1 //===-- TimeValue.h - Declare OS TimeValue Concept --------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This header file declares the operating system TimeValue concept.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/System/DataTypes.h"
17 #ifndef LLVM_SYSTEM_TIMEVALUE_H
18 #define LLVM_SYSTEM_TIMEVALUE_H
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
30 /// @brief Provides an abstraction for a fixed point in time.
37 /// A constant TimeValue representing the smallest time
38 /// value permissable 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;
43 /// A constant TimeValue representing the largest time
44 /// value permissable 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;
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;
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;
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;
68 typedef int64_t SecondsType; ///< Type used for representing seconds.
69 typedef int32_t NanoSecondsType;///< Type used for representing nanoseconds.
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)
82 /// @name Constructors
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(); }
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 );
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();
112 /// Add \p that to \p this.
114 /// @brief Incrementing assignment operator.
115 TimeValue& operator += (const TimeValue& that ) {
116 this->seconds_ += that.seconds_ ;
117 this->nanos_ += that.nanos_ ;
122 /// Subtract \p that from \p this.
124 /// @brief Decrementing assignment operator.
125 TimeValue& operator -= (const TimeValue &that ) {
126 this->seconds_ -= that.seconds_ ;
127 this->nanos_ -= that.nanos_ ;
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; }
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_ ) {
143 } else if ( this->seconds_ == that.seconds_ ) {
144 if ( this->nanos_ > that.nanos_ ) return 1;
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; }
154 /// Determine if \p this is greater than or equal to \p that.
155 /// @returns True iff *this >= that.
156 /// @brief True if this >= that.
157 int operator >= (const TimeValue &that) const {
158 if ( this->seconds_ > that.seconds_ ) {
160 } else if ( this->seconds_ == that.seconds_ ) {
161 if ( this->nanos_ >= that.nanos_ ) return 1;
166 /// Determines if two TimeValue objects represent the same moment in time.
167 /// @brief True iff *this == that.
168 /// @brief True if this == that.
169 int operator == (const TimeValue &that) const {
170 return (this->seconds_ == that.seconds_) &&
171 (this->nanos_ == that.nanos_);
174 /// Determines if two TimeValue objects represent times that are not the
176 /// @return True iff *this != that.
177 /// @brief True if this != that.
178 int operator != (const TimeValue &that) const { return !(*this == that); }
180 /// Adds two TimeValue objects together.
181 /// @returns The sum of the two operands as a new TimeValue
182 /// @brief Addition operator.
183 friend TimeValue operator + (const TimeValue &tv1, const TimeValue &tv2);
185 /// Subtracts two TimeValue objects.
186 /// @returns The difference of the two operands as a new TimeValue
187 /// @brief Subtraction operator.
188 friend TimeValue operator - (const TimeValue &tv1, const TimeValue &tv2);
195 /// Returns only the seconds component of the TimeValue. The nanoseconds
196 /// portion is ignored. No rounding is performed.
197 /// @brief Retrieve the seconds component
198 SecondsType seconds() const { return seconds_; }
200 /// Returns only the nanoseconds component of the TimeValue. The seconds
201 /// portion is ignored.
202 /// @brief Retrieve the nanoseconds component.
203 NanoSecondsType nanoseconds() const { return nanos_; }
205 /// Returns only the fractional portion of the TimeValue rounded down to the
206 /// nearest microsecond (divide by one thousand).
207 /// @brief Retrieve the fractional part as microseconds;
208 uint32_t microseconds() const {
209 return nanos_ / NANOSECONDS_PER_MICROSECOND;
212 /// Returns only the fractional portion of the TimeValue rounded down to the
213 /// nearest millisecond (divide by one million).
214 /// @brief Retrieve the fractional part as milliseconds;
215 uint32_t milliseconds() const {
216 return nanos_ / NANOSECONDS_PER_MILLISECOND;
219 /// Returns the TimeValue as a number of microseconds. Note that the value
220 /// returned can overflow because the range of a uint64_t is smaller than
221 /// the range of a TimeValue. Nevertheless, this is useful on some operating
222 /// systems and is therefore provided.
223 /// @brief Convert to a number of microseconds (can overflow)
224 uint64_t usec() const {
225 return seconds_ * MICROSECONDS_PER_SECOND +
226 ( nanos_ / NANOSECONDS_PER_MICROSECOND );
229 /// Returns the TimeValue as a number of milliseconds. Note that the value
230 /// returned can overflow because the range of a uint64_t is smaller than
231 /// the range of a TimeValue. Nevertheless, this is useful on some operating
232 /// systems and is therefore provided.
233 /// @brief Convert to a number of milliseconds (can overflow)
234 uint64_t msec() const {
235 return seconds_ * MILLISECONDS_PER_SECOND +
236 ( nanos_ / NANOSECONDS_PER_MILLISECOND );
239 /// Converts the TimeValue into the corresponding number of "ticks" for
240 /// Posix, correcting for the difference in Posix zero time.
