The progress printer was buggy where it would not print correctly
and some of the truncation logic was faulty.
The progress printer now prints something like:
go1.21.3.linux-amd64.tar.gz 21.53MiB 13.83MiB/s 33.88% ETA 00:00:03
where it shows
* the number of bytes transferred so far
* the rate of bytes transferred
(using a 1-second half-life for an exponentially weighted average)
* the progress made as a percentage
* the estimated time
(as calculated from the rate of bytes transferred)
Other changes:
* It now correctly prints the progress for very small files
* It prints at a faster rate (4Hz instead of 1Hz)
* It uses IEC units for byte quantities
(to avoid ambiguities of "kb" being kilobits or kilobytes)
Updates tailscale/corp#14772
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
469b7cabad