LLVM  3.7.0
TimeValue.h
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1 //===-- TimeValue.h - Declare OS TimeValue Concept --------------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This header file declares the operating system TimeValue concept.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_SUPPORT_TIMEVALUE_H
15 #define LLVM_SUPPORT_TIMEVALUE_H
16 
17 #include "llvm/Support/DataTypes.h"
18 #include <string>
19 
20 namespace llvm {
21 namespace sys {
22  /// This class is used where a precise fixed point in time is required. The
23  /// range of TimeValue spans many hundreds of billions of years both past and
24  /// present. The precision of TimeValue is to the nanosecond. However, the
25  /// actual precision of its values will be determined by the resolution of
26  /// the system clock. The TimeValue class is used in conjunction with several
27  /// other lib/System interfaces to specify the time at which a call should
28  /// timeout, etc.
29  /// @since 1.4
30  /// @brief Provides an abstraction for a fixed point in time.
31  class TimeValue {
32 
33  /// @name Constants
34  /// @{
35  public:
36 
37  /// A constant TimeValue representing the smallest time
38  /// value permissible by the class. MinTime is some point
39  /// in the distant past, about 300 billion years BCE.
40  /// @brief The smallest possible time value.
41  static TimeValue MinTime() {
42  return TimeValue ( INT64_MIN,0 );
43  }
44 
45  /// A constant TimeValue representing the largest time
46  /// value permissible by the class. MaxTime is some point
47  /// in the distant future, about 300 billion years AD.
48  /// @brief The largest possible time value.
49  static TimeValue MaxTime() {
50  return TimeValue ( INT64_MAX,0 );
51  }
52 
53  /// A constant TimeValue representing the base time,
54  /// or zero time of 00:00:00 (midnight) January 1st, 2000.
55  /// @brief 00:00:00 Jan 1, 2000 UTC.
56  static TimeValue ZeroTime() {
57  return TimeValue ( 0,0 );
58  }
59 
60  /// A constant TimeValue for the Posix base time which is
61  /// 00:00:00 (midnight) January 1st, 1970.
62  /// @brief 00:00:00 Jan 1, 1970 UTC.
64  return TimeValue ( PosixZeroTimeSeconds,0 );
65  }
66 
67  /// A constant TimeValue for the Win32 base time which is
68  /// 00:00:00 (midnight) January 1st, 1601.
69  /// @brief 00:00:00 Jan 1, 1601 UTC.
71  return TimeValue ( Win32ZeroTimeSeconds,0 );
72  }
73 
74  /// @}
75  /// @name Types
76  /// @{
77  public:
78  typedef int64_t SecondsType; ///< Type used for representing seconds.
79  typedef int32_t NanoSecondsType;///< Type used for representing nanoseconds.
80 
82  NANOSECONDS_PER_SECOND = 1000000000, ///< One Billion
83  MICROSECONDS_PER_SECOND = 1000000, ///< One Million
84  MILLISECONDS_PER_SECOND = 1000, ///< One Thousand
85  NANOSECONDS_PER_MICROSECOND = 1000, ///< One Thousand
86  NANOSECONDS_PER_MILLISECOND = 1000000,///< One Million
87  NANOSECONDS_PER_WIN32_TICK = 100 ///< Win32 tick is 10^7 Hz (10ns)
88  };
89 
90  /// @}
91  /// @name Constructors
92  /// @{
93  public:
94  /// \brief Default construct a time value, initializing to ZeroTime.
95  TimeValue() : seconds_(0), nanos_(0) {}
96 
97  /// Caller provides the exact value in seconds and nanoseconds. The
98  /// \p nanos argument defaults to zero for convenience.
99  /// @brief Explicit constructor
101  : seconds_( seconds ), nanos_( nanos ) { this->normalize(); }
102 
103  /// Caller provides the exact value as a double in seconds with the
104  /// fractional part representing nanoseconds.
105  /// @brief Double Constructor.
