Copyright 2012 Netflix, 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.
/**
 * Copyright 2012 Netflix, 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.netflix.hystrix;

import static com.netflix.hystrix.strategy.properties.HystrixPropertiesChainedProperty.forBoolean;
import static com.netflix.hystrix.strategy.properties.HystrixPropertiesChainedProperty.forInteger;
import static com.netflix.hystrix.strategy.properties.HystrixPropertiesChainedProperty.forString;

import com.netflix.hystrix.strategy.properties.HystrixPropertiesStrategy;
import com.netflix.hystrix.strategy.properties.HystrixProperty;
import com.netflix.hystrix.util.HystrixRollingNumber;
import com.netflix.hystrix.util.HystrixRollingPercentile;

Properties for instances of HystrixCollapser. 

Default implementation of methods uses Archaius (https://github.com/Netflix/archaius)
/**
 * Properties for instances of {@link HystrixCollapser}.
 * <p>
 * Default implementation of methods uses Archaius (https://github.com/Netflix/archaius)
 */
public abstract class HystrixCollapserProperties {

    /* defaults */
    private static final Integer default_maxRequestsInBatch = Integer.MAX_VALUE;
    private static final Integer default_timerDelayInMilliseconds = 10;
    private static final Boolean default_requestCacheEnabled = true;
    /* package */ static final Integer default_metricsRollingStatisticalWindow = 10000;// default => statisticalWindow: 10000 = 10 seconds (and default of 10 buckets so each bucket is 1 second)
    private static final Integer default_metricsRollingStatisticalWindowBuckets = 10;// default => statisticalWindowBuckets: 10 = 10 buckets in a 10 second window so each bucket is 1 second
    private static final Boolean default_metricsRollingPercentileEnabled = true;
    private static final Integer default_metricsRollingPercentileWindow = 60000; // default to 1 minute for RollingPercentile
    private static final Integer default_metricsRollingPercentileWindowBuckets = 6; // default to 6 buckets (10 seconds each in 60 second window)
    private static final Integer default_metricsRollingPercentileBucketSize = 100; // default to 100 values max per bucket

    private final HystrixProperty<Integer> maxRequestsInBatch;
    private final HystrixProperty<Integer> timerDelayInMilliseconds;
    private final HystrixProperty<Boolean> requestCacheEnabled;
    private final HystrixProperty<Integer> metricsRollingStatisticalWindowInMilliseconds; // milliseconds back that will be tracked
    private final HystrixProperty<Integer> metricsRollingStatisticalWindowBuckets; // number of buckets in the statisticalWindow
    private final HystrixProperty<Boolean> metricsRollingPercentileEnabled; // Whether monitoring should be enabled
    private final HystrixProperty<Integer> metricsRollingPercentileWindowInMilliseconds; // number of milliseconds that will be tracked in RollingPercentile
    private final HystrixProperty<Integer> metricsRollingPercentileWindowBuckets; // number of buckets percentileWindow will be divided into
    private final HystrixProperty<Integer> metricsRollingPercentileBucketSize; // how many values will be stored in each percentileWindowBucket

    protected HystrixCollapserProperties(HystrixCollapserKey collapserKey) {
        this(collapserKey, new Setter(), "hystrix");
    }

    protected HystrixCollapserProperties(HystrixCollapserKey collapserKey, Setter builder) {
        this(collapserKey, builder, "hystrix");
    }

    protected HystrixCollapserProperties(HystrixCollapserKey key, Setter builder, String propertyPrefix) {
        this.maxRequestsInBatch = getProperty(propertyPrefix, key, "maxRequestsInBatch", builder.getMaxRequestsInBatch(), default_maxRequestsInBatch);
        this.timerDelayInMilliseconds = getProperty(propertyPrefix, key, "timerDelayInMilliseconds", builder.getTimerDelayInMilliseconds(), default_timerDelayInMilliseconds);
        this.requestCacheEnabled = getProperty(propertyPrefix, key, "requestCache.enabled", builder.getRequestCacheEnabled(), default_requestCacheEnabled);
        this.metricsRollingStatisticalWindowInMilliseconds = getProperty(propertyPrefix, key, "metrics.rollingStats.timeInMilliseconds", builder.getMetricsRollingStatisticalWindowInMilliseconds(), default_metricsRollingStatisticalWindow);
        this.metricsRollingStatisticalWindowBuckets = getProperty(propertyPrefix, key, "metrics.rollingStats.numBuckets", builder.getMetricsRollingStatisticalWindowBuckets(), default_metricsRollingStatisticalWindowBuckets);
        this.metricsRollingPercentileEnabled = getProperty(propertyPrefix, key, "metrics.rollingPercentile.enabled", builder.getMetricsRollingPercentileEnabled(), default_metricsRollingPercentileEnabled);
        this.metricsRollingPercentileWindowInMilliseconds = getProperty(propertyPrefix, key, "metrics.rollingPercentile.timeInMilliseconds", builder.getMetricsRollingPercentileWindowInMilliseconds(), default_metricsRollingPercentileWindow);
        this.metricsRollingPercentileWindowBuckets = getProperty(propertyPrefix, key, "metrics.rollingPercentile.numBuckets", builder.getMetricsRollingPercentileWindowBuckets(), default_metricsRollingPercentileWindowBuckets);
        this.metricsRollingPercentileBucketSize = getProperty(propertyPrefix, key, "metrics.rollingPercentile.bucketSize", builder.getMetricsRollingPercentileBucketSize(), default_metricsRollingPercentileBucketSize);
    }

