#!/usr/bin/env bash
# A slow client against a fast model: curl reads 300 KB/s of a 600 x 32 KB stream (19.6 MB) while the
# stub writes with no delay. Samples how far the stub got and how much heap the app holds.
# Usage: backpressure.sh <none|limitRate|slow> [extra app args]
source "$(dirname "$0")/lib.sh"; set +e
MODE=${1:-none}; shift
stop_all; start_stub 0; start_app --chat.backpressure="$MODE" --chat.slow-millis=5 "$@"
echo "== chat.backpressure=$MODE  (stub delay 0 ms, 600 chunks x 32 KiB, client reads 64 KiB every 0.2 s)"
echo 0 > "$RUN/recv.bytes"
python3 scripts/slow_client.py "http://localhost:$APP_PORT/chat/stream?message=big%20600&turn=1" "$RUN/recv.bytes" &
CURL=$!
T0=$(date +%s.%N)
for pause in 1 1 2 3 4; do
  sleep "$pause"
  st=$(curl -s "localhost:$STUB_PORT/stub/stats" | sed 's/requests=[0-9]* //')
  recv=$(cat "$RUN/recv.bytes")
  now=$(date +%s.%N)
  jcmd "$(cat $RUN/app.pid)" GC.run >/dev/null 2>&1
  heap=$(jcmd "$(cat $RUN/app.pid)" GC.heap_info 2>/dev/null | grep -o "used [0-9]*K" | head -1)
  printf "t=%4.1fs  client got %5d KiB   stub: %s   app heap after GC: %s\n" "$(echo "$now - $T0" | bc)" $((recv/1024)) "$st" "$heap"
done
wait $CURL 2>/dev/null
echo "-- app log (demand + outcome):"
grep "demand\|CANCELLED\|complete\|error" $RUN/app.log | sed "s/turn 1 //" | sort | uniq -c | sort -rn | head -6
stop_all