Snowflake.php 5.4 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219
  1. <?php
  2. /*
  3. * This file is part of the godruoyi/php-snowflake.
  4. *
  5. * (c) Godruoyi <g@godruoyi.com>
  6. *
  7. * This source file is subject to the MIT license that is bundled.
  8. */
  9. namespace Godruoyi\Snowflake;
  10. class Snowflake
  11. {
  12. const MAX_TIMESTAMP_LENGTH = 41;
  13. const MAX_DATACENTER_LENGTH = 5;
  14. const MAX_WORKID_LENGTH = 5;
  15. const MAX_SEQUENCE_LENGTH = 12;
  16. const MAX_FIRST_LENGTH = 1;
  17. /**
  18. * The data center id.
  19. *
  20. * @var int
  21. */
  22. protected $datacenter;
  23. /**
  24. * The worker id.
  25. *
  26. * @var int
  27. */
  28. protected $workerid;
  29. /**
  30. * The Sequence Resolver instance.
  31. *
  32. * @var \Godruoyi\Snowflake\SequenceResolver|null
  33. */
  34. protected $sequence;
  35. /**
  36. * The start timestamp.
  37. *
  38. * @var int
  39. */
  40. protected $startTime;
  41. /**
  42. * Default sequence resolver.
  43. *
  44. * @var \Godruoyi\Snowflake\SequenceResolver|null
  45. */
  46. protected $defaultSequenceResolver;
  47. /**
  48. * Build Snowflake Instance.
  49. *
  50. * @param int $datacenter
  51. * @param int $workerid
  52. */
  53. public function __construct(int $datacenter = null, int $workerid = null)
  54. {
  55. $maxDataCenter = -1 ^ (-1 << self::MAX_DATACENTER_LENGTH);
  56. $maxWorkId = -1 ^ (-1 << self::MAX_WORKID_LENGTH);
  57. // If not set datacenter or workid, we will set a default value to use.
  58. $this->datacenter = $datacenter > $maxDataCenter || $datacenter < 0 ? mt_rand(0, 31) : $datacenter;
  59. $this->workerid = $workerid > $maxWorkId || $workerid < 0 ? mt_rand(0, 31) : $workerid;
  60. }
  61. /**
  62. * Get snowflake id.
  63. *
  64. * @return string
  65. */
  66. public function id()
  67. {
  68. $currentTime = $this->getCurrentMicrotime();
  69. while (($sequence = $this->callResolver($currentTime)) > (-1 ^ (-1 << self::MAX_SEQUENCE_LENGTH))) {
  70. usleep(1);
  71. $currentTime = $this->getCurrentMicrotime();
  72. }
  73. $workerLeftMoveLength = self::MAX_SEQUENCE_LENGTH;
  74. $datacenterLeftMoveLength = self::MAX_WORKID_LENGTH + $workerLeftMoveLength;
  75. $timestampLeftMoveLength = self::MAX_DATACENTER_LENGTH + $datacenterLeftMoveLength;
  76. return (string) ((($currentTime - $this->getStartTimeStamp()) << $timestampLeftMoveLength)
  77. | ($this->datacenter << $datacenterLeftMoveLength)
  78. | ($this->workerid << $workerLeftMoveLength)
  79. | ($sequence));
  80. }
  81. /**
  82. * Parse snowflake id.
  83. */
  84. public function parseId(string $id, $transform = false): array
  85. {
  86. $id = decbin($id);
  87. $data = [
  88. 'timestamp' => substr($id, 0, -22),
  89. 'sequence' => substr($id, -12),
  90. 'workerid' => substr($id, -17, 5),
  91. 'datacenter' => substr($id, -22, 5),
  92. ];
  93. return $transform ? array_map(function ($value) {
  94. return bindec($value);
  95. }, $data) : $data;
  96. }
  97. /**
  98. * Get current microtime timestamp.
  99. *
  100. * @return int
  101. */
  102. public function getCurrentMicrotime()
  103. {
  104. return floor(microtime(true) * 1000) | 0;
  105. }
  106. /**
  107. * Set start time (millisecond).
  108. */
  109. public function setStartTimeStamp(int $startTime)
  110. {
  111. $missTime = $this->getCurrentMicrotime() - $startTime;
  112. if ($missTime < 0) {
  113. throw new \Exception('The start time cannot be greater than the current time');
  114. }
  115. $maxTimeDiff = -1 ^ (-1 << self::MAX_TIMESTAMP_LENGTH);
  116. if ($missTime > $maxTimeDiff) {
  117. throw new \Exception(sprintf('The current microtime - starttime is not allowed to exceed -1 ^ (-1 << %d), You can reset the start time to fix this', self::MAX_TIMESTAMP_LENGTH));
  118. }
  119. $this->startTime = $startTime;
  120. return $this;
  121. }
  122. /**
  123. * Get start timestamp (millisecond), If not set default to 2019-08-08 08:08:08.
  124. *
  125. * @return int
  126. */
  127. public function getStartTimeStamp()
  128. {
  129. if ($this->startTime > 0) {
  130. return $this->startTime;
  131. }
  132. // We set a default start time if you not set.
  133. $defaultTime = '2019-08-08 08:08:08';
  134. return strtotime($defaultTime) * 1000;
  135. }
  136. /**
  137. * Set Sequence Resolver.
  138. *
  139. * @param SequenceResolver|callable $sequence
  140. */
  141. public function setSequenceResolver($sequence)
  142. {
  143. $this->sequence = $sequence;
  144. return $this;
  145. }
  146. /**
  147. * Get Sequence Resolver.
  148. *
  149. * @return \Godruoyi\Snowflake\SequenceResolver|callable|null
  150. */
  151. public function getSequenceResolver()
  152. {
  153. return $this->sequence;
  154. }
  155. /**
  156. * Get Default Sequence Resolver.
  157. *
  158. * @return \Godruoyi\Snowflake\SequenceResolver
  159. */
  160. public function getDefaultSequenceResolver(): SequenceResolver
  161. {
  162. return $this->defaultSequenceResolver ?: $this->defaultSequenceResolver = new RandomSequenceResolver();
  163. }
  164. /**
  165. * Call resolver.
  166. *
  167. * @param callable|\Godruoyi\Snowflake\SequenceResolver $resolver
  168. * @param int $maxSequence
  169. *
  170. * @return int
  171. */
  172. protected function callResolver($currentTime)
  173. {
  174. $resolver = $this->getSequenceResolver();
  175. if (is_callable($resolver)) {
  176. return $resolver($currentTime);
  177. }
  178. return is_null($resolver) || !($resolver instanceof SequenceResolver)
  179. ? $this->getDefaultSequenceResolver()->sequence($currentTime)
  180. : $resolver->sequence($currentTime);
  181. }
  182. }