com.google.caliper.model.Measurement.java Source code

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Here is the source code for com.google.caliper.model.Measurement.java

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/*
 * Copyright (C) 2012 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.caliper.model;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static javax.persistence.AccessType.FIELD;

import com.google.common.base.Function;
import com.google.common.base.Objects;
import com.google.common.collect.ImmutableListMultimap;
import com.google.common.collect.Multimaps;

import org.hibernate.annotations.Immutable;

import java.io.Serializable;

import javax.persistence.Access;
import javax.persistence.Basic;
import javax.persistence.Cacheable;
import javax.persistence.Embedded;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

/**
 * A single, weighted measurement.
 *
 * @author gak@google.com (Gregory Kick)
 */
@Entity
@Access(FIELD)
@Immutable
@Cacheable
public class Measurement implements Serializable {
    private static final long serialVersionUID = 1L;

    public static ImmutableListMultimap<String, Measurement> indexByDescription(
            Iterable<Measurement> measurements) {
        return Multimaps.index(measurements, new Function<Measurement, String>() {
            @Override
            public String apply(Measurement input) {
                return input.description;
            }
        });
    }

    @Id
    @GeneratedValue
    @ExcludeFromJson
    private int id;
    @Embedded
    private Value value;
    private double weight;
    @Basic(optional = false)
    private String description;

    private Measurement() {
        this.value = Value.DEFAULT;
        this.weight = 0.0;
        this.description = "";
    }

    private Measurement(Builder builder) {
        this.value = builder.value;
        this.description = builder.description;
        this.weight = builder.weight;
    }

    @Override
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        } else if (obj instanceof Measurement) {
            Measurement that = (Measurement) obj;
            return this.value.equals(that.value) && this.weight == that.weight
                    && this.description.equals(that.description);
        } else {
            return false;
        }
    }

    @Override
    public int hashCode() {
        return Objects.hashCode(value, weight, description);
    }

    @Override
    public String toString() {
        return Objects.toStringHelper(this).add("value", value).add("weight", weight)
                .add("description", description).toString();
    }

    public Value value() {
        return value;
    }

    public double weight() {
        return weight;
    }

    public String description() {
        return description;
    }

    public static final class Builder {
        private Value value;
        private Double weight;
        private String description;

        public Builder value(Value value) {
            this.value = checkNotNull(value);
            return this;
        }

        public Builder weight(double weight) {
            checkArgument(weight > 0);
            this.weight = weight;
            return this;
        }

        public Builder description(String description) {
            this.description = checkNotNull(description);
            return this;
        }

        public Measurement build() {
            checkArgument(value != null);
            checkArgument(weight != null);
            checkArgument(description != null);
            return new Measurement(this);
        }
    }
}