diff options
Diffstat (limited to 'src/rabbit_misc.erl')
| -rw-r--r-- | src/rabbit_misc.erl | 30 |
1 files changed, 17 insertions, 13 deletions
diff --git a/src/rabbit_misc.erl b/src/rabbit_misc.erl index 1daeeb2a..cec10ff6 100644 --- a/src/rabbit_misc.erl +++ b/src/rabbit_misc.erl @@ -38,7 +38,7 @@ -export([ensure_ok/2]). -export([makenode/1, nodeparts/1, cookie_hash/0, tcp_name/3]). -export([upmap/2, map_in_order/2]). --export([table_fold/3]). +-export([table_filter/3]). -export([dirty_read_all/1, dirty_foreach_key/2, dirty_dump_log/1]). -export([read_term_file/1, write_term_file/2]). -export([append_file/2, ensure_parent_dirs_exist/1]). @@ -145,7 +145,8 @@ -> atom()). -spec(upmap/2 :: (fun ((A) -> B), [A]) -> [B]). -spec(map_in_order/2 :: (fun ((A) -> B), [A]) -> [B]). --spec(table_fold/3 :: (fun ((any(), A) -> A), A, atom()) -> A). +-spec(table_filter/3:: (fun ((A) -> boolean()), fun ((A, boolean()) -> 'ok'), + atom()) -> [A]). -spec(dirty_read_all/1 :: (atom()) -> [any()]). -spec(dirty_foreach_key/2 :: (fun ((any()) -> any()), atom()) -> 'ok' | 'aborted'). @@ -459,20 +460,23 @@ map_in_order(F, L) -> lists:reverse( lists:foldl(fun (E, Acc) -> [F(E) | Acc] end, [], L)). -%% Fold over each entry in a table, executing the cons function in a -%% transaction. This is often far more efficient than wrapping a tx -%% around the lot. +%% Apply a pre-post-commit function to all entries in a table that +%% satisfy a predicate, and return those entries. %% %% We ignore entries that have been modified or removed. -table_fold(F, Acc0, TableName) -> +table_filter(Pred, PrePostCommitFun, TableName) -> lists:foldl( - fun (E, Acc) -> execute_mnesia_transaction( - fun () -> case mnesia:match_object(TableName, E, read) of - [] -> Acc; - _ -> F(E, Acc) - end - end) - end, Acc0, dirty_read_all(TableName)). + fun (E, Acc) -> + case execute_mnesia_transaction( + fun () -> mnesia:match_object(TableName, E, read) =/= [] + andalso Pred(E) end, + fun (false, _Tx) -> false; + (true, Tx) -> PrePostCommitFun(E, Tx), true + end) of + false -> Acc; + true -> [E | Acc] + end + end, [], dirty_read_all(TableName)). dirty_read_all(TableName) -> mnesia:dirty_select(TableName, [{'$1',[],['$1']}]). |