-module(mnesia_frag). -behaviour(mnesia_access).
%% Callback functions which provides transparent %% access of fragmented tables from any activity %% access context. lock(ActivityId, Opaque, {table , Tab}, LockKind) -> case frag_names(Tab) of [Tab] -> mnesia:lock(ActivityId, Opaque, {table, Tab}, LockKind); Frags -> DeepNs = [mnesia:lock(ActivityId, Opaque, {table, F}, LockKind) || F <- Frags], mnesia_lib:uniq(lists:append(DeepNs)) end; lock(ActivityId, Opaque, LockItem, LockKind) -> mnesia:lock(ActivityId, Opaque, LockItem, LockKind). write(ActivityId, Opaque, Tab, Rec, LockKind) -> Frag = record_to_frag_name(Tab, Rec), mnesia:write(ActivityId, Opaque, Frag, Rec, LockKind). delete(ActivityId, Opaque, Tab, Key, LockKind) -> Frag = key_to_frag_name(Tab, Key), mnesia:delete(ActivityId, Opaque, Frag, Key, LockKind). delete_object(ActivityId, Opaque, Tab, Rec, LockKind) -> Frag = record_to_frag_name(Tab, Rec), mnesia:delete_object(ActivityId, Opaque, Frag, Rec, LockKind). read(ActivityId, Opaque, Tab, Key, LockKind) -> Frag = key_to_frag_name(Tab, Key), mnesia:read(ActivityId, Opaque, Frag, Key, LockKind). match_object(ActivityId, Opaque, Tab, Pat, LockKind) -> Match = [mnesia:match_object(ActivityId, Opaque, Frag, Pat, LockKind) || Frag <- frag_names(Tab)], lists:flatten(Match). select(ActivityId, Opaque, Tab, MatchPattern, LockKind) -> Select = [mnesia:select(ActivityId, Opaque, Tab, MatchPattern, LockKind) || Frag <- frag_names(Tab)], lists:append(Select). all_keys(ActivityId, Opaque, Tab, LockKind) -> Match = [mnesia:all_keys(ActivityId, Opaque, Frag, LockKind) || Frag <- frag_names(Tab)], lists:append(Match). index_match_object(ActivityId, Opaque, Tab, Pat, Attr, LockKind) -> Match = [mnesia:index_match_object(ActivityId, Opaque, Frag, Pat, Attr, LockKind) || Frag <- frag_names(Tab)], lists:flatten(Match). index_read(ActivityId, Opaque, Tab, Key, Attr, LockKind) -> Match = [mnesia:index_read(ActivityId, Opaque, Frag, Key, Attr, LockKind) || Frag <- frag_names(Tab)], lists:append(Match). foldl(ActivityId, Opaque, Fun, Acc, Tab, LockKind) -> Fun2 = fun(Frag, A) -> mnesia:foldl(ActivityId, Opaque, Fun, A, Frag, LockKind) end, lists:foldl(Fun2, Acc, frag_names(Tab)). foldr(ActivityId, Opaque, Fun, Acc, Tab, LockKind) -> Fun2 = fun(Frag, A) -> mnesia:foldr(ActivityId, Opaque, Fun, A, Frag, LockKind) end, lists:foldr(Fun2, Acc, frag_names(Tab)). table_info(ActivityId, Opaque, {Tab, Key}, Item) -> Frag = key_to_frag_name(Tab, Key), table_info2(ActivityId, Opaque, Tab, Frag, Item); table_info(ActivityId, Opaque, Tab, Item) -> table_info2(ActivityId, Opaque, Tab, Tab, Item). table_info2(ActivityId, Opaque, Tab, Frag, Item) -> case Item of size -> SumFun = fun({_, Size}, Acc) -> Acc + Size end, lists:foldl(SumFun, 0, frag_size(ActivityId, Opaque, Tab)); memory -> SumFun = fun({_, Size}, Acc) -> Acc + Size end, lists:foldl(SumFun, 0, frag_memory(ActivityId, Opaque, Tab)); base_table -> lookup_prop(Tab, base_table); node_pool -> lookup_prop(Tab, node_pool); n_fragments -> FH = lookup_frag_hash(Tab), FH#frag_hash.n_fragments; foreign_key -> FH = lookup_frag_hash(Tab), FH#frag_hash.foreign_key; foreigners -> lookup_foreigners(Tab); n_ram_copies -> length(val({Tab, ram_copies})); n_disc_copies -> length(val({Tab, disc_copies})); n_disc_only_copies -> length(val({Tab, disc_only_copies})); frag_names -> frag_names(Tab); frag_dist -> frag_dist(Tab); frag_size -> frag_size(ActivityId, Opaque, Tab); frag_memory -> frag_memory(ActivityId, Opaque, Tab); _ -> mnesia:table_info(ActivityId, Opaque, Frag, Item) end.