These are chat archives for HdrHistogram/HdrHistogram

6th
Mar 2017
Marshall Pierce
@marshallpierce
Mar 06 2017 02:17
Sounds good.
What about the compressed version? Should I only expose the compressed version maybe?
(Let some concerned citizen package up log format upgrading as a AWS Lambda function and convert to their heart's content)
Marshall Pierce
@marshallpierce
Mar 06 2017 05:27
Also, if you end up kicking around a new format at some point, the number of significant digits is a 32-bit int but I don't see a reason why it couldn't be a byte. Though, those 3 bytes probably aren't going to make anyone's day...
It's a bit unfortunate that since Rust can do 64-bit unsigned types we end up able to have in-memory histograms that can't be serialized (when counts are above the max signed 64-bit value), but I think that's probably not worth addressing... 2^62 ought to be enough for anybody
Marshall Pierce
@marshallpierce
Mar 06 2017 15:57
I've got serialization more or less working, but it would be nice to have a structured corpus of serialized histograms to ensure interop. As a first attempt at that , I was thinking about writing a tool (to live in the Java project) that would emit some test cases as plain text files. I think the needs here are so simple that just plain old key=value (aka properties) is good enough. If we encode all the initialization parameters (lowest, highest, number of digits), the values recorded (as space separated numbers), and the base64-encoded serialized form, it should be straightforward for any implementation to use that to make sure serialization is interoperable. (This would also indirectly check that the value to counts array mapping is done correctly as well, assuming that the user of these files recreates the histogram from scratch given the provided initialization parameters and values.)