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apr_time.h
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1 /* Licensed to the Apache Software Foundation (ASF) under one or more
2  * contributor license agreements. See the NOTICE file distributed with
3  * this work for additional information regarding copyright ownership.
4  * The ASF licenses this file to You under the Apache License, Version 2.0
5  * (the "License"); you may not use this file except in compliance with
6  * the License. You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef APR_TIME_H
18 #define APR_TIME_H
19 
20 /**
21  * @file apr_time.h
22  * @brief APR Time Library
23  */
24 
25 #include "apr.h"
26 #include "apr_pools.h"
27 #include "apr_errno.h"
28 
29 #ifdef __cplusplus
30 extern "C" {
31 #endif /* __cplusplus */
32 
33 /**
34  * @defgroup apr_time Time Routines
35  * @ingroup APR
36  * @{
37  */
38 
39 /** month names */
40 APR_DECLARE_DATA extern const char apr_month_snames[12][4];
41 /** day names */
42 APR_DECLARE_DATA extern const char apr_day_snames[7][4];
43 
44 
45 /** number of microseconds since 00:00:00 January 1, 1970 UTC */
46 typedef apr_int64_t apr_time_t;
47 
48 
49 /** mechanism to properly type apr_time_t literals */
50 #define APR_TIME_C(val) APR_INT64_C(val)
51 
52 /** mechanism to properly print apr_time_t values */
53 #define APR_TIME_T_FMT APR_INT64_T_FMT
54 
55 /** intervals for I/O timeouts, in microseconds */
56 typedef apr_int64_t apr_interval_time_t;
57 /** short interval for I/O timeouts, in microseconds */
58 typedef apr_int32_t apr_short_interval_time_t;
59 
60 /** number of microseconds per second */
61 #define APR_USEC_PER_SEC APR_TIME_C(1000000)
62 
63 /** @return apr_time_t as a second */
64 #define apr_time_sec(time) ((time) / APR_USEC_PER_SEC)
65 
66 /** @return apr_time_t as a usec */
67 #define apr_time_usec(time) ((time) % APR_USEC_PER_SEC)
68 
69 /** @return apr_time_t as a msec */
70 #define apr_time_msec(time) (((time) / 1000) % 1000)
71 
72 /** @return apr_time_t as a msec */
73 #define apr_time_as_msec(time) ((time) / 1000)
74 
75 /** @return milliseconds as an apr_time_t */
76 #define apr_time_from_msec(msec) ((apr_time_t)(msec) * 1000)
77 
78 /** @return seconds as an apr_time_t */
79 #define apr_time_from_sec(sec) ((apr_time_t)(sec) * APR_USEC_PER_SEC)
80 
81 /** @return a second and usec combination as an apr_time_t */
82 #define apr_time_make(sec, usec) ((apr_time_t)(sec) * APR_USEC_PER_SEC \
83  + (apr_time_t)(usec))
84 
85 /**
86  * @return the current time
87  */
88 APR_DECLARE(apr_time_t) apr_time_now(void);
89 
90 /** @see apr_time_exp_t */
92 
93 /**
94  * a structure similar to ANSI struct tm with the following differences:
95  * - tm_usec isn't an ANSI field
96  * - tm_gmtoff isn't an ANSI field (it's a BSDism)
97  */
98 struct apr_time_exp_t {
99  /** microseconds past tm_sec */
100  apr_int32_t tm_usec;
101  /** (0-61) seconds past tm_min */
102  apr_int32_t tm_sec;
103  /** (0-59) minutes past tm_hour */
104  apr_int32_t tm_min;
105  /** (0-23) hours past midnight */
106  apr_int32_t tm_hour;
107  /** (1-31) day of the month */
108  apr_int32_t tm_mday;
109  /** (0-11) month of the year */
110  apr_int32_t tm_mon;
111  /** year since 1900 */
112  apr_int32_t tm_year;
113  /** (0-6) days since Sunday */
114  apr_int32_t tm_wday;
115  /** (0-365) days since January 1 */
116  apr_int32_t tm_yday;
117  /** daylight saving time */
118  apr_int32_t tm_isdst;
119  /** seconds east of UTC */
120  apr_int32_t tm_gmtoff;
121 };
122 
123 /**
124  * Convert an ansi time_t to an apr_time_t
125  * @param result the resulting apr_time_t
126  * @param input the time_t to convert
127  */
128 APR_DECLARE(apr_status_t) apr_time_ansi_put(apr_time_t *result,
129  time_t input);
130 
131 /**
132  * Convert a time to its human readable components using an offset
133  * from GMT.
