From 133a217190bf2ca16279f35ce8ed20819fe33fd1 Mon Sep 17 00:00:00 2001
From: Sebastian Baunsgaard <baunsgaard@apache.org>
Date: Mon, 21 Oct 2024 14:12:49 +0200
Subject: [PATCH] fast parse

---
 .../sysds/runtime/io/FrameReaderTextCSV.java  | 44 +++++++++++++------
 .../sysds/runtime/io/IOUtilFunctions.java     |  2 +-
 2 files changed, 31 insertions(+), 15 deletions(-)

diff --git a/src/main/java/org/apache/sysds/runtime/io/FrameReaderTextCSV.java b/src/main/java/org/apache/sysds/runtime/io/FrameReaderTextCSV.java
index 400b2aced90..c531c54855b 100644
--- a/src/main/java/org/apache/sysds/runtime/io/FrameReaderTextCSV.java
+++ b/src/main/java/org/apache/sysds/runtime/io/FrameReaderTextCSV.java
@@ -168,6 +168,19 @@ private void parseLine(String cellStr, String delim, Array<?>[] destA , int row,
 		 int clen,  double dfillValue, String sfillValue, boolean isFill,
 		Set<String> naValues) {
 			try{
+				int from = 0, to = 0; 
+				final int len = cellStr.length();
+				final int delimLen = delim.length();
+				int c = 0;
+				while(from < len) { // for all tokens
+					to = IOUtilFunctions.getTo(cellStr, from, delim, len, delimLen);
+					String cell =  cellStr.substring(from, to);
+					assignCellGeneric(row, destA, cell, naValues, isFill, dfillValue, sfillValue, false, c);
+					c++;
+					from = to + delimLen;
+				}
+
+
 				String[] parts = IOUtilFunctions.splitCSV(cellStr, delim, clen);
 				assignColumns(row, (int)clen, destA, parts, naValues, isFill, dfillValue, sfillValue);
 				IOUtilFunctions.checkAndRaiseErrorCSVNumColumns("", cellStr, parts, clen);
@@ -189,15 +202,23 @@ private boolean assignColumnsGeneric(int row, int nCol,  Array<?>[] destA, Strin
 		boolean isFill, double dfillValue, String sfillValue) {
 		boolean emptyValuesFound = false;
 		for(int col = 0; col < nCol; col++) {
-			emptyValuesFound = assignCellGeneric(row, destA, parts, naValues, isFill, dfillValue, sfillValue, emptyValuesFound, col);
+			emptyValuesFound = assignCellGeneric(row, destA, parts[col], naValues, isFill, dfillValue, sfillValue, emptyValuesFound, col);
 		}
+		return emptyValuesFound;
+	}
 
+	private boolean assignColumnsNoFillNoNan(int row, int nCol, Array<?>[] destA, String[] parts){
+		boolean emptyValuesFound = false;
+		for(int col = 0; col < nCol; col++) {
+			emptyValuesFound = assignCellNoNan(row, destA, parts[col], emptyValuesFound, col);
+		}
 		return emptyValuesFound;
 	}
 
-	private boolean assignCellGeneric(int row, Array<?>[] destA, String[] parts, Set<String> naValues, boolean isFill,
+
+	private static boolean assignCellGeneric(int row, Array<?>[] destA, String val, Set<String> naValues, boolean isFill,
 		double dfillValue, String sfillValue, boolean emptyValuesFound, int col) {
-		String part = IOUtilFunctions.trim(parts[col]);
+		String part = IOUtilFunctions.trim(val);
 		if(part == null || part.isEmpty() || (naValues != null && naValues.contains(part))) {
 			if(isFill && dfillValue != 0)
 				destA[col].set(row, sfillValue);
@@ -208,17 +229,12 @@ private boolean assignCellGeneric(int row, Array<?>[] destA, String[] parts, Set
 		return emptyValuesFound;
 	}
 
-	private boolean assignColumnsNoFillNoNan(int row, int nCol, Array<?>[] destA, String[] parts){
-		
-		boolean emptyValuesFound = false;
-		for(int col = 0; col < nCol; col++) {
-			String part = IOUtilFunctions.trim(parts[col]);
-			if(part.isEmpty()) 
-				emptyValuesFound = true;
-			else
-				destA[col].set(row, part);
-		}
-
+	private static boolean assignCellNoNan(int row, Array<?>[] destA, String val, boolean emptyValuesFound, int col) {
+		String part = IOUtilFunctions.trim(val);
+		if(part.isEmpty()) 
+			emptyValuesFound = true;
+		else
+			destA[col].set(row, part);
 		return emptyValuesFound;
 	}
 
diff --git a/src/main/java/org/apache/sysds/runtime/io/IOUtilFunctions.java b/src/main/java/org/apache/sysds/runtime/io/IOUtilFunctions.java
index 0feb5f484df..4cd9f24a419 100644
--- a/src/main/java/org/apache/sysds/runtime/io/IOUtilFunctions.java
+++ b/src/main/java/org/apache/sysds/runtime/io/IOUtilFunctions.java
@@ -369,7 +369,7 @@ private static boolean isEmptyMatch(final String str, final int from, final Stri
 	 * @param dLen  The length of the delimiter string
 	 * @return The next index.
 	 */
-	private static int getTo(final String str, final int from, final String delim,
+	public static int getTo(final String str, final int from, final String delim,
 		final int len, final int dLen) {
 		final char cq = CSV_QUOTE_CHAR;
 		final int fromP1 = from + 1;