Fixed the high latency which results when using a PipedWriter/PipedOu…

…tputStream and not flushing it after every write

See http://stackoverflow.com/questions/2843555/better-alternative-for-pipedreader-pipedwriter/2844689#2844689

dimdwarf-end-to-end-test/src/test/java/net/orfjackal/dimdwarf/test/runner/ServerRunner.java

@@ -75,20 +75,20 @@ private void startServer() throws IOException {
         );
         serverProcess = builder.start();
 
-        PipedOutputStream toWatcher = streamToWatcher();
+        OutputStream toWatcher = streamToWatcher();
         redirectStream(serverProcess.getInputStream(), System.out, toWatcher);
         redirectStream(serverProcess.getErrorStream(), System.err, toWatcher);
     }
 
-    private PipedOutputStream streamToWatcher() throws IOException {
+    private OutputStream streamToWatcher() throws IOException {
         assert outputWatcher == null;
         PipedInputStream in = new PipedInputStream();
-        PipedOutputStream toWatcher = new PipedOutputStream(in);
+        PipedOutputStream toWatcher = new LowLatencyPipedOutputStream(in);
         outputWatcher = new StreamWatcher(new InputStreamReader(in));
         return toWatcher;
     }
 
-    private static void redirectStream(InputStream input, OutputStream systemOut, PipedOutputStream toWatcher) {
+    private static void redirectStream(InputStream input, OutputStream systemOut, OutputStream toWatcher) {
         redirectStream(new TeeInputStream(input, toWatcher), new CloseShieldOutputStream(systemOut));
     }
 

dimdwarf-end-to-end-test/src/test/java/net/orfjackal/dimdwarf/test/util/LowLatencyPipedOutputStream.java

@@ -0,0 +1,32 @@
+// Copyright © 2008-2010 Esko Luontola <www.orfjackal.net>
+// This software is released under the Apache License 2.0.
+// The license text is at http://dimdwarf.sourceforge.net/LICENSE
+
+package net.orfjackal.dimdwarf.test.util;
+
+import java.io.*;
+
+/**
+ * {@link java.io.PipedOutputStream} should be flushed after every write, or otherwise
+ * there will be a one-second latency for the reader. This class does that automatically.
+ * <a href="http://stackoverflow.com/questions/2843555/better-alternative-for-pipedreader-pipedwriter/2844689#2844689">More information</a>.
+ */
+public class LowLatencyPipedOutputStream extends PipedOutputStream {
+
+    public LowLatencyPipedOutputStream(PipedInputStream snk) throws IOException {
+        super(snk);
+    }
+
+    public LowLatencyPipedOutputStream() {
+    }
+
+    public void write(int b) throws IOException {
+        super.write(b);
+        flush();
+    }
+
+    public void write(byte[] b, int off, int len) throws IOException {
+        super.write(b, off, len);
+        flush();
+    }
+}

dimdwarf-end-to-end-test/src/test/java/net/orfjackal/dimdwarf/test/util/LowLatencyPipedWriter.java

@@ -0,0 +1,32 @@
+// Copyright © 2008-2010 Esko Luontola <www.orfjackal.net>
+// This software is released under the Apache License 2.0.
+// The license text is at http://dimdwarf.sourceforge.net/LICENSE
+
+package net.orfjackal.dimdwarf.test.util;
+
+import java.io.*;
+
+/**
+ * {@link java.io.PipedWriter} should be flushed after every write, or otherwise
+ * there will be a one-second latency for the reader. This class does that automatically.
+ * <a href="http://stackoverflow.com/questions/2843555/better-alternative-for-pipedreader-pipedwriter/2844689#2844689">More information</a>.
+ */
+public class LowLatencyPipedWriter extends PipedWriter {
+
+    public LowLatencyPipedWriter(PipedReader snk) throws IOException {
+        super(snk);
+    }
+
+    public LowLatencyPipedWriter() {
+    }
+
+    public void write(int c) throws IOException {
+        super.write(c);
+        flush();
+    }
+
+    public void write(char[] cbuf, int off, int len) throws IOException {
+        super.write(cbuf, off, len);
+        flush();
+    }
+}

dimdwarf-end-to-end-test/src/test/java/net/orfjackal/dimdwarf/test/util/StreamWatcherTest.java

@@ -19,8 +19,8 @@ public class StreamWatcherTest {
 
     @Before
     public void setUp() throws IOException {
-        PipedWriter w = new PipedWriter();
-        PipedReader r = new PipedReader(w);
+        PipedReader r = new PipedReader();
+        PipedWriter w = new LowLatencyPipedWriter(r);
         stream = new PrintWriter(w);
         watcher = new StreamWatcher(r);
     }