decode

Author: Baunsgaard

src/main/java/org/apache/sysds/runtime/transform/decode/DecoderDummycode.java

@@ -34,142 +34,151 @@
 import org.apache.sysds.runtime.util.UtilFunctions;
 
 /**
- * Simple atomic decoder for dummycoded columns. This decoder builds internally
- * inverted column mappings from the given frame meta data. 
- *  
+ * Simple atomic decoder for dummycoded columns. This decoder builds internally inverted column mappings from the given
+ * frame meta data.
+ * 
  */
-public class DecoderDummycode extends Decoder
-{
+public class DecoderDummycode extends Decoder {
 	private static final long serialVersionUID = 4758831042891032129L;
-	
+
 	private int[] _clPos = null;
 	private int[] _cuPos = null;
-	
+
 	protected DecoderDummycode(ValueType[] schema, int[] dcCols) {
-		//dcCols refers to column IDs in output (non-dc)
+		// dcCols refers to column IDs in output (non-dc)
 		super(schema, dcCols);
 	}
 
 	@Override
 	public FrameBlock decode(MatrixBlock in, FrameBlock out) {
-		//TODO perf (exploit sparse representation for better asymptotic behavior)
 		out.ensureAllocatedColumns(in.getNumRows());
 		decode(in, out, 0, in.getNumRows());
 		return out;
 	}
 
 	@Override
 	public void decode(MatrixBlock in, FrameBlock out, int rl, int ru) {
-		if(in.isInSparseFormat()) {
-			SparseBlock sb = in.getSparseBlock();
-			for(int i = rl; i < ru; i++) {
-				if(!sb.isEmpty(i)) {
-					int apos = sb.pos(i);
-					int alen = sb.size(i) + apos;
-					int[] aix = sb.indexes(i);
-					// double[] val = sb.values(i); always 1... therefore not needed
-					int h = 0;
-					for(int j = 0; j < _colList.length && h < alen; j++) {
-						// find k, the index in aix, within the range of low and high
-						int low = _clPos[j];
-						int high = _cuPos[j];
-						while(h < alen && aix[h] < low) {
-							h++;
-						}
-						if(h < alen && aix[h] >= low && aix[h] < high) {
-							int k = aix[h];
-							int col = _colList[j] - 1;
-							out.getColumn(col).set(i, k - _clPos[j] + 1);
-						}
-						while(h < alen && aix[h] < high) {
-							h++;
-						}
+		if(in.isInSparseFormat())
+			decodeSparse(in, out, rl, ru);
+		else
+			decodeDense(in, out, rl, ru);
+	}
+
+	private void decodeDense(MatrixBlock in, FrameBlock out, int rl, int ru) {
+		for(int i = rl; i < ru; i++)
+			for(int j = 0; j < _colList.length; j++)
+				for(int k = _clPos[j]; k < _cuPos[j]; k++)
+					if(in.get(i, k - 1) != 0) {
+						int col = _colList[j] - 1;
+						out.getColumn(col).set(i, k - _clPos[j] + 1);
+						// if the non zero is found, we can skip the rest of k.
+						continue;
 					}
+	}
+
+	private void decodeSparse(MatrixBlock in, FrameBlock out, int rl, int ru) {
+		final SparseBlock sb = in.getSparseBlock();
+		for(int i = rl; i < ru; i++) {
+			decodeSparseRow(out, sb, i);
+		}
+	}
+
+	private void decodeSparseRow(FrameBlock out, final SparseBlock sb, int i) {
+		if(!sb.isEmpty(i)) {
+			final int apos = sb.pos(i);
+			final int alen = sb.size(i) + apos;
+			final int[] aix = sb.indexes(i);
+			// double[] val = sb.values(i); always 1... therefore not needed
+			int h = 0;
+			for(int j = 0; j < _colList.length && h < alen; j++) { // for each decode column.
+				// find k, the index in aix, within the range of low and high
+				int low = _clPos[j];
+				int high = _cuPos[j];
+				while(h < alen && aix[h] < low) {
+					h++;
+				}
+				if(h < alen && aix[h] >= low && aix[h] < high) {
+					int k = aix[h];
+					int col = _colList[j] - 1;
+					out.getColumn(col).set(i, k - _clPos[j] + 1);
+					h++;
+				}
+				while(h < alen && aix[h] < high) {
+					h++;
 				}
 			}
 		}
-		else {
-			for(int i = rl; i < ru; i++)
-				for(int j = 0; j < _colList.length; j++)
-					for(int k = _clPos[j]; k < _cuPos[j]; k++)
-						if(in.get(i, k - 1) != 0) {
-							int col = _colList[j] - 1;
-							out.getColumn(col).set(i, k - _clPos[j] + 1);
-							// if the non zero is found, we can skip the rest of k.
-							continue;
-						}
-		}
 	}
 
