1// Windows/TimeUtils.cpp
2
3#include "StdAfx.h"
4
5#include "Defs.h"
6#include "TimeUtils.h"
7
8namespace NWindows {
9namespace NTime {
10
11static const UInt32 kNumTimeQuantumsInSecond = 10000000;
12static const UInt32 kFileTimeStartYear = 1601;
13static const UInt32 kDosTimeStartYear = 1980;
14static const UInt32 kUnixTimeStartYear = 1970;
15static const UInt64 kUnixTimeOffset =
16    (UInt64)60 * 60 * 24 * (89 + 365 * (kUnixTimeStartYear - kFileTimeStartYear));
17static const UInt64 kNumSecondsInFileTime = (UInt64)(Int64)-1 / kNumTimeQuantumsInSecond;
18
19bool DosTimeToFileTime(UInt32 dosTime, FILETIME &ft) throw()
20{
21  #if defined(_WIN32) && !defined(UNDER_CE)
22  return BOOLToBool(::DosDateTimeToFileTime((UInt16)(dosTime >> 16), (UInt16)(dosTime & 0xFFFF), &ft));
23  #else
24  ft.dwLowDateTime = 0;
25  ft.dwHighDateTime = 0;
26  UInt64 res;
27  if (!GetSecondsSince1601(kDosTimeStartYear + (dosTime >> 25), (dosTime >> 21) & 0xF, (dosTime >> 16) & 0x1F,
28      (dosTime >> 11) & 0x1F, (dosTime >> 5) & 0x3F, (dosTime & 0x1F) * 2, res))
29    return false;
30  res *= kNumTimeQuantumsInSecond;
31  ft.dwLowDateTime = (UInt32)res;
32  ft.dwHighDateTime = (UInt32)(res >> 32);
33  return true;
34  #endif
35}
36
37static const UInt32 kHighDosTime = 0xFF9FBF7D;
38static const UInt32 kLowDosTime = 0x210000;
39
40#define PERIOD_4 (4 * 365 + 1)
41#define PERIOD_100 (PERIOD_4 * 25 - 1)
42#define PERIOD_400 (PERIOD_100 * 4 + 1)
43
44bool FileTimeToDosTime(const FILETIME &ft, UInt32 &dosTime) throw()
45{
46  #if defined(_WIN32) && !defined(UNDER_CE)
47
48  WORD datePart, timePart;
49  if (!::FileTimeToDosDateTime(&ft, &datePart, &timePart))
50  {
51    dosTime = (ft.dwHighDateTime >= 0x01C00000) ? kHighDosTime : kLowDosTime;
52    return false;
53  }
54  dosTime = (((UInt32)datePart) << 16) + timePart;
55
56  #else
57
58  unsigned year, mon, day, hour, min, sec;
59  UInt64 v64 = ft.dwLowDateTime | ((UInt64)ft.dwHighDateTime << 32);
60  Byte ms[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
61  unsigned temp;
62  UInt32 v;
63  v64 += (kNumTimeQuantumsInSecond * 2 - 1);
64  v64 /= kNumTimeQuantumsInSecond;
65  sec = (unsigned)(v64 % 60);
66  v64 /= 60;
67  min = (unsigned)(v64 % 60);
68  v64 /= 60;
69  hour = (unsigned)(v64 % 24);
70  v64 /= 24;
71
72  v = (UInt32)v64;
73
74  year = (unsigned)(kFileTimeStartYear + v / PERIOD_400 * 400);
75  v %= PERIOD_400;
76
77  temp = (unsigned)(v / PERIOD_100);
78  if (temp == 4)
79    temp = 3;
80  year += temp * 100;
81  v -= temp * PERIOD_100;
82
83  temp = v / PERIOD_4;
84  if (temp == 25)
85    temp = 24;
86  year += temp * 4;
87  v -= temp * PERIOD_4;
88
89  temp = v / 365;
90  if (temp == 4)
91    temp = 3;
92  year += temp;
93  v -= temp * 365;
94
95  if (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0))
96    ms[1] = 29;
97  for (mon = 1; mon <= 12; mon++)
98  {
99    unsigned s = ms[mon - 1];
100    if (v < s)
101      break;
102    v -= s;
103  }
104  day = (unsigned)v + 1;
105
