core/src/main/java/org/apache/brooklyn/core/feed/FeedConfig.java - brooklyn-server - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you 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 org.apache.brooklyn.core.feed;

 import static com.google.common.base.Preconditions.checkNotNull;

 import org.apache.brooklyn.api.sensor.AttributeSensor;
 import org.apache.brooklyn.core.entity.Entities;
 import org.apache.brooklyn.core.sensor.Sensors;
 import org.apache.brooklyn.feed.http.HttpPollConfig;
 import org.apache.brooklyn.util.collections.MutableList;
 import org.apache.brooklyn.util.guava.Functionals;
 import org.apache.brooklyn.util.javalang.JavaClassNames;
 import org.apache.brooklyn.util.text.Strings;
 import org.apache.brooklyn.util.time.Duration;

 import com.google.common.base.Function;
 import com.google.common.base.Functions;
 import com.google.common.base.Objects;
 import com.google.common.base.Predicate;

 /**
  * Configuration for a poll, or a subscription etc, that is being added to a feed.
  *
  * @author aled
  */
 public class FeedConfig<V, T, F extends FeedConfig<V, T, F>> {

     /** The onSuccess or onError functions can return this value to indicate that the sensor should not change. */
     public static final Object UNCHANGED = Entities.UNCHANGED;
     /** The onSuccess or onError functions can return this value to indicate that the sensor value should be removed
      * (cf 'null', but useful in dynamic situations) */
     public static final Object REMOVE = Entities.REMOVE;

     /** Indicates that no sensor is being used here. This sensor is suppressed,
      * but is useful where you want to use the feeds with custom success/exception/failure functions
      * which directly set multiple sensors, e.g. dynamically based on the poll response.
      * <p>
      * See {@link HttpPollConfig#forMultiple()} and its usages.
      * (It can work for any poll config, but conveniences have not been supplied for others.)  */
     public static final AttributeSensor<Void> NO_SENSOR = Sensors.newSensor(Void.class, "brooklyn.no.sensor");

     private final AttributeSensor<T> sensor;
     private Function<? super V, T> onsuccess;
     private Function<? super V, T> onfailure;
     private Function<? super Exception, T> onexception;
     private Predicate<? super V> checkSuccess;
     private boolean suppressDuplicates;
     private boolean enabled = true;

     // allow 30 seconds before logging at WARN, if there has been no success yet;
     // after success WARN immediately
     // TODO these should both be configurable
     /**
      * On startup, the length of time before which a failure can be logged at WARN.
      * This grace period is useful to avoid flooding the logs if the feed is expected
      * to sometimes be unavailable for a few seconds while the process-under-management
      * initialises.
      *
      * Defaults to 30 seconds.
      */
     private Duration logWarningGraceTimeOnStartup = Duration.THIRTY_SECONDS;

     /**
      * Length of time, after a successful poll, before a subsequent failure can be logged at WARN.
      *
      * Defaults to 0.
      */
     private Duration logWarningGraceTime = Duration.millis(0);

     public FeedConfig(AttributeSensor<T> sensor) {
         this.sensor = sensor;
     }

     public FeedConfig(FeedConfig<V, T, F> other) {
         this.sensor = other.sensor;
         this.onsuccess = other.onsuccess;
         this.onfailure = other.onfailure;
         this.onexception = other.onexception;
         this.checkSuccess = other.checkSuccess;
         this.suppressDuplicates = other.suppressDuplicates;
         this.logWarningGraceTimeOnStartup = other.logWarningGraceTimeOnStartup;
         this.logWarningGraceTime = other.logWarningGraceTime;
         this.enabled = other.enabled;
     }

     @SuppressWarnings("unchecked")
     protected F self() {
         return (F) this;
     }

     public AttributeSensor<T> getSensor() {
         return sensor;
     }

     public Predicate<? super V> getCheckSuccess() {
         return checkSuccess;
     }

     public Function<? super V, T> getOnSuccess() {
         return onsuccess;
     }

     public Function<? super V, T> getOnFailure() {
         return onfailure;
     }

     public Function<? super Exception, T> getOnException() {
         return onexception;
     }

     public boolean getSupressDuplicates() {
         return suppressDuplicates;
     }

     public boolean isEnabled() {
         return enabled;
     }

     /** sets the predicate used to check whether a feed run is successful */
     public F checkSuccess(Predicate<? super V> val) {
         this.checkSuccess = checkNotNull(val, "checkSuccess");
         return self();
     }
     /** as {@link #checkSuccess(Predicate)} */
     public F checkSuccess(final Function<? super V,Boolean> val) {
         return checkSuccess(Functionals.predicate(val));
     }

