build_oci_img() {
  # RUN apk add --no-cache bash git
  docker build "$@" - <<'EOF'
  FROM ubuntu
  RUN apt update && apt install -y bc curl gcc git
  ENV CARGO_HOME=/usr/local
  RUN curl -fsSL 'https://sh.rustup.rs' | sh -s -- -y --profile minimal
  RUN /usr/local/bin/cargo install --version 0.11.3 git-delta && cp /usr/local/bin/delta /usr/local/bin/delta-0.11.3
  RUN /usr/local/bin/cargo install --version 0.12.0 git-delta && cp /usr/local/bin/delta /usr/local/bin/delta-0.12.0
  RUN echo "I've forgotten how to invalidate layer cache entries properly: 1" > /dev/null
  RUN git clone https://github.com/th1000s/delta.git
  WORKDIR delta
  RUN git checkout query_ppids
  RUN cargo build --release && cp ./target/release/delta /usr/local/bin/delta-dev
EOF
}

build_oci_img
docker run --rm -i "$(build_oci_img -q)" bash <<'EOF'
benchmark-command() {
  local num_runs="${1:-100}"
  shift
  local before
  before=$(($(date +%s%N) / 1000000))
  printf 'Running command "%s" %d times\n' "$*" "${num_runs}"
  for _ in $(seq 1 "${num_runs}"); do
    eval -- "$@" > /dev/null
  done
  local after
  after=$(($(date +%s%N) / 1000000))
  local per_run
  per_run=$(bc < <(printf 'scale=2; %d/%d\n' $((after - before)) "${num_runs}"))
  echo "${per_run} ms per run ($((after - before)) ms total)"
}

benchmark-delta-versions() {
  for v in 0.11.3 0.12.0 dev; do
    echo "Benchmarking version: $v"
    delta-${v} --version
    benchmark-command 10 "git diff --no-index a b | delta-${v} >| delta-${v}-result"
  done
}

main() {
  echo aaa > a
  echo aab > b
  git diff --no-index a b | delta
  benchmark-delta-versions
  echo "Spinning up 5000 processes"
  for i in {1..5000}; do
    nohup sleep 30 & &> /dev/null
  done
  echo "Process counts:"
  ps --no-headers -e -o fname | sort | uniq -c
  benchmark-delta-versions
}

main
EOF