134  * @param result the exploded time
135  * @param input the time to explode
136  * @param offs the number of seconds offset to apply
137  */
139  apr_time_t input,
140  apr_int32_t offs);
141 
142 /**
143  * Convert a time to its human readable components (GMT).
144  * @param result the exploded time
145  * @param input the time to explode
146  */
148  apr_time_t input);
149 
150 /**
151  * Convert a time to its human readable components in the local timezone.
152  * @param result the exploded time
153  * @param input the time to explode
154  */
156  apr_time_t input);
157 
158 /**
159  * Convert time value from human readable format to a numeric apr_time_t
160  * (elapsed microseconds since the epoch).
161  * @param result the resulting imploded time
162  * @param input the input exploded time
163  */
164 APR_DECLARE(apr_status_t) apr_time_exp_get(apr_time_t *result,
165  apr_time_exp_t *input);
166 
167 /**
168  * Convert time value from human readable format to a numeric apr_time_t that
169  * always represents GMT.
170  * @param result the resulting imploded time
171  * @param input the input exploded time
172  */
173 APR_DECLARE(apr_status_t) apr_time_exp_gmt_get(apr_time_t *result,
174  apr_time_exp_t *input);
175 
176 /**
177  * Sleep for the specified number of micro-seconds.
178  * @param t desired amount of time to sleep.
179  * @warning May sleep for longer than the specified time.
180  */
181 APR_DECLARE(void) apr_sleep(apr_interval_time_t t);
182 
183 /** length of a RFC822 Date */
184 #define APR_RFC822_DATE_LEN (30)
185 /**
186  * apr_rfc822_date formats dates in the RFC822
187  * format in an efficient manner. It is a fixed length
188  * format which requires APR_RFC822_DATA_LEN bytes of storage,
189  * including the trailing NUL terminator.
190  * @param date_str String to write to.
191  * @param t the time to convert
192  */
193 APR_DECLARE(apr_status_t) apr_rfc822_date(char *date_str, apr_time_t t);
194 
195 /** length of a CTIME date */
196 #define APR_CTIME_LEN (25)
197 /**
198  * apr_ctime formats dates in the ctime() format
199  * in an efficient manner. It is a fixed length format
200  * and requires APR_CTIME_LEN bytes of storage including
201  * the trailing NUL terminator.
202  * Unlike ANSI/ISO C ctime(), apr_ctime() does not include
203  * a \\n at the end of the string.
204  * @param date_str String to write to.
205  * @param t the time to convert
206  */
207 APR_DECLARE(apr_status_t) apr_ctime(char *date_str, apr_time_t t);
208 
209 /**
210  * Formats the exploded time according to the format specified
211  * @param s string to write to
212  * @param retsize The length of the returned string
213  * @param max The maximum length of the string
214  * @param format The format for the time string
215  * @param tm The time to convert
216  */
217 APR_DECLARE(apr_status_t) apr_strftime(char *s, apr_size_t *retsize,
218  apr_size_t max, const char *format,
219  apr_time_exp_t *tm);
220 
221 /**
222  * Improve the clock resolution for the lifetime of the given pool.
223  * Generally this is only desirable on benchmarking and other very
224  * time-sensitive applications, and has no impact on most platforms.
225  * @param p The pool to associate the finer clock resolution
226  */
228 
229 /** @} */
230 
231 #ifdef __cplusplus
232 }
233 #endif
234 
235 #endif /* ! APR_TIME_H */