From baf0ac214747e7acde49b00404ba4323e2d24954 Mon Sep 17 00:00:00 2001
From: Yingxin Cheng <yingxin.cheng@intel.com>
Date: Wed, 2 Dec 2020 22:46:35 +0800
Subject: [PATCH] crimson/onode-staged-tree: rename NodeExtentT to
 NodeExtentAccessorT

Also renamed file name and added class comments.

Signed-off-by: Yingxin Cheng <yingxin.cheng@intel.com>
---
 ...xtent_visitor.h => node_extent_accessor.h} | 22 +++++++++++++------
 .../node_extent_manager/seastore.cc           |  2 +-
 .../onode_manager/staged-fltree/node_layout.h |  4 ++--
 3 files changed, 18 insertions(+), 10 deletions(-)
 rename src/crimson/os/seastore/onode_manager/staged-fltree/{node_extent_visitor.h => node_extent_accessor.h} (90%)

diff --git a/src/crimson/os/seastore/onode_manager/staged-fltree/node_extent_visitor.h b/src/crimson/os/seastore/onode_manager/staged-fltree/node_extent_accessor.h
similarity index 90%
rename from src/crimson/os/seastore/onode_manager/staged-fltree/node_extent_visitor.h
rename to src/crimson/os/seastore/onode_manager/staged-fltree/node_extent_accessor.h
index e5c883d3ec9..0c97b9211c6 100644
--- a/src/crimson/os/seastore/onode_manager/staged-fltree/node_extent_visitor.h
+++ b/src/crimson/os/seastore/onode_manager/staged-fltree/node_extent_accessor.h
@@ -71,8 +71,16 @@ class DeltaRecorderT final: public DeltaRecorder {
   }
 };
 
+/**
+ * NodeExtentAccessorT
+ *
+ * This component is responsible to mutate the underlying NodeExtent, record
+ * mutation parameters as delta and apply the recorded modifications to the
+ * NodeExtent. It contains static information about node and field type in
+ * order to call methods of NodeLayoutReplayable.
+ */
 template <typename FieldType, node_type_t NODE_TYPE>
-class NodeExtentT {
+class NodeExtentAccessorT {
  public:
   using layout_t = NodeLayoutReplayableT<FieldType, NODE_TYPE>;
   using node_stage_t = typename layout_t::node_stage_t;
@@ -82,7 +90,7 @@ class NodeExtentT {
   using value_t = typename layout_t::value_t;
   static constexpr auto FIELD_TYPE = layout_t::FIELD_TYPE;
 
-  NodeExtentT(NodeExtentRef extent)
+  NodeExtentAccessorT(NodeExtentRef extent)
       : extent{extent},
         node_stage{reinterpret_cast<const FieldType*>(extent->get_read())} {
     if (no_recording()) {
@@ -105,11 +113,11 @@ class NodeExtentT {
       ceph_abort("impossible path");
     }
   }
-  ~NodeExtentT() = default;
-  NodeExtentT(const NodeExtentT&) = delete;
-  NodeExtentT(NodeExtentT&&) = delete;
-  NodeExtentT& operator=(const NodeExtentT&) = delete;
-  NodeExtentT& operator=(NodeExtentT&&) = delete;
+  ~NodeExtentAccessorT() = default;
+  NodeExtentAccessorT(const NodeExtentAccessorT&) = delete;
+  NodeExtentAccessorT(NodeExtentAccessorT&&) = delete;
+  NodeExtentAccessorT& operator=(const NodeExtentAccessorT&) = delete;
+  NodeExtentAccessorT& operator=(NodeExtentAccessorT&&) = delete;
 
   const node_stage_t& read() const { return node_stage; }
   laddr_t get_laddr() const { return extent->get_laddr(); }
diff --git a/src/crimson/os/seastore/onode_manager/staged-fltree/node_extent_manager/seastore.cc b/src/crimson/os/seastore/onode_manager/staged-fltree/node_extent_manager/seastore.cc
index c51ec24740c..8d88485bf72 100644
--- a/src/crimson/os/seastore/onode_manager/staged-fltree/node_extent_manager/seastore.cc
+++ b/src/crimson/os/seastore/onode_manager/staged-fltree/node_extent_manager/seastore.cc
@@ -3,7 +3,7 @@
 
 #include "seastore.h"
 
-#include "crimson/os/seastore/onode_manager/staged-fltree/node_extent_visitor.h"
+#include "crimson/os/seastore/onode_manager/staged-fltree/node_extent_accessor.h"
 #include "crimson/os/seastore/onode_manager/staged-fltree/stages/node_stage_layout.h"
 
 namespace {
diff --git a/src/crimson/os/seastore/onode_manager/staged-fltree/node_layout.h b/src/crimson/os/seastore/onode_manager/staged-fltree/node_layout.h
index 4df7d3720c9..24a50225619 100644
--- a/src/crimson/os/seastore/onode_manager/staged-fltree/node_layout.h
+++ b/src/crimson/os/seastore/onode_manager/staged-fltree/node_layout.h
@@ -8,7 +8,7 @@
 
 #include "common/likely.h"
 #include "crimson/common/log.h"
-#include "node_extent_visitor.h"
+#include "node_extent_accessor.h"
 #include "node_impl.h"
 #include "stages/node_stage_layout.h"
 
@@ -36,7 +36,7 @@ template <typename FieldType, node_type_t NODE_TYPE>
 class NodeLayoutT final : public InternalNodeImpl, public LeafNodeImpl {
  public:
   using URef = std::unique_ptr<NodeLayoutT>;
-  using extent_t = NodeExtentT<FieldType, NODE_TYPE>;
+  using extent_t = NodeExtentAccessorT<FieldType, NODE_TYPE>;
   using parent_t = typename node_impl_type<NODE_TYPE>::type;
   using marker_t = typename node_marker_type<NODE_TYPE>::type;
   using node_stage_t = typename extent_t::node_stage_t;
-- 
2.39.5