From f6dfab27481b60975d55901354f075960ab97098 Mon Sep 17 00:00:00 2001
From: Vhati <tvtronix@yahoo.com>
Date: Sun, 9 Mar 2014 03:44:40 -0400
Subject: [PATCH] Used EOLWriter to normalize line breaks instead of regex

---
 skel_common/readme_changelog.txt              |  1 +
 .../net/vhati/modmanager/core/EOLWriter.java  | 83 +++++++++++++++++++
 .../vhati/modmanager/core/ModUtilities.java   | 52 +++++++-----
 3 files changed, 117 insertions(+), 19 deletions(-)
 create mode 100644 src/main/java/net/vhati/modmanager/core/EOLWriter.java

diff --git a/skel_common/readme_changelog.txt b/skel_common/readme_changelog.txt
index 2f7eef0..37ac7f9 100644
--- a/skel_common/readme_changelog.txt
+++ b/skel_common/readme_changelog.txt
@@ -9,6 +9,7 @@ Changelog
 - Changed modman.exe to fail rather than use VirtualStore
 - Added modman_admin.exe, which always runs as administrator
 - Added a Validate warning for junk files whose names end with a tilde
+- Minor optimizations to reduce memory usage
 
 1.4:
 - Cleaned up some dodgy code when initially prompting for FTL's location
diff --git a/src/main/java/net/vhati/modmanager/core/EOLWriter.java b/src/main/java/net/vhati/modmanager/core/EOLWriter.java
new file mode 100644
index 0000000..d0ab65e
--- /dev/null
+++ b/src/main/java/net/vhati/modmanager/core/EOLWriter.java
@@ -0,0 +1,83 @@
+package net.vhati.modmanager.core;
+
+import java.io.FilterWriter;
+import java.io.IOException;
+import java.io.Writer;
+
+
+/**
+ * A filter that replaces \r, \n, or \r\n, with a standard EOL string.
+ *
+ * Essentially, s.replaceAll( "\r(?!\n)|(?<!\r)\n|\r\n", eol );
+ *
+ * Filters can be chained to share one destination buffer, while each regex
+ * call creates and returns a new string.
+ */
+public class EOLWriter extends FilterWriter {
+
+	private String eol;
+	private boolean sawCR = false;
+
+
+	/**
+	 * Creates a new EOLWriter.
+	 *
+	 * @param out a Writer object to provide the underlying stream
+	 * @param eol the string to substitute where line breaks occur
+	 */
+	public EOLWriter( Writer out, String eol ) {
+		super( out );
+		this.eol = eol;
+	}
+
+
+	@Override
+	public void write( int c ) throws IOException {
+		if ( c == '\r' ) {
+			this.out.write( eol );
+			sawCR = true;
+		}
+		else if ( c == '\n' ) {
+			// If in the middle of \r\n, don't bother adding another eol.
+			if ( !sawCR ) this.out.write( eol );
+			sawCR = false;
+		}
+		else {
+			this.out.write( c );
+			sawCR = false;
+		}
+	}
+
+	@Override
+	public void write( char cbuf[], int off, int len ) throws IOException {
+		int end = off + len;
+		for ( int i=off; i < end; i++ ) {
+			if ( cbuf[i] == '\r' ) {
+				this.out.write( cbuf, off, i-off );  // Write everything up to here.
+				off = i + 1;                         // Skip this char.
+				this.out.write( eol );               // Write EOL instead.
+				sawCR = true;
+			}
+			else if ( cbuf[i] == '\n' ) {
+				this.out.write( cbuf, off, i-off );  // Write everything up to here.
+				off = i + 1;                         // Skip this char.
+				if ( sawCR ) {
+					sawCR = false;
+				} else {
+					this.out.write( eol );             // Write EOL instead.
+				}
+			}
+			else {
+				sawCR = false;                       // Keep scanning for breaks.
+			}
+		}
+		if ( off < end ) {                       // Write all remaining chars.
+			this.out.write( cbuf, off, end-off );
+		}
+	}
+
+	@Override
+	public void write( String str, int off, int len ) throws IOException {
+		write( str.toCharArray(), off, len );
+	}
+}
diff --git a/src/main/java/net/vhati/modmanager/core/ModUtilities.java b/src/main/java/net/vhati/modmanager/core/ModUtilities.java
index 070f274..c99875e 100644
--- a/src/main/java/net/vhati/modmanager/core/ModUtilities.java
+++ b/src/main/java/net/vhati/modmanager/core/ModUtilities.java
@@ -10,7 +10,7 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.io.StringReader;
-import java.io.StringWriter;
+import java.io.Writer;
 import java.nio.ByteBuffer;
 import java.nio.charset.CharacterCodingException;
 import java.nio.charset.Charset;
@@ -176,16 +176,20 @@ public class ModUtilities {
 		String dstText = decodeText( dstStream, dstDescription ).text;
 		dstText = xmlDeclPtn.matcher(dstText).replaceFirst( "" );
 
