From 6bbeedc932121d953c769451f8987ffa8a31ef9f Mon Sep 17 00:00:00 2001
From: Armin Braun <me@obrown.io>
Date: Tue, 1 Dec 2020 02:44:36 +0100
Subject: [PATCH] Reset Deflater/Inflater after Use in DeflateCompressor
 (#65617) (#65646)

We should reset after use, not before reuse. Otherwise we keep the input buffers
on these objects around for a long time and they can grow to O(MB).
---
 .../elasticsearch/common/compress/DeflateCompressor.java  | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/server/src/main/java/org/elasticsearch/common/compress/DeflateCompressor.java b/server/src/main/java/org/elasticsearch/common/compress/DeflateCompressor.java
index f3e229b3496..411198e9307 100644
--- a/server/src/main/java/org/elasticsearch/common/compress/DeflateCompressor.java
+++ b/server/src/main/java/org/elasticsearch/common/compress/DeflateCompressor.java
@@ -229,9 +229,10 @@ public class DeflateCompressor implements Compressor {
     public BytesReference uncompress(BytesReference bytesReference) throws IOException {
         final BytesStreamOutput buffer = baos.get();
         final Inflater inflater = inflaterRef.get();
-        inflater.reset();
         try (InflaterOutputStream ios = new InflaterOutputStream(buffer, inflater)) {
             bytesReference.slice(HEADER.length, bytesReference.length() - HEADER.length).writeTo(ios);
+        } finally {
+            inflater.reset();
         }
         final BytesReference res = buffer.copyBytes();
         buffer.reset();
@@ -245,11 +246,12 @@ public class DeflateCompressor implements Compressor {
     @Override
     public BytesReference compress(BytesReference bytesReference) throws IOException {
         final BytesStreamOutput buffer = baos.get();
-        final Deflater deflater = deflaterRef.get();
-        deflater.reset();
         buffer.write(HEADER);
+        final Deflater deflater = deflaterRef.get();
         try (DeflaterOutputStream dos = new DeflaterOutputStream(buffer, deflater, true)) {
             bytesReference.writeTo(dos);
+        } finally {
+            deflater.reset();
         }
         final BytesReference res = buffer.copyBytes();
         buffer.reset();