     @SuppressWarnings("unused")
     /** @deprecated since 0.7.0, kept for rebind */ @Deprecated
     private F checkSuccessLegacy(final Function<? super V,Boolean> val) {
         return checkSuccess(new Predicate<V>() {
             @Override
             public boolean apply(V input) {
                 return val.apply(input);
             }
         });
     }

     public F onSuccess(Function<? super V,T> val) {
         this.onsuccess = checkNotNull(val, "onSuccess");
         return self();
     }

     public F setOnSuccess(T val) {
         return onSuccess(Functions.constant(val));
     }

     /**
      * A failure is when the connection is fine (no exception) but the other end returns a result object V
      * which the feed can tell indicates a failure (e.g. HTTP code 404)
      */
     public F onFailure(Function<? super V,T> val) {
         this.onfailure = checkNotNull(val, "onFailure");
         return self();
     }

     /** @see #onFailure(Function) */
     public F setOnFailure(T val) {
         return onFailure(Functions.constant(val));
     }

     /**
      * Registers a callback to be used by {@link #onSuccess(Function)} and {@link #onFailure(Function)},
      * i.e. whenever a result comes back, but not in case of exceptions being thrown (ie problems communicating)
      */
     public F onResult(Function<? super V, T> val) {
         onSuccess(val);
         return onFailure(val);
     }

     /** @see #onResult(Function) */
     public F setOnResult(T val) {
         return onResult(Functions.constant(val));
     }

     /**
      * An exception is when there is an error in the communication
      */
     public F onException(Function<? super Exception,T> val) {
         this.onexception = checkNotNull(val, "onException");
         return self();
     }

     /** @see #onException(Function) */
     public F setOnException(T val) {
         return onException(Functions.constant(val));
     }

     /**
      * A convenience for indicating a behaviour to occur for both {@link #onException(Function)}
      * (error connecting) and {@link #onFailure(Function)} (successful communication but failure
      * report from remote end)
      */
     public F onFailureOrException(Function<Object,T> val) {
         onFailure(val);
         return onException(val);
     }

     /** @see #onFailureOrException(Function) */
     public F setOnFailureOrException(T val) {
         return onFailureOrException(Functions.constant(val));
     }

     public F suppressDuplicates(boolean val) {
         suppressDuplicates = val;
         return self();
     }

     public F logWarningGraceTimeOnStartup(Duration val) {
         this.logWarningGraceTimeOnStartup = checkNotNull(val);
         return self();
     }

     public F logWarningGraceTime(Duration val) {
         this.logWarningGraceTime = checkNotNull(val);
         return self();
     }

     public Duration getLogWarningGraceTimeOnStartup() {
         return logWarningGraceTimeOnStartup;
     }

     public Duration getLogWarningGraceTime() {
         return logWarningGraceTime;
     }

     /**
      * Whether this feed is enabled (defaulting to true).
      */
     public F enabled(boolean val) {
         enabled = val;
         return self();
     }

     public boolean hasSuccessHandler() {
         return this.onsuccess != null;
     }

     public boolean hasFailureHandler() {
         return this.onfailure != null;
     }

     public boolean hasExceptionHandler() {
         return this.onexception != null;
     }

     public boolean hasCheckSuccessHandler() {
         return this.checkSuccess != null;
     }

