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Posted to commits@couchdb.apache.org by rn...@apache.org on 2020/09/03 17:42:24 UTC
[couchdb] 03/07: consolidate id mutation logic into one function
This is an automated email from the ASF dual-hosted git repository.
rnewson pushed a commit to branch prototype/fdb-layer-ebtree-immutable
in repository https://gitbox.apache.org/repos/asf/couchdb.git
commit ebd269457ba98774809955ae6a20f585f9ffa8f2
Author: Robert Newson <rn...@apache.org>
AuthorDate: Thu Jul 23 19:02:24 2020 +0100
consolidate id mutation logic into one function
---
src/ebtree/src/ebtree.erl | 64 +++++++++++++++++++----------------------------
1 file changed, 26 insertions(+), 38 deletions(-)
diff --git a/src/ebtree/src/ebtree.erl b/src/ebtree/src/ebtree.erl
index d9bc30b..34f42e6 100644
--- a/src/ebtree/src/ebtree.erl
+++ b/src/ebtree/src/ebtree.erl
@@ -549,15 +549,7 @@ split_child(Tx, #tree{} = Tree, #node{} = Parent0, #node{} = Child) ->
umerge_members(Tree, Parent0#node.level, [{FirstRightKey, LastRightKey, RightId, RightReduction}],
lists:keydelete(Child#node.id, 3, Parent0#node.members)))
},
- Parent2 =
- if Parent1#node.id == ?NODE_ROOT_ID ->
- Parent1;
- Parent0#node.members == Parent1#node.members ->
- Parent1;
- true ->
- clear_node(Tx, Tree, Parent1),
- Parent1#node{id = new_node_id(Tx, Tree)}
- end,
+ Parent2 = new_node_id_if_cacheable(Tx, Tree, Parent0, Parent1),
clear_node(Tx, Tree, Child),
set_nodes(Tx, Tree, [LeftChild, RightChild, Parent2]),
{Parent2, LeftChild, RightChild}.
@@ -612,15 +604,7 @@ insert_nonfull(Tx, #tree{} = Tree, #node{} = Node0, Key, Value) ->
members = lists:keyreplace(ChildId1, 3, Node1#node.members,
{NewFirstKey, NewLastKey, ChildId2, NewReduction})
},
- Node3 = if
- Node2#node.id == ?NODE_ROOT_ID ->
- Node2;
- Node0#node.members == Node2#node.members ->
- Node2;
- true ->
- clear_node(Tx, Tree, Node2),
- Node2#node{id = new_node_id(Tx, Tree)}
- end,
+ Node3 = new_node_id_if_cacheable(Tx, Tree, Node0, Node2),
set_node(Tx, Tree, Node0, Node3),
{Node3#node.id, reduce_node(Tree, Node3)}.
@@ -686,16 +670,7 @@ delete(Tx, #tree{} = Tree, #node{} = Parent0, Key) ->
Parent1 = Parent0#node{
members = Members3
},
- Parent2 = if
- Parent1#node.id == ?NODE_ROOT_ID ->
- Parent1;
- Parent0#node.members == Parent1#node.members ->
- Parent1;
- true ->
- clear_node(Tx, Tree, Parent1),
- Parent1#node{id = new_node_id(Tx, Tree)}
- end,
-
+ Parent2 = new_node_id_if_cacheable(Tx, Tree, Parent0, Parent1),
clear_nodes(Tx, Tree, [Child0, Sibling]),
set_nodes(Tx, Tree, NewNodes),
Parent2;
@@ -706,16 +681,7 @@ delete(Tx, #tree{} = Tree, #node{} = Parent0, Key) ->
members = lists:keyreplace(ChildId0, 3, Parent0#node.members,
{first_key(Child1), last_key(Child1), Child1#node.id, reduce_node(Tree, Child1)})
},
- Parent2 = if
- Parent1#node.id == ?NODE_ROOT_ID ->
- Parent1;
- Parent0#node.members == Parent1#node.members ->
- Parent1;
- true ->
- clear_node(Tx, Tree, Parent1),
- Parent1#node{id = new_node_id(Tx, Tree)}
- end,
- Parent2
+ new_node_id_if_cacheable(Tx, Tree, Parent0, Parent1)
end.
@@ -1090,6 +1056,28 @@ last_key(Members) when is_list(Members) ->
end.
+new_node_id_if_cacheable(Tx, #tree{} = Tree, #node{} = Old, #node{} = New) ->
+ MembersChanged = Old#node.members /= New#node.members,
+ NodeIsCacheable = node_is_cacheable(New),
+ if
+ MembersChanged andalso NodeIsCacheable ->
+ clear_node(Tx, Tree, New),
+ New#node{id = new_node_id(Tx, Tree)};
+ true ->
+ New
+ end.
+
+
+node_is_cacheable(#node{id = ?NODE_ROOT_ID}) ->
+ false;
+
+node_is_cacheable(#node{level = 0}) ->
+ false;
+
+node_is_cacheable(#node{}) ->
+ true.
+
+
new_node_id(Tx, Tree) ->
NextId = get_meta(Tx, Tree, ?META_NEXT_ID),
set_meta(Tx, Tree, ?META_NEXT_ID, NextId + 1),