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#include "llvm/Support/DataTypes.h"
15#include <string>
16
17#ifndef LLVM_SYSTEM_TIMEVALUE_H
18#define LLVM_SYSTEM_TIMEVALUE_H
19
20namespace llvm {
21namespace 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 const TimeValue MinTime;
42
43    /// A constant TimeValue representing the largest time
44    /// value permissible by the class. MaxTime is some point
45    /// in the distant future, about 300 billion years AD.
46    /// @brief The largest possible time value.
47    static const TimeValue MaxTime;
48
49    /// A constant TimeValue representing the base time,
50    /// or zero time of 00:00:00 (midnight) January 1st, 2000.
51    /// @brief 00:00:00 Jan 1, 2000 UTC.
52    static const TimeValue ZeroTime;
53
54    /// A constant TimeValue for the Posix base time which is
55    /// 00:00:00 (midnight) January 1st, 1970.
56    /// @brief 00:00:00 Jan 1, 1970 UTC.
57    static const TimeValue PosixZeroTime;
58
59    /// A constant TimeValue for the Win32 base time which is
60    /// 00:00:00 (midnight) January 1st, 1601.
61    /// @brief 00:00:00 Jan 1, 1601 UTC.
62    static const TimeValue Win32ZeroTime;
63
64  /// @}
65  /// @name Types
66  /// @{
67  public:
68    typedef int64_t SecondsType;    ///< Type used for representing seconds.
69    typedef int32_t NanoSecondsType;///< Type used for representing nanoseconds.
70
71    enum TimeConversions {
72      NANOSECONDS_PER_SECOND = 1000000000,  ///< One Billion
73      MICROSECONDS_PER_SECOND = 1000000,    ///< One Million
74      MILLISECONDS_PER_SECOND = 1000,       ///< One Thousand
75      NANOSECONDS_PER_MICROSECOND = 1000,   ///< One Thousand
76      NANOSECONDS_PER_MILLISECOND = 1000000,///< One Million
77      NANOSECONDS_PER_POSIX_TICK = 100,     ///< Posix tick is 100 Hz (10ms)
78      NANOSECONDS_PER_WIN32_TICK = 100      ///< Win32 tick is 100 Hz (10ms)
79    };
80
81  /// @}
82  /// @name Constructors
83  /// @{
84  public:
85    /// Caller provides the exact value in seconds and nanoseconds. The
86    /// \p nanos argument defaults to zero for convenience.
87    /// @brief Explicit constructor
88    explicit TimeValue (SecondsType seconds, NanoSecondsType nanos = 0)
89      : seconds_( seconds ), nanos_( nanos ) { this->normalize(); }
90
91    /// Caller provides the exact value as a double in seconds with the
92    /// fractional part representing nanoseconds.
93    /// @brief Double Constructor.
94    explicit TimeValue( double new_time )
95      : seconds_( 0 ) , nanos_ ( 0 ) {
96      SecondsType integer_part = static_cast<SecondsType>( new_time );
97      seconds_ = integer_part;
98      nanos_ = static_cast<NanoSecondsType>( (new_time -
99               static_cast<double>(integer_part)) * NANOSECONDS_PER_SECOND );
100      this->normalize();
101    }
102
103    /// This is a static constructor that returns a TimeValue that represents
104    /// the current time.
105    /// @brief Creates a TimeValue with the current time (UTC).
106    static TimeValue now();
107
108  /// @}
109  /// @name Operators
110  /// @{
111  public:
112    /// Add \p that to \p this.
113    /// @returns this
114    /// @brief Incrementing assignment operator.
115    TimeValue& operator += (const TimeValue& that ) {
116      this->seconds_ += that.seconds_  ;
117      this->nanos_ += that.nanos_ ;
118      this->normalize();
119      return *this;
120    }
121
122    /// Subtract \p that from \p this.
123    /// @returns this
124    /// @brief Decrementing assignment operator.
125    TimeValue& operator -= (const TimeValue &that ) {
126      this->seconds_ -= that.seconds_ ;
127      this->nanos_ -= that.nanos_ ;
128      this->normalize();
129      return *this;
130    }
131
132    /// Determine if \p this is less than \p that.
133    /// @returns True iff *this < that.
134    /// @brief True if this < that.
135    int operator < (const TimeValue &that) const { return that > *this; }
136
137    /// Determine if \p this is greather than \p that.
138    /// @returns True iff *this > that.
139    /// @brief True if this > that.
140    int operator > (const TimeValue &that) const {
141      if ( this->seconds_ > that.seconds_ ) {
142          return 1;
143      } else if ( this->seconds_ == that.seconds_ ) {
144          if ( this->nanos_ > that.nanos_ ) return 1;
145      }
146      return 0;
147    }
148
149    /// Determine if \p this is less than or equal to \p that.
150    /// @returns True iff *this <= that.
