src/main/java/org/apache/sysds/runtime/transform/encode/EncoderOmit.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.sysds.runtime.transform.encode;

import org.apache.wink.json4j.JSONException;
import org.apache.wink.json4j.JSONObject;
import org.apache.sysds.runtime.matrix.data.FrameBlock;
import org.apache.sysds.runtime.matrix.data.MatrixBlock;
import org.apache.sysds.runtime.transform.TfUtils;
import org.apache.sysds.runtime.transform.TfUtils.TfMethod;
import org.apache.sysds.runtime.transform.meta.TfMetaUtils;
import org.apache.sysds.runtime.util.UtilFunctions;

public class EncoderOmit extends Encoder 
{	
	private static final long serialVersionUID = 1978852120416654195L;

	private int _rmRows = 0;

	public EncoderOmit(JSONObject parsedSpec, String[] colnames, int clen) 
		throws JSONException 
	{
		super(null, clen);
		if (!parsedSpec.containsKey(TfMethod.OMIT.toString()))
			return;
		int[] collist = TfMetaUtils.parseJsonIDList(parsedSpec, colnames, TfMethod.OMIT.toString());
		initColList(collist);
	}
	
	public int getNumRemovedRows() {
		return _rmRows;
	}
	
	public boolean omit(String[] words, TfUtils agents) 
	{
		if( !isApplicable() )
			return false;
		
		for(int i=0; i<_colList.length; i++) {
			int colID = _colList[i];
			if(TfUtils.isNA(agents.getNAStrings(),UtilFunctions.unquote(words[colID-1].trim())))
				return true;
		}
		return false;
	}

	@Override
	public MatrixBlock encode(FrameBlock in, MatrixBlock out) {
		return apply(in, out);
	}
	
	@Override
	public void build(FrameBlock in) {	
		//do nothing
	}
	
	@Override
	public MatrixBlock apply(FrameBlock in, MatrixBlock out) 
	{
		//determine output size
		int numRows = 0;
		for(int i=0; i<out.getNumRows(); i++) {
			boolean valid = true;
			for(int j=0; j<_colList.length; j++)
				valid &= !Double.isNaN(out.quickGetValue(i, _colList[j]-1));
			numRows += valid ? 1 : 0;
		}
		
		//copy over valid rows into the output
		MatrixBlock ret = new MatrixBlock(numRows, out.getNumColumns(), false);
		int pos = 0;
		for(int i=0; i<in.getNumRows(); i++) {
			//determine if valid row or omit
			boolean valid = true;
			for(int j=0; j<_colList.length; j++)
				valid &= !Double.isNaN(out.quickGetValue(i, _colList[j]-1));
			//copy row if necessary
			if( valid ) {
				for(int j=0; j<out.getNumColumns(); j++)
					ret.quickSetValue(pos, j, out.quickGetValue(i, j));
				pos++;
			}
		}
	
		//keep info an remove rows
		_rmRows = out.getNumRows() - pos;
		
		return ret; 
	}

	@Override
	public FrameBlock getMetaData(FrameBlock out) {
		//do nothing
		return out;
	}
	
	@Override
	public void initMetaData(FrameBlock meta) {
		//do nothing
	}
}