timex.h
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1 /*
2  * Copyright (C) 2010 Kaspar Schleiser <kaspar@schleiser.de>
3  * Copyright (C) 2014 Oliver Hahm <oliver.hahm@inria.fr>
4  *
5  * This file is subject to the terms and conditions of the GNU Lesser
6  * General Public License v2.1. See the file LICENSE in the top level
7  * directory for more details.
8  */
9 
10 #pragma once
11 
22 #include <stdint.h>
23 #include <inttypes.h>
24 #include "time_units.h"
25 
26 #ifdef __cplusplus
27 extern "C" {
28 #endif
29 
33 #define TIMEX_MAX_STR_LEN (20)
34 /* 20 =
35  * + 10 byte: 2^32-1 for seconds
36  * + 1 byte: decimal point
37  * + 6 byte: microseconds (normalized)
38  * + 2 byte: " s" (unit)
39  * + 1 byte: '\0'
40  */
41 
48 typedef struct {
49  uint32_t seconds;
50  uint32_t microseconds;
51 } timex_t;
52 
61 timex_t timex_add(const timex_t a, const timex_t b);
62 
71 timex_t timex_sub(const timex_t a, const timex_t b);
72 
81 timex_t timex_set(uint32_t seconds, uint32_t microseconds);
82 
93 int timex_cmp(const timex_t a, const timex_t b);
94 
100 static inline void timex_normalize(timex_t *time)
101 {
102  time->seconds += (time->microseconds / US_PER_SEC);
103  time->microseconds %= US_PER_SEC;
104 }
105 
114 static inline int timex_isnormalized(const timex_t *time)
115 {
116  return (time->microseconds < US_PER_SEC);
117 }
118 
126 static inline uint64_t timex_uint64(const timex_t a)
127 {
128  return (uint64_t) a.seconds * US_PER_SEC + a.microseconds;
129 }
130 
138 static inline timex_t timex_from_uint64(const uint64_t timestamp)
139 {
140  return timex_set(timestamp / US_PER_SEC, timestamp % US_PER_SEC);
141 }
142 
155 const char *timex_to_str(timex_t t, char *timestamp);
156 
157 #ifdef __cplusplus
158 }
159 #endif
160 
#define US_PER_SEC
The number of microseconds per second.
Definition: time_units.h:84
timex_t timex_add(const timex_t a, const timex_t b)
Adds two timestamps.
int timex_cmp(const timex_t a, const timex_t b)
Compares two timex timestamps.
static void timex_normalize(timex_t *time)
Corrects timex structure so that microseconds < 1000000.
Definition: timex.h:100
const char * timex_to_str(timex_t t, char *timestamp)
Converts a timex timestamp to a string.
static int timex_isnormalized(const timex_t *time)
Tests a timex timestamp for normalization.
Definition: timex.h:114
timex_t timex_sub(const timex_t a, const timex_t b)
Subtracts two timestamps.
static uint64_t timex_uint64(const timex_t a)
Converts a timex timestamp to a 64 bit value.
Definition: timex.h:126
static timex_t timex_from_uint64(const uint64_t timestamp)
Converts a 64 bit value of microseconds to a timex timestamp.
Definition: timex.h:138
timex_t timex_set(uint32_t seconds, uint32_t microseconds)
Initializes a timex timestamp.
Adds include for missing inttype definitions.
A timex timestamp.
Definition: timex.h:48
uint32_t seconds
number of seconds
Definition: timex.h:49
uint32_t microseconds
number of microseconds
Definition: timex.h:50
Utility header providing time unit defines.