rtemplate binary cache for static strings and optimized encoding of v…

…ariables
jreijn · Aug 16, 2022 · d7e781c · d7e781c
1 parent d17a85e
commit d7e781c
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Showing 4 changed files with 92 additions and 40 deletions.
diff --git a/rtemplate.conf b/rtemplate.conf
@@ -1,9 +1,9 @@
 javaDir=src
 templateDir=template
 autoTab=true
-jTemplatePre=writer.write("
+jTemplatePre=write("
 jTemplatePost=");
-jOutPre=writer.write(
+jOutPre=writeValue(
 jOutPost=);
 tPre0=#H
 tPost0=#

diff --git a/src/main/java/com/jeroenreijn/examples/view/RtemplateView.java b/src/main/java/com/jeroenreijn/examples/view/RtemplateView.java
@@ -1,7 +1,10 @@
 package com.jeroenreijn.examples.view;
 
+import java.io.OutputStream;
+import java.io.PrintStream;
 import java.io.PrintWriter;
 import java.io.Writer;
+import java.nio.charset.StandardCharsets;
 import java.util.Map;
 
 import javax.servlet.http.HttpServletRequest;
@@ -24,10 +27,10 @@ protected void renderMergedTemplateModel(Map<String, Object> model, HttpServletR
 		com.jeroenreijn.examples.model.i18nLayout i18n=(com.jeroenreijn.examples.model.i18nLayout)model.get("i18n");
 		response.setContentType("text/html");
 		response.setCharacterEncoding("UTF-8");
-		try (PrintWriter writer = response.getWriter()) {
-			RtemplateViewInstance vi=new RtemplateViewInstance(context, writer, presentations, i18n);
+		try (OutputStream os = response.getOutputStream()) {
+			// PrintStream ps=new PrintStream(os, false, StandardCharsets.UTF_8);
+			RtemplateViewInstance vi=new RtemplateViewInstance(context, os, presentations, i18n);
 			vi.render();
-			writer.flush();
 		}
 	}
 }
diff --git a/src/main/java/com/jeroenreijn/examples/view/RtemplateViewInstance.java b/src/main/java/com/jeroenreijn/examples/view/RtemplateViewInstance.java
@@ -1,7 +1,13 @@
 package com.jeroenreijn.examples.view;
 
 import java.io.IOException;
+import java.io.OutputStream;
 import java.io.PrintWriter;
+import java.nio.ByteBuffer;
+import java.nio.CharBuffer;
+import java.nio.charset.CharsetEncoder;
+import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
 
 import org.springframework.web.servlet.support.RequestContext;
 
