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/Support/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 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;
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;
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 int operator == (const TimeValue &that) const {
169 return (this->seconds_ == that.seconds_) &&
170 (this->nanos_ == that.nanos_);
173 /// Determines if two TimeValue objects represent times that are not the
175 /// @return True iff *this != that.
176 /// @brief True if this != that.
177 int operator != (const TimeValue &that) const { return !(*this == that); }
179 /// Adds two TimeValue objects together.
180 /// @returns The sum of the two operands as a new TimeValue
181 /// @brief Addition operator.
182 friend TimeValue operator + (const TimeValue &tv1, const TimeValue &tv2);
184 /// Subtracts two TimeValue objects.
185 /// @returns The difference of the two operands as a new TimeValue
186 /// @brief Subtraction operator.
187 friend TimeValue operator - (const TimeValue &tv1, const TimeValue &tv2);
194 /// Returns only the seconds component of the TimeValue. The nanoseconds
195 /// portion is ignored. No rounding is performed.
196 /// @brief Retrieve the seconds component
197 SecondsType seconds() const { return seconds_; }
199 /// Returns only the nanoseconds component of the TimeValue. The seconds
200 /// portion is ignored.
201 /// @brief Retrieve the nanoseconds component.
202 NanoSecondsType nanoseconds() const { return nanos_; }
204 /// Returns only the fractional portion of the TimeValue rounded down to the
205 /// nearest microsecond (divide by one thousand).
206 /// @brief Retrieve the fractional part as microseconds;
207 uint32_t microseconds() const {
208 return nanos_ / NANOSECONDS_PER_MICROSECOND;
211 /// Returns only the fractional portion of the TimeValue rounded down to the
212 /// nearest millisecond (divide by one million).
213 /// @brief Retrieve the fractional part as milliseconds;
214 uint32_t milliseconds() const {
215 return nanos_ / NANOSECONDS_PER_MILLISECOND;
218 /// Returns the TimeValue as a number of microseconds. Note that the value
219 /// returned can overflow because the range of a uint64_t is smaller than
220 /// the range of a TimeValue. Nevertheless, this is useful on some operating
221 /// systems and is therefore provided.
222 /// @brief Convert to a number of microseconds (can overflow)
223 uint64_t usec() const {
224 return seconds_ * MICROSECONDS_PER_SECOND +
225 ( nanos_ / NANOSECONDS_PER_MICROSECOND );
228 /// Returns the TimeValue as a number of milliseconds. 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 milliseconds (can overflow)
233 uint64_t msec() const {
234 return seconds_ * MILLISECONDS_PER_SECOND +
235 ( nanos_ / NANOSECONDS_PER_MILLISECOND );
238 /// Converts the TimeValue into the corresponding number of "ticks" for
239 /// Posix, correcting for the difference in Posix zero time.
240 /// @brief Convert to unix time (100 nanoseconds since 12:00:00a Jan 1,1970)
241 uint64_t toPosixTime() const {
242 uint64_t result = seconds_ - PosixZeroTime.seconds_;
243 result += nanos_ / NANOSECONDS_PER_POSIX_TICK;
247 /// Converts the TimeValue into the corresponding number of seconds
248 /// since the epoch (00:00:00 Jan 1,1970).
249 uint64_t toEpochTime() const {
250 return seconds_ - PosixZeroTime.seconds_;
253 /// Converts the TimeValue into the corresponding number of "ticks" for
254 /// Win32 platforms, correcting for the difference in Win32 zero time.
255 /// @brief Convert to windows time (seconds since 12:00:00a Jan 1, 1601)
256 uint64_t toWin32Time() const {
257 uint64_t result = seconds_ - Win32ZeroTime.seconds_;
258 result += nanos_ / NANOSECONDS_PER_WIN32_TICK;
262 /// Provides the seconds and nanoseconds as results in its arguments after
263 /// correction for the Posix zero time.