106  explicit TimeValue( double new_time )
107  : seconds_( 0 ) , nanos_ ( 0 ) {
108  SecondsType integer_part = static_cast<SecondsType>( new_time );
109  seconds_ = integer_part;
110  nanos_ = static_cast<NanoSecondsType>( (new_time -
111  static_cast<double>(integer_part)) * NANOSECONDS_PER_SECOND );
112  this->normalize();
113  }
114 
115  /// This is a static constructor that returns a TimeValue that represents
116  /// the current time.
117  /// @brief Creates a TimeValue with the current time (UTC).
118  static TimeValue now();
119 
120  /// @}
121  /// @name Operators
122  /// @{
123  public:
124  /// Add \p that to \p this.
125  /// @returns this
126  /// @brief Incrementing assignment operator.
128  this->seconds_ += that.seconds_ ;
129  this->nanos_ += that.nanos_ ;
130  this->normalize();
131  return *this;
132  }
133 
134  /// Subtract \p that from \p this.
135  /// @returns this
136  /// @brief Decrementing assignment operator.
138  this->seconds_ -= that.seconds_ ;
139  this->nanos_ -= that.nanos_ ;
140  this->normalize();
141  return *this;
142  }
143 
144  /// Determine if \p this is less than \p that.
145  /// @returns True iff *this < that.
146  /// @brief True if this < that.
147  int operator < (const TimeValue &that) const { return that > *this; }
148 
149  /// Determine if \p this is greather than \p that.
150  /// @returns True iff *this > that.
151  /// @brief True if this > that.
152  int operator > (const TimeValue &that) const {
153  if ( this->seconds_ > that.seconds_ ) {
154  return 1;
155  } else if ( this->seconds_ == that.seconds_ ) {
156  if ( this->nanos_ > that.nanos_ ) return 1;
157  }
158  return 0;
159  }
160 
161  /// Determine if \p this is less than or equal to \p that.
162  /// @returns True iff *this <= that.
163  /// @brief True if this <= that.
164  int operator <= (const TimeValue &that) const { return that >= *this; }
165 
166  /// Determine if \p this is greater than or equal to \p that.
167  /// @returns True iff *this >= that.
168  int operator >= (const TimeValue &that) const {
169  if ( this->seconds_ > that.seconds_ ) {
170  return 1;
171  } else if ( this->seconds_ == that.seconds_ ) {
172  if ( this->nanos_ >= that.nanos_ ) return 1;
173  }
174  return 0;
175  }
176 
177  /// Determines if two TimeValue objects represent the same moment in time.
178  /// @returns True iff *this == that.
179  int operator == (const TimeValue &that) const {
180  return (this->seconds_ == that.seconds_) &&
181  (this->nanos_ == that.nanos_);
182  }
183 
184  /// Determines if two TimeValue objects represent times that are not the
185  /// same.
186  /// @returns True iff *this != that.
187  int operator != (const TimeValue &that) const { return !(*this == that); }
188 
189  /// Adds two TimeValue objects together.
190  /// @returns The sum of the two operands as a new TimeValue
191  /// @brief Addition operator.
192  friend TimeValue operator + (const TimeValue &tv1, const TimeValue &tv2);
193 
194  /// Subtracts two TimeValue objects.
195  /// @returns The difference of the two operands as a new TimeValue
196  /// @brief Subtraction operator.
197  friend TimeValue operator - (const TimeValue &tv1, const TimeValue &tv2);
198 
199  /// @}
200  /// @name Accessors
201  /// @{
202  public:
203 
204  /// Returns only the seconds component of the TimeValue. The nanoseconds
205  /// portion is ignored. No rounding is performed.
206  /// @brief Retrieve the seconds component
207  SecondsType seconds() const { return seconds_; }
208 
209  /// Returns only the nanoseconds component of the TimeValue. The seconds
210  /// portion is ignored.
211  /// @brief Retrieve the nanoseconds component.
212  NanoSecondsType nanoseconds() const { return nanos_; }
213 
214  /// Returns only the fractional portion of the TimeValue rounded down to the
215  /// nearest microsecond (divide by one thousand).
216  /// @brief Retrieve the fractional part as microseconds;
217  uint32_t microseconds() const {
218  return nanos_ / NANOSECONDS_PER_MICROSECOND;
219  }
220 
221  /// Returns only the fractional portion of the TimeValue rounded down to the
222  /// nearest millisecond (divide by one million).
