chore: import upstream snapshot with attribution

cmd/gortex/daemon_compact_test.go

@@ -0,0 +1,56 @@
+package main
+
+import "testing"
+
+// TestShouldCompactStore pins the boot-compaction trigger: all three gates
+// (majority-dead file, absolute reclaimable floor, disk headroom for the
+// VACUUM copy) must hold, and each boundary is exclusive — equality on any
+// gate means "don't". Pure-function table so the policy is exercised without
+// a store or a filesystem.
+func TestShouldCompactStore(t *testing.T) {
+	const (
+		gib = int64(1) << 30
+		tib = uint64(1) << 40
+	)
+	cases := []struct {
+		name  string
+		free  int64
+		total int64
+		avail uint64
+		want  bool
+	}{
+		{name: "all gates hold", free: 2 * gib, total: 3 * gib, avail: tib, want: true},
+		{name: "the observed live store shape (4.4/6.8 GB)", free: 4707074048, total: 7301444403, avail: tib, want: true},
+
+		// Fraction gate: freelist must be a strict MAJORITY of the file.
+		{name: "exactly half free — no", free: 2 * gib, total: 4 * gib, avail: tib, want: false},
+		{name: "just under half free — no", free: 2*gib - 1, total: 4 * gib, avail: tib, want: false},
+		{name: "just over half free — yes", free: 2*gib + 1, total: 4 * gib, avail: tib, want: true},
+
+		// Absolute floor: a small file's majority is still not worth minutes
+		// of exclusive I/O.
+		{name: "90% free but only 900 MiB — no", free: 900 << 20, total: 1 << 30, avail: tib, want: false},
+		{name: "exactly 1 GiB free — no (floor is exclusive)", free: gib, total: gib + 2, avail: tib, want: false},
+
+		// Headroom gate: available disk must strictly exceed total × 1.5,
+		// because VACUUM transiently needs up to a full extra copy.
+		{name: "avail exactly 1.5× — no", free: 2 * gib, total: 3 * gib, avail: uint64(3*gib) + uint64(3*gib)/2, want: false},
+		{name: "avail just over 1.5× — yes", free: 2 * gib, total: 3 * gib, avail: uint64(3*gib) + uint64(3*gib)/2 + 1, want: true},
+		{name: "tight disk — no", free: 2 * gib, total: 3 * gib, avail: uint64(3 * gib), want: false},
+
+		// Degenerate inputs: an unreadable store reports zeros; never fire.
+		{name: "zero stats", free: 0, total: 0, avail: tib, want: false},
+		{name: "zero free", free: 0, total: 4 * gib, avail: tib, want: false},
+		{name: "zero total", free: 2 * gib, total: 0, avail: tib, want: false},
+		{name: "negative total", free: 2 * gib, total: -1, avail: tib, want: false},
+		{name: "zero avail", free: 2 * gib, total: 3 * gib, avail: 0, want: false},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := shouldCompactStore(tc.free, tc.total, tc.avail); got != tc.want {
+				t.Errorf("shouldCompactStore(free=%d, total=%d, avail=%d) = %v, want %v",
+					tc.free, tc.total, tc.avail, got, tc.want)
+			}
+		})
+	}
+}