These are chat archives for HdrHistogram/HdrHistogram

7th
Aug 2015
Alec
@ahothan
Aug 07 2015 14:59
@mikeb01 are you planning to support different size of counters like in the java version (16 and 32-bit)? Just learnt the hard way that there were 16-bit counters compressed logs by running my test agaings the jhiccup log @giltene pointed to ;-(
Alec
@ahothan
Aug 07 2015 15:08
@giltene I thought I was done with it after writing the log readers/writers classes and decode the jhiccup log. It busted on the cookie check and now I know why the cookie had this 8 << 4 in it and I see all those Int, Short histogram classes, this whole code is bigger in scope than I realized.
Obviously 32-bit counters take less space and would work in a lot of cases. If encoded size was the main purpose, something like GPB (Google Protocol Buffer) to encode a histogram would make sense as it would automatically encode each count with the smallest number of bits (GPB is pretty fast in C) and would avoid using zlib.
Or was the main purpose to save space in application memory?
Michael Barker
@mikeb01
Aug 07 2015 20:49
@ahothan No I wasn't going to support them directly. The log reading code should deal with them though and widen the values into the 64bit implementation. I would consider doing the 16/32 bit if someone had a real need. I was considering changing it to use the default word size for the machine it is running on.