223  /// @brief Retrieve the fractional part as milliseconds;
224  uint32_t milliseconds() const {
225  return nanos_ / NANOSECONDS_PER_MILLISECOND;
226  }
227 
228  /// Returns the TimeValue as a number of microseconds. Note that the value
229  /// returned can overflow because the range of a uint64_t is smaller than
230  /// the range of a TimeValue. Nevertheless, this is useful on some operating
231  /// systems and is therefore provided.
232  /// @brief Convert to a number of microseconds (can overflow)
233  uint64_t usec() const {
234  return seconds_ * MICROSECONDS_PER_SECOND +
235  ( nanos_ / NANOSECONDS_PER_MICROSECOND );
236  }
237 
238  /// Returns the TimeValue as a number of milliseconds. Note that the value
239  /// returned can overflow because the range of a uint64_t is smaller than
240  /// the range of a TimeValue. Nevertheless, this is useful on some operating
241  /// systems and is therefore provided.
242  /// @brief Convert to a number of milliseconds (can overflow)
243  uint64_t msec() const {
244  return seconds_ * MILLISECONDS_PER_SECOND +
245  ( nanos_ / NANOSECONDS_PER_MILLISECOND );
246  }
247 
248  /// Converts the TimeValue into the corresponding number of seconds
249  /// since the epoch (00:00:00 Jan 1,1970).
250  uint64_t toEpochTime() const {
251  return seconds_ - PosixZeroTimeSeconds;
252  }
253 
254  /// Converts the TimeValue into the corresponding number of "ticks" for
255  /// Win32 platforms, correcting for the difference in Win32 zero time.
256  /// @brief Convert to Win32's FILETIME
257  /// (100ns intervals since 00:00:00 Jan 1, 1601 UTC)
258  uint64_t toWin32Time() const {
259  uint64_t result = (uint64_t)10000000 * (seconds_ - Win32ZeroTimeSeconds);
260  result += nanos_ / NANOSECONDS_PER_WIN32_TICK;
261  return result;
262  }
263 
264  /// Provides the seconds and nanoseconds as results in its arguments after
265  /// correction for the Posix zero time.
266  /// @brief Convert to timespec time (ala POSIX.1b)
267  void getTimespecTime( uint64_t& seconds, uint32_t& nanos ) const {
268  seconds = seconds_ - PosixZeroTimeSeconds;
269  nanos = nanos_;
270  }
271 
272  /// Provides conversion of the TimeValue into a readable time & date.
273  /// @returns std::string containing the readable time value
274  /// @brief Convert time to a string.
275  std::string str() const;
276 
277  /// @}
278  /// @name Mutators
279  /// @{
280  public:
281  /// The seconds component of the TimeValue is set to \p sec without
282  /// modifying the nanoseconds part. This is useful for whole second
283  /// arithmetic.
284  /// @brief Set the seconds component.
285  void seconds (SecondsType sec ) {
286  this->seconds_ = sec;
287  this->normalize();
288  }
289 
290  /// The nanoseconds component of the TimeValue is set to \p nanos without
291  /// modifying the seconds part. This is useful for basic computations
292  /// involving just the nanoseconds portion. Note that the TimeValue will be
293  /// normalized after this call so that the fractional (nanoseconds) portion
294  /// will have the smallest equivalent value.
295  /// @brief Set the nanoseconds component using a number of nanoseconds.
296  void nanoseconds ( NanoSecondsType nanos ) {
297  this->nanos_ = nanos;
298  this->normalize();
299  }
300 
301  /// The seconds component remains unchanged.
302  /// @brief Set the nanoseconds component using a number of microseconds.
303  void microseconds ( int32_t micros ) {
304  this->nanos_ = micros * NANOSECONDS_PER_MICROSECOND;
305  this->normalize();
306  }
307 
308  /// The seconds component remains unchanged.
309  /// @brief Set the nanoseconds component using a number of milliseconds.