106  dosTime = kLowDosTime;
107  if (year < kDosTimeStartYear)
108    return false;
109  year -= kDosTimeStartYear;
110  dosTime = kHighDosTime;
111  if (year >= 128)
112    return false;
113  dosTime = (year << 25) | (mon << 21) | (day << 16) | (hour << 11) | (min << 5) | (sec >> 1);
114  #endif
115  return true;
116}
117
118void UnixTimeToFileTime(UInt32 unixTime, FILETIME &ft) throw()
119{
120  UInt64 v = (kUnixTimeOffset + (UInt64)unixTime) * kNumTimeQuantumsInSecond;
121  ft.dwLowDateTime = (DWORD)v;
122  ft.dwHighDateTime = (DWORD)(v >> 32);
123}
124
125bool UnixTime64ToFileTime(Int64 unixTime, FILETIME &ft) throw()
126{
127  if (unixTime > kNumSecondsInFileTime - kUnixTimeOffset)
128  {
129    ft.dwLowDateTime = ft.dwHighDateTime = (UInt32)(Int32)-1;
130    return false;
131  }
132  Int64 v = (Int64)kUnixTimeOffset + unixTime;
133  if (v < 0)
134  {
135    ft.dwLowDateTime = ft.dwHighDateTime = 0;
136    return false;
137  }
138  UInt64 v2 = (UInt64)v * kNumTimeQuantumsInSecond;
139  ft.dwLowDateTime = (DWORD)v2;
140  ft.dwHighDateTime = (DWORD)(v2 >> 32);
141  return true;
142}
143
144Int64 FileTimeToUnixTime64(const FILETIME &ft) throw()
145{
146  UInt64 winTime = (((UInt64)ft.dwHighDateTime) << 32) + ft.dwLowDateTime;
147  return (Int64)(winTime / kNumTimeQuantumsInSecond) - kUnixTimeOffset;
148}
149
150bool FileTimeToUnixTime(const FILETIME &ft, UInt32 &unixTime) throw()
151{
152  UInt64 winTime = (((UInt64)ft.dwHighDateTime) << 32) + ft.dwLowDateTime;
153  winTime /= kNumTimeQuantumsInSecond;
154  if (winTime < kUnixTimeOffset)
155  {
156    unixTime = 0;
157    return false;
158  }
159  winTime -= kUnixTimeOffset;
160  if (winTime > 0xFFFFFFFF)
161  {
162    unixTime = 0xFFFFFFFF;
163    return false;
164  }
165  unixTime = (UInt32)winTime;
166  return true;
167}
168
169bool GetSecondsSince1601(unsigned year, unsigned month, unsigned day,
170  unsigned hour, unsigned min, unsigned sec, UInt64 &resSeconds) throw()
171{
172  resSeconds = 0;
173  if (year < kFileTimeStartYear || year >= 10000 || month < 1 || month > 12 ||
174      day < 1 || day > 31 || hour > 23 || min > 59 || sec > 59)
175    return false;
176  UInt32 numYears = year - kFileTimeStartYear;
177  UInt32 numDays = numYears * 365 + numYears / 4 - numYears / 100 + numYears / 400;
178  Byte ms[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
179  if (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0))
180    ms[1] = 29;
181  month--;
182  for (unsigned i = 0; i < month; i++)
183    numDays += ms[i];
184  numDays += day - 1;
185  resSeconds = ((UInt64)(numDays * 24 + hour) * 60 + min) * 60 + sec;
186  return true;
187}
188
189void GetCurUtcFileTime(FILETIME &ft) throw()
190{
191  // Both variants provide same low resolution on WinXP: about 15 ms.
192  // But GetSystemTimeAsFileTime is much faster.
193
194  #ifdef UNDER_CE
195  SYSTEMTIME st;
196  GetSystemTime(&st);
197  SystemTimeToFileTime(&st, &ft);
198  #else
199  GetSystemTimeAsFileTime(&ft);
200  #endif
201}
202
203}}
204