 	@Override
 	public Decoder subRangeDecoder(int colStart, int colEnd, int dummycodedOffset) {
 		List<Integer> dcList = new ArrayList<>();
 		List<Integer> clPosList = new ArrayList<>();
 		List<Integer> cuPosList = new ArrayList<>();
-		
+
 		// get the column IDs for the sub range of the dummycode columns and their destination positions,
 		// where they will be decoded to
-		for( int j=0; j<_colList.length; j++ ) {
+		for(int j = 0; j < _colList.length; j++) {
 			int colID = _colList[j];
-			if (colID >= colStart && colID < colEnd) {
+			if(colID >= colStart && colID < colEnd) {
 				dcList.add(colID - (colStart - 1));
 				clPosList.add(_clPos[j] - dummycodedOffset);
 				cuPosList.add(_cuPos[j] - dummycodedOffset);
 			}
 		}
-		if (dcList.isEmpty())
+		if(dcList.isEmpty())
 			return null;
 		// create sub-range decoder
 		int[] colList = dcList.stream().mapToInt(i -> i).toArray();
-		DecoderDummycode subRangeDecoder = new DecoderDummycode(
-			Arrays.copyOfRange(_schema, colStart - 1, colEnd - 1), colList);
+		DecoderDummycode subRangeDecoder = new DecoderDummycode(Arrays.copyOfRange(_schema, colStart - 1, colEnd - 1),
+			colList);
 		subRangeDecoder._clPos = clPosList.stream().mapToInt(i -> i).toArray();
 		subRangeDecoder._cuPos = cuPosList.stream().mapToInt(i -> i).toArray();
 		return subRangeDecoder;
 	}
-	
+
 	@Override
 	public void updateIndexRanges(long[] beginDims, long[] endDims) {
 		if(_colList == null)
 			return;
-		
+
 		long lowerColDest = beginDims[1];
 		long upperColDest = endDims[1];
 		for(int i = 0; i < _colList.length; i++) {
 			long numDistinct = _cuPos[i] - _clPos[i];
-			
+
 			if(_cuPos[i] <= beginDims[1] + 1)
 				if(numDistinct > 0)
 					lowerColDest -= numDistinct - 1;
-			
+
 			if(_cuPos[i] <= endDims[1] + 1)
 				if(numDistinct > 0)
 					upperColDest -= numDistinct - 1;
 		}
 		beginDims[1] = lowerColDest;
 		endDims[1] = upperColDest;
 	}
-	
+
 	@Override
 	public void initMetaData(FrameBlock meta) {
-		_clPos = new int[_colList.length]; //col lower pos 
-		_cuPos = new int[_colList.length]; //col upper pos 
-		for( int j=0, off=0; j<_colList.length; j++ ) {
+		_clPos = new int[_colList.length]; // col lower pos
+		_cuPos = new int[_colList.length]; // col upper pos
+		for(int j = 0, off = 0; j < _colList.length; j++) {
 			int colID = _colList[j];
-			ColumnMetadata d = meta.getColumnMetadata()[colID-1];
-			String v = meta.getString(0, colID-1);
+			ColumnMetadata d = meta.getColumnMetadata()[colID - 1];
+			String v = meta.getString(0, colID - 1);
 			int ndist;
-			if(v.length() > 1 && v.charAt(0) == '¿'){
+			if(v.length() > 1 && v.charAt(0) == '¿') {
 				ndist = UtilFunctions.parseToInt(v.substring(1));
 			}
 			else {
-				ndist = d.isDefault() ? 0 : (int)d.getNumDistinct() ;
+				ndist = d.isDefault() ? 0 : (int) d.getNumDistinct();
 			}
 
-			ndist = ndist < -1 ? 0: ndist; // safety if all values was null.
-			
+			ndist = ndist < -1 ? 0 : ndist; // safety if all values was null.
+
 			_clPos[j] = off + colID;
-			_cuPos[j] = _clPos[j] + ndist ;
+			_cuPos[j] = _clPos[j] + ndist;
 			off += ndist - 1;
 		}
 	}