#!/bin/bash
# usage: page_split_bench.sh <clients> <seconds> <runs> <prefix> [<prefix> ...]
#
# Inserts of random keys into a btree (many page splits), 50 rows per
# transaction, with pgbench:
#   A: read committed, no serializable transaction around
#   B: the same inside BEGIN ISOLATION LEVEL SERIALIZABLE (--max-tries 50)
# One cluster per prefix (release builds), run round-robin, median TPS.
# The clusters live in $WORKDIR (default ./psbench, on disk): millions of
# inserted rows and their WAL would fill a tmpfs /tmp.
C=$1; T=$2; R=$3; shift 3
W=${WORKDIR:-$PWD/psbench}; rm -rf $W; mkdir -p $W
cat > $W/A.sql <<'EOF'
INSERT INTO t (k) SELECT (random() * 2000000000)::int FROM generate_series(1, 50);
EOF
cat > $W/B.sql <<'EOF'
BEGIN ISOLATION LEVEL SERIALIZABLE;
INSERT INTO t (k) SELECT (random() * 2000000000)::int FROM generate_series(1, 50);
COMMIT;
EOF
i=0
for P in "$@"; do
  i=$((i + 1)); port=$((56500 + i))
  $P/bin/initdb -D $W/d$i -U postgres --no-sync >/dev/null 2>&1
  cat >> $W/d$i/postgresql.conf <<EOF
shared_buffers = 1GB
fsync = off
synchronous_commit = off
full_page_writes = off
autovacuum = off
EOF
  $P/bin/pg_ctl -D $W/d$i -o "-p $port -k /tmp" -l $W/log$i -w start >/dev/null
done
trap 'i=0; for P in "$@"; do i=$((i + 1)); $P/bin/pg_ctl -D $W/d$i -m immediate -w stop >/dev/null 2>&1; done; rm -rf $W' EXIT
for w in A B; do
  for r in $(seq 1 $R); do
    i=0
    for P in "$@"; do
      i=$((i + 1)); port=$((56500 + i))
      $P/bin/psql -X -q -h /tmp -p $port -U postgres postgres \
        -c "DROP TABLE IF EXISTS t" -c "CREATE TABLE t (k int)" -c "CREATE INDEX ON t (k)" -c "CHECKPOINT"
      $P/bin/pgbench -n -h /tmp -p $port -U postgres -c $C -j $C -T $T --max-tries=50 \
        -f $W/$w.sql postgres > $W/pgbench.out 2>&1
      tps=$(grep -oE 'tps = [0-9.]+' $W/pgbench.out | grep -oE '[0-9.]+')
      [ -n "$tps" ] || { echo "pgbench failed ($w, $P):" >&2; tail -3 $W/pgbench.out >&2; }
      echo "$w $i $tps" | tee -a $W/raw
    done
  done
done
echo "TPS ($C clients, $T s, $R runs): median [min - max]"
for w in A B; do
  i=0
  for P in "$@"; do
    i=$((i + 1))
    awk -v w=$w -v n=$i '$1==w && $2==n && $3 != "" {print $3}' $W/raw | sort -n |
      awk -v w=$w -v p=$P '{a[NR]=$1} END {printf "  %s  %-40s %8.0f  [%.0f - %.0f]  (%d runs)\n", w, p, a[int((NR+1)/2)], a[1], a[NR], NR}'
  done
done