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) 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 /// @brief True if this >= that. 157 int operator >= (const TimeValue &that) const { 158 if ( this->seconds_ > that.seconds_ ) { 159 return 1; 160 } else if ( this->seconds_ == that.seconds_ ) { 161 if ( this->nanos_ >= that.nanos_ ) return 1; 162 } 163 return 0; 164 } 165 166 /// 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_); 172 } 173 174 /// Determines if two TimeValue objects represent times that are not the 175 /// same. 176 /// @return True iff *this != that. 177 /// @brief True if this != that. 178 int operator != (const TimeValue &that) const { return !(*this == that); } 179 180 /// 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); 184 185 /// 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); 189 190 /// @} 191 /// @name Accessors 192 /// @{ 193 public: 194 195 /// 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_; } 199 200 /// 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_; } 204 205 /// 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; 210 } 211 212 /// 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; 217 } 218 219 /// 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 ); 227 } 228 229 /// 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 ); 237 } 238 239 /// 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; 245 return result; 246 } 247 248 /// 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_; 252 } 253 254 /// 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; 260 return result; 261 } 262 263 /// 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_; 268 nanos = nanos_; 269 } 270 271 /// 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; 275 276 /// @} 277 /// @name Mutators 278 /// @{ 279 public: 280 /// The seconds component of the TimeValue is set to \p sec without 281 /// modifying the nanoseconds part. This is useful for whole second 282 /// arithmetic. 283 /// @brief Set the seconds component. 284 void seconds (SecondsType sec ) { 285 this->seconds_ = sec; 286 this->normalize(); 287 } 288 289 /// 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; 297 this->normalize(); 298 } 299 300 /// 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; 304 this->normalize(); 305 } 306 307 /// 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; 311 this->normalize(); 312 } 313 314 /// @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; 319 this->normalize(); 320 } 321 322 /// @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; 327 this->normalize(); 328 } 329 330 /// 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_; 335 nanos_ = 0; 336 this->normalize(); 337 } 338 339 /// 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; 345 } 346 347 /// @} 348 /// @name Implementation 349 /// @{ 350 private: 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. 354 void normalize(); 355 356 /// @} 357 /// @name Data 358 /// @{ 359 private: 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 363 /// @} 364 365 }; 366 367 inline TimeValue operator + (const TimeValue &tv1, const TimeValue &tv2) { 368 TimeValue sum (tv1.seconds_ + tv2.seconds_, tv1.nanos_ + tv2.nanos_); 369 sum.normalize (); 370 return sum; 371 } 372 373 inline TimeValue operator - (const TimeValue &tv1, const TimeValue &tv2) { 374 TimeValue difference (tv1.seconds_ - tv2.seconds_, tv1.nanos_ - tv2.nanos_ ); 375 difference.normalize (); 376 return difference; 377 } 378 379 } 380 } 381 382 #endif 383