-		StringBuilder buf = new StringBuilder( srcText.length() +100+ dstText.length() );
-		buf.append( "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n" );
-		buf.append( dstText );
-		buf.append( "\n\n<!-- Appended by Slipstream -->\n\n" );
-		buf.append( srcText );
-		buf.append( "\n" );
+		// Concatenate, filtering the stream to standardize newlines and encode.
+		//
+		CharsetEncoder encoder = Charset.forName( "UTF-8" ).newEncoder();
+		ByteArrayOutputStream tmpData = new ByteArrayOutputStream();
+		Writer writer = new EOLWriter( new BufferedWriter( new OutputStreamWriter( tmpData, encoder ) ), "\r\n" );
 
-		String mergedString = Pattern.compile("\n").matcher( buf ).replaceAll("\r\n");
+		writer.append( "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n" );
+		writer.append( dstText );
+		writer.append( "\n\n<!-- Appended by Slipstream -->\n\n" );
+		writer.append( srcText );
+		writer.append( "\n" );
+		writer.flush();
+		InputStream result = new ByteArrayInputStream( tmpData.toByteArray() );
 
-		InputStream result = encodeText( mergedString, "UTF-8", srcDescription+"+"+dstDescription );
 		return result;
 	}
 
@@ -227,12 +231,17 @@ public class ModUtilities {
 		patcher.setGlobalPanic( globalPanic );
 		Document mergedDoc = patcher.patch( mainDoc, appendDoc );
 
-		StringWriter writer = new StringWriter();
-		SloppyXMLOutputProcessor.sloppyPrint( mergedDoc, writer, encoding );
-		String mergedString = writer.toString();
-		mergedString = mergedString.replaceAll( "\r(?!\n)|(?<!\r)\n|\r\n", "\r\n" );  // sloppyPrint needs normalizing!?
+		// Bake XML into text, filtering the stream to standardize newlines and encode.
+		// TODO: sloppyPrint() needs EOL normalizing!?
+		//
+		CharsetEncoder encoder = Charset.forName( encoding ).newEncoder();
+		ByteArrayOutputStream tmpData = new ByteArrayOutputStream();
+		Writer writer = new EOLWriter( new BufferedWriter( new OutputStreamWriter( tmpData, encoder ) ), "\r\n" );
+
+		SloppyXMLOutputProcessor.sloppyPrint( mergedDoc, writer, encoding );
+		writer.flush();
+		InputStream result = new ByteArrayInputStream( tmpData.toByteArray() );
 
-		InputStream result = encodeText( mergedString, encoding, mainDescription+"+"+appendDescription );
 		return result;
 	}
 
@@ -262,12 +271,17 @@ public class ModUtilities {
 		Document doc = parseStrictOrSloppyXML( srcText, srcDescription+" (wrapped)" );
 		srcText = null;
 
-		StringWriter writer = new StringWriter();
-		SloppyXMLOutputProcessor.sloppyPrint( doc, writer, encoding );
-		String resultString = writer.toString();
-		resultString = resultString.replaceAll( "\r(?!\n)|(?<!\r)\n|\r\n", "\r\n" );  // sloppyPrint needs normalizing!?
+		// Bake XML into text, filtering the stream to standardize newlines and encode.
+		// TODO: sloppyPrint() needs EOL normalizing!?
+		//
+		CharsetEncoder encoder = Charset.forName( encoding ).newEncoder();
+		ByteArrayOutputStream tmpData = new ByteArrayOutputStream();
+		Writer writer = new EOLWriter( new BufferedWriter( new OutputStreamWriter( tmpData, encoder ) ), "\r\n" );
+
+		SloppyXMLOutputProcessor.sloppyPrint( doc, writer, encoding );
+		writer.flush();
+		InputStream result = new ByteArrayInputStream( tmpData.toByteArray() );
 
-		InputStream result = encodeText( resultString, encoding, srcDescription+" (cleaned)" );
 		return result;
 	}