StringByteIterator.java

/**                                                                                                                                                                                
 * Copyright (c) 2010 Yahoo! Inc. All rights reserved.                                                                                                                             
 *                                                                                                                                                                                 
 * 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. See accompanying                                                                                                                 
 * LICENSE file.                                                                                                                                                                   
 */

package com.yahoo.ycsb;

import java.util.Map;
import java.util.HashMap;

public class StringByteIterator extends ByteIterator {
	String str;
	int off;

	/**
	 * Put all of the entries of one map into the other, converting
	 * String values into ByteIterators.
	 */
	public static void putAllAsByteIterators(Map<String, ByteIterator> out, Map<String, String> in) {
	       for(String s: in.keySet()) { out.put(s, new StringByteIterator(in.get(s))); }
	} 

	/**
	 * Put all of the entries of one map into the other, converting
	 * ByteIterator values into Strings.
	 */
	public static void putAllAsStrings(Map<String, String> out, Map<String, ByteIterator> in) {
	       for(String s: in.keySet()) { out.put(s, in.get(s).toString()); }
	} 

	/**
	 * Create a copy of a map, converting the values from Strings to
	 * StringByteIterators.
	 */
	public static HashMap<String, ByteIterator> getByteIteratorMap(Map<String, String> m) {
		HashMap<String, ByteIterator> ret =
			new HashMap<String,ByteIterator>();

		for(String s: m.keySet()) {
			ret.put(s, new StringByteIterator(m.get(s)));
		}
		return ret;
	}

	/**
	 * Create a copy of a map, converting the values from
	 * StringByteIterators to Strings.
	 */
	public static HashMap<String, String> getStringMap(Map<String, ByteIterator> m) {
		HashMap<String, String> ret = new HashMap<String,String>();

		for(String s: m.keySet()) {
			ret.put(s, m.get(s).toString());;
		}
		return ret;
	}

	public StringByteIterator(String s) {
		this.str = s;
		this.off = 0;
	}
	@Override
	public boolean hasNext() {
		return off < str.length();
	}

	@Override
	public byte nextByte() {
		byte ret = (byte)str.charAt(off);
		off++;
		return ret;
	}

	@Override
	public long bytesLeft() {
		return str.length() - off;
	}

	/**
	 * Specialization of general purpose toString() to avoid unnecessary
	 * copies.
	 * <p>
	 * Creating a new StringByteIterator, then calling toString()
	 * yields the original String object, and does not perform any copies
	 * or String conversion operations.
	 * </p>
	 */
	@Override
	public String toString() {
		if(off > 0) {
			return super.toString();
		} else {
			return str;
		}
	}
}