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 #ifndef LLVM_SUPPORT_TIMEVALUE_H
15 #define LLVM_SUPPORT_TIMEVALUE_H
17 #include "llvm/Support/DataTypes.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 TimeValue MinTime() {
42 return TimeValue ( INT64_MIN,0 );
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 );
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 );
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.
63 static TimeValue PosixZeroTime() {
64 return TimeValue ( PosixZeroTimeSeconds,0 );
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.
70 static TimeValue Win32ZeroTime() {
71 return TimeValue ( Win32ZeroTimeSeconds,0 );
78 typedef int64_t SecondsType; ///< Type used for representing seconds.
79 typedef int32_t NanoSecondsType;///< Type used for representing nanoseconds.
81 enum TimeConversions {
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)
91 /// @name Constructors
94 /// \brief Default construct a time value, initializing to ZeroTime.
95 TimeValue() : seconds_(0), nanos_(0) {}
97 /// Caller provides the exact value in seconds and nanoseconds. The
98 /// \p nanos argument defaults to zero for convenience.
99 /// @brief Explicit constructor
100 explicit TimeValue (SecondsType seconds, NanoSecondsType nanos = 0)
101 : seconds_( seconds ), nanos_( nanos ) { this->normalize(); }
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 );
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();
124 /// Add \p that to \p this.
126 /// @brief Incrementing assignment operator.
127 TimeValue& operator += (const TimeValue& that ) {
128 this->seconds_ += that.seconds_ ;
129 this->nanos_ += that.nanos_ ;
134 /// Subtract \p that from \p this.
136 /// @brief Decrementing assignment operator.
137 TimeValue& operator -= (const TimeValue &that ) {
138 this->seconds_ -= that.seconds_ ;
139 this->nanos_ -= that.nanos_ ;
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; }
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_ ) {
155 } else if ( this->seconds_ == that.seconds_ ) {
156 if ( this->nanos_ > that.nanos_ ) return 1;
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; }
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_ ) {
171 } else if ( this->seconds_ == that.seconds_ ) {
172 if ( this->nanos_ >= that.nanos_ ) return 1;
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_);
184 /// Determines if two TimeValue objects represent times that are not the
186 /// @returns True iff *this != that.
187 int operator != (const TimeValue &that) const { return !(*this == that); }
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);
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);
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_; }
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_; }
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;
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;
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 );
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 );
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;
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;
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;
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;
281 /// The seconds component of the TimeValue is set to \p sec without
282 /// modifying the nanoseconds part. This is useful for whole second
284 /// @brief Set the seconds component.
285 void seconds (SecondsType sec ) {
286 this->seconds_ = sec;
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;
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;
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;
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) *
319 NANOSECONDS_PER_MICROSECOND;
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) *
327 NANOSECONDS_PER_MILLISECOND;
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
334 void fromEpochTime( SecondsType seconds ) {
335 seconds_ = seconds + PosixZeroTimeSeconds;
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;
349 /// @name Implementation
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.
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
365 static const SecondsType PosixZeroTimeSeconds;
366 static const SecondsType Win32ZeroTimeSeconds;
371 inline TimeValue operator + (const TimeValue &tv1, const TimeValue &tv2) {
372 TimeValue sum (tv1.seconds_ + tv2.seconds_, tv1.nanos_ + tv2.nanos_);
377 inline TimeValue operator - (const TimeValue &tv1, const TimeValue &tv2) {
378 TimeValue difference (tv1.seconds_ - tv2.seconds_, tv1.nanos_ - tv2.nanos_ );
379 difference.normalize ();