310  void milliseconds ( int32_t millis ) {
311  this->nanos_ = millis * NANOSECONDS_PER_MILLISECOND;
312  this->normalize();
313  }
314 
315  /// @brief Converts from microsecond format to TimeValue format
316  void usec( int64_t microseconds ) {
317  this->seconds_ = microseconds / MICROSECONDS_PER_SECOND;
318  this->nanos_ = NanoSecondsType(microseconds % MICROSECONDS_PER_SECOND) *
320  this->normalize();
321  }
322 
323  /// @brief Converts from millisecond format to TimeValue format
324  void msec( int64_t milliseconds ) {
325  this->seconds_ = milliseconds / MILLISECONDS_PER_SECOND;
326  this->nanos_ = NanoSecondsType(milliseconds % MILLISECONDS_PER_SECOND) *
328  this->normalize();
329  }
330 
331  /// Converts the \p seconds argument from PosixTime to the corresponding
332  /// TimeValue and assigns that value to \p this.
333  /// @brief Convert seconds form PosixTime to TimeValue
335  seconds_ = seconds + PosixZeroTimeSeconds;
336  nanos_ = 0;
337  this->normalize();
338  }
339 
340  /// Converts the \p win32Time argument from Windows FILETIME to the
341  /// corresponding TimeValue and assigns that value to \p this.
342  /// @brief Convert seconds form Windows FILETIME to TimeValue
343  void fromWin32Time( uint64_t win32Time ) {
344  this->seconds_ = win32Time / 10000000 + Win32ZeroTimeSeconds;
345  this->nanos_ = NanoSecondsType(win32Time % 10000000) * 100;
346  }
347 
348  /// @}
349  /// @name Implementation
350  /// @{
351  private:
352  /// This causes the values to be represented so that the fractional
353  /// part is minimized, possibly incrementing the seconds part.
354  /// @brief Normalize to canonical form.
355  void normalize();
356 
357  /// @}
358  /// @name Data
359  /// @{
360  private:
361  /// Store the values as a <timeval>.
362  SecondsType seconds_;///< Stores the seconds part of the TimeVal
363  NanoSecondsType nanos_; ///< Stores the nanoseconds part of the TimeVal
364 
365  static const SecondsType PosixZeroTimeSeconds;
366  static const SecondsType Win32ZeroTimeSeconds;
367  /// @}
368 
369  };
370 
371 inline TimeValue operator + (const TimeValue &tv1, const TimeValue &tv2) {
372  TimeValue sum (tv1.seconds_ + tv2.seconds_, tv1.nanos_ + tv2.nanos_);
373  sum.normalize ();
374  return sum;
375 }
376 
377 inline TimeValue operator - (const TimeValue &tv1, const TimeValue &tv2) {
378  TimeValue difference (tv1.seconds_ - tv2.seconds_, tv1.nanos_ - tv2.nanos_ );
379  difference.normalize ();
380  return difference;
381 }
382 
383 }
384 }
385 
386 #endif
std::string str() const
Provides conversion of the TimeValue into a readable time & date.
TimeValue()
Default construct a time value, initializing to ZeroTime.
Definition: TimeValue.h:95
static TimeValue now()
This is a static constructor that returns a TimeValue that represents the current time...
static TimeValue MinTime()
A constant TimeValue representing the smallest time value permissible by the class.
Definition: TimeValue.h:41
TimeValue(SecondsType seconds, NanoSecondsType nanos=0)
Caller provides the exact value in seconds and nanoseconds.
Definition: TimeValue.h:100
void microseconds(int32_t micros)
The seconds component remains unchanged.
Definition: TimeValue.h:303
void seconds(SecondsType sec)
The seconds component of the TimeValue is set to sec without modifying the nanoseconds part...
Definition: TimeValue.h:285
int32_t NanoSecondsType
Type used for representing nanoseconds.
Definition: TimeValue.h:79
TimeValue operator-(const TimeValue &tv1, const TimeValue &tv2)
Definition: TimeValue.h:377
static TimeValue MaxTime()
A constant TimeValue representing the largest time value permissible by the class.
Definition: TimeValue.h:49
SecondsType seconds() const
Returns only the seconds component of the TimeValue.
Definition: TimeValue.h:207
uint64_t usec() const
Returns the TimeValue as a number of microseconds.