     @Override
     public String toString() {
         StringBuilder result = new StringBuilder();
         result.append(toStringBaseName());
         result.append("[");
         boolean contents = false;
         Object source = toStringPollSource();
         AttributeSensor<T> s = getSensor();
         if (Strings.isNonBlank(Strings.toString(source))) {
             if (s!=null) {
                 result.append(s.getName());
                 result.append(" <- ");
             }
             result.append(Strings.toUniqueString(source, 40));
             contents = true;
         } else if (s!=null) {
             result.append(s.getName());
             contents = true;
         }
         MutableList<Object> fields = toStringOtherFields();
         if (fields!=null) {
             for (Object field: fields) {
                 if (Strings.isNonBlank(Strings.toString(field))) {
                     if (contents) result.append("; ");
                     contents = true;
                     result.append(field);
                 }
             }
         }
         result.append("]");
         return result.toString();
     }

     /** can be overridden to supply a simpler base name than the class name */
     protected String toStringBaseName() {
         return JavaClassNames.simpleClassName(this);
     }
     /** can be overridden to supply add'l info for the {@link #toString()}; subclasses can add to the returned value */
     protected MutableList<Object> toStringOtherFields() {
         return MutableList.<Object>of();
     }
     /** can be overridden to supply add'l info for the {@link #toString()}, placed before the sensor with -> */
     protected Object toStringPollSource() {
         return null;
     }
     /** all configs should supply a unique tag element, inserted into the feed */
     protected String getUniqueTag() {
         return toString();
     }

     /** returns fields which should be used for equality, including by default {@link #toStringOtherFields()} and {@link #toStringPollSource()};
      * subclasses can add to the returned value */
     protected MutableList<Object> equalsFields() {
         MutableList<Object> result = MutableList.of().appendIfNotNull(getSensor()).appendIfNotNull(toStringPollSource());
         for (Object field: toStringOtherFields()) result.appendIfNotNull(field);
         return result;
     }

     @Override
     public int hashCode() {
         int hc = super.hashCode();
         for (Object f: equalsFields())
             hc = Objects.hashCode(hc, f);
         return hc;
     }

     @Override
     public boolean equals(Object obj) {
         if (this == obj) return true;
         if (!super.equals(obj)) return false;
         PollConfig<?,?,?> other = (PollConfig<?,?,?>) obj;
         if (!Objects.equal(getUniqueTag(), other.getUniqueTag())) return false;
         if (!Objects.equal(equalsFields(), other.equalsFields())) return false;
         return true;
     }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you 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 org.apache.brooklyn.core.feed;

	import static com.google.common.base.Preconditions.checkNotNull;

	import org.apache.brooklyn.api.sensor.AttributeSensor;
	import org.apache.brooklyn.core.entity.Entities;
	import org.apache.brooklyn.core.sensor.Sensors;
	import org.apache.brooklyn.feed.http.HttpPollConfig;
	import org.apache.brooklyn.util.collections.MutableList;
	import org.apache.brooklyn.util.guava.Functionals;
	import org.apache.brooklyn.util.javalang.JavaClassNames;
	import org.apache.brooklyn.util.text.Strings;
	import org.apache.brooklyn.util.time.Duration;

	import com.google.common.base.Function;
	import com.google.common.base.Functions;
	import com.google.common.base.Objects;
	import com.google.common.base.Predicate;

	/**
	* Configuration for a poll, or a subscription etc, that is being added to a feed.
	*
	* @author aled
	*/
	public class FeedConfig<V, T, F extends FeedConfig<V, T, F>> {

	/** The onSuccess or onError functions can return this value to indicate that the sensor should not change. */
	public static final Object UNCHANGED = Entities.UNCHANGED;
	/** The onSuccess or onError functions can return this value to indicate that the sensor value should be removed
	* (cf 'null', but useful in dynamic situations) */
	public static final Object REMOVE = Entities.REMOVE;

	/** Indicates that no sensor is being used here. This sensor is suppressed,
	* but is useful where you want to use the feeds with custom success/exception/failure functions
	* which directly set multiple sensors, e.g. dynamically based on the poll response.
	* <p>
	* See {@link HttpPollConfig#forMultiple()} and its usages.
	* (It can work for any poll config, but conveniences have not been supplied for others.) */
	public static final AttributeSensor<Void> NO_SENSOR = Sensors.newSensor(Void.class, "brooklyn.no.sensor");

	private final AttributeSensor<T> sensor;
	private Function<? super V, T> onsuccess;
	private Function<? super V, T> onfailure;
	private Function<? super Exception, T> onexception;
	private Predicate<? super V> checkSuccess;
	private boolean suppressDuplicates;
	private boolean enabled = true;

