| 580,9 → 580,17 |
|---|
| Variant 1, Version 7 UUID |
| - 48 bit Unix Time in milliseconds |
| - 4 bit Version (fix 0x7) |
| - 12 bit Random |
| - 12 bit Data |
| - 2 bit Variant (fix 0b10) |
| - 62 bit Random |
| - 62 bit Data |
| |
| Structure of data (74 bits): |
| - OPTIONAL : Sub-millisecond timestamp fraction (0-12 bits) |
| - OPTIONAL : Carefully seeded counter |
| - Random generated bits for any remaining space |
| |
| Since we don't know if timestamp fraction or counters are implemented |
| (and if so, how many bits), we don't decode this information |
| */ |
| |
| echo sprintf("%-32s %s\n", "Version:", "[0x7] Unix Epoch Time"); |
| 1221,15 → 1229,13 |
|---|
| // Variant 1, Version 7 (Unix Epoch) UUID |
| # -------------------------------------- |
| |
| function gen_uuid_v7() { |
| return gen_uuid_unix_epoch(); |
| function gen_uuid_v7(int $num_ms_frac_bits=12) { |
| return gen_uuid_unix_epoch($num_ms_frac_bits); |
| } |
| function gen_uuid_unix_epoch() { |
| // Start with an UUIDv4 |
| $uuid = gen_uuid_random(); |
| function gen_uuid_unix_epoch(int $num_ms_frac_bits=12) { |
| $uuid_nibbles = ''; |
| |
| // Add the timestamp |
| usleep(1000); // Wait 1ms, to make sure that the time part changes if multiple UUIDs are generated |
| // Add the timestamp (milliseconds Unix) |
| if (function_exists('gmp_init')) { |
| list($ms,$sec) = explode(' ', microtime(false)); |
| $sec = gmp_init($sec, 10); |
| 1236,18 → 1242,70 |
|---|
| $ms = gmp_init(substr($ms,2,3), 10); |
| $unix_ts = gmp_strval(gmp_add(gmp_mul($sec, '1000'), $ms),16); |
| } else { |
| $unix_ts = dechex((int)round(microtime(true)*1000)); |
| $unix_ts = dechex((int)ceil(microtime(true)*1000)); |
| } |
| $unix_ts = str_pad($unix_ts, 12, '0', STR_PAD_LEFT); |
| for ($i=0;$i<8;$i++) $uuid[$i] = substr($unix_ts, $i, 1); |
| for ($i=0;$i<4;$i++) $uuid[9+$i] = substr($unix_ts, 8+$i, 1); |
| $uuid_nibbles = $unix_ts; |
| |
| // set version |
| $uuid[14] = '7'; |
| // Version = 7 |
| $uuid_nibbles .= '7'; |
| |
| return $uuid; |
| // Optional: millisecond fraction (max 12 bits) |
| if (($num_ms_frac_bits < 0) || ($num_ms_frac_bits > 12)) throw new Exception("Invalid msec frac bits (must be 0..12)"); |
| if ($num_ms_frac_bits > 0) { |
| $seconds_fraction = (float)explode(' ',microtime(false))[0]; |
| $nanoseconds_fraction = $seconds_fraction * 1000000; |
| $resolution_ns = 1000000 / pow(2,$num_ms_frac_bits); |
| $val = (int)ceil($nanoseconds_fraction / $resolution_ns); |
| |
| // Currently, for the output we only allow frac bits 0, 4, 8, 12 (0-3 nibbles), |
| // since UUIDs are usually sorted in their hex notation |
| $num_nibbles = (int)ceil($num_ms_frac_bits/4); |
| $nibble_string = str_pad(dechex($val), $num_nibbles, '0', STR_PAD_LEFT); |
| $uuid_nibbles .= $nibble_string; |
| } else { |
| $resolution_ns = 1000000; |
| } |
| |
| // TODO Not implemented: Optional counter (to be defined as parameter to this method) |
| // The counter bits need to be spread before and after the variant bits |
| |
| // Fill with random bits (and the variant bits) |
| $uuid = gen_uuid_random(); |
| $uuid = str_replace('-', '', $uuid); |
| for ($i=0; $i<strlen($uuid_nibbles); $i++) $uuid[$i] = $uuid_nibbles[$i]; |
| |
| // Wait to make sure that the time part changes if multiple UUIDs are generated |
| // We don't use usleep(), because it often does not sleep long enough! |
| // $resolution_us = (int)ceil($resolution_ns/1000); |
| // if ($resolution_us > 0) usleep($resolution_us); |
| // We use this naive approach instead: |
| if ($num_ms_frac_bits > 0) { |
| $seconds_fraction = (float)explode(' ',microtime(false))[0]; |
| $nanoseconds_fraction = $seconds_fraction * 1000000; |
| $resolution_ns = 1000000 / pow(2,$num_ms_frac_bits); |
| $val = (int)ceil($nanoseconds_fraction / $resolution_ns); |
| do { |
| $seconds_fraction = (float)explode(' ',microtime(false))[0]; |
| $nanoseconds_fraction = $seconds_fraction * 1000000; |
| $resolution_ns = 1000000 / pow(2,$num_ms_frac_bits); |
| $val2 = (int)ceil($nanoseconds_fraction / $resolution_ns); |
| } while ($val == $val2); |
| } else { |
| $unix_ts = dechex((int)ceil(microtime(true)*1000)); |
| do { |
| $unix_ts2 = dechex((int)ceil(microtime(true)*1000)); |
| } while ($unix_ts == $unix_ts2); |
| } |
| |
| // Output |
| return substr($uuid, 0, 8).'-'. |
| substr($uuid, 8, 4).'-'. |
| substr($uuid, 12, 4).'-'. |
| substr($uuid, 16, 4).'-'. |
| substr($uuid, 20, 12); |
| } |
| |
| # -------------------------------------- |
| // Variant 1, Version 8 (Custom) UUID |
| # -------------------------------------- |