1 /*
2 +----------------------------------------------------------------------+
3 | PHP Version 7 |
4 +----------------------------------------------------------------------+
5 | Copyright (c) 1997-2018 The PHP Group |
6 +----------------------------------------------------------------------+
7 | This source file is subject to version 3.01 of the PHP license, |
8 | that is bundled with this package in the file LICENSE, and is |
9 | available through the world-wide-web at the following url: |
10 | http://www.php.net/license/3_01.txt |
11 | If you did not receive a copy of the PHP license and are unable to |
12 | obtain it through the world-wide-web, please send a note to |
13 | license@php.net so we can mail you a copy immediately. |
14 +----------------------------------------------------------------------+
15 | Author: Stig Sæther Bakken <ssb@php.net> |
16 +----------------------------------------------------------------------+
17 */
18
19 #include "php.h"
20
21 #include <stdlib.h>
22 #if HAVE_UNISTD_H
23 #include <unistd.h>
24 #endif
25
26 #include <string.h>
27 #include <errno.h>
28
29 #include <stdio.h>
30 #ifdef PHP_WIN32
31 #include "win32/time.h"
32 #else
33 #include <sys/time.h>
34 #endif
35
36 #include "php_lcg.h"
37 #include "uniqid.h"
38
39 #ifdef HAVE_GETTIMEOFDAY
40 ZEND_TLS struct timeval prev_tv = { 0, 0 };
41
42 /* {{{ proto string uniqid([string prefix [, bool more_entropy]])
43 Generates a unique ID */
PHP_FUNCTION(uniqid)44 PHP_FUNCTION(uniqid)
45 {
46 char *prefix = "";
47 zend_bool more_entropy = 0;
48 zend_string *uniqid;
49 int sec, usec;
50 size_t prefix_len = 0;
51 struct timeval tv;
52
53 ZEND_PARSE_PARAMETERS_START(0, 2)
54 Z_PARAM_OPTIONAL
55 Z_PARAM_STRING(prefix, prefix_len)
56 Z_PARAM_BOOL(more_entropy)
57 ZEND_PARSE_PARAMETERS_END();
58
59 /* This implementation needs current microsecond to change,
60 * hence we poll time until it does. This is much faster than
61 * calling usleep(1) which may cause the kernel to schedule
62 * another process, causing a pause of around 10ms.
63 */
64 do {
65 (void)gettimeofday((struct timeval *) &tv, (struct timezone *) NULL);
66 } while (tv.tv_sec == prev_tv.tv_sec && tv.tv_usec == prev_tv.tv_usec);
67
68 prev_tv.tv_sec = tv.tv_sec;
69 prev_tv.tv_usec = tv.tv_usec;
70
71 sec = (int) tv.tv_sec;
72 usec = (int) (tv.tv_usec % 0x100000);
73
74 /* The max value usec can have is 0xF423F, so we use only five hex
75 * digits for usecs.
76 */
77 if (more_entropy) {
78 uniqid = strpprintf(0, "%s%08x%05x%.8F", prefix, sec, usec, php_combined_lcg() * 10);
79 } else {
80 uniqid = strpprintf(0, "%s%08x%05x", prefix, sec, usec);
81 }
82
83 RETURN_STR(uniqid);
84 }
85 #endif
86 /* }}} */
87
88 /*
89 * Local variables:
90 * tab-width: 4
91 * c-basic-offset: 4
92 * End:
93 * vim600: sw=4 ts=4 fdm=marker
94 * vim<600: sw=4 ts=4
95 */
96
