#!/bin/bash

set -eu
set -o pipefail

base_dir=$(dirname "$0")

prepare_sql()
{
  size=$1
  db_name=$2

  cat <<SQL
DROP DATABASE IF EXISTS ${db_name};
CREATE DATABASE ${db_name};
\\c ${db_name}

CREATE TABLE data (int32 integer);
SELECT setseed(0.29);
INSERT INTO data
  SELECT random() * 10000
    FROM generate_series(1, ${size});
SQL
}

measure()
{
  local format=$1
  local n_tries=6
  for i in $(seq ${n_tries}); do
    LANG=C \
      PAGER=cat \
      psql \
      --no-psqlrc \
      --command "\\timing" \
      --command "COPY data TO '/dev/null' WITH (FORMAT ${format})" \
      --command "COPY data TO '/dev/null' WITH (FORMAT ${format})" \
      --command "COPY data TO '/dev/null' WITH (FORMAT ${format})" | \
      grep --text -o '^Time: [0-9.]* ms' | \
      grep -o '[0-9.]*'
  done | sort --numeric-sort | head -n 9 | tail -n 1
}

result_suffix=""
if [ $# -gt 0 ]; then
  result_suffix="-$1"
fi
result="${base_dir}/result${result_suffix}.csv"
echo "Format,N records,Elapsed time (ms)" | \
  tee "${result}"
sizes=()
sizes+=(100000)
sizes+=(1000000)
sizes+=(10000000)
for size in "${sizes[@]}"; do
  export PGDATABASE="copy_${size}"
  echo "${size}: preparing"
  prepare_sql "${size}" "${PGDATABASE}" | \
    psql -d postgres

  echo "${size}: text"
  elapsed_time=$(measure text)
  echo "text,${size},${elapsed_time}" | \
    tee -a "${result}"

  echo "${size}: csv"
  elapsed_time=$(measure csv)
  echo "csv,${size},${elapsed_time}" | \
    tee -a "${result}"

  echo "${size}: binary"
  elapsed_time=$(measure binary)
  echo "binary,${size},${elapsed_time}" | \
    tee -a "${result}"
done