diff options
Diffstat (limited to 'src/rabbit_misc.erl')
| -rw-r--r-- | src/rabbit_misc.erl | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/src/rabbit_misc.erl b/src/rabbit_misc.erl index 053bde54..5730fdc0 100644 --- a/src/rabbit_misc.erl +++ b/src/rabbit_misc.erl @@ -46,6 +46,7 @@ -export([ensure_ok/2]). -export([localnode/1, tcp_name/3]). -export([intersperse/2, upmap/2, map_in_order/2]). +-export([table_foreach/2]). -export([dirty_read_all/1, dirty_foreach_key/2, dirty_dump_log/1]). -export([append_file/2, ensure_parent_dirs_exist/1]). -export([format_stderr/2]). @@ -97,6 +98,7 @@ -spec(intersperse/2 :: (A, [A]) -> [A]). -spec(upmap/2 :: (fun ((A) -> B), [A]) -> [B]). -spec(map_in_order/2 :: (fun ((A) -> B), [A]) -> [B]). +-spec(table_foreach/2 :: (fun ((any()) -> any()), atom()) -> 'ok'). -spec(dirty_read_all/1 :: (atom()) -> [any()]). -spec(dirty_foreach_key/2 :: (fun ((any()) -> any()), atom()) -> 'ok' | 'aborted'). @@ -295,6 +297,21 @@ map_in_order(F, L) -> lists:reverse( lists:foldl(fun (E, Acc) -> [F(E) | Acc] end, [], L)). +%% For each entry in a table, execute a function in a transaction. +%% This is often far more efficient than wrapping a tx around the lot. +%% +%% We ignore entries that have been modified or removed. +table_foreach(F, TableName) -> + lists:foreach( + fun (E) -> execute_mnesia_transaction( + fun () -> case mnesia:match_object(TableName, E, read) of + [] -> ok; + _ -> F(E) + end + end) + end, dirty_read_all(TableName)), + ok. + dirty_read_all(TableName) -> mnesia:dirty_select(TableName, [{'$1',[],['$1']}]). |