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      1 /* Portions are Copyright (C) 2011 Google Inc */
      2 /* ***** BEGIN LICENSE BLOCK *****
      3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
      4  *
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      6  * 1.1 (the "License"); you may not use this file except in compliance with
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     11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
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     13  * License.
     14  *
     15  * The Original Code is the Netscape Portable Runtime (NSPR).
     16  *
     17  * The Initial Developer of the Original Code is
     18  * Netscape Communications Corporation.
     19  * Portions created by the Initial Developer are Copyright (C) 1998-2000
     20  * the Initial Developer. All Rights Reserved.
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     25  * either the GNU General Public License Version 2 or later (the "GPL"), or
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     35  *
     36  * ***** END LICENSE BLOCK ***** */
     37 
     38 /*
     39  *---------------------------------------------------------------------------
     40  *
     41  * prtime.h --
     42  *
     43  *     NSPR date and time functions
     44  * CVS revision 3.10
     45  * This file contains definitions of NSPR's basic types required by
     46  * prtime.cc. These types have been copied over from the following NSPR
     47  * files prtime.h, prtypes.h(CVS revision 3.35), prlong.h(CVS revision 3.13)
     48  *
     49  *---------------------------------------------------------------------------
     50  */
     51 
     52 #ifndef BASE_PRTIME_H__
     53 #define BASE_PRTIME_H__
     54 
     55 #include "base/base_api.h"
     56 #include "base/third_party/nspr/prtypes.h"
     57 
     58 #define PR_ASSERT DCHECK
     59 
     60 #define LL_I2L(l, i)    ((l) = (PRInt64)(i))
     61 #define LL_MUL(r, a, b) ((r) = (a) * (b))
     62 
     63 /**********************************************************************/
     64 /************************* TYPES AND CONSTANTS ************************/
     65 /**********************************************************************/
     66 
     67 #define PR_MSEC_PER_SEC		1000UL
     68 #define PR_USEC_PER_SEC		1000000UL
     69 #define PR_NSEC_PER_SEC		1000000000UL
     70 #define PR_USEC_PER_MSEC	1000UL
     71 #define PR_NSEC_PER_MSEC	1000000UL
     72 
     73 /*
     74  * PRTime --
     75  *
     76  *     NSPR represents basic time as 64-bit signed integers relative
     77  *     to midnight (00:00:00), January 1, 1970 Greenwich Mean Time (GMT).
     78  *     (GMT is also known as Coordinated Universal Time, UTC.)
     79  *     The units of time are in microseconds. Negative times are allowed
     80  *     to represent times prior to the January 1970 epoch. Such values are
     81  *     intended to be exported to other systems or converted to human
     82  *     readable form.
     83  *
     84  *     Notes on porting: PRTime corresponds to time_t in ANSI C.  NSPR 1.0
     85  *     simply uses PRInt64.
     86  */
     87 
     88 typedef PRInt64 PRTime;
     89 
     90 /*
     91  * Time zone and daylight saving time corrections applied to GMT to
     92  * obtain the local time of some geographic location
     93  */
     94 
     95 typedef struct PRTimeParameters {
     96     PRInt32 tp_gmt_offset;     /* the offset from GMT in seconds */
     97     PRInt32 tp_dst_offset;     /* contribution of DST in seconds */
     98 } PRTimeParameters;
     99 
    100 /*
    101  * PRExplodedTime --
    102  *
    103  *     Time broken down into human-readable components such as year, month,
    104  *     day, hour, minute, second, and microsecond.  Time zone and daylight
    105  *     saving time corrections may be applied.  If they are applied, the
    106  *     offsets from the GMT must be saved in the 'tm_params' field so that
    107  *     all the information is available to reconstruct GMT.
    108  *
    109  *     Notes on porting: PRExplodedTime corrresponds to struct tm in
    110  *     ANSI C, with the following differences:
    111  *       - an additional field tm_usec;
    112  *       - replacing tm_isdst by tm_params;
    113  *       - the month field is spelled tm_month, not tm_mon;
    114  *       - we use absolute year, AD, not the year since 1900.
