content: /*
   *   Copyright 2009 Joubin Houshyar
   * 
   *   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 org.jredis.ri.alphazero.semantics;
  
  import java.io.UnsupportedEncodingException;
  import java.lang.reflect.UndeclaredThrowableException;
  import java.util.Map;
  import java.util.concurrent.ConcurrentHashMap;
  
  import org.jredis.NotSupportedException;
  import org.jredis.ri.alphazero.JRedisSupport;
  import org.jredis.ri.alphazero.support.DefaultCodec;
  import org.jredis.semantics.KeyCodec;
  
  /**
   * Default {@link KeyCodec} provider for JRedis RI.
   * 
   * @author  Joubin Houshyar (alphazero@sensesay.net)
   * @version alpha.0, Nov 25, 2009
   * @since   alpha.0
   * 
   */
  
  public class DefaultKeyCodec<K extends Object> implements KeyCodec<K> {
  	private static final KeyCodec<Object> instance;
  	static {
  		instance = new DefaultKeyCodec<Object>();
  	}
  	/**  */
  	static final private Map<String, byte[]>	keyByteCache = new ConcurrentHashMap<String, byte[]>();
  	
  	public static final KeyCodec<Object> provider() { return instance; }
  	
  	/** TODO: jvm arg me ... defaults to FALSE now */
  	public static final boolean	CacheKeys	= false;
  
  	/* (non-Javadoc)
  	 * @see org.jredis.Codec#decode(byte[])
  	 */
  	public K decode (byte[] bytes) { throw new NotSupportedException("key decode not supported."); }
  
  	/* (non-Javadoc)
  	 * @see org.jredis.Codec#encode(java.lang.Object)
  	 */
  	public byte[] encode (K key) {
  		if(null == key) throw new IllegalArgumentException("key is null");
  		if(key instanceof String) {
  			return encodeString((String) key);
  		}
  		else if (key instanceof byte[]){
  			byte[] bkey = (byte[]) key ;
  			if(bkey.length == 0) throw new IllegalArgumentException("key is zerolewn");
  			return bkey;
  		}
  		else {
  			String msg = String.format("only String and byte[] keys are supported", key.getClass().getCanonicalName());
  			throw new IllegalArgumentException(msg);
  		}
  	}
  	public static byte[] encodeString(String key) throws IllegalArgumentException {
  		if(null == key) throw new IllegalArgumentException("key is null");
  		byte[] bytes = null;
  		if(JRedisSupport.CacheKeys == true)
  			bytes = keyByteCache.get(key);
  		if(null == bytes) {
  //			bytes = key.getBytes(DefaultCodec.SUPPORTED_CHARSET); // java 1.6
  			try {
  	            bytes = key.getBytes(DefaultCodec.SUPPORTED_CHARSET_NAME);
              }
              catch (UnsupportedEncodingException e) {
  	            throw new UndeclaredThrowableException(e);
              }
  			for(byte b : bytes) {
  				if (b == (byte)32 || b == (byte)10 || b == (byte)13)
  					throw new IllegalArgumentException ("Key includes invalid byte value: " + (int)b);
  			}
  			
  			if(JRedisSupport.CacheKeys == true)
  				keyByteCache.put(key, bytes);
  		}
  		return bytes;
  	}
  
  	/* (non-Javadoc)
  	 * @see org.jredis.Codec#supports(java.lang.Class)
  	 */
  	static byte[] ba = new byte[0];
  	static Class<?> BAClass = ba.getClass();
  	public boolean supports (Class<?> type) { 
  		return type == String.class || type.equals(BAClass); 
  	}
  }
  