1 files changed, 42 insertions, 0 deletions
diff --git a/tools/finditers/finditers.go b/tools/finditers/finditers.go
new file mode 100644
index 0000000..31a7e33
--- /dev/null
+++ b/tools/finditers/finditers.go
@@ -0,0 +1,42 @@
+package main
+
+import (
+	"encoding/hex"
+	"fmt"
+	"sort"
+	"testing"
+	"time"
+
+	"gitlab.com/rhogenson/roseh.moe/internal/pwhash"
+)
+
+func mustHex(t testing.TB, s string) []byte {
+	t.Helper()
+	b, err := hex.DecodeString(s)
+	if err != nil {
+		t.Fatalf("Invalid hex %q: %s", s, err)
+	}
+	return b
+}
+
+var iterations int
+
+func BenchmarkHashIter(b *testing.B) {
+	const pw = "atypical evasion foyer roulette throng awning stability exchange humorless vowed"
+	salt := mustHex(b, "4250af599e07cde7")
+	for b.Loop() {
+		pwhash.HashIter(pw, salt, iterations)
+	}
+}
+
+func main() {
+	const targetDuration = 5 * time.Second
+	for iterations = 4096; time.Duration(testing.Benchmark(BenchmarkHashIter).NsPerOp()) < targetDuration; iterations *= 2 {
+	}
+	lo := iterations / 2
+	hi := iterations
+	fmt.Println(lo + sort.Search(hi-lo, func(i int) bool {
+		iterations = lo + i
+		return time.Duration(testing.Benchmark(BenchmarkHashIter).NsPerOp()) > targetDuration
+	}))
+}