Apache Portable Runtime
apr_time.h
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00001 /* Licensed to the Apache Software Foundation (ASF) under one or more
00002  * contributor license agreements.  See the NOTICE file distributed with
00003  * this work for additional information regarding copyright ownership.
00004  * The ASF licenses this file to You under the Apache License, Version 2.0
00005  * (the "License"); you may not use this file except in compliance with
00006  * the License.  You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 
00017 #ifndef APR_TIME_H
00018 #define APR_TIME_H
00019 
00020 /**
00021  * @file apr_time.h
00022  * @brief APR Time Library
00023  */
00024 
00025 #include "apr.h"
00026 #include "apr_pools.h"
00027 #include "apr_errno.h"
00028 
00029 #ifdef __cplusplus
00030 extern "C" {
00031 #endif /* __cplusplus */
00032 
00033 /**
00034  * @defgroup apr_time Time Routines
00035  * @ingroup APR 
00036  * @{
00037  */
00038 
00039 /** month names */
00040 APR_DECLARE_DATA extern const char apr_month_snames[12][4];
00041 /** day names */
00042 APR_DECLARE_DATA extern const char apr_day_snames[7][4];
00043 
00044 
00045 /** number of microseconds since 00:00:00 january 1, 1970 UTC */
00046 typedef apr_int64_t apr_time_t;
00047 
00048 
00049 /** mechanism to properly type apr_time_t literals */
00050 #define APR_TIME_C(val) APR_INT64_C(val)
00051 
00052 /** mechanism to properly print apr_time_t values */
00053 #define APR_TIME_T_FMT APR_INT64_T_FMT
00054 
00055 /** intervals for I/O timeouts, in microseconds */
00056 typedef apr_int64_t apr_interval_time_t;
00057 /** short interval for I/O timeouts, in microseconds */
00058 typedef apr_int32_t apr_short_interval_time_t;
00059 
00060 /** number of microseconds per second */
00061 #define APR_USEC_PER_SEC APR_TIME_C(1000000)
00062 
00063 /** @return apr_time_t as a second */
00064 #define apr_time_sec(time) ((time) / APR_USEC_PER_SEC)
00065 
00066 /** @return apr_time_t as a usec */
00067 #define apr_time_usec(time) ((time) % APR_USEC_PER_SEC)
00068 
00069 /** @return apr_time_t as a msec */
00070 #define apr_time_msec(time) (((time) / 1000) % 1000)
00071 
00072 /** @return apr_time_t as a msec */
00073 #define apr_time_as_msec(time) ((time) / 1000)
00074 
00075 /** @return milliseconds as an apr_time_t */
00076 #define apr_time_from_msec(msec) ((apr_time_t)(msec) * 1000)
00077 
00078 /** @return seconds as an apr_time_t */
00079 #define apr_time_from_sec(sec) ((apr_time_t)(sec) * APR_USEC_PER_SEC)
00080 
00081 /** @return a second and usec combination as an apr_time_t */
00082 #define apr_time_make(sec, usec) ((apr_time_t)(sec) * APR_USEC_PER_SEC \
00083                                 + (apr_time_t)(usec))
00084 
00085 /**
00086  * @return the current time
00087  */
00088 APR_DECLARE(apr_time_t) apr_time_now(void);
00089 
00090 /** @see apr_time_exp_t */
00091 typedef struct apr_time_exp_t apr_time_exp_t;
00092 
00093 /**
00094  * a structure similar to ANSI struct tm with the following differences:
00095  *  - tm_usec isn't an ANSI field
00096  *  - tm_gmtoff isn't an ANSI field (it's a bsdism)
00097  */
00098 struct apr_time_exp_t {
00099     /** microseconds past tm_sec */
00100     apr_int32_t tm_usec;
00101     /** (0-61) seconds past tm_min */
00102     apr_int32_t tm_sec;
00103     /** (0-59) minutes past tm_hour */
00104     apr_int32_t tm_min;
00105     /** (0-23) hours past midnight */
00106     apr_int32_t tm_hour;
00107     /** (1-31) day of the month */
00108     apr_int32_t tm_mday;
00109     /** (0-11) month of the year */
00110     apr_int32_t tm_mon;
00111     /** year since 1900 */
00112     apr_int32_t tm_year;
00113     /** (0-6) days since sunday */
00114     apr_int32_t tm_wday;
00115     /** (0-365) days since jan 1 */
00116     apr_int32_t tm_yday;
00117     /** daylight saving time */
00118     apr_int32_t tm_isdst;
00119     /** seconds east of UTC */
00120     apr_int32_t tm_gmtoff;
00121 };
00122 
00123 /**
00124  * convert an ansi time_t to an apr_time_t
00125  * @param result the resulting apr_time_t
00126  * @param input the time_t to convert
00127  */
00128 APR_DECLARE(apr_status_t) apr_time_ansi_put(apr_time_t *result, 
00129                                                     time_t input);
00130 
00131 /**
