On Oct 22, 2009, at 16:36 , Kenton Varda wrote: > You note that small messages seem faster with smaller buffer sizes, > but larger messages are slower. I am guessing that by "small > messages" you mean ones which are significantly smaller than the > buffer size, and "large messages" means larger than the buffer size.
Right. I just used the messages and benchmark framework in SVN: http://code.google.com/p/protobuf/source/browse/#svn/trunk/benchmarks The small message is 228 bytes, the large message is 82.6 kB > One thing you might try: if the message is smaller than 4096 (or > whatever the buffer size constant is), then allocate a buffer > exactly as big as the message to avoid waste. You can call > getSerializedSize() to find out the message size ahead of time. > Note that calling this doesn't actually waste any time since the > result is cached, and it would have to be called during > serialization anyway. That is a good idea. This would be a tiny patch to the AbstractMessageLite.writeTo(OutputStream). It already effectively does this for toByteString() and toByteArray(), but doing this for writeTo(OutputStream) would probably be a win: either it uses the JDK's preferred buffer size for big messages, which would halve the number of calls to .write(), or would use an exact sized buffer for smaller messages, which (should? might?) result in reduced garbage collection. I'll put testing this on my TODO list. It is a trivial code change, but benchmarking it carefully takes time. Basically this all started because I was curious how many times my data was being copied between a protocol message and the wire. I should eventually try some of these tweaks on a "larger" application that is doing network I/O, so I'll eventually do some digging in that context. Evan -- Evan Jones http://evanjones.ca/ --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Protocol Buffers" group. To post to this group, send email to protobuf@googlegroups.com To unsubscribe from this group, send email to protobuf+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/protobuf?hl=en -~----------~----~----~----~------~----~------~--~---
