#!/usr/bin/env bash set -euo pipefail # Compare a criterion benchmark between two git branches.## Usage:#   script/compare-bench CRATE [BASE_BRANCH] [FEATURE_BRANCH]## CRATE is the cargo package to benchmark (e.g. `streaming_diff`); by default# the bench target of the same name is run.## The bench target name can be overridden via the BENCH_NAME environment# variable. The `--save-baseline <name>` flag is appended automatically. if [[ $# -lt 1 ]]; then    echo "usage: script/compare-bench CRATE [BASE_BRANCH] [FEATURE_BRANCH]" >&2    exit 1fi CRATE="$1"BASE_BRANCH="${2:-main}"FEATURE_BRANCH="${3:-streaming-edits-f32}"BENCH_NAME="${BENCH_NAME:-$CRATE}" BENCH_CMD=(    cargo bench -p "$CRATE" --bench "$BENCH_NAME" --profile release-fast --    --warm-up-time 1 --measurement-time 5) run_bench() {    local baseline_name="$1"    "${BENCH_CMD[@]}" --save-baseline "$baseline_name"} # Refuse to run with uncommitted changes, since we switch branches.if ! git diff --quiet || ! git diff --cached --quiet; then    echo "error: working tree has uncommitted changes; commit or stash first" >&2    exit 1fi # Remember where we started so we can restore it on exit.ORIGINAL_REF="$(git symbolic-ref --quiet --short HEAD || git rev-parse HEAD)"restore() {    git checkout --quiet "$ORIGINAL_REF"}trap restore EXIT echo "==> Benchmarking $BASE_BRANCH"git checkout --quiet "$BASE_BRANCH"run_bench "$BASE_BRANCH" echo "==> Benchmarking $FEATURE_BRANCH"git checkout --quiet "$FEATURE_BRANCH"run_bench "$FEATURE_BRANCH" echo "==> Comparison"if command -v critcmp >/dev/null 2>&1; then    critcmp "$BASE_BRANCH" "$FEATURE_BRANCH"else    echo "critcmp not found; showing criterion's own comparison instead."    echo "Install it with: cargo install critcmp"    "${BENCH_CMD[@]}" --load-baseline "$FEATURE_BRANCH" --baseline "$BASE_BRANCH"fi