api/src/main/java/com/datatorrent/api/Attribute.java - apex-core - Git at Google

 /**
  * Copyright (C) 2015 DataTorrent, 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.datatorrent.api;

 import java.io.Serializable;
 import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;

 import com.datatorrent.api.StringCodec.Boolean2String;
 import com.datatorrent.api.StringCodec.Enum2String;
 import com.datatorrent.api.StringCodec.Integer2String;
 import com.datatorrent.api.StringCodec.Long2String;
 import com.datatorrent.api.StringCodec.String2String;

 import com.datatorrent.netlet.util.DTThrowable;

 /**
  * Attribute represents the attribute which can be set on various components in the system.
  *
  * @param <T> type of the value which can be stored against the attribute.
  * @since 2.0.0
  */
 public class Attribute<T> implements Serializable
 {
   public final T defaultValue;
   public final String name;
   public final StringCodec<T> codec;

   public Attribute(StringCodec<T> codec)
   {
     this(null, null, codec);
   }

   public Attribute(T defaultValue)
   {
     this(null, defaultValue, null);
   }

   public Attribute(T defaultValue, StringCodec<T> codec)
   {
     this(null, defaultValue, codec);
   }

   private Attribute(String name, T defaultValue, StringCodec<T> codec)
   {
     this.name = name;
     this.defaultValue = defaultValue;
     this.codec = codec;
   }

   @Override
   public int hashCode()
   {
     return name.hashCode();
   }

   @Override
   public boolean equals(Object obj)
   {
     if (obj == null) {
       return false;
     }
     if (getClass() != obj.getClass()) {
       return false;
     }
     @SuppressWarnings(value = "unchecked")
     final Attribute<T> other = (Attribute<T>)obj;
     return !((this.name == null) ? (other.name != null) : !this.name.equals(other.name));
   }

   public String getName()
   {
     return "attr" + name.substring(name.lastIndexOf('.'));
   }

   public String getSimpleName()
   {
     return name.substring(name.lastIndexOf('.') + 1);
   }

   @Override
   public String toString()
   {
     return "Attribute{" + "defaultValue=" + defaultValue + ", name=" + name + ", codec=" + codec + '}';
   }

   private static final long serialVersionUID = 201310111904L;

   /**
    * Parameterized and scoped context attribute map that supports serialization.
    * Derived from io.netty.util.AttributeMap
    *
    * @since 0.3.2
    */
   public static interface AttributeMap extends Cloneable
   {
     /**
      * Return the attribute value for the given key. If the map does not have an
      * entry for the key, null is returned.
      *
      * @param <T>
      * @param key
      * @return AttributeValue
      */
     <T> T get(Attribute<T> key);

     /**
      * Return true if value for an attribute is set. It returns false if the
      * value for the attribute was never set.
      *
      * @param key attribute key
      * @return true if the value for the attribute was set, false otherwise.
      */
     boolean contains(Attribute<?> key);

     /**
      * Assign value for a particular attributes.
      *
      * @param <T>   Type of the value
      * @param key   Attribute which is being assigned the value
      * @param value Value which is being assigned.
      * @return Previous value against the attribute or null if it was not assigned.
      */
     <T> T put(Attribute<T> key, T value);

     Set<Map.Entry<Attribute<?>, Object>> entrySet();

     /**
      * Clone the current map.
      * @return a shallow copy of this AtrributeMap.
      * @throws java.lang.CloneNotSupportedException
      */
     AttributeMap clone() throws CloneNotSupportedException;

     /**
      * DefaultAttributeMap is the default implementation of AttributeMap. It's backed by a map internally.
      */
     public static class DefaultAttributeMap implements AttributeMap, Serializable
     {
       private HashMap<Attribute<?>, Object> map;

       public DefaultAttributeMap()
       {
         this(new HashMap<Attribute<?>, Object>());
       }

       private DefaultAttributeMap(HashMap<Attribute<?>, Object> map)
       {
         super();
         this.map = map;
       }

       @Override
       @SuppressWarnings(value = "unchecked")
       public <T> T get(Attribute<T> key)
       {
         return (T)map.get(key);
       }

       @Override
       public String toString()
       {
         return this.map.toString();
       }

       @Override
       @SuppressWarnings("unchecked")
       public DefaultAttributeMap clone() throws CloneNotSupportedException
       {
         DefaultAttributeMap clone = (DefaultAttributeMap)super.clone();
         clone.map = (HashMap< Attribute< ?>, Object>)map.clone();
         return clone;
       }

