1 | /* |
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2 | * localtime_r.c |
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3 | * Original Author: Adapted from tzcode maintained by Arthur David Olson. |
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4 | * Modifications: |
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5 | * - Changed to mktm_r and added __tzcalc_limits - 04/10/02, Jeff Johnston |
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6 | * - Fixed bug in mday computations - 08/12/04, Alex Mogilnikov <alx@intellectronika.ru> |
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7 | * - Fixed bug in __tzcalc_limits - 08/12/04, Alex Mogilnikov <alx@intellectronika.ru> |
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8 | * - Implement localtime_r() with gmtime_r() and the conditional code moved |
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9 | * from _mktm_r() - 05/09/14, Freddie Chopin <freddie_chopin@op.pl> |
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10 | * |
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11 | * Converts the calendar time pointed to by tim_p into a broken-down time |
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12 | * expressed as local time. Returns a pointer to a structure containing the |
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13 | * broken-down time. |
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14 | */ |
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15 | |
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16 | #include "local.h" |
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17 | |
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18 | struct tm * |
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19 | localtime_r (const time_t *__restrict tim_p, |
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20 | struct tm *__restrict res) |
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21 | { |
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22 | long offset; |
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23 | int hours, mins, secs; |
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24 | int year; |
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25 | __tzinfo_type *const tz = __gettzinfo (); |
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26 | const int *ip; |
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27 | |
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28 | res = gmtime_r (tim_p, res); |
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29 | |
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30 | year = res->tm_year + YEAR_BASE; |
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31 | ip = __month_lengths[isleap(year)]; |
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32 | |
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33 | TZ_LOCK; |
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34 | _tzset_unlocked (); |
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35 | if (_daylight) |
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36 | { |
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37 | if (year == tz->__tzyear || __tzcalc_limits (year)) |
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38 | res->tm_isdst = (tz->__tznorth |
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39 | ? (*tim_p >= tz->__tzrule[0].change |
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40 | && *tim_p < tz->__tzrule[1].change) |
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41 | : (*tim_p >= tz->__tzrule[0].change |
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42 | || *tim_p < tz->__tzrule[1].change)); |
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43 | else |
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44 | res->tm_isdst = -1; |
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45 | } |
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46 | else |
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47 | res->tm_isdst = 0; |
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48 | |
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49 | offset = (res->tm_isdst == 1 |
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50 | ? tz->__tzrule[1].offset |
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51 | : tz->__tzrule[0].offset); |
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52 | |
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53 | hours = (int) (offset / SECSPERHOUR); |
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54 | offset = offset % SECSPERHOUR; |
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55 | |
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56 | mins = (int) (offset / SECSPERMIN); |
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57 | secs = (int) (offset % SECSPERMIN); |
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58 | |
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59 | res->tm_sec -= secs; |
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60 | res->tm_min -= mins; |
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61 | res->tm_hour -= hours; |
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62 | |
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63 | if (res->tm_sec >= SECSPERMIN) |
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64 | { |
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65 | res->tm_min += 1; |
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66 | res->tm_sec -= SECSPERMIN; |
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67 | } |
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68 | else if (res->tm_sec < 0) |
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69 | { |
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70 | res->tm_min -= 1; |
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71 | res->tm_sec += SECSPERMIN; |
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72 | } |
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73 | if (res->tm_min >= MINSPERHOUR) |
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74 | { |
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75 | res->tm_hour += 1; |
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76 | res->tm_min -= MINSPERHOUR; |
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77 | } |
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78 | else if (res->tm_min < 0) |
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79 | { |
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80 | res->tm_hour -= 1; |
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81 | res->tm_min += MINSPERHOUR; |
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82 | } |
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83 | if (res->tm_hour >= HOURSPERDAY) |
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84 | { |
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85 | ++res->tm_yday; |
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86 | ++res->tm_wday; |
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87 | if (res->tm_wday > 6) |
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88 | res->tm_wday = 0; |
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89 | ++res->tm_mday; |
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90 | res->tm_hour -= HOURSPERDAY; |
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91 | if (res->tm_mday > ip[res->tm_mon]) |
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92 | { |
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93 | res->tm_mday -= ip[res->tm_mon]; |
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94 | res->tm_mon += 1; |
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95 | if (res->tm_mon == 12) |
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96 | { |
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97 | res->tm_mon = 0; |
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98 | res->tm_year += 1; |
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99 | res->tm_yday = 0; |
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100 | } |
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101 | } |
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102 | } |
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103 | else if (res->tm_hour < 0) |
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104 | { |
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105 | res->tm_yday -= 1; |
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106 | res->tm_wday -= 1; |
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107 | if (res->tm_wday < 0) |
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108 | res->tm_wday = 6; |
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109 | res->tm_mday -= 1; |
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110 | res->tm_hour += 24; |
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111 | if (res->tm_mday == 0) |
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112 | { |
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113 | res->tm_mon -= 1; |
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114 | if (res->tm_mon < 0) |
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115 | { |
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116 | res->tm_mon = 11; |
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117 | res->tm_year -= 1; |
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118 | res->tm_yday = 364 + isleap(res->tm_year + YEAR_BASE); |
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119 | } |
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120 | res->tm_mday = ip[res->tm_mon]; |
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121 | } |
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122 | } |
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123 | TZ_UNLOCK; |
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124 | |
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125 | return (res); |
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126 | } |
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