	// allow 30 seconds before logging at WARN, if there has been no success yet;
	// after success WARN immediately
	// TODO these should both be configurable
	/**
	* On startup, the length of time before which a failure can be logged at WARN.
	* This grace period is useful to avoid flooding the logs if the feed is expected
	* to sometimes be unavailable for a few seconds while the process-under-management
	* initialises.
	*
	* Defaults to 30 seconds.
	*/
	private Duration logWarningGraceTimeOnStartup = Duration.THIRTY_SECONDS;

	/**
	* Length of time, after a successful poll, before a subsequent failure can be logged at WARN.
	*
	* Defaults to 0.
	*/
	private Duration logWarningGraceTime = Duration.millis(0);

	public FeedConfig(AttributeSensor<T> sensor) {
	this.sensor = sensor;
	}

	public FeedConfig(FeedConfig<V, T, F> other) {
	this.sensor = other.sensor;
	this.onsuccess = other.onsuccess;
	this.onfailure = other.onfailure;
	this.onexception = other.onexception;
	this.checkSuccess = other.checkSuccess;
	this.suppressDuplicates = other.suppressDuplicates;
	this.logWarningGraceTimeOnStartup = other.logWarningGraceTimeOnStartup;
	this.logWarningGraceTime = other.logWarningGraceTime;
	this.enabled = other.enabled;
	}

	@SuppressWarnings("unchecked")
	protected F self() {
	return (F) this;
	}

	public AttributeSensor<T> getSensor() {
	return sensor;
	}

	public Predicate<? super V> getCheckSuccess() {
	return checkSuccess;
	}

	public Function<? super V, T> getOnSuccess() {
	return onsuccess;
	}

	public Function<? super V, T> getOnFailure() {
	return onfailure;
	}

	public Function<? super Exception, T> getOnException() {
	return onexception;
	}

	public boolean getSupressDuplicates() {
	return suppressDuplicates;
	}

	public boolean isEnabled() {
	return enabled;
	}

	/** sets the predicate used to check whether a feed run is successful */
	public F checkSuccess(Predicate<? super V> val) {
	this.checkSuccess = checkNotNull(val, "checkSuccess");
	return self();
	}
	/** as {@link #checkSuccess(Predicate)} */
	public F checkSuccess(final Function<? super V,Boolean> val) {
	return checkSuccess(Functionals.predicate(val));
	}

	@SuppressWarnings("unused")
	/** @deprecated since 0.7.0, kept for rebind */ @Deprecated
	private F checkSuccessLegacy(final Function<? super V,Boolean> val) {
	return checkSuccess(new Predicate<V>() {
	@Override
	public boolean apply(V input) {
	return val.apply(input);
	}
	});
	}

	public F onSuccess(Function<? super V,T> val) {
	this.onsuccess = checkNotNull(val, "onSuccess");
	return self();
	}

	public F setOnSuccess(T val) {
	return onSuccess(Functions.constant(val));
	}

	/**
	* A failure is when the connection is fine (no exception) but the other end returns a result object V
	* which the feed can tell indicates a failure (e.g. HTTP code 404)
	*/
	public F onFailure(Function<? super V,T> val) {
	this.onfailure = checkNotNull(val, "onFailure");
	return self();
	}

	/** @see #onFailure(Function) */
	public F setOnFailure(T val) {
	return onFailure(Functions.constant(val));
	}

	/**
	* Registers a callback to be used by {@link #onSuccess(Function)} and {@link #onFailure(Function)},
	* i.e. whenever a result comes back, but not in case of exceptions being thrown (ie problems communicating)
	*/
	public F onResult(Function<? super V, T> val) {
	onSuccess(val);
	return onFailure(val);
	}

	/** @see #onResult(Function) */
	public F setOnResult(T val) {
	return onResult(Functions.constant(val));
	}

	/**
	* An exception is when there is an error in the communication
	*/
	public F onException(Function<? super Exception,T> val) {
	this.onexception = checkNotNull(val, "onException");
	return self();
	}

