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 com.netflix.hystrix.util.InternMap;

A key to represent a HystrixCommand for monitoring, circuit-breakers, metrics publishing, caching and other such uses. 

This interface is intended to work natively with Enums so that implementing code can be an enum that implements this interface.
/**
 * A key to represent a {@link HystrixCommand} for monitoring, circuit-breakers, metrics publishing, caching and other such uses.
 * <p>
 * This interface is intended to work natively with Enums so that implementing code can be an enum that implements this interface.
 */
public interface HystrixCommandKey extends HystrixKey {
    class Factory {
        private Factory() {
        }

        // used to intern instances so we don't keep re-creating them millions of times for the same key
        private static final InternMap<String, HystrixCommandKeyDefault> intern
                = new InternMap<String, HystrixCommandKeyDefault>(
                new InternMap.ValueConstructor<String, HystrixCommandKeyDefault>() {
                    @Override
                    public HystrixCommandKeyDefault create(String key) {
                        return new HystrixCommandKeyDefault(key);
                    }
                });


        
Retrieve (or create) an interned HystrixCommandKey instance for a given name.
Params:
name – command name
Returns:
HystrixCommandKey instance that is interned (cached) so a given name will always retrieve the same instance./**
         * Retrieve (or create) an interned HystrixCommandKey instance for a given name.
         * 
         * @param name command name
         * @return HystrixCommandKey instance that is interned (cached) so a given name will always retrieve the same instance.
         */
        public static HystrixCommandKey asKey(String name) {
            return intern.interned(name);
        }

        private static class HystrixCommandKeyDefault extends HystrixKey.HystrixKeyDefault implements HystrixCommandKey {
            public HystrixCommandKeyDefault(String name) {
                super(name);
            }
        }

        /* package-private */ static int getCommandCount() {
            return intern.size();
        }
    }

}