       @Override
       @SuppressWarnings(value = "unchecked")
       public <T> T put(Attribute<T> key, T value)
       {
         return (T)map.put(key, value);
       }

       @Override
       public Set<Entry<Attribute<?>, Object>> entrySet()
       {
         return map.entrySet();
       }

       @Override
       public boolean equals(Object o)
       {
         if (this == o) {
           return true;
         }
         if (!(o instanceof DefaultAttributeMap)) {
           return false;
         }
         DefaultAttributeMap that = (DefaultAttributeMap)o;
         return !(map != null ? !map.equals(that.map) : that.map != null);
       }

       @Override
       public int hashCode()
       {
         return map != null ? map.hashCode() : 0;
       }

       @Override
       public boolean contains(Attribute<?> key)
       {
         return map.containsKey(key);
       }

       private static final long serialVersionUID = 201306051022L;
     }

     /**
      * This class inspects and initializes the attributes with their field names so that they can be used
      * from properties files.
      *
      * Engine uses it internally to initialize the Interfaces that may have Attributes defined in them.
      */
     public static class AttributeInitializer
     {
       static final HashMap<Class<?>, Set<Attribute<Object>>> map = new HashMap<Class<?>, Set<Attribute<Object>>>();

       public static Map<Attribute<Object>, Object> getAllAttributes(Context context, Class<?> clazz)
       {
         Map<Attribute<Object>, Object> result = new HashMap<Attribute<Object>, Object>();
         try {
           for (Field f: clazz.getDeclaredFields()) {
             if (Modifier.isStatic(f.getModifiers()) && Attribute.class.isAssignableFrom(f.getType())) {
               @SuppressWarnings(value = "unchecked")
               Attribute<Object> attribute = (Attribute<Object>)f.get(null);
               result.put(attribute, context.getValue(attribute));
             }
           }
         }
         catch (Exception ex) {
           DTThrowable.rethrow(ex);
         }
         return result;
       }

       public static Set<Attribute<Object>> getAttributes(Class<?> clazz)
       {
         return map.get(clazz);
       }

       /**
        * Initialize the static attributes defined in the class.
        *
        * @param clazz class whose static attributes need to be initialized.
        * @return 0 if the clazz was already initialized, identity hash code of the clazz otherwise.
        */
       /* both for Enum2String */
       @SuppressWarnings(value = {"unchecked", "rawtypes"})
       public static long initialize(final Class<?> clazz)
       {
         if (map.containsKey(clazz)) {
           return 0;
         }
         Set<Attribute<Object>> set = new HashSet<Attribute<Object>>();
         try {
           for (Field f: clazz.getDeclaredFields()) {
             if (Modifier.isStatic(f.getModifiers()) && Attribute.class.isAssignableFrom(f.getType())) {
               Attribute<Object> attribute = (Attribute<Object>)f.get(null);
               if (attribute.name == null) {
                 Field nameField = Attribute.class.getDeclaredField("name");
                 nameField.setAccessible(true);
                 nameField.set(attribute, clazz.getCanonicalName() + '.' + f.getName());
                 nameField.setAccessible(false);
               }
               /* Handle trivial cases here even though this may spoil API users. */
               if (attribute.codec == null) {
                 StringCodec<?> codec = null;
                 if (attribute.defaultValue != null) {
                   Class<?> klass = attribute.defaultValue.getClass();
                   if (klass == String.class) {
                     codec = new String2String();
                   }
                   else if (klass == Integer.class) {
                     codec = new Integer2String();
                   }
                   else if (klass == Long.class) {
                     codec = new Long2String();
                   }
                   else if (klass == Boolean.class) {
                     codec = new Boolean2String();
                   }
                   else if (Enum.class.isAssignableFrom(klass)) {
                     codec = new Enum2String(klass);
                   }
                 }
                 if (codec != null) {
                   Field codecField = Attribute.class.getDeclaredField("codec");
                   codecField.setAccessible(true);
                   codecField.set(attribute, codec);
                   codecField.setAccessible(false);
                 }
               }
               set.add(attribute);
             }
           }
         }
         catch (Exception ex) {
           DTThrowable.rethrow(ex);
         }
         map.put(clazz, set);
         return (long)clazz.getModifiers() << 32 | clazz.hashCode();
       }