    private static HystrixProperty<Integer> getProperty(String propertyPrefix, HystrixCollapserKey key, String instanceProperty, Integer builderOverrideValue, Integer defaultValue) {
        return forInteger()
              .add(propertyPrefix + ".collapser." + key.name() + "." + instanceProperty, builderOverrideValue)
              .add(propertyPrefix + ".collapser.default." + instanceProperty, defaultValue)
              .build();
              

    }

    private static HystrixProperty<Boolean> getProperty(String propertyPrefix, HystrixCollapserKey key, String instanceProperty, Boolean builderOverrideValue, Boolean defaultValue) {
        return forBoolean()
                .add(propertyPrefix + ".collapser." + key.name() + "." + instanceProperty, builderOverrideValue)
                .add(propertyPrefix + ".collapser.default." + instanceProperty, defaultValue)
                .build();
    }

    
Whether request caching is enabled for HystrixCollapser.execute and HystrixCollapser.queue invocations. Deprecated as of 1.4.0-RC7 in favor of requestCacheEnabled() (to match HystrixCommandProperties.requestCacheEnabled() 
Returns:
HystrixProperty<Boolean>/**
     * Whether request caching is enabled for {@link HystrixCollapser#execute} and {@link HystrixCollapser#queue} invocations.
     *
     * Deprecated as of 1.4.0-RC7 in favor of requestCacheEnabled() (to match {@link HystrixCommandProperties#requestCacheEnabled()}
     *
     * @return {@code HystrixProperty<Boolean>}
     */
    @Deprecated
    public HystrixProperty<Boolean> requestCachingEnabled() {
        return requestCacheEnabled;
    }

    
Whether request caching is enabled for HystrixCollapser.execute and HystrixCollapser.queue invocations. 
Returns:
HystrixProperty<Boolean>/**
     * Whether request caching is enabled for {@link HystrixCollapser#execute} and {@link HystrixCollapser#queue} invocations.
     *
     * @return {@code HystrixProperty<Boolean>}
     */
    public HystrixProperty<Boolean> requestCacheEnabled() {
        return requestCacheEnabled;
    }

    
The maximum number of requests allowed in a batch before triggering a batch execution.
Returns:
HystrixProperty<Integer>/**
     * The maximum number of requests allowed in a batch before triggering a batch execution.
     * 
     * @return {@code HystrixProperty<Integer>}
     */
    public HystrixProperty<Integer> maxRequestsInBatch() {
        return maxRequestsInBatch;
    }

    
The number of milliseconds between batch executions (unless maxRequestsInBatch is hit which will cause a batch to execute early. 
Returns:
HystrixProperty<Integer>/**
     * The number of milliseconds between batch executions (unless {@link #maxRequestsInBatch} is hit which will cause a batch to execute early.
     * 
     * @return {@code HystrixProperty<Integer>}
     */
    public HystrixProperty<Integer> timerDelayInMilliseconds() {
        return timerDelayInMilliseconds;
    }

    
Duration of statistical rolling window in milliseconds. This is passed into HystrixRollingNumber inside HystrixCommandMetrics. 
Returns:
HystrixProperty<Integer>/**
     * Duration of statistical rolling window in milliseconds. This is passed into {@link HystrixRollingNumber} inside {@link HystrixCommandMetrics}.
     *
     * @return {@code HystrixProperty<Integer>}
     */
    public HystrixProperty<Integer> metricsRollingStatisticalWindowInMilliseconds() {
        return metricsRollingStatisticalWindowInMilliseconds;
    }

