From c77fc4cfe9393943db607dfe5a1e6a608e37126c Mon Sep 17 00:00:00 2001
From: Corey Kosak <coreykosak@deephaven.io>
Date: Mon, 4 Nov 2024 22:00:13 -0500
Subject: [PATCH] Support non-space delimiter and add a test for it

---
 .../io/deephaven/csv/reading/CsvReader.java   |  2 +-
 .../csv/reading/cells/FixedCellGrabber.java   |  6 +++--
 .../java/io/deephaven/csv/CsvReaderTest.java  | 26 +++++++++++++++++++
 3 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/src/main/java/io/deephaven/csv/reading/CsvReader.java b/src/main/java/io/deephaven/csv/reading/CsvReader.java
index 68899ae..a6fb63d 100644
--- a/src/main/java/io/deephaven/csv/reading/CsvReader.java
+++ b/src/main/java/io/deephaven/csv/reading/CsvReader.java
@@ -107,7 +107,7 @@ private static Result fixedReadLogic(
         final String[] headers = FixedHeaderFinder.determineHeadersToUse(specs, lineGrabber, columnWidths);
         final int numCols = headers.length;
         final CellGrabber grabber = new FixedCellGrabber(lineGrabber, columnWidths.getValue(),
-                specs.ignoreSurroundingSpaces(), specs.useUtf32CountingConvention());
+                specs.ignoreSurroundingSpaces(), (byte)specs.delimiter(), specs.useUtf32CountingConvention());
         return commonReadLogic(specs, grabber, null, numCols, numCols, headers, sinkFactory);
     }
 
diff --git a/src/main/java/io/deephaven/csv/reading/cells/FixedCellGrabber.java b/src/main/java/io/deephaven/csv/reading/cells/FixedCellGrabber.java
index 1732010..5402fd1 100644
--- a/src/main/java/io/deephaven/csv/reading/cells/FixedCellGrabber.java
+++ b/src/main/java/io/deephaven/csv/reading/cells/FixedCellGrabber.java
@@ -29,6 +29,7 @@ public static CellGrabber makeLineGrabber(InputStream stream) {
     private final CellGrabber lineGrabber;
     private final int[] columnWidths;
     private final boolean ignoreSurroundingSpaces;
+    private final byte delimiterAsByte;
     private final boolean utf32CountingMode;
     private final ByteSlice rowText;
     private boolean needsUnderlyingRefresh;
@@ -38,10 +39,11 @@ public static CellGrabber makeLineGrabber(InputStream stream) {
 
     /** Constructor. */
     public FixedCellGrabber(final CellGrabber lineGrabber, final int[] columnWidths, boolean ignoreSurroundingSpaces,
-            boolean utf32CountingMode) {
+            byte delimiterAsByte, boolean utf32CountingMode) {
         this.lineGrabber = lineGrabber;
         this.columnWidths = columnWidths;
         this.ignoreSurroundingSpaces = ignoreSurroundingSpaces;
+        this.delimiterAsByte = delimiterAsByte;
         this.utf32CountingMode = utf32CountingMode;
         this.rowText = new ByteSlice();
         this.needsUnderlyingRefresh = true;
@@ -77,7 +79,7 @@ public void grabNext(ByteSlice dest, MutableBoolean lastInRow, MutableBoolean en
         endOfInput.setValue(false);
 
         if (ignoreSurroundingSpaces) {
-            ReaderUtil.trimWhitespace(dest);
+            dest.trimPadding(delimiterAsByte);
         }
     }
 
diff --git a/src/test/java/io/deephaven/csv/CsvReaderTest.java b/src/test/java/io/deephaven/csv/CsvReaderTest.java
index fb48d22..f5c3da4 100644
--- a/src/test/java/io/deephaven/csv/CsvReaderTest.java
+++ b/src/test/java/io/deephaven/csv/CsvReaderTest.java
@@ -1979,6 +1979,32 @@ public void fixedColumnWidthsShortRows(boolean allowMissingColumns) throws CsvRe
         }
     }
 
+    /**
+     * We support other ASCII delimiters. In fixed-width mode, the meaning of "ignoreSurroundingSpaces" is expanded
+     * to mean "ignore surrounding delimiters".
+     */
+    @Test
+    public void alternateDelimiter() throws CsvReaderException {
+        final String input =
+                ""
+                        + "Sym___Type_____Price___SecurityId\n"
+                        + "GOOG__Dividend_0.25____200\n"
+                        + "T_____Dividend_0.15____300\n"
+                        + "Z_____Dividend_0.18____500\n";
+
+        final ColumnSet expected =
+                ColumnSet.of(
+                        Column.ofRefs("Sym", "GOOG", "T", "Z"),
+                        Column.ofRefs("Type", "Dividend", "Dividend", "Dividend"),
+                        Column.ofValues("Price", 0.25, 0.15, 0.18),
+                        Column.ofValues("SecurityId", 200, 300, 500));
+
+        final CsvSpecs specs =
+                defaultCsvBuilder().hasFixedWidthColumns(true).delimiter('_').ignoreSurroundingSpaces(true).build();
+
+        invokeTest(specs, input, expected);
+    }
+
     /**
      * If there is no header row, the caller needs to specify column widths.
      */