contrib: add benchmark scripts

contrib/bench_row.sh

@@ -0,0 +1,31 @@
+# run one or more benchmarks, for use together with bench_table.sh
+# usage: ./bench_row.sh [-i] [-c crit_bench]..
+
+{
+    git log --oneline | head -n1
+
+    while getopts i:c: flag; do
+        case "$flag" in
+            i)
+                cargo bench -p bench-iai 2>|/dev/null \
+                    | awk -v b="$OPTARG" '
+                        $0 == b {inside=1}
+                        $0 == "" {inside=0}
+                        inside && $1 == "Estimated" {print $3, $4, $5}
+                    '
+                ;;
+            c)
+                # try to reduce noise by selecting max throughput of multiple runs
+                for _ in $(seq 100); do
+                    cargo bench -p bench-crit -- --quick "$OPTARG" 2>|/dev/null \
+                        | awk 'NR == 2 {print $4}'
+                done | sort -rV | head -n1
+                ;;
+            *)
+                exit 1
+                ;;
+        esac
+    done
+} | tr "\n" "\t"
+
+echo

contrib/bench_table.sh

@@ -0,0 +1,40 @@
+# run benchmarks over a range of commits and assemble a table
+# usage: ./contrib/bench_table.sh [-r RANGE] -- BENCHMARKS
+
+range="master.."
+while getopts r: flag; do
+    case "$flag" in
+        r) range=$OPTARG;;
+        *) exit 1;;
+    esac
+done
+shift $((OPTIND-1))
+
+[ -z "$*" ] && exit 1
+
+make bench || exit 1
+
+current="$(git rev-parse --abbrev-ref HEAD)"
+
+trap "git checkout $current" EXIT
+
+< /proc/cpuinfo grep "model name" | head -n1
+{
+    {
+        echo "commit"
+        OPTIND=1
+        while getopts i:c: flag "$@"; do
+            case "$flag" in
+                i) echo "iai:$OPTARG [cycles]";;
+                c) echo "criterion:$OPTARG [MB/s]";;
+                *) exit 1
+            esac
+        done
+    } | tr "\n" "\t"
+    echo
+    set -x
+    for commit in $(git rev-list --reverse --topo-order "$range"); do
+        git checkout "$commit" >/dev/null
+        ./contrib/bench_row.sh "$@" | tee /proc/self/fd/2
+    done
+} | column -t -s"$(printf "\t")"