From f2891bfe8ef3e0a75ed2cc1501a960367e597f39 Mon Sep 17 00:00:00 2001
From: Alexander Golovlev <golovlev@gmail.com>
Date: Tue, 14 Oct 2025 21:06:52 +0300
Subject: [PATCH 1/2] Enable more HTTP decompression methods for remote cache

---
 .../lib/remote/http/HttpDownloadHandler.java    | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/main/java/com/google/devtools/build/lib/remote/http/HttpDownloadHandler.java b/src/main/java/com/google/devtools/build/lib/remote/http/HttpDownloadHandler.java
index 561329fd2ef4e7..5c9d068bbe84d0 100644
--- a/src/main/java/com/google/devtools/build/lib/remote/http/HttpDownloadHandler.java
+++ b/src/main/java/com/google/devtools/build/lib/remote/http/HttpDownloadHandler.java
@@ -20,6 +20,8 @@
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelPromise;
+import io.netty.handler.codec.compression.Brotli;
+import io.netty.handler.codec.compression.Zstd;
 import io.netty.handler.codec.http.DefaultFullHttpRequest;
 import io.netty.handler.codec.http.HttpContent;
 import io.netty.handler.codec.http.HttpHeaderNames;
@@ -42,6 +44,19 @@
 /** ChannelHandler for downloads. */
 final class HttpDownloadHandler extends AbstractHttpHandler<HttpObject> {
 
+  private static final String ACCEPT_ENCODING;
+  static {
+    StringBuilder acceptEncoding = new StringBuilder(HttpHeaderValues.GZIP);
+    acceptEncoding.append(",").append(HttpHeaderValues.DEFLATE).append(",").append(HttpHeaderValues.SNAPPY);
+    if (Brotli.isAvailable()) {
+      acceptEncoding.append(",").append(HttpHeaderValues.BR);
+    }
+    if (Zstd.isAvailable()) {
+      acceptEncoding.append(",").append(HttpHeaderValues.ZSTD);
+    }
+    ACCEPT_ENCODING = acceptEncoding.toString();
+  }
+
   private OutputStream out;
   private boolean keepAlive = HttpVersion.HTTP_1_1.isKeepAliveDefault();
   private boolean downloadSucceeded;
@@ -180,7 +195,7 @@ private HttpRequest buildRequest(String path, String host) {
     httpRequest.headers().set(HttpHeaderNames.HOST, host);
     httpRequest.headers().set(HttpHeaderNames.CONNECTION, HttpHeaderValues.KEEP_ALIVE);
     httpRequest.headers().set(HttpHeaderNames.ACCEPT, "*/*");
-    httpRequest.headers().set(HttpHeaderNames.ACCEPT_ENCODING, HttpHeaderValues.GZIP);
+    httpRequest.headers().set(HttpHeaderNames.ACCEPT_ENCODING, ACCEPT_ENCODING);
     return httpRequest;
   }
 

From 7603fc3741e248ed4b1ba34031eeb1ffca4e5258 Mon Sep 17 00:00:00 2001
From: Alexander Golovlev <golovlev@gmail.com>
Date: Fri, 17 Oct 2025 16:27:48 +0300
Subject: [PATCH 2/2] Extracted into static helper function

---
 .../lib/remote/http/HttpDownloadHandler.java  | 28 +++++++++++--------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/src/main/java/com/google/devtools/build/lib/remote/http/HttpDownloadHandler.java b/src/main/java/com/google/devtools/build/lib/remote/http/HttpDownloadHandler.java
index 5c9d068bbe84d0..08d5e3d38ba2ed 100644
--- a/src/main/java/com/google/devtools/build/lib/remote/http/HttpDownloadHandler.java
+++ b/src/main/java/com/google/devtools/build/lib/remote/http/HttpDownloadHandler.java
@@ -16,7 +16,9 @@
 import static com.google.common.base.Preconditions.checkState;
 
 import com.google.auth.Credentials;
+import com.google.common.base.Joiner;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Lists;
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelPromise;
@@ -35,27 +37,18 @@
 import io.netty.handler.codec.http.HttpVersion;
 import io.netty.handler.codec.http.LastHttpContent;
 import io.netty.handler.timeout.ReadTimeoutException;
+import io.netty.util.AsciiString;
 import io.netty.util.internal.StringUtil;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
+import java.util.ArrayList;
 import java.util.Map.Entry;
 
 /** ChannelHandler for downloads. */
 final class HttpDownloadHandler extends AbstractHttpHandler<HttpObject> {
 
-  private static final String ACCEPT_ENCODING;
-  static {
-    StringBuilder acceptEncoding = new StringBuilder(HttpHeaderValues.GZIP);
-    acceptEncoding.append(",").append(HttpHeaderValues.DEFLATE).append(",").append(HttpHeaderValues.SNAPPY);
-    if (Brotli.isAvailable()) {
-      acceptEncoding.append(",").append(HttpHeaderValues.BR);
-    }
-    if (Zstd.isAvailable()) {
-      acceptEncoding.append(",").append(HttpHeaderValues.ZSTD);
-    }
-    ACCEPT_ENCODING = acceptEncoding.toString();
-  }
+  private static final String ACCEPT_ENCODING = getAcceptEncoding();
 
   private OutputStream out;
   private boolean keepAlive = HttpVersion.HTTP_1_1.isKeepAliveDefault();
@@ -247,4 +240,15 @@ private void reset(ChannelHandlerContext ctx) {
       response = null;
     }
   }
+
+  private static String getAcceptEncoding() {
+    ArrayList<AsciiString> acceptEncoding = Lists.newArrayList(HttpHeaderValues.GZIP, HttpHeaderValues.DEFLATE, HttpHeaderValues.SNAPPY);
+    if (Brotli.isAvailable()) {
+      acceptEncoding.add(HttpHeaderValues.BR);
+    }
+    if (Zstd.isAvailable()) {
+      acceptEncoding.add(HttpHeaderValues.ZSTD);
+    }
+    return Joiner.on(",").join(acceptEncoding);
+  }
 }