Change #255407

Comments

ratelimit: download finetune

When a download size is known and rate limiting is in effect, adjust the
duration of each measurement step and its rate for maximum precision.

Since it is unpredictable how long the last bytes of a download will
take, download speed can be thrown off if the "last bytes" are a
significant amount of the total download. Make the "last bytes" small in
comparision to the rest and "stretch" the rate limit intervals to
accommodate the difference.

Fix ngtcp2 receive data acknowldgements to be based on a local window
size tracking. This allows window updates controlled by rate limits.

Fix ratelimit wait time calculation to accomodate negative tokens.

h3 rate limit, update timeers

Make download rate limits work correctly in ngtcp2. Fix multi handling
of rate limits to set a timer for when limits will update again.

Without running the transfer on limit updates, protocols like h2/h3 may
stall if the server does not send due to stream windows being too small.

scorecard: measure download speedlimits

When running scorecard with --limit-rate=n, show the reported download
speed averages plus percentage deviation from the limit.

Closes #20228

Changed files

• lib/http2.c
• lib/multi.c
• lib/progress.c
• lib/ratelimit.c
• lib/ratelimit.h
• lib/sendf.c
• lib/vquic/curl_ngtcp2.c
• tests/http/scorecard.py
• tests/http/test_02_download.py
• tests/unit/unit3216.c