     }

   }

 }
	/**
	* Copyright (C) 2015 DataTorrent, 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.datatorrent.api;

	import java.io.Serializable;
	import java.lang.reflect.Field;
	import java.lang.reflect.Modifier;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.Map;
	import java.util.Map.Entry;
	import java.util.Set;

	import com.datatorrent.api.StringCodec.Boolean2String;
	import com.datatorrent.api.StringCodec.Enum2String;
	import com.datatorrent.api.StringCodec.Integer2String;
	import com.datatorrent.api.StringCodec.Long2String;
	import com.datatorrent.api.StringCodec.String2String;

	import com.datatorrent.netlet.util.DTThrowable;

	/**
	* Attribute represents the attribute which can be set on various components in the system.
	*
	* @param <T> type of the value which can be stored against the attribute.
	* @since 2.0.0
	*/
	public class Attribute<T> implements Serializable
	{
	public final T defaultValue;
	public final String name;
	public final StringCodec<T> codec;

	public Attribute(StringCodec<T> codec)
	{
	this(null, null, codec);
	}

	public Attribute(T defaultValue)
	{
	this(null, defaultValue, null);
	}

	public Attribute(T defaultValue, StringCodec<T> codec)
	{
	this(null, defaultValue, codec);
	}

	private Attribute(String name, T defaultValue, StringCodec<T> codec)
	{
	this.name = name;
	this.defaultValue = defaultValue;
	this.codec = codec;
	}

	@Override
	public int hashCode()
	{
	return name.hashCode();
	}

	@Override
	public boolean equals(Object obj)
	{
	if (obj == null) {
	return false;
	}
	if (getClass() != obj.getClass()) {
	return false;
	}
	@SuppressWarnings(value = "unchecked")
	final Attribute<T> other = (Attribute<T>)obj;
	return !((this.name == null) ? (other.name != null) : !this.name.equals(other.name));
	}

	public String getName()
	{
	return "attr" + name.substring(name.lastIndexOf('.'));
	}

	public String getSimpleName()
	{
	return name.substring(name.lastIndexOf('.') + 1);
	}

	@Override
	public String toString()
	{
	return "Attribute{" + "defaultValue=" + defaultValue + ", name=" + name + ", codec=" + codec + '}';
	}

	private static final long serialVersionUID = 201310111904L;

	/**
	* Parameterized and scoped context attribute map that supports serialization.
	* Derived from io.netty.util.AttributeMap
	*
	* @since 0.3.2
	*/
	public static interface AttributeMap extends Cloneable
	{
	/**
	* Return the attribute value for the given key. If the map does not have an
	* entry for the key, null is returned.
	*
	* @param <T>
	* @param key
	* @return AttributeValue
	*/
	<T> T get(Attribute<T> key);

	/**
	* Return true if value for an attribute is set. It returns false if the
	* value for the attribute was never set.
	*
	* @param key attribute key
	* @return true if the value for the attribute was set, false otherwise.
	*/
	boolean contains(Attribute<?> key);

	/**
	* Assign value for a particular attributes.
	*
	* @param <T> Type of the value
	* @param key Attribute which is being assigned the value
	* @param value Value which is being assigned.
	* @return Previous value against the attribute or null if it was not assigned.
	*/
	<T> T put(Attribute<T> key, T value);

	Set<Map.Entry<Attribute<?>, Object>> entrySet();

	/**
	* Clone the current map.
	* @return a shallow copy of this AtrributeMap.
	* @throws java.lang.CloneNotSupportedException
	*/
	AttributeMap clone() throws CloneNotSupportedException;

	/**
	* DefaultAttributeMap is the default implementation of AttributeMap. It's backed by a map internally.
	*/
	public static class DefaultAttributeMap implements AttributeMap, Serializable
	{
	private HashMap<Attribute<?>, Object> map;

	public DefaultAttributeMap()
	{
	this(new HashMap<Attribute<?>, Object>());
	}

	private DefaultAttributeMap(HashMap<Attribute<?>, Object> map)
	{
	super();
	this.map = map;
	}

	@Override
	@SuppressWarnings(value = "unchecked")
	public <T> T get(Attribute<T> key)
	{
	return (T)map.get(key);
	}

	@Override
	public String toString()
	{
	return this.map.toString();
	}

	@Override
	@SuppressWarnings("unchecked")
	public DefaultAttributeMap clone() throws CloneNotSupportedException
	{
	DefaultAttributeMap clone = (DefaultAttributeMap)super.clone();
	clone.map = (HashMap< Attribute< ?>, Object>)map.clone();
	return clone;
	}

