1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* 3 * The contents of this file are subject to the Mozilla Public 4 * License Version 1.1 (the "License"); you may not use this file 5 * except in compliance with the License. You may obtain a copy of 6 * the License at http://www.mozilla.org/MPL/ 7 * 8 * Software distributed under the License is distributed on an "AS 9 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or 10 * implied. See the License for the specific language governing 11 * rights and limitations under the License. 12 * 13 * The Original Code is the Netscape Portable Runtime (NSPR). 14 * 15 * The Initial Developer of the Original Code is Netscape 16 * Communications Corporation. Portions created by Netscape are 17 * Copyright (C) 1998-2000 Netscape Communications Corporation. All 18 * Rights Reserved. 19 * 20 * Contributor(s): 21 * 22 * Alternatively, the contents of this file may be used under the 23 * terms of the GNU General Public License Version 2 or later (the 24 * "GPL"), in which case the provisions of the GPL are applicable 25 * instead of those above. If you wish to allow use of your 26 * version of this file only under the terms of the GPL and not to 27 * allow others to use your version of this file under the MPL, 28 * indicate your decision by deleting the provisions above and 29 * replace them with the notice and other provisions required by 30 * the GPL. If you do not delete the provisions above, a recipient 31 * may use your version of this file under either the MPL or the 32 * GPL. 33 */ 34 35 /* 36 *---------------------------------------------------------------------- 37 * 38 * prtime.h -- 39 * 40 * NSPR date and time functions 41 * 42 *----------------------------------------------------------------------- 43 */ 44 45 #ifndef prtime_h___ 46 #define prtime_h___ 47 48 #include "prlong.h" 49 50 PR_BEGIN_EXTERN_C 51 52 /**********************************************************************/ 53 /************************* TYPES AND CONSTANTS ************************/ 54 /**********************************************************************/ 55 56 #define PR_MSEC_PER_SEC 1000UL 57 #define PR_USEC_PER_SEC 1000000UL 58 #define PR_NSEC_PER_SEC 1000000000UL 59 #define PR_USEC_PER_MSEC 1000UL 60 #define PR_NSEC_PER_MSEC 1000000UL 61 62 /* 63 * PRTime -- 64 * 65 * NSPR represents basic time as 64-bit signed integers relative 66 * to midnight (00:00:00), January 1, 1970 Greenwich Mean Time (GMT). 67 * (GMT is also known as Coordinated Universal Time, UTC.) 68 * The units of time are in microseconds. Negative times are allowed 69 * to represent times prior to the January 1970 epoch. Such values are 70 * intended to be exported to other systems or converted to human 71 * readable form. 72 * 73 * Notes on porting: PRTime corresponds to time_t in ANSI C. NSPR 1.0 74 * simply uses PRInt64. 75 */ 76 77 typedef PRInt64 PRTime; 78 79 /* 80 * Time zone and daylight saving time corrections applied to GMT to 81 * obtain the local time of some geographic location 82 */ 83 84 typedef struct PRTimeParameters { 85 PRInt32 tp_gmt_offset; /* the offset from GMT in seconds */ 86 PRInt32 tp_dst_offset; /* contribution of DST in seconds */ 87 } PRTimeParameters; 88 89 /* 90 * PRExplodedTime -- 91 * 92 * Time broken down into human-readable components such as year, month, 93 * day, hour, minute, second, and microsecond. Time zone and daylight 94 * saving time corrections may be applied. If they are applied, the 95 * offsets from the GMT must be saved in the 'tm_params' field so that 96 * all the information is available to reconstruct GMT. 97 * 98 * Notes on porting: PRExplodedTime corrresponds to struct tm in 99 * ANSI C, with the following differences: 100 * - an additional field tm_usec; 101 * - replacing tm_isdst by tm_params; 102 * - the month field is spelled tm_month, not tm_mon; 103 * - we use absolute year, AD, not the year since 1900. 