From 475c5a0cf923a084dd5f7f04af1518f78384c02b Mon Sep 17 00:00:00 2001
From: Andreas Herrmann <andreas.herrmann@tweag.io>
Date: Tue, 24 Jan 2023 15:32:40 +0100
Subject: [PATCH] Remove skipBytes in favor of offset

Addressing review comment
https://github.com/bazelbuild/bazel/pull/14258#discussion_r1071370986
---
 .../lib/remote/http/HttpDownloadHandler.java    | 17 +++--------------
 1 file changed, 3 insertions(+), 14 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 35bea78d11ca37..89e78e11df2730 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
@@ -47,8 +47,6 @@ final class HttpDownloadHandler extends AbstractHttpHandler<HttpObject> {
   private String path;
   /** the offset at which to download */
   private long offset;
-  /** the bytes to skip in a full or chunked response */
-  private OptionalInt skipBytes;
 
   public HttpDownloadHandler(
       Credentials credentials, ImmutableList<Entry<String, String>> extraHttpHeaders) {
@@ -91,14 +89,6 @@ protected void channelRead0(ChannelHandlerContext ctx, HttpObject msg) throws Ex
       if (contentLengthSet) {
         contentLength = HttpUtil.getContentLength(response);
       }
-      if (offset != 0) {
-        // We are in a retried download and received a full response.
-        // We need to skip `offset` bytes of the response to continue writing from the offset.
-        if (!skipBytes.isPresent()) {
-          // This is the first chunk, or the full response.
-          skipBytes = OptionalInt.of((int)offset);
-        }
-      }
       downloadSucceeded = response.status().equals(HttpResponseStatus.OK);
       if (!downloadSucceeded) {
         out = new ByteArrayOutputStream();
@@ -111,13 +101,13 @@ protected void channelRead0(ChannelHandlerContext ctx, HttpObject msg) throws Ex
 
       ByteBuf content = ((HttpContent) msg).content();
       int readableBytes = content.readableBytes();
-      if (skipBytes.isPresent() && skipBytes.getAsInt() > 0) {
-        int skipNow = skipBytes.getAsInt();
+      if (offset > 0) {
+        int skipNow = (int)offset;
         if (skipNow >= readableBytes) {
           skipNow = readableBytes;
         }
         content.readerIndex(content.readerIndex() + skipNow);
-        skipBytes = OptionalInt.of(skipBytes.getAsInt() - skipNow);
+        offset -= skipNow;
         readableBytes = readableBytes - skipNow;
       }
       content.readBytes(out, readableBytes);
@@ -153,7 +143,6 @@ public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise)
     out = cmd.out();
     path = constructPath(cmd.uri(), cmd.digest().getHash(), cmd.casDownload());
     offset = cmd.offset();
-    skipBytes = OptionalInt.empty();
     HttpRequest request = buildRequest(path, constructHost(cmd.uri()));
     addCredentialHeaders(request, cmd.uri());
     addExtraRemoteHeaders(request);