Definition: TimeValue.h:233
NanoSecondsType nanoseconds() const
Returns only the nanoseconds component of the TimeValue.
Definition: TimeValue.h:212
void msec(int64_t milliseconds)
Converts from millisecond format to TimeValue format.
Definition: TimeValue.h:324
void milliseconds(int32_t millis)
The seconds component remains unchanged.
Definition: TimeValue.h:310
int operator<=(const TimeValue &that) const
Determine if this is less than or equal to that.
Definition: TimeValue.h:164
static TimeValue ZeroTime()
A constant TimeValue representing the base time, or zero time of 00:00:00 (midnight) January 1st...
Definition: TimeValue.h:56
TimeValue(double new_time)
Caller provides the exact value as a double in seconds with the fractional part representing nanoseco...
Definition: TimeValue.h:106
TimeValue & operator+=(const TimeValue &that)
Add that to this.
Definition: TimeValue.h:127
uint64_t toEpochTime() const
Converts the TimeValue into the corresponding number of seconds since the epoch (00:00:00 Jan 1...
Definition: TimeValue.h:250
int operator<(const TimeValue &that) const
Determine if this is less than that.
Definition: TimeValue.h:147
uint64_t msec() const
Returns the TimeValue as a number of milliseconds.
Definition: TimeValue.h:243
void fromWin32Time(uint64_t win32Time)
Converts the win32Time argument from Windows FILETIME to the corresponding TimeValue and assigns that...
Definition: TimeValue.h:343
int operator==(const TimeValue &that) const
Determines if two TimeValue objects represent the same moment in time.
Definition: TimeValue.h:179
int operator!=(const TimeValue &that) const
Determines if two TimeValue objects represent times that are not the same.
Definition: TimeValue.h:187
TimeValue operator+(const TimeValue &tv1, const TimeValue &tv2)
Definition: TimeValue.h:371
int64_t SecondsType
Type used for representing seconds.
Definition: TimeValue.h:78
static TimeValue Win32ZeroTime()
A constant TimeValue for the Win32 base time which is 00:00:00 (midnight) January 1st...
Definition: TimeValue.h:70
int operator>=(const TimeValue &that) const
Determine if this is greater than or equal to that.
Definition: TimeValue.h:168
uint32_t milliseconds() const
Returns only the fractional portion of the TimeValue rounded down to the nearest millisecond (divide ...
Definition: TimeValue.h:224
void fromEpochTime(SecondsType seconds)
Converts the seconds argument from PosixTime to the corresponding TimeValue and assigns that value to...
Definition: TimeValue.h:334
void usec(int64_t microseconds)
Converts from microsecond format to TimeValue format.
Definition: TimeValue.h:316
int operator>(const TimeValue &that) const
Determine if this is greather than that.
Definition: TimeValue.h:152
friend TimeValue operator+(const TimeValue &tv1, const TimeValue &tv2)
Adds two TimeValue objects together.
Definition: TimeValue.h:371
void getTimespecTime(uint64_t &seconds, uint32_t &nanos) const
Provides the seconds and nanoseconds as results in its arguments after correction for the Posix zero ...
Definition: TimeValue.h:267
This class is used where a precise fixed point in time is required.
Definition: TimeValue.h:31
uint32_t microseconds() const
Returns only the fractional portion of the TimeValue rounded down to the nearest microsecond (divide ...
Definition: TimeValue.h:217
static TimeValue PosixZeroTime()
A constant TimeValue for the Posix base time which is 00:00:00 (midnight) January 1st...
Definition: TimeValue.h:63
friend TimeValue operator-(const TimeValue &tv1, const TimeValue &tv2)
Subtracts two TimeValue objects.
Definition: TimeValue.h:377
TimeValue & operator-=(const TimeValue &that)
Subtract that from this.
Definition: TimeValue.h:137
uint64_t toWin32Time() const
Converts the TimeValue into the corresponding number of "ticks" for Win32 platforms, correcting for the difference in Win32 zero time.
Definition: TimeValue.h:258
void nanoseconds(NanoSecondsType nanos)
The nanoseconds component of the TimeValue is set to nanos without modifying the seconds part...
Definition: TimeValue.h:296