264 /// @brief Convert to timespec time (ala POSIX.1b)
265 void getTimespecTime( uint64_t& seconds, uint32_t& nanos ) const {
266 seconds = seconds_ - PosixZeroTime.seconds_;
270 /// Provides conversion of the TimeValue into a readable time & date.
271 /// @returns std::string containing the readable time value
272 /// @brief Convert time to a string.
273 std::string str() const;
279 /// The seconds component of the TimeValue is set to \p sec without
280 /// modifying the nanoseconds part. This is useful for whole second
282 /// @brief Set the seconds component.
283 void seconds (SecondsType sec ) {
284 this->seconds_ = sec;
288 /// The nanoseconds component of the TimeValue is set to \p nanos without
289 /// modifying the seconds part. This is useful for basic computations
290 /// involving just the nanoseconds portion. Note that the TimeValue will be
291 /// normalized after this call so that the fractional (nanoseconds) portion
292 /// will have the smallest equivalent value.
293 /// @brief Set the nanoseconds component using a number of nanoseconds.
294 void nanoseconds ( NanoSecondsType nanos ) {
295 this->nanos_ = nanos;
299 /// The seconds component remains unchanged.
300 /// @brief Set the nanoseconds component using a number of microseconds.
301 void microseconds ( int32_t micros ) {
302 this->nanos_ = micros * NANOSECONDS_PER_MICROSECOND;
306 /// The seconds component remains unchanged.
307 /// @brief Set the nanoseconds component using a number of milliseconds.
308 void milliseconds ( int32_t millis ) {
309 this->nanos_ = millis * NANOSECONDS_PER_MILLISECOND;
313 /// @brief Converts from microsecond format to TimeValue format
314 void usec( int64_t microseconds ) {
315 this->seconds_ = microseconds / MICROSECONDS_PER_SECOND;
316 this->nanos_ = NanoSecondsType(microseconds % MICROSECONDS_PER_SECOND) *
317 NANOSECONDS_PER_MICROSECOND;
321 /// @brief Converts from millisecond format to TimeValue format
322 void msec( int64_t milliseconds ) {
323 this->seconds_ = milliseconds / MILLISECONDS_PER_SECOND;
324 this->nanos_ = NanoSecondsType(milliseconds % MILLISECONDS_PER_SECOND) *
325 NANOSECONDS_PER_MILLISECOND;
329 /// Converts the \p seconds argument from PosixTime to the corresponding
330 /// TimeValue and assigns that value to \p this.
331 /// @brief Convert seconds form PosixTime to TimeValue
332 void fromEpochTime( SecondsType seconds ) {
333 seconds_ = seconds + PosixZeroTime.seconds_;
338 /// Converts the \p win32Time argument from Windows FILETIME to the
339 /// corresponding TimeValue and assigns that value to \p this.
340 /// @brief Convert seconds form Windows FILETIME to TimeValue
341 void fromWin32Time( uint64_t win32Time ) {
342 this->seconds_ = win32Time / 10000000 + Win32ZeroTime.seconds_;
343 this->nanos_ = NanoSecondsType(win32Time % 10000000) * 100;
347 /// @name Implementation
350 /// This causes the values to be represented so that the fractional
351 /// part is minimized, possibly incrementing the seconds part.
352 /// @brief Normalize to canonical form.
359 /// Store the values as a <timeval>.
360 SecondsType seconds_;///< Stores the seconds part of the TimeVal
361 NanoSecondsType nanos_; ///< Stores the nanoseconds part of the TimeVal
366 inline TimeValue operator + (const TimeValue &tv1, const TimeValue &tv2) {
367 TimeValue sum (tv1.seconds_ + tv2.seconds_, tv1.nanos_ + tv2.nanos_);
372 inline TimeValue operator - (const TimeValue &tv1, const TimeValue &tv2) {
373 TimeValue difference (tv1.seconds_ - tv2.seconds_, tv1.nanos_ - tv2.nanos_ );
374 difference.normalize ();