151    /// @brief True if this <= that.
152    int operator <= (const TimeValue &that) const { return that >= *this; }
153
154    /// Determine if \p this is greater than or equal to \p that.
155    /// @returns True iff *this >= that.
156    int operator >= (const TimeValue &that) const {
157      if ( this->seconds_ > that.seconds_ ) {
158          return 1;
159      } else if ( this->seconds_ == that.seconds_ ) {
160          if ( this->nanos_ >= that.nanos_ ) return 1;
161      }
162      return 0;
163    }
164
165    /// Determines if two TimeValue objects represent the same moment in time.
166    /// @returns True iff *this == that.
167    int operator == (const TimeValue &that) const {
168      return (this->seconds_ == that.seconds_) &&
169             (this->nanos_ == that.nanos_);
170    }
171
172    /// Determines if two TimeValue objects represent times that are not the
173    /// same.
174    /// @returns True iff *this != that.
175    int operator != (const TimeValue &that) const { return !(*this == that); }
176
177    /// Adds two TimeValue objects together.
178    /// @returns The sum of the two operands as a new TimeValue
179    /// @brief Addition operator.
180    friend TimeValue operator + (const TimeValue &tv1, const TimeValue &tv2);
181
182    /// Subtracts two TimeValue objects.
183    /// @returns The difference of the two operands as a new TimeValue
184    /// @brief Subtraction operator.
185    friend TimeValue operator - (const TimeValue &tv1, const TimeValue &tv2);
186
187  /// @}
188  /// @name Accessors
189  /// @{
190  public:
191
192    /// Returns only the seconds component of the TimeValue. The nanoseconds
193    /// portion is ignored. No rounding is performed.
194    /// @brief Retrieve the seconds component
195    SecondsType seconds() const { return seconds_; }
196
197    /// Returns only the nanoseconds component of the TimeValue. The seconds
198    /// portion is ignored.
199    /// @brief Retrieve the nanoseconds component.
200    NanoSecondsType nanoseconds() const { return nanos_; }
201
202    /// Returns only the fractional portion of the TimeValue rounded down to the
203    /// nearest microsecond (divide by one thousand).
204    /// @brief Retrieve the fractional part as microseconds;
205    uint32_t microseconds() const {
206      return nanos_ / NANOSECONDS_PER_MICROSECOND;
207    }
208
209    /// Returns only the fractional portion of the TimeValue rounded down to the
210    /// nearest millisecond (divide by one million).
211    /// @brief Retrieve the fractional part as milliseconds;
212    uint32_t milliseconds() const {
213      return nanos_ / NANOSECONDS_PER_MILLISECOND;
214    }
215
216    /// Returns the TimeValue as a number of microseconds. Note that the value
217    /// returned can overflow because the range of a uint64_t is smaller than
218    /// the range of a TimeValue. Nevertheless, this is useful on some operating
219    /// systems and is therefore provided.
220    /// @brief Convert to a number of microseconds (can overflow)
221    uint64_t usec() const {
222      return seconds_ * MICROSECONDS_PER_SECOND +
223             ( nanos_ / NANOSECONDS_PER_MICROSECOND );
224    }
225
226    /// Returns the TimeValue as a number of milliseconds. Note that the value
227    /// returned can overflow because the range of a uint64_t is smaller than
228    /// the range of a TimeValue. Nevertheless, this is useful on some operating
229    /// systems and is therefore provided.
230    /// @brief Convert to a number of milliseconds (can overflow)
231    uint64_t msec() const {
232      return seconds_ * MILLISECONDS_PER_SECOND +
233             ( nanos_ / NANOSECONDS_PER_MILLISECOND );
234    }
235
236    /// Converts the TimeValue into the corresponding number of "ticks" for
237    /// Posix, correcting for the difference in Posix zero time.
238    /// @brief Convert to unix time (100 nanoseconds since 12:00:00a Jan 1,1970)
239    uint64_t toPosixTime() const {
240      uint64_t result = seconds_ - PosixZeroTime.seconds_;
241      result += nanos_ / NANOSECONDS_PER_POSIX_TICK;
242      return result;
243    }
244
245    /// Converts the TimeValue into the corresponding number of seconds
246    /// since the epoch (00:00:00 Jan 1,1970).
247    uint64_t toEpochTime() const {
248      return seconds_ - PosixZeroTime.seconds_;
249    }
250
251    /// Converts the TimeValue into the corresponding number of "ticks" for
252    /// Win32 platforms, correcting for the difference in Win32 zero time.
253    /// @brief Convert to windows time (seconds since 12:00:00a Jan 1, 1601)
254    uint64_t toWin32Time() const {
255      uint64_t result = seconds_ - Win32ZeroTime.seconds_;
256      result += nanos_ / NANOSECONDS_PER_WIN32_TICK;
257      return result;
258    }
259
260    /// Provides the seconds and nanoseconds as results in its arguments after
261    /// correction for the Posix zero time.
