From 2ecf983ce00dc338ce2bf85d35abf6b2b35df635 Mon Sep 17 00:00:00 2001
From: Oliver Siegmar <oliver@siegmar.de>
Date: Mon, 1 Jan 2024 18:44:28 +0100
Subject: [PATCH] optimize performance

---
 .../de/siegmar/fastcsv/writer/CsvWriter.java  | 30 ++++++++++++++-----
 1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/lib/src/main/java/de/siegmar/fastcsv/writer/CsvWriter.java b/lib/src/main/java/de/siegmar/fastcsv/writer/CsvWriter.java
index aa44bbce..0c0382e0 100644
--- a/lib/src/main/java/de/siegmar/fastcsv/writer/CsvWriter.java
+++ b/lib/src/main/java/de/siegmar/fastcsv/writer/CsvWriter.java
@@ -143,15 +143,15 @@ private void writeInternal(final String value, final int fieldIdx) throws IOExce
             return;
         }
 
-        final boolean hasDelimiters = hasDelimiters(value, fieldIdx, length);
-        final boolean needsQuotes = hasDelimiters
+        final boolean needsEscape = containsControlCharacter(value, fieldIdx, length);
+        final boolean needsQuotes = needsEscape
             || quoteStrategy != null && quoteStrategy.quoteNonEmpty(currentLineNo, fieldIdx, value);
 
         if (needsQuotes) {
             writer.write(quoteCharacter);
         }
 
-        if (hasDelimiters) {
+        if (needsEscape) {
             writeEscaped(writer, value, quoteCharacter);
         } else {
             writer.write(value, 0, length);
@@ -162,12 +162,28 @@ private void writeInternal(final String value, final int fieldIdx) throws IOExce
         }
     }
 
-    @SuppressWarnings("checkstyle:BooleanExpressionComplexity")
-    private boolean hasDelimiters(final String value, final int fieldIdx, final int length) {
+    @SuppressWarnings({
+        "checkstyle:BooleanExpressionComplexity",
+        "checkstyle:ReturnCount",
+        "checkstyle:MagicNumber",
+        "PMD.AvoidLiteralsInIfCondition"
+    })
+    private boolean containsControlCharacter(final String value, final int fieldIdx, final int length) {
+        if (fieldIdx == 0 && value.charAt(0) == commentCharacter) {
+            return true;
+        }
+
+        // For longer values, indexOf is faster than iterating over the string
+        if (length > 20) {
+            return value.indexOf(quoteCharacter) != -1
+                || value.indexOf(fieldSeparator) != -1
+                || value.indexOf(LF) != -1
+                || value.indexOf(CR) != -1;
+        }
+
         for (int i = 0; i < length; i++) {
             final char c = value.charAt(i);
-            if (c == quoteCharacter || c == fieldSeparator || c == LF || c == CR
-                || c == commentCharacter && fieldIdx == 0 && i == 0) {
+            if (c == quoteCharacter || c == fieldSeparator || c == LF || c == CR) {
                 return true;
             }
         }