	@Override
	@SuppressWarnings(value = "unchecked")
	public <T> T put(Attribute<T> key, T value)
	{
	return (T)map.put(key, value);
	}

	@Override
	public Set<Entry<Attribute<?>, Object>> entrySet()
	{
	return map.entrySet();
	}

	@Override
	public boolean equals(Object o)
	{
	if (this == o) {
	return true;
	}
	if (!(o instanceof DefaultAttributeMap)) {
	return false;
	}
	DefaultAttributeMap that = (DefaultAttributeMap)o;
	return !(map != null ? !map.equals(that.map) : that.map != null);
	}

	@Override
	public int hashCode()
	{
	return map != null ? map.hashCode() : 0;
	}

	@Override
	public boolean contains(Attribute<?> key)
	{
	return map.containsKey(key);
	}

	private static final long serialVersionUID = 201306051022L;
	}

	/**
	* This class inspects and initializes the attributes with their field names so that they can be used
	* from properties files.
	*
	* Engine uses it internally to initialize the Interfaces that may have Attributes defined in them.
	*/
	public static class AttributeInitializer
	{
	static final HashMap<Class<?>, Set<Attribute<Object>>> map = new HashMap<Class<?>, Set<Attribute<Object>>>();

	public static Map<Attribute<Object>, Object> getAllAttributes(Context context, Class<?> clazz)
	{
	Map<Attribute<Object>, Object> result = new HashMap<Attribute<Object>, Object>();
	try {
	for (Field f: clazz.getDeclaredFields()) {
	if (Modifier.isStatic(f.getModifiers()) && Attribute.class.isAssignableFrom(f.getType())) {
	@SuppressWarnings(value = "unchecked")
	Attribute<Object> attribute = (Attribute<Object>)f.get(null);
	result.put(attribute, context.getValue(attribute));
	}
	}
	}
	catch (Exception ex) {
	DTThrowable.rethrow(ex);
	}
	return result;
	}

	public static Set<Attribute<Object>> getAttributes(Class<?> clazz)
	{
	return map.get(clazz);
	}

	/**
	* Initialize the static attributes defined in the class.
	*
	* @param clazz class whose static attributes need to be initialized.
	* @return 0 if the clazz was already initialized, identity hash code of the clazz otherwise.
	*/
	/* both for Enum2String */
	@SuppressWarnings(value = {"unchecked", "rawtypes"})
	public static long initialize(final Class<?> clazz)
	{
	if (map.containsKey(clazz)) {
	return 0;
	}
	Set<Attribute<Object>> set = new HashSet<Attribute<Object>>();
	try {
	for (Field f: clazz.getDeclaredFields()) {
	if (Modifier.isStatic(f.getModifiers()) && Attribute.class.isAssignableFrom(f.getType())) {
	Attribute<Object> attribute = (Attribute<Object>)f.get(null);
	if (attribute.name == null) {
	Field nameField = Attribute.class.getDeclaredField("name");
	nameField.setAccessible(true);
	nameField.set(attribute, clazz.getCanonicalName() + '.' + f.getName());
	nameField.setAccessible(false);
	}
	/* Handle trivial cases here even though this may spoil API users. */
	if (attribute.codec == null) {
	StringCodec<?> codec = null;
	if (attribute.defaultValue != null) {
	Class<?> klass = attribute.defaultValue.getClass();
	if (klass == String.class) {
	codec = new String2String();
	}
	else if (klass == Integer.class) {
	codec = new Integer2String();
	}
	else if (klass == Long.class) {
	codec = new Long2String();
	}
	else if (klass == Boolean.class) {
	codec = new Boolean2String();
	}
	else if (Enum.class.isAssignableFrom(klass)) {
	codec = new Enum2String(klass);
	}
	}
	if (codec != null) {
	Field codecField = Attribute.class.getDeclaredField("codec");
	codecField.setAccessible(true);
	codecField.set(attribute, codec);
	codecField.setAccessible(false);
	}
	}
	set.add(attribute);
	}
	}
	}
	catch (Exception ex) {
	DTThrowable.rethrow(ex);
	}
	map.put(clazz, set);
	return (long)clazz.getModifiers() << 32 \| clazz.hashCode();
	}

	}

	}

	}