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authorRobert Newson <rnewson@apache.org>2020-07-22 16:39:43 +0100
committerGitHub <noreply@github.com>2020-07-22 16:39:43 +0100
commit0a31cd86700fda734820f5bdf918103d1bd25e33 (patch)
treef63e7bcd4c9f9b9da0ec3577129913079adb3f4c
parent46ee05e215cad6419b642fca0bae85e36e27bd67 (diff)
parent983ff1c5a17c64e0c874374e4b0c00705c413341 (diff)
downloadcouchdb-0a31cd86700fda734820f5bdf918103d1bd25e33.tar.gz
Merge pull request #3023 from apache/prototype/fdb-layer-ebtree-order
Use stored order without complaint
-rw-r--r--src/ebtree/src/ebtree.erl33
1 files changed, 16 insertions, 17 deletions
diff --git a/src/ebtree/src/ebtree.erl b/src/ebtree/src/ebtree.erl
index f27f7d493..0ff8935ee 100644
--- a/src/ebtree/src/ebtree.erl
+++ b/src/ebtree/src/ebtree.erl
@@ -73,7 +73,8 @@ open(Db, Prefix, Order) ->
%% @doc Open a new ebtree, initialising it if doesn't already exist.
%% @param Db An erlfdb database or transaction.
%% @param Prefix The key prefix applied to all ebtree keys.
-%% @param Order The maximum number of items allowed in an ebtree node (must be an even number).
+%% @param Order The maximum number of items allowed in an ebtree node (must be an even number). Ignored
+%% if ebtree is already initialised.
%% @param Options Supported options are {reduce_fun, Fun} and {collate_fun, Fun}.
%% @returns A data structure representing the ebtree, to be passed to all other functions.
-spec open(term(), binary(), pos_integer(), list()) -> #tree{}.
@@ -82,27 +83,26 @@ open(Db, Prefix, Order, Options) when is_binary(Prefix), is_integer(Order), Orde
CollateFun = proplists:get_value(collate_fun, Options, fun collate_raw/2),
EncodeFun = proplists:get_value(encode_fun, Options, fun encode_erlang/2),
- Tree0 = init_tree(Prefix, Order),
- Tree1 = Tree0#tree{
+ Tree = #tree{
+ prefix = Prefix,
reduce_fun = ReduceFun,
collate_fun = CollateFun,
encode_fun = EncodeFun
},
erlfdb:transactional(Db, fun(Tx) ->
- case get_meta(Tx, Tree1, ?META_ORDER) of
+ case get_meta(Tx, Tree, ?META_ORDER) of
not_found ->
erlfdb:clear_range_startswith(Tx, Prefix),
- set_meta(Tx, Tree1, ?META_ORDER, Order),
- set_meta(Tx, Tree1, ?META_NEXT_ID, 1),
- set_node(Tx, Tree1, #node{id = ?NODE_ROOT_ID});
- Order ->
- ok;
- Else ->
- erlang:error({order_mismatch, Else})
+ set_meta(Tx, Tree, ?META_ORDER, Order),
+ set_meta(Tx, Tree, ?META_NEXT_ID, 1),
+ set_node(Tx, Tree, #node{id = ?NODE_ROOT_ID}),
+ init_order(Tree, Order);
+ ActualOrder when is_integer(ActualOrder) ->
+ init_order(Tree, ActualOrder)
end
- end),
- Tree1.
+ end).
+
%% @doc a special value guaranteed to be smaller than any value in an ebtree.
min() ->
@@ -958,10 +958,9 @@ encode_erlang(decode, Bin) ->
%% private functions
-init_tree(Prefix, Order)
- when is_binary(Prefix), is_integer(Order), Order > 2, Order rem 2 == 0 ->
- #tree{
- prefix = Prefix,
+init_order(#tree{} = Tree, Order)
+ when is_integer(Order), Order > 2, Order rem 2 == 0 ->
+ Tree#tree{
min = Order div 2,
max = Order
}.