	/** @see #onException(Function) */
	public F setOnException(T val) {
	return onException(Functions.constant(val));
	}

	/**
	* A convenience for indicating a behaviour to occur for both {@link #onException(Function)}
	* (error connecting) and {@link #onFailure(Function)} (successful communication but failure
	* report from remote end)
	*/
	public F onFailureOrException(Function<Object,T> val) {
	onFailure(val);
	return onException(val);
	}

	/** @see #onFailureOrException(Function) */
	public F setOnFailureOrException(T val) {
	return onFailureOrException(Functions.constant(val));
	}

	public F suppressDuplicates(boolean val) {
	suppressDuplicates = val;
	return self();
	}

	public F logWarningGraceTimeOnStartup(Duration val) {
	this.logWarningGraceTimeOnStartup = checkNotNull(val);
	return self();
	}

	public F logWarningGraceTime(Duration val) {
	this.logWarningGraceTime = checkNotNull(val);
	return self();
	}

	public Duration getLogWarningGraceTimeOnStartup() {
	return logWarningGraceTimeOnStartup;
	}

	public Duration getLogWarningGraceTime() {
	return logWarningGraceTime;
	}

	/**
	* Whether this feed is enabled (defaulting to true).
	*/
	public F enabled(boolean val) {
	enabled = val;
	return self();
	}

	public boolean hasSuccessHandler() {
	return this.onsuccess != null;
	}

	public boolean hasFailureHandler() {
	return this.onfailure != null;
	}

	public boolean hasExceptionHandler() {
	return this.onexception != null;
	}

	public boolean hasCheckSuccessHandler() {
	return this.checkSuccess != null;
	}

	@Override
	public String toString() {
	StringBuilder result = new StringBuilder();
	result.append(toStringBaseName());
	result.append("[");
	boolean contents = false;
	Object source = toStringPollSource();
	AttributeSensor<T> s = getSensor();
	if (Strings.isNonBlank(Strings.toString(source))) {
	if (s!=null) {
	result.append(s.getName());
	result.append(" <- ");
	}
	result.append(Strings.toUniqueString(source, 40));
	contents = true;
	} else if (s!=null) {
	result.append(s.getName());
	contents = true;
	}
	MutableList<Object> fields = toStringOtherFields();
	if (fields!=null) {
	for (Object field: fields) {
	if (Strings.isNonBlank(Strings.toString(field))) {
	if (contents) result.append("; ");
	contents = true;
	result.append(field);
	}
	}
	}
	result.append("]");
	return result.toString();
	}

	/** can be overridden to supply a simpler base name than the class name */
	protected String toStringBaseName() {
	return JavaClassNames.simpleClassName(this);
	}
	/** can be overridden to supply add'l info for the {@link #toString()}; subclasses can add to the returned value */
	protected MutableList<Object> toStringOtherFields() {
	return MutableList.<Object>of();
	}
	/** can be overridden to supply add'l info for the {@link #toString()}, placed before the sensor with -> */
	protected Object toStringPollSource() {
	return null;
	}
	/** all configs should supply a unique tag element, inserted into the feed */
	protected String getUniqueTag() {
	return toString();
	}

	/** returns fields which should be used for equality, including by default {@link #toStringOtherFields()} and {@link #toStringPollSource()};
	* subclasses can add to the returned value */
	protected MutableList<Object> equalsFields() {
	MutableList<Object> result = MutableList.of().appendIfNotNull(getSensor()).appendIfNotNull(toStringPollSource());
	for (Object field: toStringOtherFields()) result.appendIfNotNull(field);
	return result;
	}

	@Override
	public int hashCode() {
	int hc = super.hashCode();
	for (Object f: equalsFields())
	hc = Objects.hashCode(hc, f);
	return hc;
	}

	@Override
	public boolean equals(Object obj) {
	if (this == obj) return true;
	if (!super.equals(obj)) return false;
	PollConfig<?,?,?> other = (PollConfig<?,?,?>) obj;
	if (!Objects.equal(getUniqueTag(), other.getUniqueTag())) return false;
	if (!Objects.equal(equalsFields(), other.equalsFields())) return false;
	return true;
	}
	}