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