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CSV manipulation library.
There is a newer version: 1.2.0
/*
 * #%L
 * Nerd4j CSV
 * %%
 * Copyright (C) 2013 Nerd4j
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as 
 * published by the Free Software Foundation, either version 3 of the 
 * License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Lesser Public License for more details.
 * 
 * You should have received a copy of the GNU General Lesser Public 
 * License along with this program.  If not, see
 * .
 * #L%
 */
package org.nerd4j.csv.parser;

import java.io.IOException;
import java.io.Writer;
import java.util.Arrays;


/**
 * Default implementation for the {@link FieldBuilder} interface.
 * 
 * @author Nerd4j Team
 */
final class FieldBuilderImpl implements FieldBuilder
{
	
	/** Last issued mark position or -1. */
	private int markPos;
	
	/** Last issued mark length. */
	private int markLen;
	
	/** Current valid data length (pointer to next appendable position). */
    protected int length;
    
    /** Character array data. */
    private char[] data;
	
    
    
    /**
     * Default constructor.
     * 
     */
    public FieldBuilderImpl()
    {
        
        this( 16 );
        
    }
    
    /**
     * Constructor with parameters.
     * 
     * @param size initial field builder size.
     */
    public FieldBuilderImpl( int size )
    {
        
        super();
        
        this.clear();
        this.data = new char[ size ];
        
    }
	
	
	/* ******************* */
	/*  INTERFACE METHODS  */
	/* ******************* */
	
    
    /**
     * {@inheritDoc}
     */
    @Override
    public void append( char character )
    {
        
        /*
         * If the array size is not enough to keep all
         * the characters we double the array capacity.
         */
        if( ++length > data.length )
            data = Arrays.copyOf( data, data.length << 1 );
        
        data[length-1] = character;
        
    }
    
    /**
     * {@inheritDoc}
     */
    @Override
    public void append( int character )
    {
        
        /*
         * If the array size is not enough to keep all
         * the characters we double the array capacity.
         */
        if( ++length > data.length )
            data = Arrays.copyOf( data, data.length << 1 );
        
        data[length-1] = (char) character;
        
    }
    
    /**
     * {@inheritDoc}
     */
    @Override
    public void mark()
    {
        
        /*
         * If it is the first mark we set the mark
         * position and length.
         */
        if( markPos < 0 || length > markPos + markLen )
        {
            this.markPos = length;
            this.markLen = 1;
        }
        /*
         * If the mark has been already set we just
         * increment the mark length.
         */
        else
            markLen++;
        
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void rollbackToMark()
    {
        
        /*
         * If the writing length (next char position)
         * is within the mark area (markPos + markLen)
         * then it has to be rolled back to the marked
         * position.
         */
        if( markPos < length && length <= markPos + markLen )
            length = markPos;
        
        markLen =  0;
        markPos = -1;
        
    }
    
    /**
     * {@inheritDoc}
     */
    @Override
    public int getMarkedPosition()
    {
        
        if( markPos > -1 && length > markPos + markLen )
        {
            markLen =  0;
            markPos = -1;
        }
        
        return markPos;
        
    }
	
	/**
     * {@inheritDoc}
     */
    @Override
    public int length()
    {
        
        return length;
        
    }
	
	/**
	 * {@inheritDoc}
	 * 
	 * Handles mark clearings, implementations should handle their resource
	 * clearing too.
	 * 
	 */
	@Override
	public void clear()
	{
		
	    this.length = 0;
	    this.markLen = 0;
	    this.markPos = -1;
		
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public String toString()
	{
		
		return length <= 0 ? null : new String( data, 0, length );
		
	}
	
	@Override
    public String toString( int offset, int length )
    {

        throw new UnsupportedOperationException();
        
    }
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	public void writeTo( Writer writer ) throws IOException
	{
		
		if( length > 0 )
		    writer.write( data, 0, length );
		
	}
	
	/**
     * {@inheritDoc}
     */
    @Override
    public void writeTo( Writer writer, int offset, int length ) throws IOException
    {
        
        throw new UnsupportedOperationException();
        
    }
	
}