Tom Scogland 4a7b0afde2 Log performance improvement (#23925) ... * util.tty.log: read up to 100 lines if ready Rework to read up to 100 lines from the captured stdin as long as data is ready to be read immediately. Adds a helper function to poll with `select` for ready data. This showed a roughly 5-10x perf improvement for high-rate writes through the logger with relatively short lines. * util.tty.log: Defer flushes to end of ready reads Rather than flush per line, flush per set of reads. Since this is a non-blocking loop, the total perceived wait is short. * util.tty.log: only scan each line once, usually Rather than always find all control characters then substitute them all, use `subn` to count the number of control characters replaced. Only if control characters exist find out what they are. This could be made truly single pass with sub with a function, but it's a more intrusive change and this got 99%ish of the performance improvement (roughly another 2x in some cases). * util.tty.log: remove check for `readable` Python < 3 does not support a readable check on streams, should not be necessary here since we control the only use and it's explicitly a stream to be read.		2021-05-31 20:33:14 -07:00
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util	Log performance improvement (#23925)	2021-05-31 20:33:14 -07:00
__init__.py	copyrights: update all files with license headers for 2021	2021-01-02 12:12:00 -08:00