websocket URP flush hangs with large buffer

over 4k hits limit so flush waits until something reads, but the
read is in the same thread after the flush.

We are just using _outputStream to accumulate the bytes to be send
so change this to use a ByteArrayOutputStream and take over its bytes
and clear it when we flush.

Change-Id: I17b90e1c7d4302f153b5832e60ac0e0f2b86ace9
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/156565
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolan.mcnamara@collabora.com>

1 files changed, 11 insertions, 24 deletions

diff --git a/ridljar/com/sun/star/lib/connections/websocket/WebsocketConnection.java b/ridljar/com/sun/star/lib/connections/websocket/WebsocketConnection.java
index a3aed227c81d..fb81c4ff8801 100644
--- a/ridljar/com/sun/star/lib/connections/websocket/WebsocketConnection.java
+++ b/ridljar/com/sun/star/lib/connections/websocket/WebsocketConnection.java
@@ -20,7 +20,7 @@ package com.sun.star.lib.connections.websocket;
 
 
 import java.io.BufferedInputStream;
-import java.io.BufferedOutputStream;
+import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
@@ -61,10 +61,8 @@ public class WebsocketConnection extends WebSocketClient implements XConnection,
 
     protected String       _description;
     protected InputStream  _inputStream;
-    protected OutputStream _outputStream;
-
-    protected InputStream _outputStreamReader;
     protected OutputStream _inputStreamWriter;
+    protected ByteArrayOutputStream _outputStream;
 
     protected ArrayList<XStreamListener>       _listeners;
 
@@ -83,14 +81,10 @@ public class WebsocketConnection extends WebSocketClient implements XConnection,
 
         PipedOutputStream inputStreamWriter = new PipedOutputStream();
         PipedInputStream inputPipe = new PipedInputStream(inputStreamWriter);
-        PipedOutputStream outputPipe = new PipedOutputStream();
-        PipedInputStream outputStreamReader = new PipedInputStream(outputPipe);
-
 
         _inputStream = new BufferedInputStream(inputPipe);
         _inputStreamWriter = inputStreamWriter;
-        _outputStream = new BufferedOutputStream(outputPipe);
-        _outputStreamReader = outputStreamReader;
+        _outputStream = new ByteArrayOutputStream();
 
         _listeners = new ArrayList<XStreamListener>();
 
@@ -206,23 +200,16 @@ public class WebsocketConnection extends WebSocketClient implements XConnection,
      */
     public void flush() throws com.sun.star.io.IOException,
         com.sun.star.uno.RuntimeException {
-        try {
-            _outputStream.flush();
-
-            Integer available = _outputStreamReader.available();
-
-            byte[] outputBytes = new byte[available + outgoingPrefix.length];
-            System.arraycopy(outgoingPrefix, 0, outputBytes, 0, outgoingPrefix.length);
-
-            _outputStreamReader.read(outputBytes, outgoingPrefix.length, available);
 
-            send(outputBytes);
-        } catch(IOException ioException) {
-            com.sun.star.io.IOException unoIOException = new com.sun.star.io.IOException(ioException);
-            notifyListeners_error(unoIOException);
-
-            throw unoIOException;
+        byte[] accumulatedBytes;
+        synchronized (_outputStream) {
+            accumulatedBytes = _outputStream.toByteArray();
+            _outputStream.reset();
         }
+        byte[] outputBytes = new byte[accumulatedBytes.length + outgoingPrefix.length];
+        System.arraycopy(outgoingPrefix, 0, outputBytes, 0, outgoingPrefix.length);
+        System.arraycopy(accumulatedBytes, 0, outputBytes, outgoingPrefix.length, accumulatedBytes.length);
+        send(outputBytes);
 
         if (DEBUG)
             System.err.println(String.format("##### %s - flushed", getClass().getName()));