    115  *     The corresponding type in NSPR 1.0 is called PRTime.  Below is
    116  *     a table of date/time type correspondence in the three APIs:
    117  *         API          time since epoch          time in components
    118  *       ANSI C             time_t                  struct tm
    119  *       NSPR 1.0           PRInt64                   PRTime
    120  *       NSPR 2.0           PRTime                  PRExplodedTime
    121  */
    122 
    123 typedef struct PRExplodedTime {
    124     PRInt32 tm_usec;		    /* microseconds past tm_sec (0-99999)  */
    125     PRInt32 tm_sec;             /* seconds past tm_min (0-61, accomodating
    126                                    up to two leap seconds) */
    127     PRInt32 tm_min;             /* minutes past tm_hour (0-59) */
    128     PRInt32 tm_hour;            /* hours past tm_day (0-23) */
    129     PRInt32 tm_mday;            /* days past tm_mon (1-31, note that it
    130 				                starts from 1) */
    131     PRInt32 tm_month;           /* months past tm_year (0-11, Jan = 0) */
    132     PRInt16 tm_year;            /* absolute year, AD (note that we do not
    133 				                count from 1900) */
    134 
    135     PRInt8 tm_wday;		        /* calculated day of the week
    136 				                (0-6, Sun = 0) */
    137     PRInt16 tm_yday;            /* calculated day of the year
    138 				                (0-365, Jan 1 = 0) */
    139 
    140     PRTimeParameters tm_params;  /* time parameters used by conversion */
    141 } PRExplodedTime;
    142 
    143 /*
    144  * PRTimeParamFn --
    145  *
    146  *     A function of PRTimeParamFn type returns the time zone and
    147  *     daylight saving time corrections for some geographic location,
    148  *     given the current time in GMT.  The input argument gmt should
    149  *     point to a PRExplodedTime that is in GMT, i.e., whose
    150  *     tm_params contains all 0's.
    151  *
    152  *     For any time zone other than GMT, the computation is intended to
    153  *     consist of two steps:
    154  *       - Figure out the time zone correction, tp_gmt_offset.  This number
    155  *         usually depends on the geographic location only.  But it may
    156  *         also depend on the current time.  For example, all of China
    157  *         is one time zone right now.  But this situation may change
    158  *         in the future.
    159  *       - Figure out the daylight saving time correction, tp_dst_offset.
    160  *         This number depends on both the geographic location and the
    161  *         current time.  Most of the DST rules are expressed in local
    162  *         current time.  If so, one should apply the time zone correction
    163  *         to GMT before applying the DST rules.
    164  */
    165 
    166 typedef PRTimeParameters (PR_CALLBACK *PRTimeParamFn)(const PRExplodedTime *gmt);
    167 
    168 /**********************************************************************/
    169 /****************************** FUNCTIONS *****************************/
    170 /**********************************************************************/
    171 
    172 NSPR_API(PRTime)
    173 PR_ImplodeTime(const PRExplodedTime *exploded);
    174 
    175 /*
    176  * Adjust exploded time to normalize field overflows after manipulation.
    177  * Note that the following fields of PRExplodedTime should not be
    178  * manipulated:
    179  *   - tm_month and tm_year: because the number of days in a month and
    180  *     number of days in a year are not constant, it is ambiguous to
    181  *     manipulate the month and year fields, although one may be tempted
    182  *     to.  For example, what does "a month from January 31st" mean?
    183  *   - tm_wday and tm_yday: these fields are calculated by NSPR.  Users
    184  *     should treat them as "read-only".
    185  */
    186 
    187 NSPR_API(void) PR_NormalizeTime(
    188     PRExplodedTime *exploded, PRTimeParamFn params);
    189 
    190 /**********************************************************************/
    191 /*********************** TIME PARAMETER FUNCTIONS *********************/
    192 /**********************************************************************/
    193 
    194 /* Time parameters that represent Greenwich Mean Time */
    195 NSPR_API(PRTimeParameters) PR_GMTParameters(const PRExplodedTime *gmt);
    196 
    197 /*
    198  * This parses a time/date string into a PRTime
    199  * (microseconds after "1-Jan-1970 00:00:00 GMT").
    200  * It returns PR_SUCCESS on success, and PR_FAILURE
    201  * if the time/date string can't be parsed.
    202  *
    203  * Many formats are handled, including:
    204  *
    205  *   14 Apr 89 03:20:12
    206  *   14 Apr 89 03:20 GMT
    207  *   Fri, 17 Mar 89 4:01:33
    208  *   Fri, 17 Mar 89 4:01 GMT
    209  *   Mon Jan 16 16:12 PDT 1989
    210  *   Mon Jan 16 16:12 +0130 1989
    211  *   6 May 1992 16:41-JST (Wednesday)
    212  *   22-AUG-1993 10:59:12.82
    213  *   22-AUG-1993 10:59pm
    214  *   22-AUG-1993 12:59am
    215  *   22-AUG-1993 12:59 PM
    216  *   Friday, August 04, 1995 3:54 PM
    217  *   06/21/95 04:24:34 PM
    218  *   20/06/95 21:07
    219  *   95-06-08 19:32:48 EDT
    220  *
    221  * If the input string doesn't contain a description of the timezone,
    222  * we consult the `default_to_gmt' to decide whether the string should
    223  * be interpreted relative to the local time zone (PR_FALSE) or GMT (PR_TRUE).
    224  * The correct value for this argument depends on what standard specified
    225  * the time string which you are parsing.
    226  */
    227 
    228 /*
    229  * This is the only funtion that should be called from outside base, and only
    230  * from the unit test.
    231  */
    232 
    233 BASE_API PRStatus PR_ParseTimeString (
    234 	const char *string,
    235 	PRBool default_to_gmt,
    236 	PRTime *result);
    237 
    238 #endif  // BASE_PRTIME_H__
    239