@@ -14,96 +20,118 @@
  * each query. This is the object that serves a single query.
  */
 public class RtemplateViewInstance {
-	private PrintWriter writer;
+	private OutputStream os;
 	private Iterable<Presentation> presentations;
 	private i18nLayout i18n;
 	private RequestContext context;
+	private CharsetEncoder encoder=StandardCharsets.UTF_8.newEncoder();
+	CharBuffer cb=CharBuffer.wrap(new char[4096]);
+	byte[] arr=new byte[4096*5];
+	ByteBuffer bb=ByteBuffer.wrap(arr);
+	static private StringCache sc=new StringCache();
 	/**
 	 * Create object that servers a single query and stores all data sources.
 	 * @param context
 	 * @param writer
 	 * @param presentations
 	 * @param i18n
 	 */
-	public RtemplateViewInstance(RequestContext context, PrintWriter writer, Iterable<Presentation> presentations, i18nLayout i18n) {
+	public RtemplateViewInstance(RequestContext context, OutputStream os, Iterable<Presentation> presentations, i18nLayout i18n) {
 		this.context=context;
-		this.writer=writer;
+		this.os=os;
 		this.presentations=presentations;
 		this.i18n=i18n;
 	}
+	private void write(String s) throws IOException
+	{
+		sc.write(os, s);
+	}
+	private void writeValue(String s)  throws IOException 
+	{
+		os.write(s.getBytes(StandardCharsets.UTF_8));
+	}
 	/**
 	 * Execute rendering of the page into the stored writer object.
 	 */
-	public void render() {
-		writer.write("<!DOCTYPE html>\n<html>\n");
+	public void render()  throws IOException {
+		write("<!DOCTYPE html>\n<html>\n");
 		head();
-		writer.write("    <body>\n        <div class=\"container\">\n            <div class=\"pb-2 mt-4 mb-3 border-bottom\">\n                <h1>");
+		write("    <body>\n        <div class=\"container\">\n            <div class=\"pb-2 mt-4 mb-3 border-bottom\">\n                <h1>");
 		writeHtml(i18n.message("example.title"));
-		writer.write(" - Rtemplate</h1>\n            </div>\n");
+		write(" - Rtemplate</h1>\n            </div>\n");
 		for(Presentation p: presentations)
 		{
 			presentation(p);
 		}
-		writer.write("        </div>\n");
+		write("        </div>\n");
 		scripts();
-		writer.write("    </body>\n</html>\t\n");
+		write("    </body>\n</html>\t\n");
 	}
 	/**
 	 * Write a string through HTML escaping to the writer.
 	 * For the sake of simplicity no library is used. In real world usage this would
 	 * be backed by an escaping library.
 	 * @param message
 	 */
-	private void writeHtml(String message) {
+	private void writeHtml(String message)  throws IOException {
+		cb.clear();
+		if(message.length()>2048)
+		{
+			throw new RuntimeException("Too long");
+		}
 		for(int i=0;i<message.length();++i)
 		{
 			char ch=message.charAt(i);
 			switch (ch) {
 			case '<':
-				writer.write("&lt;");
+				cb.append("&lt;");
 				break;
 			case '>':
-				writer.write("&gt;");
+				cb.append("&gt;");
 				break;
 			case '&':
-				writer.write("&amp;");
+				cb.append("&amp;");
 				break;
 			case '"':
-				writer.write("&quot;");
+				cb.append("&quot;");
 				break;
 			default:
-				writer.write(ch);
+				cb.append(ch);
 				break;
 			}
 		}
+		bb.clear();
+		cb.flip();
+		encoder.encode(cb, bb, true);
+		os.write(arr, 0, bb.position());
 	}
 	/**
 	 * Render a single presentation.
 	 * @param p
 	 */
-	private void presentation(Presentation p) {
-		writer.write("<div class=\"card mb-3 shadow-sm rounded\">\n    <div class=\"card-header\">\n        <h5 class=\"card-title\">");
-		writer.write(p.getTitle());
-		writer.write(" - ");
-		writer.write(p.getSpeakerName());
-		writer.write("</h5>\n    </div>\n    <div class=\"card-body\">\n        ");
-		writer.write(p.getSummary());
-		writer.write("\n    </div>\n</div>\n");
+	private void presentation(Presentation p)  throws IOException {
+		write("<div class=\"card mb-3 shadow-sm rounded\">\n    <div class=\"card-header\">\n        <h5 class=\"card-title\">");
+		writeHtml(p.getTitle());
+		write(" - ");
+		writeHtml(p.getSpeakerName());
+		write("</h5>\n    </div>\n    <div class=\"card-body\">\n        ");
+		writeValue(p.getSummary());
+		write("\n    </div>\n</div>\n");
 	}
 	/** Render the head part of the HTML page. */
-	private void head() {
-		writer.write("<head>\n    <meta charset=\"UTF-8\"/>\n    <meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\"/>\n    <meta http-equiv=\"X-UA-Compatible\" content=\"IE=Edge\"/>\n    <title>");
-		writer.write(i18n.message("example.title"));
-		writer.write(" - Rtemplate</title>\n    <link rel=\"stylesheet\" href=\"");
-		writer.write(context.getContextPath());
-		writer.write("/webjars/bootstrap/4.3.1/css/bootstrap.min.css\"/>\n</head>\n");
+	private void head()  throws IOException {
+		write("<head>\n    <meta charset=\"UTF-8\"/>\n    <meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\"/>\n    <meta http-equiv=\"X-UA-Compatible\" content=\"IE=Edge\"/>\n    <title>");
+		writeHtml(i18n.message("example.title"));
+		write(" - Rtemplate</title>\n    <link rel=\"stylesheet\" href=\"");
+		writeValue(context.getContextPath());
+		write("/webjars/bootstrap/4.3.1/css/bootstrap.min.css\"/>\n</head>\n");
 	}
 	/** Render the scripts part of the HTML page. */
-	private void scripts() {
-		writer.write("<script src=\"");
-		writer.write(context.getContextPath());
-		writer.write("/webjars/jquery/3.1.1/jquery.min.js\"></script>\n<script src=\"");
-		writer.write(context.getContextPath());
-		writer.write("/webjars/bootstrap/4.3.1/js/bootstrap.min.js\"></script>\n");
+	private void scripts()  throws IOException {
+		write("<script src=\"");
+		writeValue(context.getContextPath());
+		write("/webjars/jquery/3.1.1/jquery.min.js\"></script>\n<script src=\"");
+		writeValue(context.getContextPath());
+		write("/webjars/bootstrap/4.3.1/js/bootstrap.min.js\"></script>\n");
 	}
 }
diff --git a/src/main/java/com/jeroenreijn/examples/view/StringCache.java b/src/main/java/com/jeroenreijn/examples/view/StringCache.java
@@ -0,0 +1,21 @@
+package com.jeroenreijn.examples.view;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.charset.StandardCharsets;
+import java.util.HashMap;
+import java.util.Map;
+
+public class StringCache {
+	private Map<String, byte[]> stringRendered=new HashMap<>();
+
+	public void write(OutputStream os, String s) throws IOException {
+		byte[] data=stringRendered.get(s);
+		if(data==null)
+		{
+			data=s.getBytes(StandardCharsets.UTF_8);
+			stringRendered.put(s, data);
+		}
+		os.write(data);
+	}
+}