00132  * convert a time to its human readable components using an offset
00133  * from GMT
00134  * @param result the exploded time
00135  * @param input the time to explode
00136  * @param offs the number of seconds offset to apply
00137  */
00138 APR_DECLARE(apr_status_t) apr_time_exp_tz(apr_time_exp_t *result,
00139                                           apr_time_t input,
00140                                           apr_int32_t offs);
00141 
00142 /**
00143  * convert a time to its human readable components in GMT timezone
00144  * @param result the exploded time
00145  * @param input the time to explode
00146  */
00147 APR_DECLARE(apr_status_t) apr_time_exp_gmt(apr_time_exp_t *result, 
00148                                            apr_time_t input);
00149 
00150 /**
00151  * convert a time to its human readable components in local timezone
00152  * @param result the exploded time
00153  * @param input the time to explode
00154  */
00155 APR_DECLARE(apr_status_t) apr_time_exp_lt(apr_time_exp_t *result, 
00156                                           apr_time_t input);
00157 
00158 /**
00159  * Convert time value from human readable format to a numeric apr_time_t 
00160  * e.g. elapsed usec since epoch
00161  * @param result the resulting imploded time
00162  * @param input the input exploded time
00163  */
00164 APR_DECLARE(apr_status_t) apr_time_exp_get(apr_time_t *result, 
00165                                            apr_time_exp_t *input);
00166 
00167 /**
00168  * Convert time value from human readable format to a numeric apr_time_t that
00169  * always represents GMT
00170  * @param result the resulting imploded time
00171  * @param input the input exploded time
00172  */
00173 APR_DECLARE(apr_status_t) apr_time_exp_gmt_get(apr_time_t *result, 
00174                                                apr_time_exp_t *input);
00175 
00176 /**
00177  * Sleep for the specified number of micro-seconds.
00178  * @param t desired amount of time to sleep.
00179  * @warning May sleep for longer than the specified time. 
00180  */
00181 APR_DECLARE(void) apr_sleep(apr_interval_time_t t);
00182 
00183 /** length of a RFC822 Date */
00184 #define APR_RFC822_DATE_LEN (30)
00185 /**
00186  * apr_rfc822_date formats dates in the RFC822
00187  * format in an efficient manner.  It is a fixed length
00188  * format which requires the indicated amount of storage,
00189  * including the trailing NUL terminator.
00190  * @param date_str String to write to.
00191  * @param t the time to convert 
00192  */
00193 APR_DECLARE(apr_status_t) apr_rfc822_date(char *date_str, apr_time_t t);
00194 
00195 /** length of a CTIME date */
00196 #define APR_CTIME_LEN (25)
00197 /**
00198  * apr_ctime formats dates in the ctime() format
00199  * in an efficient manner.  it is a fixed length format
00200  * and requires the indicated amount of storage including
00201  * the trailing NUL terminator.
00202  * Unlike ANSI/ISO C ctime(), apr_ctime() does not include
00203  * a \n at the end of the string.
00204  * @param date_str String to write to.
00205  * @param t the time to convert 
00206  */
00207 APR_DECLARE(apr_status_t) apr_ctime(char *date_str, apr_time_t t);
00208 
00209 /**
00210  * formats the exploded time according to the format specified
00211  * @param s string to write to
00212  * @param retsize The length of the returned string
00213  * @param max The maximum length of the string
00214  * @param format The format for the time string
00215  * @param tm The time to convert
00216  */
00217 APR_DECLARE(apr_status_t) apr_strftime(char *s, apr_size_t *retsize, 
00218                                        apr_size_t max, const char *format, 
00219                                        apr_time_exp_t *tm);
00220 
00221 /**
00222  * Improve the clock resolution for the lifetime of the given pool.
00223  * Generally this is only desireable on benchmarking and other very
00224  * time-sensitive applications, and has no impact on most platforms.
00225  * @param p The pool to associate the finer clock resolution 
00226  */
00227 APR_DECLARE(void) apr_time_clock_hires(apr_pool_t *p);
00228 
00229 /** @} */
00230 
00231 #ifdef __cplusplus
00232 }
00233 #endif
00234 
00235 #endif  /* ! APR_TIME_H */
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