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authorUlf Wiger <[email protected]>2011-08-01 18:38:17 +0200
committerDan Gudmundsson <[email protected]>2011-09-15 15:34:18 +0200
commit43647249896ca972844796cdd8e23d485749a7ed (patch)
treecd2dc156a037b50d7daa29d6c309c2f638d13d82
parent2566dbcc68213fdd0aba0323dc43c7fa70a9bba0 (diff)
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[mnesia] Mnesia schema merge tested with 2 nodes, r13b04 -> r14b (dev)
The do_merge_schema function now converts cstructs from a remote node when it detects that they are different. In order to be compatible the other way around, mnesia_controller:get_cstructs() detects a remote caller, and converts the cstructs before sending them.
-rw-r--r--lib/mnesia/src/mnesia_controller.erl59
-rw-r--r--lib/mnesia/src/mnesia_schema.erl26
2 files changed, 77 insertions, 8 deletions
diff --git a/lib/mnesia/src/mnesia_controller.erl b/lib/mnesia/src/mnesia_controller.erl
index d4b2c7b5cc..8a02fe0226 100644
--- a/lib/mnesia/src/mnesia_controller.erl
+++ b/lib/mnesia/src/mnesia_controller.erl
@@ -57,7 +57,8 @@
release_schema_commit_lock/0,
create_table/1,
get_disc_copy/1,
- get_cstructs/0,
+ get_remote_cstructs/0, % new function
+ get_cstructs/0, % old function
sync_and_block_table_whereabouts/4,
sync_del_table_copy_whereabouts/2,
block_table/1,
@@ -278,9 +279,63 @@ rec_tabs([], _, _, Init) ->
unlink(Init),
ok.
-get_cstructs() ->
+%% New function that does exactly what get_cstructs() used to do.
+%% When this function is called, we know that the calling node knows
+%% how to convert cstructs on the receiving end (should they differ).
+get_remote_cstructs() ->
call(get_cstructs).
+%% Old function kept for backwards compatibility; converts cstructs before sending.
+get_cstructs() ->
+ {cstructs, Cstructs, Running} = Reply = call(get_cstructs),
+ case is_remote_call() of
+ {true, Node} ->
+ {cstructs, normalize_cstructs(Cstructs, Node), Running};
+ false ->
+ Reply
+ end.
+
+is_remote_call() ->
+ case node(group_leader()) of
+ N when N =/= node() ->
+ {true, N};
+ _ ->
+ false
+ end.
+
+normalize_cstructs(Cstructs, Node) ->
+ %% backward-compatibility hack; normalize before returning
+ case rpc:call(Node, mnesia_lib, val, [{schema,cstruct}]) of
+ {badrpc, _} ->
+ %% assume it's not a schema merge
+ Cstructs;
+ #cstruct{} ->
+ %% same format
+ Cstructs;
+ Cstruct ->
+ %% some other format
+ RemoteFields = [F || {F,_} <- rpc:call(Node, mnesia_schema, cs2list, [Cstruct])],
+ [convert_cs(Cs, RemoteFields) || Cs <- Cstructs]
+ end.
+
+convert_cs(Cs, Fields) ->
+ MyFields = record_info(fields, cstruct),
+ convert(tl(tuple_to_list(Cs)), MyFields, Fields, []).
+
+convert([H|T], [F|FsL], [F|FsR], Acc) ->
+ convert(T, FsL, FsR, [H|Acc]);
+convert([H|T], [Fl|FsL] = L, [Fr|FsR] = R, Acc) ->
+ case {lists:member(Fl, FsR), lists:member(Fr, FsL)} of
+ {true, false} ->
+ convert(T, L, FsR, [H|Acc]);
+ {false, true} ->
+ %% Field Fl doesn't exist on receiver side; skip.
+ convert(T, FsL, R, Acc)
+ end;
+convert([], _, _, Acc) ->
+ list_to_tuple([cstruct|lists:reverse(Acc)]).
+
+
update(Fun) ->
call({update,Fun}).
diff --git a/lib/mnesia/src/mnesia_schema.erl b/lib/mnesia/src/mnesia_schema.erl
index fef72ad39c..e5cea16f0c 100644
--- a/lib/mnesia/src/mnesia_schema.erl
+++ b/lib/mnesia/src/mnesia_schema.erl
@@ -2733,7 +2733,8 @@ do_merge_schema(LockTabs0) ->
Tid, Store, T, mnesia_lib:intersect(Ns, OtherNodes))
|| {T,Ns} <- LockTabs],
case rpc:call(Node, mnesia_controller, get_cstructs, []) of
- {cstructs, Cstructs, RemoteRunning1} ->
+ {cstructs, Cstructs0, RemoteRunning1} ->
+ {Cstructs, DeleteFields} = normalize_remote_cstructs(Cstructs0, Node),
LockedAlready = Running ++ [Node],
{New, Old} = mnesia_recover:connect_nodes(RemoteRunning1),
RemoteRunning = mnesia_lib:intersect(New ++ Old, RemoteRunning1),
@@ -2754,19 +2755,20 @@ do_merge_schema(LockTabs0) ->
%% Announce that Node is running
A = [{op, announce_im_running, node(),
- cs2list(SchemaCs), Running, RemoteRunning}],
+ [{K,V} || {K,V} <- cs2list(SchemaCs),
+ not lists:member(K, DeleteFields)], Running, RemoteRunning}],
do_insert_schema_ops(Store, A),
-
+
%% Introduce remote tables to local node
do_insert_schema_ops(Store, make_merge_schema(Node, Cstructs)),
-
+
%% Introduce local tables to remote nodes
Tabs = val({schema, tables}),
Ops = [{op, merge_schema, get_create_list(T)}
|| T <- Tabs,
not lists:keymember(T, #cstruct.name, Cstructs)],
do_insert_schema_ops(Store, Ops),
-
+
%% Ensure that the txn will be committed on all nodes
NewNodes = RemoteRunning -- Running,
mnesia_lib:set(prepare_op, {announce_im_running,NewNodes}),
@@ -2782,6 +2784,18 @@ do_merge_schema(LockTabs0) ->
not_merged
end.
+normalize_remote_cstructs([#cstruct{}|_] = Cstructs, _) ->
+ {Cstructs, []};
+normalize_remote_cstructs([T|_] = Cstructs, Node) when element(1,T) == cstruct ->
+ Flds = [F || {F, _} <- rpc:call(Node, ?MODULE, cs2list, [T])],
+ DeleteFields = record_info(fields, cstruct) -- Flds,
+ NewCstructs = lists:map(
+ fun(Cs) ->
+ CsL = lists:zip(Flds, tl(tuple_to_list(Cs))),
+ #cstruct{} = list2cs(CsL)
+ end, Cstructs),
+ {NewCstructs, DeleteFields}.
+
tab_to_nodes(Tab) when is_atom(Tab) ->
Cs = val({Tab, cstruct}),
mnesia_lib:cs_to_nodes(Cs).
@@ -2919,7 +2933,7 @@ do_make_merge_schema(Node, RemoteCs) ->
%% Choose remote cstruct,
%% since it's the master
[{op, merge_schema, cs2list(RemoteCs)}];
-
+
true ->
Str = io_lib:format("Bad cookie in table definition"
" ~w: ~w = ~w, ~w = ~w~n",