source: timeline/src/main/java/geniusweb/progress/ProgressRounds.java@ 42

package geniusweb.progress;

import java.util.Date;

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

/**
 * progress in terms of number of rounds. The round has to be updated by the
 * user of this class, calling {@link #advance()}. immutable.
 */
public class ProgressRounds implements Progress {

        private final Integer duration;
        private final Integer currentRound;
        private final Date endtime;

        /**
         * 
         * @param deadline     length max number of rounds, must be positive (not 0)
         * @param currentRound the current round number (can be from 0 to deadlne).
         *                     When = deadline, it means the progress has gone past
         *                     the deadline.
         * @param end          the termination time of this session.
         */
        @JsonCreator
        public ProgressRounds(@JsonProperty("duration") Integer deadline,
                        @JsonProperty("currentRound") Integer currentRound,
                        @JsonProperty("endtime") Date end) {
                if (deadline <= 0)
                        throw new IllegalArgumentException(
                                        "deadline must be positive but is " + deadline);
                if (currentRound < 0 || currentRound > deadline) {
                        throw new IllegalArgumentException(
                                        "current round must be inside [0," + deadline + "]");
                }
                this.duration = deadline;
                this.currentRound = currentRound;
                this.endtime = end;
        }

        @Override
        public Date getTerminationTime() {
                return endtime;
        }

        /**
         * 
         * @return the current round. First round is 0. It is recommended that you
         *         use the functions in {@link Progress} instead of this, to ensure
         *         your code works with all implementations of Progress including
         *         future developments.
         */
        public Integer getCurrentRound() {
                return currentRound;
        }

        /**
         * 
         * @return total number of rounds. It is recommended that you use the
         *         functions in {@link Progress} instead of this, to ensure your
         *         code works with all implementations of Progress including future
         *         developments.
         */
        public Integer getTotalRounds() {
                return duration;
        }

        @Override
        public Double get(Long currentTimeMs) {
                // deadline and current both are limited to MAXINT is 32 bits; double
                // fits 52
                // bits so this should not result in accuracy issues
                double ratio = (double) currentRound / (double) duration;
                if (ratio > 1d)
                        ratio = 1d;
                else if (ratio < 0d)
                        ratio = 0d;
                return ratio;
        }

        @Override
        public boolean isPastDeadline(Long currentTimeMs) {
                return currentRound >= duration || currentTimeMs > endtime.getTime();
        }

        /**
         * 
         * @return new ProgressRounds with round 1 advanced (or this, if
         *         currentRound= duration). This is up to the user, as it is up to
         *         the used protocol what exactly is a round.
         */
        public ProgressRounds advance() {
                if (duration == currentRound)
                        return this;
                return new ProgressRounds(duration, currentRound + 1, endtime);
        }

        @Override
        public int hashCode() {
                final int prime = 31;
                int result = 1;
                result = prime * result
                                + ((currentRound == null) ? 0 : currentRound.hashCode());
                result = prime * result
                                + ((duration == null) ? 0 : duration.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;
                ProgressRounds other = (ProgressRounds) obj;
                if (currentRound == null) {
                        if (other.currentRound != null)
                                return false;
                } else if (!currentRound.equals(other.currentRound))
                        return false;
                if (duration == null) {
                        if (other.duration != null)
                                return false;
                } else if (!duration.equals(other.duration))
                        return false;
                return true;
        }

        @Override
        public String toString() {
                return "ProgressRounds[" + currentRound + " of " + duration + "]";
        }

}