104 * The corresponding type in NSPR 1.0 is called PRTime. Below is 105 * a table of date/time type correspondence in the three APIs: 106 * API time since epoch time in components 107 * ANSI C time_t struct tm 108 * NSPR 1.0 PRInt64 PRTime 109 * NSPR 2.0 PRTime PRExplodedTime 110 */ 111 112 typedef struct PRExplodedTime { 113 PRInt32 tm_usec; /* microseconds past tm_sec (0-99999) */ 114 PRInt32 tm_sec; /* seconds past tm_min (0-61, accomodating 115 up to two leap seconds) */ 116 PRInt32 tm_min; /* minutes past tm_hour (0-59) */ 117 PRInt32 tm_hour; /* hours past tm_day (0-23) */ 118 PRInt32 tm_mday; /* days past tm_mon (1-31, note that it 119 starts from 1) */ 120 PRInt32 tm_month; /* months past tm_year (0-11, Jan = 0) */ 121 PRInt16 tm_year; /* absolute year, AD (note that we do not 122 count from 1900) */ 123 124 PRInt8 tm_wday; /* calculated day of the week 125 (0-6, Sun = 0) */ 126 PRInt16 tm_yday; /* calculated day of the year 127 (0-365, Jan 1 = 0) */ 128 129 PRTimeParameters tm_params; /* time parameters used by conversion */ 130 } PRExplodedTime; 131 132 /* 133 * PRTimeParamFn -- 134 * 135 * A function of PRTimeParamFn type returns the time zone and 136 * daylight saving time corrections for some geographic location, 137 * given the current time in GMT. The input argument gmt should 138 * point to a PRExplodedTime that is in GMT, i.e., whose 139 * tm_params contains all 0's. 140 * 141 * For any time zone other than GMT, the computation is intended to 142 * consist of two steps: 143 * - Figure out the time zone correction, tp_gmt_offset. This number 144 * usually depends on the geographic location only. But it may 145 * also depend on the current time. For example, all of China 146 * is one time zone right now. But this situation may change 147 * in the future. 148 * - Figure out the daylight saving time correction, tp_dst_offset. 149 * This number depends on both the geographic location and the 150 * current time. Most of the DST rules are expressed in local 151 * current time. If so, one should apply the time zone correction 152 * to GMT before applying the DST rules. 153 */ 154 155 typedef PRTimeParameters (PR_CALLBACK *PRTimeParamFn)(const PRExplodedTime *gmt); 156 157 /**********************************************************************/ 158 /****************************** FUNCTIONS *****************************/ 159 /**********************************************************************/ 160 161 /* 162 * The PR_Now routine returns the current time relative to the 163 * epoch, midnight, January 1, 1970 UTC. The units of the returned 164 * value are microseconds since the epoch. 165 * 166 * The values returned are not guaranteed to advance in a linear fashion 167 * due to the application of time correction protocols which synchronize 168 * computer clocks to some external time source. Consequently it should 169 * not be depended on for interval timing. 170 * 171 * The implementation is machine dependent. 172 * Cf. time_t time(time_t *tp) in ANSI C. 173 */ 174 #if defined(HAVE_WATCOM_BUG_2) 175 PRTime __pascal __export __loadds 176 #else 177 NSPR_API(PRTime) 178 #endif 179 PR_Now(void); 180 181 /* 182 * Expand time binding it to time parameters provided by PRTimeParamFn. 183 * The calculation is envisoned to proceed in the following steps: 184 * - From given PRTime, calculate PRExplodedTime in GMT 185 * - Apply the given PRTimeParamFn to the GMT that we just calculated 186 * to obtain PRTimeParameters. 187 * - Add the PRTimeParameters offsets to GMT to get the local time 188 * as PRExplodedTime. 