From 6bd552f6a32ca93826cb491f9b4bd757f9698227 Mon Sep 17 00:00:00 2001
From: Daniel Gultsch <daniel@gultsch.de>
Date: Mon, 14 Feb 2022 11:46:57 +0100
Subject: [PATCH] flush stanzas in batches

---
 .../eu/siacs/conversations/xml/TagWriter.java | 22 +++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/src/main/java/eu/siacs/conversations/xml/TagWriter.java b/src/main/java/eu/siacs/conversations/xml/TagWriter.java
index 4f429377a..2c2b8ac2c 100644
--- a/src/main/java/eu/siacs/conversations/xml/TagWriter.java
+++ b/src/main/java/eu/siacs/conversations/xml/TagWriter.java
@@ -8,12 +8,15 @@ import java.io.OutputStreamWriter;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
 
 import eu.siacs.conversations.Config;
 import eu.siacs.conversations.xmpp.stanzas.AbstractStanza;
 
 public class TagWriter {
 
+    private static final int FLUSH_DELAY = 400;
+
     private OutputStreamWriter outputStream;
     private boolean finished = false;
     private final LinkedBlockingQueue<AbstractStanza> writeQueue = new LinkedBlockingQueue<AbstractStanza>();
@@ -21,6 +24,8 @@ public class TagWriter {
 
     private final Thread asyncStanzaWriter = new Thread() {
 
+        private final AtomicInteger batchStanzaCount = new AtomicInteger(0);
+
         @Override
         public void run() {
             stanzaWriterCountDownLatch = new CountDownLatch(1);
@@ -29,12 +34,21 @@ public class TagWriter {
                     break;
                 }
                 try {
-                    AbstractStanza output = writeQueue.take();
-                    outputStream.write(output.toString());
-                    if (writeQueue.size() == 0) {
+                    final AbstractStanza stanza = writeQueue.poll(FLUSH_DELAY, TimeUnit.MILLISECONDS);
+                    if (stanza != null) {
+                        batchStanzaCount.incrementAndGet();
+                        outputStream.write(stanza.toString());
+                    } else {
+                        final int batch = batchStanzaCount.getAndSet(0);
+                        if (batch > 1) {
+                            Log.d(Config.LOGTAG, "flushing " + batch + " stanzas");
+                        }
                         outputStream.flush();
+                        final AbstractStanza nextStanza = writeQueue.take();
+                        batchStanzaCount.incrementAndGet();
+                        outputStream.write(nextStanza.toString());
                     }
-                } catch (Exception e) {
+                } catch (final Exception e) {
                     break;
                 }
             }