feat: add upstream and verbose flags to command line interface

feat: add upstream support allowing to chain cache servers if needed
fix: tweaked garbage collection to be better

vfs/disk/disk_test.go

@@ -85,3 +85,62 @@ func TestInit(t *testing.T) {
 		t.Errorf("Stat failed: got %s, want %s", s.Name(), "key")
 	}
 }
+
+func TestDiskSizeDiscrepancy(t *testing.T) {
+	t.Parallel()
+	td := t.TempDir()
+
+	assumedSize := int64(6 + 5 + 6) // 6 + 5 + 6 bytes for key, key1, key2
+	os.WriteFile(filepath.Join(td, "key2"), []byte("value2"), 0644)
+
+	m := New(td, 1024)
+	if 6 != m.Size() {
+		t.Errorf("Size failed: got %d, want %d", m.Size(), 6)
+	}
+
+	if err := m.Set("key", []byte("value")); err != nil {
+		t.Errorf("Set failed: %v", err)
+	}
+
+	if err := m.Set("key1", []byte("value1")); err != nil {
+		t.Errorf("Set failed: %v", err)
+	}
+
+	if assumedSize != m.Size() {
+		t.Errorf("Size failed: got %d, want %d", m.Size(), assumedSize)
+	}
+
+	if d, err := m.Get("key"); err != nil {
+		t.Errorf("Get failed: %v", err)
+	} else if string(d) != "value" {
+		t.Errorf("Get failed: got %s, want %s", d, "value")
+	}
+
+	if d, err := m.Get("key1"); err != nil {
+		t.Errorf("Get failed: %v", err)
+	} else if string(d) != "value1" {
+		t.Errorf("Get failed: got %s, want %s", d, "value1")
+	}
+
+	m = New(td, 1024)
+
+	if assumedSize != m.Size() {
+		t.Errorf("Size failed: got %d, want %d", m.Size(), assumedSize)
+	}
+
+	if d, err := m.Get("key"); err != nil {
+		t.Errorf("Get failed: %v", err)
+	} else if string(d) != "value" {
+		t.Errorf("Get failed: got %s, want %s", d, "value")
+	}
+
+	if d, err := m.Get("key1"); err != nil {
+		t.Errorf("Get failed: %v", err)
+	} else if string(d) != "value1" {
+		t.Errorf("Get failed: got %s, want %s", d, "value1")
+	}
+
+	if assumedSize != m.Size() {
+		t.Errorf("Size failed: got %d, want %d", m.Size(), assumedSize)
+	}
+}