+#define VALID64(x) (((x) & 7ULL) == 0ULL)
+
+/* Use six characters to cover the offsets common in smallish journal
+ * files without adding too many zeros. */
+#define OFSfmt "%06"PRIx64
+
+static inline bool VALID_REALTIME(uint64_t u) {
+ /* This considers timestamps until the year 3112 valid. That should be plenty room... */
+ return u > 0 && u < (1ULL << 55);
+}
+
+static inline bool VALID_MONOTONIC(uint64_t u) {
+ /* This considers timestamps until 1142 years of runtime valid. */
+ return u < (1ULL << 55);
+}
+
+static inline bool VALID_EPOCH(uint64_t u) {
+ /* This allows changing the key for 1142 years, every usec. */
+ return u < (1ULL << 55);
+}