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 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 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) seconds_(seconds)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. TimeValue(double new_time)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 seconds()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. nanoseconds()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; 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; 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) usec()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) msec()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) toPosixTime()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). toEpochTime()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) toWin32Time()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) getTimespecTime(uint64_t & seconds,uint32_t & nanos)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. seconds(SecondsType sec)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. nanoseconds(NanoSecondsType nanos)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. microseconds(int32_t micros)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. milliseconds(int32_t millis)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 usec(int64_t microseconds)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 msec(int64_t milliseconds)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 fromEpochTime(SecondsType seconds)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 fromWin32Time(uint64_t win32Time)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 }; 363 364 inline 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 } 369 370 inline 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