File Coverage

include/horus_time.h

Criterion	Covered	Total	%
statement	29	29	100.0
branch	1	2	50.0
condition			n/a
subroutine			n/a
pod			n/a
total	30	31	96.7

#ifndef HORUS_TIME_H
#define HORUS_TIME_H

/*
 * horus_time.h - Timestamp helpers for UUID generation
 *
 * Gregorian: 60-bit count of 100-nanosecond intervals since Oct 15, 1582
 * Unix epoch: 48-bit milliseconds since Jan 1, 1970
 */

#include
#include

/* Offset between UUID epoch (1582-10-15) and Unix epoch (1970-01-01)
 * in 100-nanosecond intervals */
#define HORUS_UUID_EPOCH_OFFSET UINT64_C(0x01B21DD213814000)

/* ── Gregorian timestamp (for v1, v6) ───────────────────────────── */

static inline uint64_t horus_gregorian_100ns(void) {
#if defined(CLOCK_REALTIME) && !defined(__APPLE__)
    /* Use clock_gettime for nanosecond resolution where available */
    struct timespec ts;
    clock_gettime(CLOCK_REALTIME, &ts);
    return ((uint64_t)ts.tv_sec * 10000000ULL)
         + ((uint64_t)ts.tv_nsec / 100ULL)
         + HORUS_UUID_EPOCH_OFFSET;
#else
    /* Fallback: gettimeofday gives microsecond resolution */
    struct timeval tv;
    gettimeofday(&tv, NULL);
    return ((uint64_t)tv.tv_sec * 10000000ULL)
         + ((uint64_t)tv.tv_usec * 10ULL)
         + HORUS_UUID_EPOCH_OFFSET;
#endif
}

/* ── Unix epoch milliseconds (for v7) ──────────────────────────── */

static inline uint64_t horus_unix_epoch_ms(void) {
    struct timeval tv;
    gettimeofday(&tv, NULL);
    return ((uint64_t)tv.tv_sec * 1000ULL) + ((uint64_t)tv.tv_usec / 1000ULL);
}

/* ── Extract Gregorian timestamp from v1 UUID bytes ─────────────── */

static inline uint64_t horus_extract_time_v1(const unsigned char *bytes) {
    /* v1 layout: time_low (bytes 0-3), time_mid (bytes 4-5),
     * time_hi_and_version (bytes 6-7, version in high nibble) */
    uint64_t time_low  = ((uint64_t)bytes[0] << 24) | ((uint64_t)bytes[1] << 16)
                       | ((uint64_t)bytes[2] << 8)  | (uint64_t)bytes[3];
    uint64_t time_mid  = ((uint64_t)bytes[4] << 8)  | (uint64_t)bytes[5];
    uint64_t time_hi   = ((uint64_t)(bytes[6] & 0x0F) << 8) | (uint64_t)bytes[7];

    return (time_hi << 48) | (time_mid << 32) | time_low;
}

/* ── Extract Gregorian timestamp from v6 UUID bytes ─────────────── */

static inline uint64_t horus_extract_time_v6(const unsigned char *bytes) {
    /* v6 layout: time_high (bytes 0-3), time_mid (bytes 4-5),
     * time_low_and_version (bytes 6-7, version in high nibble of byte 6) */
    uint64_t time_high = ((uint64_t)bytes[0] << 24) | ((uint64_t)bytes[1] << 16)
                       | ((uint64_t)bytes[2] << 8)  | (uint64_t)bytes[3];
    uint64_t time_mid  = ((uint64_t)bytes[4] << 8)  | (uint64_t)bytes[5];
    uint64_t time_low  = ((uint64_t)(bytes[6] & 0x0F) << 8) | (uint64_t)bytes[7];

    return (time_high << 28) | (time_mid << 12) | time_low;
}

/* ── Extract Unix epoch ms from v7 UUID bytes ───────────────────── */

static inline uint64_t horus_extract_time_v7(const unsigned char *bytes) {
    /* v7 layout: 48-bit Unix ms timestamp in bytes 0-5 */
    return ((uint64_t)bytes[0] << 40) | ((uint64_t)bytes[1] << 32)
         | ((uint64_t)bytes[2] << 24) | ((uint64_t)bytes[3] << 16)
         | ((uint64_t)bytes[4] << 8)  | (uint64_t)bytes[5];
}

/* ── Convert Gregorian 100ns ticks to Unix epoch seconds (NV) ──── */

static inline double horus_gregorian_to_unix(uint64_t ticks) {
    if (ticks < HORUS_UUID_EPOCH_OFFSET) return 0.0;
    return (double)(ticks - HORUS_UUID_EPOCH_OFFSET) / 10000000.0;
}

/* ── Convert Unix epoch ms to Unix epoch seconds (NV) ──────────── */

static inline double horus_ms_to_unix(uint64_t ms) {
    return (double)ms / 1000.0;
}

#endif /* HORUS_TIME_H */