github.com/jfrog/frogbot@v1.1.1-0.20231221090046-821a26f50338/action/node_modules/uuid/v1.js (about)

     1  var rng = require('./lib/rng');
     2  var bytesToUuid = require('./lib/bytesToUuid');
     3  
     4  // **`v1()` - Generate time-based UUID**
     5  //
     6  // Inspired by https://github.com/LiosK/UUID.js
     7  // and http://docs.python.org/library/uuid.html
     8  
     9  var _nodeId;
    10  var _clockseq;
    11  
    12  // Previous uuid creation time
    13  var _lastMSecs = 0;
    14  var _lastNSecs = 0;
    15  
    16  // See https://github.com/uuidjs/uuid for API details
    17  function v1(options, buf, offset) {
    18    var i = buf && offset || 0;
    19    var b = buf || [];
    20  
    21    options = options || {};
    22    var node = options.node || _nodeId;
    23    var clockseq = options.clockseq !== undefined ? options.clockseq : _clockseq;
    24  
    25    // node and clockseq need to be initialized to random values if they're not
    26    // specified.  We do this lazily to minimize issues related to insufficient
    27    // system entropy.  See #189
    28    if (node == null || clockseq == null) {
    29      var seedBytes = rng();
    30      if (node == null) {
    31        // Per 4.5, create and 48-bit node id, (47 random bits + multicast bit = 1)
    32        node = _nodeId = [
    33          seedBytes[0] | 0x01,
    34          seedBytes[1], seedBytes[2], seedBytes[3], seedBytes[4], seedBytes[5]
    35        ];
    36      }
    37      if (clockseq == null) {
    38        // Per 4.2.2, randomize (14 bit) clockseq
    39        clockseq = _clockseq = (seedBytes[6] << 8 | seedBytes[7]) & 0x3fff;
    40      }
    41    }
    42  
    43    // UUID timestamps are 100 nano-second units since the Gregorian epoch,
    44    // (1582-10-15 00:00).  JSNumbers aren't precise enough for this, so
    45    // time is handled internally as 'msecs' (integer milliseconds) and 'nsecs'
    46    // (100-nanoseconds offset from msecs) since unix epoch, 1970-01-01 00:00.
    47    var msecs = options.msecs !== undefined ? options.msecs : new Date().getTime();
    48  
    49    // Per 4.2.1.2, use count of uuid's generated during the current clock
    50    // cycle to simulate higher resolution clock
    51    var nsecs = options.nsecs !== undefined ? options.nsecs : _lastNSecs + 1;
    52  
    53    // Time since last uuid creation (in msecs)
    54    var dt = (msecs - _lastMSecs) + (nsecs - _lastNSecs)/10000;
    55  
    56    // Per 4.2.1.2, Bump clockseq on clock regression
    57    if (dt < 0 && options.clockseq === undefined) {
    58      clockseq = clockseq + 1 & 0x3fff;
    59    }
    60  
    61    // Reset nsecs if clock regresses (new clockseq) or we've moved onto a new
    62    // time interval
    63    if ((dt < 0 || msecs > _lastMSecs) && options.nsecs === undefined) {
    64      nsecs = 0;
    65    }
    66  
    67    // Per 4.2.1.2 Throw error if too many uuids are requested
    68    if (nsecs >= 10000) {
    69      throw new Error('uuid.v1(): Can\'t create more than 10M uuids/sec');
    70    }
    71  
    72    _lastMSecs = msecs;
    73    _lastNSecs = nsecs;
    74    _clockseq = clockseq;
    75  
    76    // Per 4.1.4 - Convert from unix epoch to Gregorian epoch
    77    msecs += 12219292800000;
    78  
    79    // `time_low`
    80    var tl = ((msecs & 0xfffffff) * 10000 + nsecs) % 0x100000000;
    81    b[i++] = tl >>> 24 & 0xff;
    82    b[i++] = tl >>> 16 & 0xff;
    83    b[i++] = tl >>> 8 & 0xff;
    84    b[i++] = tl & 0xff;
    85  
    86    // `time_mid`
    87    var tmh = (msecs / 0x100000000 * 10000) & 0xfffffff;
    88    b[i++] = tmh >>> 8 & 0xff;
    89    b[i++] = tmh & 0xff;
    90  
    91    // `time_high_and_version`
    92    b[i++] = tmh >>> 24 & 0xf | 0x10; // include version
    93    b[i++] = tmh >>> 16 & 0xff;
    94  
    95    // `clock_seq_hi_and_reserved` (Per 4.2.2 - include variant)
    96    b[i++] = clockseq >>> 8 | 0x80;
    97  
    98    // `clock_seq_low`
    99    b[i++] = clockseq & 0xff;
   100  
   101    // `node`
   102    for (var n = 0; n < 6; ++n) {
   103      b[i + n] = node[n];
   104    }
   105  
   106    return buf ? buf : bytesToUuid(b);
   107  }
   108  
   109  module.exports = v1;