Run bench at Git ref helper script

scripts/run_bench_at_ref.sh

@@ -0,0 +1,129 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+
+usage() {
+  cat <<'EOF'
+usage:
+  ./scripts/run_bench_at_ref.sh <git-ref>
+
+Runs benchmarks for a specific git ref (tag, commit, or branch) and appends
+the results to bench/history.jsonl.
+
+Uses a temporary worktree to avoid disrupting your current working directory.
+
+Arguments:
+  git-ref    Git reference to benchmark (e.g., v0.4.0, abc1234, HEAD~3)
+
+Environment:
+  PARRHESIA_BENCH_RUNS               Number of runs (default: 3)
+  PARRHESIA_BENCH_MACHINE_ID         Machine identifier (default: hostname -s)
+
+All PARRHESIA_BENCH_* knobs from run_bench_compare.sh are forwarded.
+
+Example:
+  # Benchmark a specific tag
+  ./scripts/run_bench_at_ref.sh v0.4.0
+
+  # Benchmark a commit
+  ./scripts/run_bench_at_ref.sh abc1234
+
+  # Quick single-run benchmark
+  PARRHESIA_BENCH_RUNS=1 ./scripts/run_bench_at_ref.sh v0.3.0
+EOF
+}
+
+if [[ $# -eq 0 || "${1:-}" == "-h" || "${1:-}" == "--help" ]]; then
+  usage
+  exit 0
+fi
+
+GIT_REF="$1"
+
+# --- Validate ref exists -----------------------------------------------------
+
+if ! git rev-parse --verify "$GIT_REF" >/dev/null 2>&1; then
+  echo "Error: git ref '$GIT_REF' not found" >&2
+  exit 1
+fi
+
+RESOLVED_COMMIT="$(git rev-parse "$GIT_REF")"
+echo "Benchmarking ref: $GIT_REF ($RESOLVED_COMMIT)"
+echo
+
+# --- Setup worktree ----------------------------------------------------------
+
+WORKTREE_DIR="$(mktemp -d)"
+trap 'echo "Cleaning up worktree..."; git worktree remove --force "$WORKTREE_DIR" 2>/dev/null || rm -rf "$WORKTREE_DIR"' EXIT
+
+echo "Creating temporary worktree at $WORKTREE_DIR"
+git worktree add --detach "$WORKTREE_DIR" "$GIT_REF" >/dev/null 2>&1
+
+# --- Run benchmark in worktree -----------------------------------------------
+
+cd "$WORKTREE_DIR"
+
+# Always copy latest benchmark scripts to ensure consistency
+echo "Copying latest benchmark infrastructure from current..."
+mkdir -p scripts bench
+cp "$ROOT_DIR/scripts/run_bench_update.sh" scripts/
+cp "$ROOT_DIR/scripts/run_bench_compare.sh" scripts/
+cp "$ROOT_DIR/scripts/run_nostr_bench.sh" scripts/
+if [[ -f "$ROOT_DIR/scripts/run_nostr_bench_strfry.sh" ]]; then
+  cp "$ROOT_DIR/scripts/run_nostr_bench_strfry.sh" scripts/
+fi
+if [[ -f "$ROOT_DIR/scripts/run_nostr_bench_nostr_rs_relay.sh" ]]; then
+  cp "$ROOT_DIR/scripts/run_nostr_bench_nostr_rs_relay.sh" scripts/
+fi
+if [[ -f "$ROOT_DIR/bench/chart.gnuplot" ]]; then
+  cp "$ROOT_DIR/bench/chart.gnuplot" bench/
+fi
+echo
+
+echo "Installing dependencies..."
+mix deps.get
+echo
+
+echo "Running benchmark in worktree..."
+echo
+
+RUNS="${PARRHESIA_BENCH_RUNS:-3}"
+
+# Run the benchmark update script which will append to history.jsonl
+# Allow it to fail (e.g., README update might fail on old versions) but continue
+PARRHESIA_BENCH_RUNS="$RUNS" \
+PARRHESIA_BENCH_MACHINE_ID="${PARRHESIA_BENCH_MACHINE_ID:-}" \
+  ./scripts/run_bench_update.sh || echo "Benchmark script exited with error (may be expected for old versions)"
+
+# --- Copy results back -------------------------------------------------------
+
+echo
+echo "Copying results back to main repository..."
+
+if [[ -f "$WORKTREE_DIR/bench/history.jsonl" ]]; then
+  HISTORY_FILE="$ROOT_DIR/bench/history.jsonl"
+
+  # Get the last line from worktree history (the one just added)
+  NEW_ENTRY="$(tail -n 1 "$WORKTREE_DIR/bench/history.jsonl")"
+
+  # Check if this exact entry already exists in the main history
+  if grep -Fxq "$NEW_ENTRY" "$HISTORY_FILE" 2>/dev/null; then
+    echo "Note: Entry already exists in $HISTORY_FILE, skipping append"
+  else
+    echo "Appending result to $HISTORY_FILE"
+    echo "$NEW_ENTRY" >> "$HISTORY_FILE"
+  fi
+else
+  echo "Warning: No history.jsonl found in worktree" >&2
+  exit 1
+fi
+
+# --- Done --------------------------------------------------------------------
+
+echo
+echo "Benchmark complete for $GIT_REF"
+echo
+echo "To regenerate the chart with updated history:"
+echo "  # The chart generation reads from bench/history.jsonl"
+echo "  # You can manually trigger chart regeneration if needed"