189 */ 190 191 NSPR_API(void) PR_ExplodeTime( 192 PRTime usecs, PRTimeParamFn params, PRExplodedTime *exploded); 193 194 /* Reverse operation of PR_ExplodeTime */ 195 #if defined(HAVE_WATCOM_BUG_2) 196 PRTime __pascal __export __loadds 197 #else 198 NSPR_API(PRTime) 199 #endif 200 PR_ImplodeTime(const PRExplodedTime *exploded); 201 202 /* 203 * Adjust exploded time to normalize field overflows after manipulation. 204 * Note that the following fields of PRExplodedTime should not be 205 * manipulated: 206 * - tm_month and tm_year: because the number of days in a month and 207 * number of days in a year are not constant, it is ambiguous to 208 * manipulate the month and year fields, although one may be tempted 209 * to. For example, what does "a month from January 31st" mean? 210 * - tm_wday and tm_yday: these fields are calculated by NSPR. Users 211 * should treat them as "read-only". 212 */ 213 214 NSPR_API(void) PR_NormalizeTime( 215 PRExplodedTime *exploded, PRTimeParamFn params); 216 217 /**********************************************************************/ 218 /*********************** TIME PARAMETER FUNCTIONS *********************/ 219 /**********************************************************************/ 220 221 /* Time parameters that suit current host machine */ 222 NSPR_API(PRTimeParameters) PR_LocalTimeParameters(const PRExplodedTime *gmt); 223 224 /* Time parameters that represent Greenwich Mean Time */ 225 NSPR_API(PRTimeParameters) PR_GMTParameters(const PRExplodedTime *gmt); 226 227 /* 228 * Time parameters that represent the US Pacific Time Zone, with the 229 * current daylight saving time rules (for testing only) 230 */ 231 NSPR_API(PRTimeParameters) PR_USPacificTimeParameters(const PRExplodedTime *gmt); 232 233 /* 234 * This parses a time/date string into a PRTime 235 * (microseconds after "1-Jan-1970 00:00:00 GMT"). 236 * It returns PR_SUCCESS on success, and PR_FAILURE 237 * if the time/date string can't be parsed. 238 * 239 * Many formats are handled, including: 240 * 241 * 14 Apr 89 03:20:12 242 * 14 Apr 89 03:20 GMT 243 * Fri, 17 Mar 89 4:01:33 244 * Fri, 17 Mar 89 4:01 GMT 245 * Mon Jan 16 16:12 PDT 1989 246 * Mon Jan 16 16:12 +0130 1989 247 * 6 May 1992 16:41-JST (Wednesday) 248 * 22-AUG-1993 10:59:12.82 249 * 22-AUG-1993 10:59pm 250 * 22-AUG-1993 12:59am 251 * 22-AUG-1993 12:59 PM 252 * Friday, August 04, 1995 3:54 PM 253 * 06/21/95 04:24:34 PM 254 * 20/06/95 21:07 255 * 95-06-08 19:32:48 EDT 256 * 257 * If the input string doesn't contain a description of the timezone, 258 * we consult the `default_to_gmt' to decide whether the string should 259 * be interpreted relative to the local time zone (PR_FALSE) or GMT (PR_TRUE). 260 * The correct value for this argument depends on what standard specified 261 * the time string which you are parsing. 262 */ 263 264 NSPR_API(PRStatus) PR_ParseTimeString ( 265 const char *string, 266 PRBool default_to_gmt, 267 PRTime *result); 268 269 /* 270 * FIXME: should we also have a formatting function, such as asctime, ctime, 271 * and strftime in standard C library? But this would involve 272 * internationalization issues. Might want to provide a US English version. 273 */ 274 275 /**********************************************************************/ 276 /*********************** OLD COMPATIBILITYFUNCTIONS *******************/ 277 /**********************************************************************/ 278 #ifndef NO_NSPR_10_SUPPORT 279 280 /* Format a time value into a buffer. Same semantics as strftime() */ 281 NSPR_API(PRUint32) PR_FormatTime(char *buf, int buflen, const char *fmt, 282 const PRExplodedTime *tm); 283 284 /* Format a time value into a buffer. Time is always in US English format, regardless 285 * of locale setting. 286 */ 287 NSPR_API(PRUint32) 288 PR_FormatTimeUSEnglish( char* buf, PRUint32 bufSize, 289 const char* format, const PRExplodedTime* tm ); 290 291 #endif /* NO_NSPR_10_SUPPORT */ 292 293 PR_END_EXTERN_C 294 295 #endif /* prtime_h___ */ 296