241 /// @brief Convert to unix time (100 nanoseconds since 12:00:00a Jan 1,1970)
242 uint64_t toPosixTime() const {
243 uint64_t result = seconds_ - PosixZeroTime.seconds_;
244 result += nanos_ / NANOSECONDS_PER_POSIX_TICK;
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_ - PosixZeroTime.seconds_;
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 windows time (seconds since 12:00:00a Jan 1, 1601)
257 uint64_t toWin32Time() const {
258 uint64_t result = seconds_ - Win32ZeroTime.seconds_;
259 result += nanos_ / NANOSECONDS_PER_WIN32_TICK;
263 /// Provides the seconds and nanoseconds as results in its arguments after
264 /// correction for the Posix zero time.
265 /// @brief Convert to timespec time (ala POSIX.1b)
266 void getTimespecTime( uint64_t& seconds, uint32_t& nanos ) const {
267 seconds = seconds_ - PosixZeroTime.seconds_;
271 /// Provides conversion of the TimeValue into a readable time & date.
272 /// @returns std::string containing the readable time value
273 /// @brief Convert time to a string.
274 std::string str() const;
280 /// The seconds component of the TimeValue is set to \p sec without
281 /// modifying the nanoseconds part. This is useful for whole second
283 /// @brief Set the seconds component.
284 void seconds (SecondsType sec ) {
285 this->seconds_ = sec;
289 /// The nanoseconds component of the TimeValue is set to \p nanos without
290 /// modifying the seconds part. This is useful for basic computations
291 /// involving just the nanoseconds portion. Note that the TimeValue will be
292 /// normalized after this call so that the fractional (nanoseconds) portion
293 /// will have the smallest equivalent value.
294 /// @brief Set the nanoseconds component using a number of nanoseconds.
295 void nanoseconds ( NanoSecondsType nanos ) {
296 this->nanos_ = nanos;
300 /// The seconds component remains unchanged.
301 /// @brief Set the nanoseconds component using a number of microseconds.
302 void microseconds ( int32_t micros ) {
303 this->nanos_ = micros * NANOSECONDS_PER_MICROSECOND;
307 /// The seconds component remains unchanged.
308 /// @brief Set the nanoseconds component using a number of milliseconds.
309 void milliseconds ( int32_t millis ) {
310 this->nanos_ = millis * NANOSECONDS_PER_MILLISECOND;
314 /// @brief Converts from microsecond format to TimeValue format
315 void usec( int64_t microseconds ) {
316 this->seconds_ = microseconds / MICROSECONDS_PER_SECOND;
317 this->nanos_ = NanoSecondsType(microseconds % MICROSECONDS_PER_SECOND) *
318 NANOSECONDS_PER_MICROSECOND;
322 /// @brief Converts from millisecond format to TimeValue format
323 void msec( int64_t milliseconds ) {
324 this->seconds_ = milliseconds / MILLISECONDS_PER_SECOND;
325 this->nanos_ = NanoSecondsType(milliseconds % MILLISECONDS_PER_SECOND) *
326 NANOSECONDS_PER_MILLISECOND;
330 /// Converts the \p seconds argument from PosixTime to the corresponding
331 /// TimeValue and assigns that value to \p this.
332 /// @brief Convert seconds form PosixTime to TimeValue
333 void fromEpochTime( SecondsType seconds ) {
334 seconds_ = seconds + PosixZeroTime.seconds_;
339 /// Converts the \p win32Time argument from Windows FILETIME to the
340 /// corresponding TimeValue and assigns that value to \p this.
341 /// @brief Convert seconds form Windows FILETIME to TimeValue
342 void fromWin32Time( uint64_t win32Time ) {
343 this->seconds_ = win32Time / 10000000 + Win32ZeroTime.seconds_;
344 this->nanos_ = NanoSecondsType(win32Time % 10000000) * 100;
348 /// @name Implementation
351 /// This causes the values to be represented so that the fractional
352 /// part is minimized, possibly incrementing the seconds part.
353 /// @brief Normalize to canonical form.
360 /// Store the values as a <timeval>.
361 SecondsType seconds_;///< Stores the seconds part of the TimeVal
362 NanoSecondsType nanos_; ///< Stores the nanoseconds part of the TimeVal
367 inline TimeValue operator + (const TimeValue &tv1, const TimeValue &tv2) {
368 TimeValue sum (tv1.seconds_ + tv2.seconds_, tv1.nanos_ + tv2.nanos_);
373 inline TimeValue operator - (const TimeValue &tv1, const TimeValue &tv2) {
374 TimeValue difference (tv1.seconds_ - tv2.seconds_, tv1.nanos_ - tv2.nanos_ );
375 difference.normalize ();