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 #ifndef LLVM_SUPPORT_TIMEVALUE_H 15 #define LLVM_SUPPORT_TIMEVALUE_H 16 17 #include "llvm/Support/DataTypes.h" 18 #include <string> 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 /// \brief Default construct a time value, initializing to ZeroTime. 86 TimeValue() : seconds_(0), nanos_(0) {} 87 88 /// Caller provides the exact value in seconds and nanoseconds. The 89 /// \p nanos argument defaults to zero for convenience. 90 /// @brief Explicit constructor 91 explicit TimeValue (SecondsType seconds, NanoSecondsType nanos = 0) 92 : seconds_( seconds ), nanos_( nanos ) { this->normalize(); } 93 94 /// Caller provides the exact value as a double in seconds with the 95 /// fractional part representing nanoseconds. 96 /// @brief Double Constructor. 97 explicit TimeValue( double new_time ) 98 : seconds_( 0 ) , nanos_ ( 0 ) { 99 SecondsType integer_part = static_cast<SecondsType>( new_time ); 100 seconds_ = integer_part; 101 nanos_ = static_cast<NanoSecondsType>( (new_time - 102 static_cast<double>(integer_part)) * NANOSECONDS_PER_SECOND ); 103 this->normalize(); 104 } 105 106 /// This is a static constructor that returns a TimeValue that represents 107 /// the current time. 108 /// @brief Creates a TimeValue with the current time (UTC). 109 static TimeValue now(); 110 111 /// @} 112 /// @name Operators 113 /// @{ 114 public: 115 /// Add \p that to \p this. 116 /// @returns this 117 /// @brief Incrementing assignment operator. 118 TimeValue& operator += (const TimeValue& that ) { 119 this->seconds_ += that.seconds_ ; 120 this->nanos_ += that.nanos_ ; 121 this->normalize(); 122 return *this; 123 } 124 125 /// Subtract \p that from \p this. 126 /// @returns this 127 /// @brief Decrementing assignment operator. 128 TimeValue& operator -= (const TimeValue &that ) { 129 this->seconds_ -= that.seconds_ ; 130 this->nanos_ -= that.nanos_ ; 131 this->normalize(); 132 return *this; 133 } 134 135 /// Determine if \p this is less than \p that. 136 /// @returns True iff *this < that. 137 /// @brief True if this < that. 138 int operator < (const TimeValue &that) const { return that > *this; } 139 140 /// Determine if \p this is greather than \p that. 141 /// @returns True iff *this > that. 142 /// @brief True if this > that. 143 int operator > (const TimeValue &that) const { 144 if ( this->seconds_ > that.seconds_ ) { 145 return 1; 146 } else if ( this->seconds_ == that.seconds_ ) { 147 if ( this->nanos_ > that.nanos_ ) return 1; 148 } 149 return 0; 150 } 151 152 /// Determine if \p this is less than or equal to \p that. 153 /// @returns True iff *this <= that. 154 /// @brief True if this <= that. 155 int operator <= (const TimeValue &that) const { return that >= *this; } 156 157 /// Determine if \p this is greater than or equal to \p that. 158 /// @returns True iff *this >= that. 159 int operator >= (const TimeValue &that) const { 160 if ( this->seconds_ > that.seconds_ ) { 161 return 1; 162 } else if ( this->seconds_ == that.seconds_ ) { 163 if ( this->nanos_ >= that.nanos_ ) return 1; 164 } 165 return 0; 166 } 167 168 /// Determines if two TimeValue objects represent the same moment in time. 169 /// @returns True iff *this == that. 170 int operator == (const TimeValue &that) const { 171 return (this->seconds_ == that.seconds_) && 172 (this->nanos_ == that.nanos_); 173 } 174 175 /// Determines if two TimeValue objects represent times that are not the 176 /// same. 177 /// @returns True iff *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_ - PosixZeroTimeSeconds; 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_ - PosixZeroTimeSeconds; 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 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; 261 return result; 262 } 263 264 /// 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; 269 nanos = nanos_; 270 } 271 272 /// 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; 276 277 /// @} 278 /// @name Mutators 279 /// @{ 280 public: 281 /// The seconds component of the TimeValue is set to \p sec without 282 /// modifying the nanoseconds part. This is useful for whole second 283 /// arithmetic. 284 /// @brief Set the seconds component. 285 void seconds (SecondsType sec ) { 286 this->seconds_ = sec; 287 this->normalize(); 288 } 289 290 /// 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; 298 this->normalize(); 299 } 300 301 /// 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; 305 this->normalize(); 306 } 307 308 /// 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; 312 this->normalize(); 313 } 314 315 /// @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; 320 this->normalize(); 321 } 322 323 /// @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; 328 this->normalize(); 329 } 330 331 /// 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; 336 nanos_ = 0; 337 this->normalize(); 338 } 339 340 /// 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; 346 } 347 348 /// @} 349 /// @name Implementation 350 /// @{ 351 private: 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. 355 void normalize(); 356 357 /// @} 358 /// @name Data 359 /// @{ 360 private: 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 364 365 static const SecondsType PosixZeroTimeSeconds; 366 static const SecondsType Win32ZeroTimeSeconds; 367 /// @} 368 369 }; 370 371 inline TimeValue operator + (const TimeValue &tv1, const TimeValue &tv2) { 372 TimeValue sum (tv1.seconds_ + tv2.seconds_, tv1.nanos_ + tv2.nanos_); 373 sum.normalize (); 374 return sum; 375 } 376 377 inline TimeValue operator - (const TimeValue &tv1, const TimeValue &tv2) { 378 TimeValue difference (tv1.seconds_ - tv2.seconds_, tv1.nanos_ - tv2.nanos_ ); 379 difference.normalize (); 380 return difference; 381 } 382 383 } 384 } 385 386 #endif 387
