1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "ppapi/shared_impl/time_conversion.h" 6 7 namespace ppapi { 8 9 namespace { 10 11 // Since WebKit doesn't use ticks for event times, we have to compute what 12 // the time ticks would be assuming the wall clock time doesn't change. 13 // 14 // This should only be used for WebKit times which we can't change the 15 // definition of. 16 double GetTimeToTimeTicksDeltaInSeconds() { 17 static double time_to_ticks_delta_seconds = 0.0; 18 if (time_to_ticks_delta_seconds == 0.0) { 19 double wall_clock = TimeToPPTime(base::Time::Now()); 20 double ticks = TimeTicksToPPTimeTicks(base::TimeTicks::Now()); 21 time_to_ticks_delta_seconds = ticks - wall_clock; 22 } 23 return time_to_ticks_delta_seconds; 24 } 25 26 } // namespace 27 28 PP_Time TimeToPPTime(base::Time t) { 29 return t.ToDoubleT(); 30 } 31 32 base::Time PPTimeToTime(PP_Time t) { 33 // The time code handles exact "0" values as special, and produces 34 // a "null" Time object. But calling code would expect t==0 to represent the 35 // epoch (according to the description of PP_Time). Hence we just return the 36 // epoch in this case. 37 if (t == 0.0) 38 return base::Time::UnixEpoch(); 39 return base::Time::FromDoubleT(t); 40 } 41 42 PP_TimeTicks TimeTicksToPPTimeTicks(base::TimeTicks t) { 43 return static_cast<double>(t.ToInternalValue()) / 44 base::Time::kMicrosecondsPerSecond; 45 } 46 47 PP_TimeTicks EventTimeToPPTimeTicks(double event_time) { 48 return event_time + GetTimeToTimeTicksDeltaInSeconds(); 49 } 50 51 double PPTimeTicksToEventTime(PP_TimeTicks t) { 52 return t - GetTimeToTimeTicksDeltaInSeconds(); 53 } 54 55 double PPGetLocalTimeZoneOffset(const base::Time& time) { 56 // Explode it to local time and then unexplode it as if it were UTC. Also 57 // explode it to UTC and unexplode it (this avoids mismatching rounding or 58 // lack thereof). The time zone offset is their difference. 59 base::Time::Exploded exploded = { 0 }; 60 base::Time::Exploded utc_exploded = { 0 }; 61 time.LocalExplode(&exploded); 62 time.UTCExplode(&utc_exploded); 63 if (exploded.HasValidValues() && utc_exploded.HasValidValues()) { 64 base::Time adj_time = base::Time::FromUTCExploded(exploded); 65 base::Time cur = base::Time::FromUTCExploded(utc_exploded); 66 return (adj_time - cur).InSecondsF(); 67 } 68 return 0.0; 69 } 70 71 } // namespace ppapi 72