    
Number of buckets the rolling statistical window is broken into. This is passed into HystrixRollingNumber inside HystrixCollapserMetrics. 
Returns:
HystrixProperty<Integer>/**
     * Number of buckets the rolling statistical window is broken into. This is passed into {@link HystrixRollingNumber} inside {@link HystrixCollapserMetrics}.
     *
     * @return {@code HystrixProperty<Integer>}
     */
    public HystrixProperty<Integer> metricsRollingStatisticalWindowBuckets() {
        return metricsRollingStatisticalWindowBuckets;
    }

    
Whether percentile metrics should be captured using HystrixRollingPercentile inside HystrixCollapserMetrics. 
Returns:
HystrixProperty<Boolean>/**
     * Whether percentile metrics should be captured using {@link HystrixRollingPercentile} inside {@link HystrixCollapserMetrics}.
     *
     * @return {@code HystrixProperty<Boolean>}
     */
    public HystrixProperty<Boolean> metricsRollingPercentileEnabled() {
        return metricsRollingPercentileEnabled;
    }

    
Duration of percentile rolling window in milliseconds. This is passed into HystrixRollingPercentile inside HystrixCollapserMetrics. 
Returns:
HystrixProperty<Integer>/**
     * Duration of percentile rolling window in milliseconds. This is passed into {@link HystrixRollingPercentile} inside {@link HystrixCollapserMetrics}.
     *
     * @return {@code HystrixProperty<Integer>}
     */
    public HystrixProperty<Integer> metricsRollingPercentileWindowInMilliseconds() {
        return metricsRollingPercentileWindowInMilliseconds;
    }

    
Number of buckets the rolling percentile window is broken into. This is passed into HystrixRollingPercentile inside HystrixCollapserMetrics. 
Returns:
HystrixProperty<Integer>/**
     * Number of buckets the rolling percentile window is broken into. This is passed into {@link HystrixRollingPercentile} inside {@link HystrixCollapserMetrics}.
     *
     * @return {@code HystrixProperty<Integer>}
     */
    public HystrixProperty<Integer> metricsRollingPercentileWindowBuckets() {
        return metricsRollingPercentileWindowBuckets;
    }

    
Maximum number of values stored in each bucket of the rolling percentile. This is passed into HystrixRollingPercentile inside HystrixCollapserMetrics. 
Returns:
HystrixProperty<Integer>/**
     * Maximum number of values stored in each bucket of the rolling percentile. This is passed into {@link HystrixRollingPercentile} inside {@link HystrixCollapserMetrics}.
     *
     * @return {@code HystrixProperty<Integer>}
     */
    public HystrixProperty<Integer> metricsRollingPercentileBucketSize() {
        return metricsRollingPercentileBucketSize;
    }

    
Factory method to retrieve the default Setter.
/**
     * Factory method to retrieve the default Setter.
     */
    public static Setter Setter() {
        return new Setter();
    }

    
Factory method to retrieve the default Setter.
Groovy has a bug (GROOVY-6286) which does not allow method names and inner classes to have the same name
This method fixes Issue #967 and allows Groovy consumers to choose this method and not trigger the bug
/**
     * Factory method to retrieve the default Setter.
     * Groovy has a bug (GROOVY-6286) which does not allow method names and inner classes to have the same name
     * This method fixes Issue #967 and allows Groovy consumers to choose this method and not trigger the bug
     */
    public static Setter defaultSetter() {
        return Setter();
    }

    
Fluent interface that allows chained setting of properties that can be passed into a HystrixCollapser constructor to inject instance specific property overrides. 
 See HystrixPropertiesStrategy for more information on order of precedence. 

Example:

 
HystrixCollapserProperties.Setter()
          .setMaxRequestsInBatch(100)
          .setTimerDelayInMilliseconds(10);
 
@NotThreadSafe
/**
     * Fluent interface that allows chained setting of properties that can be passed into a {@link HystrixCollapser} constructor to inject instance specific property overrides.
     * <p>
     * See {@link HystrixPropertiesStrategy} for more information on order of precedence.
     * <p>
     * Example:
     * <p>
     * <pre> {@code
     * HystrixCollapserProperties.Setter()
     *           .setMaxRequestsInBatch(100)
     *           .setTimerDelayInMilliseconds(10);
     * } </pre>
     * 
     * @NotThreadSafe
     */
    public static class Setter {
        @Deprecated private Boolean collapsingEnabled = null;
        private Integer maxRequestsInBatch = null;
        private Integer timerDelayInMilliseconds = null;
        private Boolean requestCacheEnabled = null;
        private Integer metricsRollingStatisticalWindowInMilliseconds = null;
        private Integer metricsRollingStatisticalWindowBuckets = null;
        private Integer metricsRollingPercentileBucketSize = null;
        private Boolean metricsRollingPercentileEnabled = null;
        private Integer metricsRollingPercentileWindowInMilliseconds = null;
        private Integer metricsRollingPercentileWindowBuckets = null;

