crimson/onode-staged-tree: implement tree-level erase interfaces

Define and implement erase related interfaces from BTree, BTree::Cursor,
tree_cursor_t, Node to LeafNode.

Signed-off-by: Yingxin Cheng <yingxin.cheng@intel.com>

diff --git a/src/crimson/os/seastore/onode_manager/staged-fltree/fltree_onode_manager.cc b/src/crimson/os/seastore/onode_manager/staged-fltree/fltree_onode_manager.cc
index 031bf42e7ae7432175a33935283ec1a428e850f9..b80e237e763321ba04e2c719096fd2f5e11f18af 100644 (file)
--- a/src/crimson/os/seastore/onode_manager/staged-fltree/fltree_onode_manager.cc
+++ b/src/crimson/os/seastore/onode_manager/staged-fltree/fltree_onode_manager.cc
@@ -105,7 +105,7 @@ FLTreeOnodeManager::write_dirty_ret FLTreeOnodeManager::write_dirty(
        return seastar::now();
       }
       case FLTreeOnode::status_t::DELETED: {
-       return tree.erase(trans, flonode).safe_then([](auto) {});
+       return tree.erase(trans, flonode);
       }
       case FLTreeOnode::status_t::STABLE: {
        return seastar::now();

diff --git a/src/crimson/os/seastore/onode_manager/staged-fltree/node.cc b/src/crimson/os/seastore/onode_manager/staged-fltree/node.cc
index 2c64f94810db84332968c5a388353fd056e99182..578e91011784c3baa0d1ea9f90b646340e956bae 100644 (file)
--- a/src/crimson/os/seastore/onode_manager/staged-fltree/node.cc
+++ b/src/crimson/os/seastore/onode_manager/staged-fltree/node.cc
@@ -95,6 +95,13 @@ void tree_cursor_t::assert_next_to(
 #endif
 }
 
+tree_cursor_t::future<Ref<tree_cursor_t>>
+tree_cursor_t::erase(context_t c, bool get_next)
+{
+  assert(is_tracked());
+  return ref_leaf_node->erase(c, position, get_next);
+}
+
 MatchKindCMP tree_cursor_t::compare_to(
     const tree_cursor_t& o, value_magic_t magic) const
 {
@@ -322,6 +329,23 @@ node_future<std::pair<Ref<tree_cursor_t>, bool>> Node::insert(
   );
 }
 
+node_future<std::size_t> Node::erase(
+    context_t c, const key_hobj_t& key)
+{
+  return lower_bound(c, key).safe_then([c] (auto result) {
+    if (result.match() != MatchKindBS::EQ) {
+      return node_ertr::make_ready_future<std::size_t>(0);
+    }
+    auto ref_cursor = result.p_cursor;
+    return ref_cursor->erase(c, false
+    ).safe_then([ref_cursor] (auto next_cursor) {
+      assert(ref_cursor->is_invalid());
+      assert(!next_cursor);
+      return std::size_t(1);
+    });
+  });
+}
+
 node_future<tree_stats_t> Node::get_tree_stats(context_t c)
 {
   return seastar::do_with(
@@ -870,6 +894,14 @@ LeafNode::get_next_cursor(context_t c, const search_position_t& pos)
   }
 }
 
+node_future<Ref<tree_cursor_t>>
+LeafNode::erase(context_t c, const search_position_t& pos, bool get_next)
+{
+  ceph_abort("not implemented");
+  return node_ertr::make_ready_future<Ref<tree_cursor_t>>(
+      tree_cursor_t::get_invalid());
+}
+
 node_future<> LeafNode::extend_value(
     context_t c, const search_position_t& pos, value_size_t extend_size)
 {

diff --git a/src/crimson/os/seastore/onode_manager/staged-fltree/node.h b/src/crimson/os/seastore/onode_manager/staged-fltree/node.h
index 7bca8f3ec63b09234430be671fd24ba00750220a..778d386c06661ea7b4707afea4c71e962ce6bfce 100644 (file)
--- a/src/crimson/os/seastore/onode_manager/staged-fltree/node.h
+++ b/src/crimson/os/seastore/onode_manager/staged-fltree/node.h
@@ -128,6 +128,9 @@ class tree_cursor_t final
   /// Check that this is next to prv
   void assert_next_to(const tree_cursor_t&, value_magic_t) const;
 
+  /// Erases the key-value pair from tree.
+  future<Ref<tree_cursor_t>> erase(context_t, bool get_next);
+
   MatchKindCMP compare_to(const tree_cursor_t&, value_magic_t) const;
 
   // public to Value
@@ -352,6 +355,15 @@ class Node
   node_future<std::pair<Ref<tree_cursor_t>, bool>> insert(
       context_t, const key_hobj_t&, value_config_t);
 
+  /**
+   * erase
+   *
+   * Removes a key-value pair from the sub-tree formed by this node.
+   *
+   * Returns the number of erased key-value pairs (0 or 1).
+   */
+  node_future<std::size_t> erase(context_t, const key_hobj_t&);
+
   /// Recursively collects the statistics of the sub-tree formed by this node
   node_future<tree_stats_t> get_tree_stats(context_t);
 
@@ -559,6 +571,17 @@ class LeafNode final : public Node {
   std::tuple<key_view_t, const value_header_t*> get_kv(const search_position_t&) const;
   node_future<Ref<tree_cursor_t>> get_next_cursor(context_t, const search_position_t&);
 
