php生成固定长度纯数字编码的方法

本文实例讲述了php生成固定长度纯数字编码的方法。分享给大家供大家参考。具体如下：

很多时候我们需要一些固定长度的数字编码，如订单编号、卡号、用户编号等等！但是经常我们有的是存储在数据库中的有序编号，我们可以通过它直接转成一个固定长度的数字编码，然后更新到数据库中形成此记录的唯一编号。

2. /**
3. * 根据日期或者是给定前缀生成唯一编号
4. * User: minyifei.cn
5. * Date: 15/7/7
6. */
7. namespace Minyifei\Libs;
8. class SequenceNumber {
9. /**
10. * 根据显示宽度获取指定的 mapbit
11. *
12. * @param integer $width 编号显示宽度
13. *
14. * @return array
15. */
16. private static function _getMapbit($width)
17. {
18. $mapBits = array(
19. 4=>array(
20. 10, 2, 11, 3, 0, 1, 9, 7, 12, 6, 4, 8, 5,
21. ),
22. 5=>array(
23. 4, 3, 13, 15, 7, 8, 6, 2, 1, 10, 5, 12, 0, 11, 14, 9,
24. ),
25. 6=>array(
26. 2, 7, 10, 9, 16, 3, 6, 8, 0, 4, 1, 12, 11, 13, 18, 5, 15, 17, 14,
27. ),
28. 7=>array(
29. 18, 0, 2, 22, 8, 3, 1, 14, 17, 12, 4, 19, 11, 9, 13, 5, 6, 15, 10, 16, 20, 7, 21,
30. ),
31. 8=>array(
32. 11, 8, 4, 0, 16, 14, 22, 7, 3, 5, 13, 18, 24, 25, 23, 10, 1, 12, 6, 21, 17, 2, 15, 9, 19, 20,
33. ),
34. 9=>array(
35. 24, 23, 27, 3, 9, 16, 25, 13, 28, 12, 0, 4, 10, 18, 11, 2, 17, 1, 21, 26, 5, 15, 7, 20, 22, 14, 19, 6, 8,
36. ),
37. 10=>array(
38. 32, 3, 1, 28, 21, 18, 30, 7, 12, 22, 20, 13, 16, 15, 6, 17, 9, 25, 11, 8, 4, 27, 14, 31, 5, 23, 24, 29, 0, 10, 19, 26, 2,
39. ),
40. 11=>array(
41. 9, 13, 2, 29, 11, 32, 14, 33, 24, 8, 27, 4, 22, 20, 5, 0, 21, 25, 17, 28, 34, 6, 23, 26, 30, 3, 7, 19, 16, 15, 12, 31, 1, 35, 10, 18,
42. ),
43. 12=>array(
44. 31, 4, 16, 33, 35, 29, 17, 37, 12, 28, 32, 22, 7, 10, 14, 26, 0, 9, 8, 3, 20, 2, 13, 5, 36, 27, 23, 15, 19, 34, 38, 11, 24, 25, 30, 21, 18, 6, 1,
45. ),
46. );
47. return $mapBits[intval($width)];
48. }
49. /**
50. * 格式化给定时间戳
51. *
52. * @param integer $ts timestamp, if null use current timestamp
53. *
54. * @return string
55. */
56. private static function _fmtTS($ts=null)
57. {
58. $ts = $ts ?: time();
59. return date(self::$_fmt, $ts);
60. }
61. /**
62. * 根据id获取一个随机唯一编码
63. * @param $id 编号
64. * @param int $prefix 前缀
65. * @param int $width 除前缀外长度
66. * @return string
67. */
68. public static function generateNumber($id,$prefix=10,$width=8)
69. {
70. return sprintf("%s%s", $prefix,self::encode($id, $width));
71. }
72. /**
73. * 编码转换
74. *
75. * @param integer $id id
76. * @param integer $width 编号额外组成部分的显示宽度
77. *
78. * @return integer
79. */
80. public static function encode($id, $width)
81. {
82. $maximum = intval(str_repeat(9, $width));
83. $superscript = intval(log($maximum) / log(2));
84. $r = 0;
85. $sign = 0x1 << $superscript;
86. $id |= $sign;
87. $mapbit = self::_getMapbit($width);
88. for ($x = 0; $x < $superscript; $x++) {
89. $v = ($id >> $x) & 0x1;
90. $r |= ($v << $mapbit[$x]);
91. }
92. $r += $maximum - pow(2, $superscript) + 1;
93. return sprintf("%0${width}s", $r);
94. }
95. /**
96. * 获取唯一编号
97. *
98. * @param integer $id id, mostly database primary key
99. * @param integer $width 编号显示宽度
100. * @param integer $ts timestamp
101. *
102. * @return string
103. */
104. public static function get($id, $width, $ts=null)
105. {
106. return sprintf('%s%s', self::_fmtTS($ts), self::encode($id, $width));
107. }
108. }

希望本文所述对大家的php程序设计有所帮助。