xref: /curl/lib/timediff.c (revision e9a7d4a1)
1 /***************************************************************************
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6  *                             \___|\___/|_| \_\_____|
7  *
8  * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
9  *
10  * This software is licensed as described in the file COPYING, which
11  * you should have received as part of this distribution. The terms
12  * are also available at https://curl.se/docs/copyright.html.
13  *
14  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15  * copies of the Software, and permit persons to whom the Software is
16  * furnished to do so, under the terms of the COPYING file.
17  *
18  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19  * KIND, either express or implied.
20  *
21  * SPDX-License-Identifier: curl
22  *
23  ***************************************************************************/
24 
25 #include "timediff.h"
26 
27 #include <limits.h>
28 
29 /*
30  * Converts number of milliseconds into a timeval structure.
31  *
32  * Return values:
33  *    NULL IF tv is NULL or ms < 0 (eg. no timeout -> blocking select)
34  *    tv with 0 in both fields IF ms == 0 (eg. 0ms timeout -> polling select)
35  *    tv with converted fields IF ms > 0 (eg. >0ms timeout -> waiting select)
36  */
curlx_mstotv(struct timeval * tv,timediff_t ms)37 struct timeval *curlx_mstotv(struct timeval *tv, timediff_t ms)
38 {
39   if(!tv)
40     return NULL;
41 
42   if(ms < 0)
43     return NULL;
44 
45   if(ms > 0) {
46     timediff_t tv_sec = ms / 1000;
47     timediff_t tv_usec = (ms % 1000) * 1000; /* max=999999 */
48 #ifdef HAVE_SUSECONDS_T
49 #if TIMEDIFF_T_MAX > TIME_T_MAX
50     /* tv_sec overflow check in case time_t is signed */
51     if(tv_sec > TIME_T_MAX)
52       tv_sec = TIME_T_MAX;
53 #endif
54     tv->tv_sec = (time_t)tv_sec;
55     tv->tv_usec = (suseconds_t)tv_usec;
56 #elif defined(_WIN32) /* maybe also others in the future */
57 #if TIMEDIFF_T_MAX > LONG_MAX
58     /* tv_sec overflow check on Windows there we know it is long */
59     if(tv_sec > LONG_MAX)
60       tv_sec = LONG_MAX;
61 #endif
62     tv->tv_sec = (long)tv_sec;
63     tv->tv_usec = (long)tv_usec;
64 #else
65 #if TIMEDIFF_T_MAX > INT_MAX
66     /* tv_sec overflow check in case time_t is signed */
67     if(tv_sec > INT_MAX)
68       tv_sec = INT_MAX;
69 #endif
70     tv->tv_sec = (int)tv_sec;
71     tv->tv_usec = (int)tv_usec;
72 #endif
73   }
74   else {
75     tv->tv_sec = 0;
76     tv->tv_usec = 0;
77   }
78 
79   return tv;
80 }
81 
82 /*
83  * Converts a timeval structure into number of milliseconds.
84  */
curlx_tvtoms(struct timeval * tv)85 timediff_t curlx_tvtoms(struct timeval *tv)
86 {
87   return (tv->tv_sec*1000) + (timediff_t)(((double)tv->tv_usec)/1000.0);
88 }
89