+  /**
+   * erase
+   *
+   * Removes a key-value pair from the position.
+   *
+   * If get_next is true, returns the cursor pointing to the next key-value
+   * pair that followed the erased element, which can be nullptr if is end.
+   */
+  node_future<Ref<tree_cursor_t>> erase(
+      context_t, const search_position_t&, bool get_next);
+
   template <bool VALIDATE>
   void do_track_cursor(tree_cursor_t& cursor) {
     if constexpr (VALIDATE) {

diff --git a/src/crimson/os/seastore/onode_manager/staged-fltree/tree.h b/src/crimson/os/seastore/onode_manager/staged-fltree/tree.h
index 298698d4d47701a33441f30c827f0d67f6bdd12a..06e9ca11429990340a58ab745d951b75ac813a01 100644 (file)
--- a/src/crimson/os/seastore/onode_manager/staged-fltree/tree.h
+++ b/src/crimson/os/seastore/onode_manager/staged-fltree/tree.h
@@ -18,14 +18,11 @@
 /**
  * tree.h
  *
- * An example implementation to expose tree interfaces to users. The current
- * interface design is based on:
- * - ceph::os::Transaction::create/touch/remove()
- * - ceph::ObjectStore::collection_list()
- * - ceph::BlueStore::get_onode()
- * - db->get_iterator(PREFIIX_OBJ) by ceph::BlueStore::fsck()
- *
- * TODO: Redesign the interfaces based on real onode manager requirements.
+ * A special-purpose and b-tree-based implementation that:
+ * - Fulfills requirements of OnodeManager to index ordered onode key-values;
+ * - Runs above seastore block and transaction layer;
+ * - Specially optimized for onode key structures and seastore
+ *   delta/transaction semantics;
  */
 
 namespace crimson::os::seastore::onode {
@@ -113,6 +110,21 @@ class Btree {
       });
     }
 
+    btree_future<Cursor> erase(Transaction& t) {
+      assert(!is_end());
+      auto this_obj = *this;
+      return p_cursor->erase(p_tree->get_context(t), true
+      ).safe_then([this_obj, this] (Ref<tree_cursor_t> next_cursor) {
+        assert(p_cursor->is_invalid());
+        if (next_cursor) {
+          assert(!next_cursor->is_end());
+          return Cursor{p_tree, next_cursor};
+        } else {
+          return Cursor{p_tree};
+        }
+      });
+    }
+
    private:
     Cursor(Btree* p_tree, Ref<tree_cursor_t> _p_cursor) : p_tree(p_tree) {
       if (_p_cursor->is_invalid()) {
@@ -213,6 +225,10 @@ class Btree {
     );
   }
 
+  btree_future<Cursor> get_next(Transaction& t, Cursor& cursor) {
+    return cursor.get_next(t);
+  }
+
   /*
    * modifiers
    */
@@ -236,27 +252,29 @@ class Btree {
     );
   }
 
-  btree_future<size_t> erase(Transaction& t, const ghobject_t& obj) {
-    // TODO
-    return btree_ertr::make_ready_future<size_t>(0u);
-  }
-
-  btree_future<Cursor> erase(Transaction &t, Cursor& pos) {
-    // TODO
-    return btree_ertr::make_ready_future<Cursor>(
-        Cursor::make_end(this));
+  btree_future<std::size_t> erase(Transaction& t, const ghobject_t& obj) {
+    return seastar::do_with(
+      full_key_t<KeyT::HOBJ>(obj),
+      [this, &t](auto& key) -> btree_future<std::size_t> {
+        return get_root(t).safe_then([this, &t, &key](auto root) {
+          return root->erase(get_context(t), key);
+        });
+      }
+    );
   }
 
-  btree_future<Cursor> erase(Transaction &t, Cursor& first, Cursor& last) {
-    // TODO
-    return btree_ertr::make_ready_future<Cursor>(
-        Cursor::make_end(this));
+  btree_future<Cursor> erase(Transaction& t, Cursor& pos) {
+    return pos.erase(t);
   }
 
-  btree_future<Cursor> erase(Transaction &t, Value &value) {
-    // TODO
-    return btree_ertr::make_ready_future<Cursor>(
-        Cursor::make_end(this));
+  btree_future<> erase(Transaction& t, Value& value) {
+    assert(value.is_tracked());
+    auto ref_cursor = value.p_cursor;
+    return ref_cursor->erase(get_context(t), false
+    ).safe_then([ref_cursor] (auto next_cursor) {
+      assert(ref_cursor->is_invalid());
+      assert(!next_cursor);
+    });
   }
 
   /*

diff --git a/src/crimson/os/seastore/onode_manager/staged-fltree/value.h b/src/crimson/os/seastore/onode_manager/staged-fltree/value.h
index 4cbdd4825952828bdede5cebfecc4fdf09502e49..207e3c58eb898d50372943a5b0c47c2e98ad4133 100644 (file)
--- a/src/crimson/os/seastore/onode_manager/staged-fltree/value.h
+++ b/src/crimson/os/seastore/onode_manager/staged-fltree/value.h
@@ -233,6 +233,9 @@ class Value {
   NodeExtentManager& nm;
   const ValueBuilder& vb;
   Ref<tree_cursor_t> p_cursor;
+
+  template <typename ValueImpl>
+  friend class Btree;
 };
 
 /**