262    /// @brief Convert to timespec time (ala POSIX.1b)
263    void getTimespecTime( uint64_t& seconds, uint32_t& nanos ) const {
264      seconds = seconds_ - PosixZeroTime.seconds_;
265      nanos = nanos_;
266    }
267
268    /// Provides conversion of the TimeValue into a readable time & date.
269    /// @returns std::string containing the readable time value
270    /// @brief Convert time to a string.
271    std::string str() const;
272
273  /// @}
274  /// @name Mutators
275  /// @{
276  public:
277    /// The seconds component of the TimeValue is set to \p sec without
278    /// modifying the nanoseconds part.  This is useful for whole second
279    /// arithmetic.
280    /// @brief Set the seconds component.
281    void seconds (SecondsType sec ) {
282      this->seconds_ = sec;
283      this->normalize();
284    }
285
286    /// The nanoseconds component of the TimeValue is set to \p nanos without
287    /// modifying the seconds part. This is useful for basic computations
288    /// involving just the nanoseconds portion. Note that the TimeValue will be
289    /// normalized after this call so that the fractional (nanoseconds) portion
290    /// will have the smallest equivalent value.
291    /// @brief Set the nanoseconds component using a number of nanoseconds.
292    void nanoseconds ( NanoSecondsType nanos ) {
293      this->nanos_ = nanos;
294      this->normalize();
295    }
296
297    /// The seconds component remains unchanged.
298    /// @brief Set the nanoseconds component using a number of microseconds.
299    void microseconds ( int32_t micros ) {
300      this->nanos_ = micros * NANOSECONDS_PER_MICROSECOND;
301      this->normalize();
302    }
303
304    /// The seconds component remains unchanged.
305    /// @brief Set the nanoseconds component using a number of milliseconds.
306    void milliseconds ( int32_t millis ) {
307      this->nanos_ = millis * NANOSECONDS_PER_MILLISECOND;
308      this->normalize();
309    }
310
311    /// @brief Converts from microsecond format to TimeValue format
312    void usec( int64_t microseconds ) {
313      this->seconds_ = microseconds / MICROSECONDS_PER_SECOND;
314      this->nanos_ = NanoSecondsType(microseconds % MICROSECONDS_PER_SECOND) *
315        NANOSECONDS_PER_MICROSECOND;
316      this->normalize();
317    }
318
319    /// @brief Converts from millisecond format to TimeValue format
320    void msec( int64_t milliseconds ) {
321      this->seconds_ = milliseconds / MILLISECONDS_PER_SECOND;
322      this->nanos_ = NanoSecondsType(milliseconds % MILLISECONDS_PER_SECOND) *
323        NANOSECONDS_PER_MILLISECOND;
324      this->normalize();
325    }
326
327    /// Converts the \p seconds argument from PosixTime to the corresponding
328    /// TimeValue and assigns that value to \p this.
329    /// @brief Convert seconds form PosixTime to TimeValue
330    void fromEpochTime( SecondsType seconds ) {
331      seconds_ = seconds + PosixZeroTime.seconds_;
332      nanos_ = 0;
333      this->normalize();
334    }
335
336    /// Converts the \p win32Time argument from Windows FILETIME to the
337    /// corresponding TimeValue and assigns that value to \p this.
338    /// @brief Convert seconds form Windows FILETIME to TimeValue
339    void fromWin32Time( uint64_t win32Time ) {
340      this->seconds_ = win32Time / 10000000 + Win32ZeroTime.seconds_;
341      this->nanos_ = NanoSecondsType(win32Time  % 10000000) * 100;
342    }
343
344  /// @}
345  /// @name Implementation
346  /// @{
347  private:
348    /// This causes the values to be represented so that the fractional
349    /// part is minimized, possibly incrementing the seconds part.
350    /// @brief Normalize to canonical form.
351    void normalize();
352
353  /// @}
354  /// @name Data
355  /// @{
356  private:
357    /// Store the values as a <timeval>.
358    SecondsType      seconds_;///< Stores the seconds part of the TimeVal
359    NanoSecondsType  nanos_;  ///< Stores the nanoseconds part of the TimeVal
360  /// @}
361
362  };
363
364inline TimeValue operator + (const TimeValue &tv1, const TimeValue &tv2) {
365  TimeValue sum (tv1.seconds_ + tv2.seconds_, tv1.nanos_ + tv2.nanos_);
366  sum.normalize ();
367  return sum;
368}
369
370inline TimeValue operator - (const TimeValue &tv1, const TimeValue &tv2) {
371  TimeValue difference (tv1.seconds_ - tv2.seconds_, tv1.nanos_ - tv2.nanos_ );
372  difference.normalize ();
373  return difference;
374}
375
376}
377}
378
379#endif
380