OSX/libsecurity_utilities/lib/timeflow.cpp

   1 /*
   2  * Copyright (c) 2000-2001,2003-2004,2011,2014 Apple Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24
  25 //
  26 // timeflow - abstract view of the flow of time
  27 //
  28 #include "timeflow.h"
  29 #include <stdint.h>
  30 #include <math.h>
  31
  32
  33 namespace Security {
  34 namespace Time {
  35
  36
  37 //
  38 // Get "now"
  39 //
  40 Absolute now()
  41 {
  42     struct timeval tv;
  43     gettimeofday(&tv, NULL);
  44     return tv.tv_sec + double(tv.tv_usec) / 1E6;
  45 }
  46
  47
  48 //
  49 // OOL Conversions
  50 //
  51 Absolute::Absolute(const struct timeval &tv)
  52 { mValue = tv.tv_sec + double(tv.tv_usec) / 1E6; }
  53
  54 Absolute::Absolute(const struct timespec &tv)
  55 { mValue = tv.tv_sec + double(tv.tv_nsec) / 1E9; }
  56
  57 Absolute::operator struct timeval () const
  58 {
  59     struct timeval tv;
  60     if (mValue > LONG_MAX) {
  61         tv.tv_sec = LONG_MAX;
  62         tv.tv_usec = 0;
  63     } else {
  64         tv.tv_sec = int32_t(mValue);
  65         double intPart;
  66         tv.tv_usec = int32_t(modf(mValue, &intPart) * 1E6);
  67     }
  68     return tv;
  69 }
  70
  71 Absolute::operator struct timespec () const
  72 {
  73     struct timespec ts;
  74     if (mValue > LONG_MAX) {
  75         ts.tv_sec = LONG_MAX;
  76         ts.tv_nsec = 0;
  77     } else {
  78         ts.tv_sec = time_t(mValue);
  79         double intPart;
  80         ts.tv_nsec = int32_t(modf(mValue, &intPart) * 1E9);
  81     }
  82     return ts;
  83 }
  84
  85 struct timeval Interval::timevalInterval() const
  86 {
  87     struct timeval tv;
  88     if (mValue > LONG_MAX) {
  89         tv.tv_sec = LONG_MAX;
  90         tv.tv_usec = 0;
  91     } else if (mValue < 0) {
  92         tv.tv_sec = tv.tv_usec = 0;
  93     } else {
  94         tv.tv_sec = int32_t(mValue);
  95         double intPart;
  96         tv.tv_usec = int32_t(modf(mValue, &intPart) * 1E6);
  97     }
  98     return tv;
  99 }
 100
 101
 102 //
 103 // Estimate resolution at given time.
 104 //
 105 // BSD select(2) has theoretical microsecond resolution, but the underlying
 106 // Mach system deals with milliseconds, so we report that conservatively.
 107 // Sometime in the future when the sun is near collapse, residual resolution
 108 // of a double will drop under 1E-3, but we won't worry about that just yet.
 109 //
 110 Interval resolution(Absolute)
 111 {
 112     return 0.001;
 113 }
 114
 115
 116 }       // end namespace Time
 117 }       // end namespace Security