out
group.GroupIndexWriter.BaseStream.Position = 0;
group.GroupIndexWriter.Write(group.Offset);
}
else
{
message = null;
}
}
}
finally
{
_guard.ExitExecute();
}
}
else
{
message = null;
}
}
public void Peek(string topicName, long offset, out GruppoMessage message)
{
message = null;
Topic topic = GetTopic(topicName);
if (topic != null)
{
topic.Peek(offset, out message);
}
}
public void Consume(string topicName, string group, out GruppoMessage message)
{
message = null;
Topic topic = GetTopic(topicName);
if (topic != null)
{
topic.Consume(group, out message);
}
}
public bool Produce(GruppoMessage message, out long offset, out DateTime timestamp)
{
if (_guard.EnterExecute())
{
try
{
lock (this)
{
// write out the message to the message stream
timestamp = DateTime.UtcNow;
long beginOffset = _produceMessageWriter.BaseStream.Position;
_produceMessageWriter.Write(timestamp.Ticks);
_produceMessageWriter.Write(message.Meta ?? string.Empty);
if (message.Body == null)
{
_produceMessageWriter.Write((int)0);
}
else
{
_produceMessageWriter.Write(message.Body.Length);
_produceMessageWriter.Write(message.Body);
}
_produceMessageWriter.Flush();
offset = _produceOffset++;
// write message start position to the index
_produceIndexWriter.Write(beginOffset);
_produceIndexWriter.Flush();
}
// check to see if the file needs to be rolled
if (_produceOffset % _fileSystem.MessageSplitSize == 0)
{
CreateProduceWriters();
}
return(true);
}
finally
{
_guard.ExitExecute();
}
}
else
{
offset = -1;
timestamp = DateTime.MinValue;
return(false);
}
}
private static GruppoMessage ReadMessage(BinaryReader messageReader, long offset, bool readBody)
{
GruppoMessage message = new GruppoMessage();
message.Offset = offset;
message.Timestamp = new DateTime(messageReader.ReadInt64());
message.Meta = messageReader.ReadString();
int length = messageReader.ReadInt32();
if (readBody)
{
message.Body = messageReader.ReadBytes(length);
}
return(message);
}
public void Produce(string topicName, string meta, byte[] body, out long offset, out DateTime timestamp)
{
Topic topic = GetTopic(topicName);
if (topic == null)
{
CreateTopic(topicName);
topic = GetTopic(topicName);
}
{
GruppoMessage message = new GruppoMessage()
{
Meta = meta,
Body = body
};
topic.Produce(message, out offset, out timestamp);
}
}
