From 8d49bc3cceee42ac6da94100ba19d234a72f371a Mon Sep 17 00:00:00 2001
From: Radoslaw Zarzynski <rzarzyns@redhat.com>
Date: Wed, 20 Feb 2019 02:44:38 +0100
Subject: [PATCH] msg/async, v2: drop magic numbers for segments.

Signed-off-by: Radoslaw Zarzynski <rzarzyns@redhat.com>
---
 src/msg/async/ProtocolV2.cc | 42 ++++++++++++++++++++++---------------
 src/msg/async/ProtocolV2.h  | 15 ++++++++++++-
 2 files changed, 39 insertions(+), 18 deletions(-)

diff --git a/src/msg/async/ProtocolV2.cc b/src/msg/async/ProtocolV2.cc
index b3f47d2d39d13..c1232c7199e31 100644
--- a/src/msg/async/ProtocolV2.cc
+++ b/src/msg/async/ProtocolV2.cc
@@ -707,9 +707,10 @@ void ProtocolV2::reset_recv_state() {
   connection->pendingReadLen.reset();
   connection->writeCallback.reset();
 
-  uint32_t cur_msg_size = rx_segments_desc[1].logical.length + \
-			  rx_segments_desc[2].logical.length + \
-			  rx_segments_desc[3].logical.length;
+  uint32_t cur_msg_size = \
+    rx_segments_desc[SegmentIndex::Msg::FRONT].logical.length + \
+    rx_segments_desc[SegmentIndex::Msg::MIDDLE].logical.length + \
+    rx_segments_desc[SegmentIndex::Msg::DATA].logical.length;
 
   if (state > THROTTLE_MESSAGE && state <= THROTTLE_DONE &&
       connection->policy.throttler_messages) {
@@ -1699,12 +1700,13 @@ CtPtr ProtocolV2::handle_message() {
   if (auth_meta->is_mode_secure()) {
     ceph_assert(session_stream_handlers.rx);
 
-    rx_segments_data[0] = \
+    rx_segments_data[SegmentIndex::Msg::HEADER] = \
       session_stream_handlers.rx->authenticated_decrypt_update(
-	std::move(rx_segments_data[0]),
+	std::move(rx_segments_data[SegmentIndex::Msg::HEADER]),
 	segment_t::DEFAULT_ALIGNMENT);
   }
-  MessageHeaderFrame header_frame(std::move(rx_segments_data[0]));
+  MessageHeaderFrame header_frame(
+    std::move(rx_segments_data[SegmentIndex::Msg::HEADER]));
   ceph_msg_header2 &header = header_frame.header();
 
   ldout(cct, 20) << __func__
@@ -1738,14 +1740,16 @@ CtPtr ProtocolV2::handle_message() {
   current_header = header;
 
   // front
-  ceph_assert(current_header.front_len == rx_segments_data[1].length());
+  ceph_assert(current_header.front_len == \
+    rx_segments_data[SegmentIndex::Msg::FRONT].length());
   ceph_assert(!front.length());
-  front = std::move(rx_segments_data[1]);
+  front = std::move(rx_segments_data[SegmentIndex::Msg::FRONT]);
 
   // middle
-  ceph_assert(current_header.middle_len == rx_segments_data[2].length());
+  ceph_assert(current_header.middle_len == \
+    rx_segments_data[SegmentIndex::Msg::MIDDLE].length());
   ceph_assert(!middle.length());
-  middle = std::move(rx_segments_data[2]);
+  middle = std::move(rx_segments_data[SegmentIndex::Msg::MIDDLE]);
 
   next_payload_len -= sizeof(ceph_msg_header2);
   next_payload_len -= front.length();
@@ -2053,9 +2057,10 @@ CtPtr ProtocolV2::throttle_bytes() {
   ldout(cct, 20) << __func__ << dendl;
 
   ceph_assert(rx_segments_desc.size() == 4);
-  uint32_t cur_msg_size = rx_segments_desc[1].logical.length + \
-			  rx_segments_desc[2].logical.length + \
-			  rx_segments_desc[3].logical.length;
+  uint32_t cur_msg_size = \
+    rx_segments_desc[SegmentIndex::Msg::FRONT].logical.length + \
+    rx_segments_desc[SegmentIndex::Msg::MIDDLE].logical.length + \
+    rx_segments_desc[SegmentIndex::Msg::DATA].logical.length;
   if (cur_msg_size) {
     if (connection->policy.throttler_bytes) {
       ldout(cct, 10) << __func__ << " wants " << cur_msg_size
@@ -2088,9 +2093,10 @@ CtPtr ProtocolV2::throttle_dispatch_queue() {
   ldout(cct, 20) << __func__ << dendl;
 
   ceph_assert(rx_segments_desc.size() == 4);
-  uint32_t cur_msg_size = rx_segments_desc[1].logical.length + \
-			  rx_segments_desc[2].logical.length + \
-			  rx_segments_desc[3].logical.length;
+  uint32_t cur_msg_size =
+    rx_segments_desc[SegmentIndex::Msg::FRONT].logical.length + \
+    rx_segments_desc[SegmentIndex::Msg::MIDDLE].logical.length + \
+    rx_segments_desc[SegmentIndex::Msg::DATA].logical.length;
 
   if (cur_msg_size) {
     if (!connection->dispatch_queue->dispatch_throttler.get_or_fail(
@@ -2450,7 +2456,9 @@ CtPtr ProtocolV2::handle_wait() {
   ldout(cct, 1) << __func__ << " received WAIT (connection race)" << dendl;
   state = WAIT;
   ceph_assert(rx_segments_data.size() == 1);
-  WaitFrame(*this, rx_segments_data[0].c_str(), rx_segments_data[0].length());
+  ceph_assert(rx_segments_desc.size() == 1);
+  WaitFrame(*this, rx_segments_data[SegmentIndex::Frame::PAYLOAD].c_str(),
+    rx_segments_data[SegmentIndex::Frame::PAYLOAD].length());
   return _fault();
 }
 
diff --git a/src/msg/async/ProtocolV2.h b/src/msg/async/ProtocolV2.h
index 8c8e4340df030..80292c5793cd7 100644
--- a/src/msg/async/ProtocolV2.h
+++ b/src/msg/async/ProtocolV2.h
@@ -127,14 +127,27 @@ public:
     struct segment_t logical;
   } __attribute__((packed));
 
-private:
   static constexpr std::size_t MAX_NUM_SEGMENTS = 4;
 
+  struct SegmentIndex {
+    struct Msg {
+      static constexpr std::size_t HEADER = 0;
+      static constexpr std::size_t FRONT = 1;
+      static constexpr std::size_t MIDDLE = 2;
+      static constexpr std::size_t DATA = 3;
+    };
+
+    struct Frame {
+      static constexpr std::size_t PAYLOAD = 0;
+    };
+  };
+
   boost::container::static_vector<onwire_segment_t,
 				  MAX_NUM_SEGMENTS> rx_segments_desc;
   boost::container::static_vector<ceph::bufferlist,
 				  MAX_NUM_SEGMENTS> rx_segments_data;
 
+private:
 
   Tag next_tag;
   ceph_msg_header2 current_header;
-- 
2.39.5