        private Setter() {
        }

        
Deprecated because the collapsingEnabled setting doesn't do anything.
/**
         * Deprecated because the collapsingEnabled setting doesn't do anything.
         */
        @Deprecated
        public Boolean getCollapsingEnabled() {
            return collapsingEnabled;
        }

        public Integer getMaxRequestsInBatch() {
            return maxRequestsInBatch;
        }

        public Integer getTimerDelayInMilliseconds() {
            return timerDelayInMilliseconds;
        }

        public Boolean getRequestCacheEnabled() {
            return requestCacheEnabled;
        }

        public Integer getMetricsRollingStatisticalWindowInMilliseconds() {
            return metricsRollingStatisticalWindowInMilliseconds;
        }

        public Integer getMetricsRollingStatisticalWindowBuckets() {
            return metricsRollingStatisticalWindowBuckets;
        }

        public Integer getMetricsRollingPercentileBucketSize() {
            return metricsRollingPercentileBucketSize;
        }

        public Boolean getMetricsRollingPercentileEnabled() {
            return metricsRollingPercentileEnabled;
        }

        public Integer getMetricsRollingPercentileWindowInMilliseconds() {
            return metricsRollingPercentileWindowInMilliseconds;
        }

        public Integer getMetricsRollingPercentileWindowBuckets() {
            return metricsRollingPercentileWindowBuckets;
        }

        
Deprecated because the collapsingEnabled setting doesn't do anything.
/**
         * Deprecated because the collapsingEnabled setting doesn't do anything.
         */
        @Deprecated
        public Setter withCollapsingEnabled(boolean value) {
            this.collapsingEnabled = value;
            return this;
        }

        public Setter withMaxRequestsInBatch(int value) {
            this.maxRequestsInBatch = value;
            return this;
        }

        public Setter withTimerDelayInMilliseconds(int value) {
            this.timerDelayInMilliseconds = value;
            return this;
        }

        public Setter withRequestCacheEnabled(boolean value) {
            this.requestCacheEnabled = value;
            return this;
        }

        public Setter withMetricsRollingStatisticalWindowInMilliseconds(int value) {
            this.metricsRollingStatisticalWindowInMilliseconds = value;
            return this;
        }

        public Setter withMetricsRollingStatisticalWindowBuckets(int value) {
            this.metricsRollingStatisticalWindowBuckets = value;
            return this;
        }

        public Setter withMetricsRollingPercentileBucketSize(int value) {
            this.metricsRollingPercentileBucketSize = value;
            return this;
        }

        public Setter withMetricsRollingPercentileEnabled(boolean value) {
            this.metricsRollingPercentileEnabled = value;
            return this;
        }

        public Setter withMetricsRollingPercentileWindowInMilliseconds(int value) {
            this.metricsRollingPercentileWindowInMilliseconds = value;
            return this;
        }

        public Setter withMetricsRollingPercentileWindowBuckets(int value) {
            this.metricsRollingPercentileWindowBuckets = value;
            return this;
        }

        
Base properties for unit testing.
/**
         * Base properties for unit testing.
         */
        /* package */static Setter getUnitTestPropertiesBuilder() {
            return new Setter()
                    .withMaxRequestsInBatch(Integer.MAX_VALUE)
                    .withTimerDelayInMilliseconds(10)
                    .withRequestCacheEnabled(true);
        }

        
Return a static representation of the properties with values from the Builder so that UnitTests can create properties that are not affected by the actual implementations which pick up their
values dynamically.
Params:
builder – collapser properties builder
Returns:
HystrixCollapserProperties/**
         * Return a static representation of the properties with values from the Builder so that UnitTests can create properties that are not affected by the actual implementations which pick up their
         * values dynamically.
         * 
         * @param builder collapser properties builder
         * @return HystrixCollapserProperties
         */
        /* package */static HystrixCollapserProperties asMock(final Setter builder) {
            return new HystrixCollapserProperties(TestHystrixCollapserKey.TEST) {

                @Override
                public HystrixProperty<Boolean> requestCachingEnabled() {
                    return HystrixProperty.Factory.asProperty(builder.requestCacheEnabled);
                }

                @Override
                public HystrixProperty<Integer> maxRequestsInBatch() {
                    return HystrixProperty.Factory.asProperty(builder.maxRequestsInBatch);
                }

                @Override
                public HystrixProperty<Integer> timerDelayInMilliseconds() {
                    return HystrixProperty.Factory.asProperty(builder.timerDelayInMilliseconds);
                }

            };
        }

        private static enum TestHystrixCollapserKey implements HystrixCollapserKey {
            TEST
        }
    }

}