Fixing Time::Max()'s behavior with Time::ToTimeT() and friends.

base/time.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Time represents an absolute point in time, internally represented as
 // microseconds (s/1,000,000) since a platform-dependent epoch.  Each
 // platform's epoch, along with other system-dependent clock interface
 // routines, is defined in time_PLATFORM.cc.
 //
 // TimeDelta represents a duration of time, internally represented in
@@ skipping 27 matching lines @@
 // For struct timeval.
 #include <sys/time.h>
 #endif
 
 #if defined(OS_WIN)
 // For FILETIME in FromFileTime, until it moves to a new converter class.
 // See TODO(iyengar) below.
 #include <windows.h>
 #endif
 
+#include <limits>
+
 namespace base {
 
 class Time;
 class TimeTicks;
 
 // TimeDelta ------------------------------------------------------------------
 
 class BASE_EXPORT TimeDelta {
  public:
   TimeDelta() : delta_(0) {
@@ skipping 181 matching lines @@
 
   // Contains the NULL time. Use Time::Now() to get the current time.
   explicit Time() : us_(0) {
   }
 
   // Returns true if the time object has not been initialized.
   bool is_null() const {
     return us_ == 0;
   }
 
+  // Returns true if the time object is the maximum time.
+  bool is_max() const {
+    return us_ == std::numeric_limits<int64>::max();
+  }
+
   // Returns the time for epoch in Unix-like system (Jan 1, 1970).
   static Time UnixEpoch();
 
   // Returns the current time. Watch out, the system might adjust its clock
   // in which case time will actually go backwards. We don't guarantee that
   // times are increasing, or that two calls to Now() won't be the same.
   static Time Now();
 
   // Returns the maximum time, which should be greater than any reasonable time
   // with which we might compare it.
   static Time Max();
 
   // Returns the current time. Same as Now() except that this function always
   // uses system time so that there are no discrepancies between the returned
   // time and system time even on virtual environments including our test bot.
   // For timing sensitive unittests, this function should be used.
   static Time NowFromSystemTime();
 
   // Converts to/from time_t in UTC and a Time class.
   // TODO(brettw) this should be removed once everybody starts using the |Time|
   // class.
   static Time FromTimeT(time_t tt);

[Mark Mentovai, 2012/09/04 13:23:14]

Max preservation for time_t, WebKit double, and JS double, but…

   time_t ToTimeT() const;
 
   // Converts time to/from a double which is the number of seconds since epoch
   // (Jan 1, 1970).  Webkit uses this format to represent time.
   // Because WebKit initializes double time value to 0 to indicate "not
   // initialized", we map it to empty Time object that also means "not
   // initialized".
   static Time FromDoubleT(double dt);
   double ToDoubleT() const;
 
   // Converts to/from the Javascript convention for times, a number of
   // milliseconds since the epoch:
   // https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Date/getTime.
   static Time FromJsTime(double ms_since_epoch);
   double ToJsTime() const;
 
 #if defined(OS_POSIX)
   static Time FromTimeVal(struct timeval t);

[Mark Mentovai, 2012/09/04 13:23:14]

no max preservation for this, or CFAbsoluteTime, or FILETIME?

   struct timeval ToTimeVal() const;
 #endif
 
 #if defined(OS_MACOSX)
   static Time FromCFAbsoluteTime(CFAbsoluteTime t);
   CFAbsoluteTime ToCFAbsoluteTime() const;
 #endif
 
 #if defined(OS_WIN)
   static Time FromFileTime(FILETIME ft);
@@ skipping 309 matching lines @@
 #endif
 };
 
 inline TimeTicks TimeDelta::operator+(TimeTicks t) const {
   return TimeTicks(t.ticks_ + delta_);
 }
 
 }  // namespace base
 
 #endif  // BASE_TIME_H_