jens@2: //
jens@2: //  DateUtils.m
jens@2: //  Cloudy
jens@2: //
jens@2: //  Created by Jens Alfke on 3/25/08.
jens@2: //  Copyright 2008 __MyCompanyName__. All rights reserved.
jens@2: //
jens@2: 
jens@2: #import "DateUtils.h"
jens@2: 
jens@2: #include <assert.h>
jens@2: #include <CoreServices/CoreServices.h>
jens@2: #include <mach/mach.h>
jens@2: #include <mach/mach_time.h>
jens@2: #include <unistd.h>
jens@2: 
jens@2: 
jens@4: /** Absolute time (since 'reference date') to NSDate. 0.0 -> nil. */
jens@4: NSDate* $date( CFAbsoluteTime time )
jens@4: {
jens@4:     CAssert(time>=0.0 && time < 1.0e15, @"Bogus timestamp %g",time);
jens@4:     return time ?[NSDate dateWithTimeIntervalSinceReferenceDate: time] :nil;
jens@4: }
jens@4: 
jens@4: 
jens@4: /** NSDate to absolute time (since 'reference date'). nil -> 0.0 */
jens@4: CFAbsoluteTime $time( NSDate* date )
jens@4: {
jens@4:     return date ?[date timeIntervalSinceReferenceDate] :0.0;
jens@4: }
jens@4: 
jens@4: 
jens@4: 
jens@2: NSTimeInterval TimeIntervalSinceBoot(void)
jens@2: {
jens@2:     // From http://developer.apple.com/qa/qa2004/qa1398.html
jens@2:     uint64_t abstime = mach_absolute_time();
jens@2:     // Have to do some pointer fun because AbsoluteToNanoseconds
jens@2:     // works in terms of UnsignedWide, which is a structure rather
jens@2:     // than a proper 64-bit integer.
jens@2:     Nanoseconds elapsedNano = AbsoluteToNanoseconds( *(AbsoluteTime *) &abstime );
jens@2:     return *(uint64_t*)&elapsedNano / 1.0e9;
jens@2: }
jens@2: