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 /* $Id$ */
20
21 #include "php.h"
22
23 #include <stdlib.h>
24 #if HAVE_UNISTD_H
25 #include <unistd.h>
26 #endif
27
28 #include <string.h>
29 #include <errno.h>
30
31 #include <stdio.h>
32 #ifdef PHP_WIN32
33 #include "win32/time.h"
34 #else
35 #include <sys/time.h>
36 #endif
37
38 #include "php_lcg.h"
39 #include "uniqid.h"
40
41 #ifdef HAVE_GETTIMEOFDAY
42 ZEND_TLS struct timeval prev_tv = { 0, 0 };
43
44 /* {{{ proto string uniqid([string prefix [, bool more_entropy]])
45 Generates a unique ID */
PHP_FUNCTION(uniqid)46 PHP_FUNCTION(uniqid)
47 {
48 char *prefix = "";
49 zend_bool more_entropy = 0;
50 zend_string *uniqid;
51 int sec, usec;
52 size_t prefix_len = 0;
53 struct timeval tv;
54
55 ZEND_PARSE_PARAMETERS_START(0, 2)
56 Z_PARAM_OPTIONAL
57 Z_PARAM_STRING(prefix, prefix_len)
58 Z_PARAM_BOOL(more_entropy)
59 ZEND_PARSE_PARAMETERS_END();
60
61 /* This implementation needs current microsecond to change,
62 * hence we poll time until it does. This is much faster than
63 * calling usleep(1) which may cause the kernel to schedule
64 * another process, causing a pause of around 10ms.
65 */
66 do {
67 (void)gettimeofday((struct timeval *) &tv, (struct timezone *) NULL);
68 } while (tv.tv_sec == prev_tv.tv_sec && tv.tv_usec == prev_tv.tv_usec);
69
70 prev_tv.tv_sec = tv.tv_sec;
71 prev_tv.tv_usec = tv.tv_usec;
72
73 sec = (int) tv.tv_sec;
74 usec = (int) (tv.tv_usec % 0x100000);
75
76 /* The max value usec can have is 0xF423F, so we use only five hex
77 * digits for usecs.
78 */
79 if (more_entropy) {
80 uniqid = strpprintf(0, "%s%08x%05x%.8F", prefix, sec, usec, php_combined_lcg() * 10);
81 } else {
82 uniqid = strpprintf(0, "%s%08x%05x", prefix, sec, usec);
83 }
84
85 RETURN_STR(uniqid);
86 }
87 #endif
88 /* }}} */
89
90 /*
91 * Local variables:
92 * tab-width: 4
93 * c-basic-offset: 4
94 * End:
95 * vim600: sw=4 ts=4 fdm=marker
96 * vim<600: sw=4 ts=4
97 */
98
