Optimize replaceNewLines() in EncodingUtil
Return input strings unchanged if no replacement is needed.
Do not create a StringBuilder if not needed.
Instead of appending char by char to the StringBuilder, copy the chunks
between replacements.
Change-Id: I14860db479a2b50d5232d97865b0b114311d53c1
diff --git a/bundles/org.eclipse.rap.rwt/src/org/eclipse/rap/rwt/internal/util/EncodingUtil.java b/bundles/org.eclipse.rap.rwt/src/org/eclipse/rap/rwt/internal/util/EncodingUtil.java
index 2da0161..f8830b7 100644
--- a/bundles/org.eclipse.rap.rwt/src/org/eclipse/rap/rwt/internal/util/EncodingUtil.java
+++ b/bundles/org.eclipse.rap.rwt/src/org/eclipse/rap/rwt/internal/util/EncodingUtil.java
@@ -1,5 +1,5 @@
/*******************************************************************************
- * Copyright (c) 2002, 2012 Innoopract Informationssysteme GmbH and others.
+ * Copyright (c) 2002, 2015 Innoopract Informationssysteme GmbH and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
@@ -95,27 +95,30 @@
* @return a copy of the input string with all newline characters replaced
*/
public static String replaceNewLines( String input, String replacement ) {
- StringBuilder resultBuffer = new StringBuilder();
+ StringBuilder resultBuffer = null;
int length = input.length();
+ int start = 0;
int i = 0;
while( i < length ) {
char ch = input.charAt( i );
- if( ch == '\n' ) {
- resultBuffer.append( replacement );
- } else if( ch == '\r' ) {
- if( i + 1 < length ) {
- char next = input.charAt( i + 1 );
- if( ch == '\r' && next == '\n' ) {
- i++;
- }
+ if( ch == '\n' || ch == '\r' ) {
+ if (resultBuffer == null) {
+ resultBuffer = new StringBuilder();
}
+ resultBuffer.append( input, start, i );
resultBuffer.append( replacement );
- } else {
- resultBuffer.append( ch );
+ if( ch == '\r' && i + 1 < length && input.charAt( i + 1 ) == '\n' ) {
+ i++;
+ }
+ start = i + 1;
}
i++;
}
- return resultBuffer.toString();
+ if (resultBuffer != null) {
+ resultBuffer.append( input, start, i );
+ return resultBuffer.toString();
+ }
+ return input;
}
/**
diff --git a/tests/org.eclipse.rap.rwt.test/src/org/eclipse/rap/rwt/internal/util/EncodingUtil_Test.java b/tests/org.eclipse.rap.rwt.test/src/org/eclipse/rap/rwt/internal/util/EncodingUtil_Test.java
index 39c02df..cfc7a0e 100644
--- a/tests/org.eclipse.rap.rwt.test/src/org/eclipse/rap/rwt/internal/util/EncodingUtil_Test.java
+++ b/tests/org.eclipse.rap.rwt.test/src/org/eclipse/rap/rwt/internal/util/EncodingUtil_Test.java
@@ -1,5 +1,5 @@
/*******************************************************************************
- * Copyright (c) 2009, 2013 EclipseSource and others.
+ * Copyright (c) 2009, 2015 EclipseSource and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
@@ -11,6 +11,7 @@
package org.eclipse.rap.rwt.internal.util;
import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertSame;
import static org.junit.Assert.assertTrue;
import java.util.Arrays;
@@ -35,25 +36,58 @@
}
@Test
- public void testReplaceNewLines() {
+ public void testReplaceNewLines_emptyString() {
+ assertSame( "", EncodingUtil.replaceNewLines( "" ) );
+ }
+
+ @Test
+ public void testReplaceNewLines_withoutNewlines() {
+ assertSame( "foo bar", EncodingUtil.replaceNewLines( "foo bar" ) );
+ }
+
+ @Test
+ public void testReplaceNewLines_unixLineBreaks() {
String stringToReplace = "First line.\nSecond line.\nThird line.";
String expected = "First line.\\nSecond line.\\nThird line.";
String result = EncodingUtil.replaceNewLines( stringToReplace );
- assertEquals( expected, result );
- stringToReplace = "First line.\rSecond line.\rThird line.";
- expected = "First line.\\nSecond line.\\nThird line.";
- result = EncodingUtil.replaceNewLines( stringToReplace );
assertEquals( expected, result );
+ }
- stringToReplace = "First line.\r\nSecond line.\r\nThird line.";
- expected = "First line.\\nSecond line.\\nThird line.";
- result = EncodingUtil.replaceNewLines( stringToReplace );
+ @Test
+ public void testReplaceNewLines_windowsLineBreaks() {
+ String stringToReplace = "First line.\r\nSecond line.\r\nThird line.";
+ String expected = "First line.\\nSecond line.\\nThird line.";
+ String result = EncodingUtil.replaceNewLines( stringToReplace );
+
assertEquals( expected, result );
+ }
- stringToReplace = "First line.\r\nSecond line.\r\nThird line.";
- expected = "First line. Second line. Third line.";
- result = EncodingUtil.replaceNewLines( stringToReplace, " " );
+ @Test
+ public void testReplaceNewLines_oldMacLineBreaks() {
+ String stringToReplace = "First line.\rSecond line.\rThird line.";
+ String expected = "First line.\\nSecond line.\\nThird line.";
+ String result = EncodingUtil.replaceNewLines( stringToReplace );
+
+ assertEquals( expected, result );
+ }
+
+ @Test
+ public void testReplaceNewLines_edgeCases() {
+ assertEquals( "\\nfoo", EncodingUtil.replaceNewLines( "\nfoo" ) );
+ assertEquals( "\\nfoo", EncodingUtil.replaceNewLines( "\r\nfoo" ) );
+ assertEquals( "foo\\n", EncodingUtil.replaceNewLines( "foo\n" ) );
+ assertEquals( "foo\\n", EncodingUtil.replaceNewLines( "foo\r\n" ) );
+ assertEquals( "\\n", EncodingUtil.replaceNewLines( "\n" ) );
+ assertEquals( "\\n", EncodingUtil.replaceNewLines( "\r\n" ) );
+ }
+
+ @Test
+ public void testReplaceNewLines_withReplacement() {
+ String stringToReplace = "First line.\r\nSecond line.\r\nThird line.";
+ String expected = "First line. Second line. Third line.";
+ String result = EncodingUtil.replaceNewLines( stringToReplace, " " );
+
assertEquals( expected, result );
}
