1 files changed, 165 insertions, 0 deletions
diff --git a/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/FilterInvokingServletOutputStream.java b/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/FilterInvokingServletOutputStream.java
new file mode 100644
index 00000000000..a605ccebfa7
--- /dev/null
+++ b/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/FilterInvokingServletOutputStream.java
@@ -0,0 +1,165 @@
+// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.jdisc.http.server.jetty;
+
+import javax.servlet.ServletOutputStream;
+import javax.servlet.WriteListener;
+import java.io.IOException;
+
+/**
+ * Invokes the response filter the first time anything is output to the underlying ServletOutputStream.
+ * The filter must be invoked before the first output call since this might cause the response
+ * to be committed, i.e. locked and potentially put on the wire.
+ * Any changes to the response after it has been committed might be ignored or cause exceptions.
+ *
+ * @author Tony Vaagenes
+ */
+class FilterInvokingServletOutputStream extends ServletOutputStream {
+    private final ServletOutputStream delegate;
+    private final OneTimeRunnable filterInvoker;
+
+    public FilterInvokingServletOutputStream(ServletOutputStream delegate, OneTimeRunnable filterInvoker) {
+        this.delegate = delegate;
+        this.filterInvoker = filterInvoker;
+    }
+
+    @Override
+    public boolean isReady() {
+        return delegate.isReady();
+    }
+
+    @Override
+    public void setWriteListener(WriteListener writeListener) {
+        delegate.setWriteListener(writeListener);
+    }
+
+
+    private void runFilterIfFirstInvocation() {
+        filterInvoker.runIfFirstInvocation();
+    }
+
+    @Override
+    public void write(int b) throws IOException {
+        runFilterIfFirstInvocation();
+        delegate.write(b);
+    }
+
+
+    @Override
+    public void write(byte[] b) throws IOException {
+        runFilterIfFirstInvocation();
+        delegate.write(b);
+    }
+
+    @Override
+    public void print(String s) throws IOException {
+        runFilterIfFirstInvocation();
+        delegate.print(s);
+    }
+
+    @Override
+    public void write(byte[] b, int off, int len) throws IOException {
+        runFilterIfFirstInvocation();
+        delegate.write(b, off, len);
+    }
+
+    @Override
+    public void print(boolean b) throws IOException {
+        runFilterIfFirstInvocation();
+        delegate.print(b);
+    }
+
+    @Override
+    public void flush() throws IOException {
+        runFilterIfFirstInvocation();
+        delegate.flush();
+    }
+
+    @Override
+    public void print(char c) throws IOException {
+        runFilterIfFirstInvocation();
+        delegate.print(c);
+    }
+
+    @Override
+    public void close() throws IOException {
+        runFilterIfFirstInvocation();
+        delegate.close();
+    }
+
+    @Override
+    public void print(int i) throws IOException {
+        runFilterIfFirstInvocation();
+        delegate.print(i);
+    }
+
+    @Override
+    public void print(long l) throws IOException {
+        runFilterIfFirstInvocation();
+        delegate.print(l);
+    }
+
+    @Override
+    public void print(float f) throws IOException {
+        runFilterIfFirstInvocation();
+        delegate.print(f);
+    }
+
+    @Override
+    public void print(double d) throws IOException {
+        runFilterIfFirstInvocation();
+        delegate.print(d);
+    }
+
+    @Override
+    public void println() throws IOException {
+        runFilterIfFirstInvocation();
+        delegate.println();
+    }
+
+    @Override
+    public void println(String s) throws IOException {
+        runFilterIfFirstInvocation();
+        delegate.println(s);
+    }
+
+    @Override
+    public void println(boolean b) throws IOException {
+        runFilterIfFirstInvocation();
+        delegate.println(b);
+    }
+
+    @Override
+    public void println(char c) throws IOException {
+        runFilterIfFirstInvocation();
+        delegate.println(c);
+    }
+
+    @Override
+    public void println(int i) throws IOException {
+        runFilterIfFirstInvocation();
+        delegate.println(i);
+    }
+
+    @Override
+    public void println(long l) throws IOException {
+        runFilterIfFirstInvocation();
+        delegate.println(l);
+    }
+
+    @Override
+    public void println(float f) throws IOException {
+        runFilterIfFirstInvocation();
+        delegate.println(f);
+    }
+
+    @Override
+    public void println(double d) throws IOException {
+        runFilterIfFirstInvocation();
+        delegate.println(d);
+    }
+
+    @Override
+    public String toString() {
+        return getClass().getCanonicalName() + " (" + delegate.toString() + ")";
+    }
+}