source: timeline/src/main/java/geniusweb/progress/ProgressTime.java@ 36

package geniusweb.progress;

import java.util.Date;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;

import geniusweb.deadline.DeadlineTime;

/**
 * keeps track of progress towards the Deadline and the time/rounds left.
 * immutable. However, the time progresses nevertheless since this refers to the
 * system clocks.
 *
 */
public class ProgressTime implements Progress {

        /**
         * time in millis as returned from {@link System#currentTimeMillis()}. Note,
         * we do not use RFC 3339 because we need millisecond accuracy.
         */
        private final Date start;

        /**
         * duration in millis. we do not use ISO 8601 because we need millisecond
         * accuracy.
         */
        private final Long duration;

        /**
         * 
         * @param d     the duration, eg {@link DeadlineTime#getDuration()}. Must be
         *              > 0.
         * @param start the start Date (unix time in millisecs since 1970). See
         *              {@link System#currentTimeMillis()}.
         */
        @JsonCreator
        public ProgressTime(@JsonProperty("duration") Long d,
                        @JsonProperty("start") Date start) {
                this.start = start;
                duration = (d == null || d <= 0) ? 1 : d;
        }

        @Override
        public Double get(Long currentTimeMs) {
                long delta = currentTimeMs - start.getTime();
                // double should have ~53 digits of precision, and we're computing
                // deltas here.
                // 2^53 millis seems plenty for our purposes so no need to use
                // BigDecimal here.
                Double ratio = delta / (double) duration;
                if (ratio > 1d)
                        ratio = 1d;
                else if (ratio < 0d)
                        ratio = 0d;
                return ratio;
        }

        @Override
        public boolean isPastDeadline(Long currentTimeMs) {
                return currentTimeMs > start.getTime() + duration;
        }

        /**
         * 
         * @return time measured in milliseconds, between the start time and
         *         midnight, January 1, 1970 UTCas returned from
         *         {@link System#currentTimeMillis()}
         * 
         */
        public Date getStart() {
                return start;
        }

        /**
         * 
         * @return duration in milliseconds.
         */
        public Long getDuration() {
                return duration;
        }

        @Override
        public Date getTerminationTime() {
                return new Date(start.getTime() + duration);
        }

        @Override
        public String toString() {
                return "ProgressTime[" + start.getTime() + " , " + duration + "ms]";
        }

        @Override
        public int hashCode() {
                final int prime = 31;
                int result = 1;
                result = prime * result
                                + ((duration == null) ? 0 : duration.hashCode());
                result = prime * result + ((start == null) ? 0 : start.hashCode());
                return result;
        }

        @Override
        public boolean equals(Object obj) {
                if (this == obj)
                        return true;
                if (obj == null)
                        return false;
                if (getClass() != obj.getClass())
                        return false;
                ProgressTime other = (ProgressTime) obj;
                if (duration == null) {
                        if (other.duration != null)
                                return false;
                } else if (!duration.equals(other.duration))
                        return false;
                if (start == null) {
                        if (other.start != null)
                                return false;
                } else if (!start.equals(other.start))
                        return false;
                return true;
        }

}