From 339e15563e4b9fd9573e06dd5a2269fee0f6a077 Mon Sep 17 00:00:00 2001
From: Stephen Atherton <stevea@apple.com>
Date: Fri, 4 Jan 2019 18:34:16 -0800
Subject: [PATCH] Bug fix in blobstore request loop where zero-content requests
 (i.e. not uploads) could cause mismatches between requests and responses. 
 Added HTTPRequest debug event.

---
 fdbclient/BlobStore.actor.cpp |  2 +-
 fdbclient/HTTP.actor.cpp      | 11 +++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/fdbclient/BlobStore.actor.cpp b/fdbclient/BlobStore.actor.cpp
index 32d0864f70..d222491695 100644
--- a/fdbclient/BlobStore.actor.cpp
+++ b/fdbclient/BlobStore.actor.cpp
@@ -511,8 +511,8 @@ ACTOR Future<Reference<HTTP::Response>> doRequest_impl(Reference<BlobStoreEndpoi
 			Future<BlobStoreEndpoint::ReusableConnection> frconn = bstore->connect();
 
 			// Make a shallow copy of the queue by calling addref() on each buffer in the chain and then prepending that chain to contentCopy
+			contentCopy.discardAll();
 			if(pContent != nullptr) {
-				contentCopy.discardAll();
 				PacketBuffer *pFirst = pContent->getUnsent();
 				PacketBuffer *pLast = nullptr;
 				for(PacketBuffer *p = pFirst; p != nullptr; p = p->nextPacketBuffer()) {
diff --git a/fdbclient/HTTP.actor.cpp b/fdbclient/HTTP.actor.cpp
index 7b763abe4a..3bfca52b6e 100644
--- a/fdbclient/HTTP.actor.cpp
+++ b/fdbclient/HTTP.actor.cpp
@@ -294,6 +294,8 @@ namespace HTTP {
 	// and be destroyed by the caller
 	// TODO:  pSent is very hackish, do something better.
 	ACTOR Future<Reference<HTTP::Response>> doRequest(Reference<IConnection> conn, std::string verb, std::string resource, HTTP::Headers headers, UnsentPacketQueue *pContent, int contentLen, Reference<IRateControl> sendRate, int64_t *pSent, Reference<IRateControl> recvRate) {
+		state TraceEvent event(SevDebug, "HTTPRequest");
+
 		state UnsentPacketQueue empty;
 		if(pContent == NULL)
 			pContent = &empty;
@@ -301,6 +303,12 @@ namespace HTTP {
 		state bool earlyResponse = false;
 		state int total_sent = 0;
 
+		event.detail("DebugID", conn->getDebugID());
+		event.detail("RemoteAddress", conn->getPeerAddress());
+		event.detail("Verb", verb);
+		event.detail("Resource", resource);
+		event.detail("RequestContentLen", contentLen);
+
 		try {
 			// Write headers to a packet buffer chain
 			PacketBuffer *pFirst = new PacketBuffer();
@@ -347,8 +355,11 @@ namespace HTTP {
 			}
 
 			Void _ = wait(responseReading);
+			event.detail("ResponseCode", r->code);
+			event.detail("ResponseContentLen", r->contentLen);
 
 			double elapsed = timer() - send_start;
+			event.detail("Elapsed", elapsed);
 			if(CLIENT_KNOBS->HTTP_VERBOSE_LEVEL > 0)
 				printf("[%s] HTTP code=%d early=%d, time=%fs %s %s contentLen=%d [%d out, response content len %d]\n",
 					conn->getDebugID().toString().c_str(), r->code, earlyResponse, elapsed, verb.c_str(), resource.c_str(), contentLen, total_sent, (int)r->contentLen);