The R13B03 release.OTP_R13B03

1 files changed, 1306 insertions, 0 deletions

diff --git a/lib/mnesia/src/mnesia_lib.erl b/lib/mnesia/src/mnesia_lib.erl
new file mode 100644
index 0000000000..dba808e66e
--- /dev/null
+++ b/lib/mnesia/src/mnesia_lib.erl
@@ -0,0 +1,1306 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 1996-2009. All Rights Reserved.
+%% 
+%% The contents of this file are subject to the Erlang Public License,
+%% Version 1.1, (the "License"); you may not use this file except in
+%% compliance with the License. You should have received a copy of the
+%% Erlang Public License along with this software. If not, it can be
+%% retrieved online at http://www.erlang.org/.
+%% 
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and limitations
+%% under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+%%
+%% This module contains all sorts of various which doesn't fit
+%% anywhere else. Basically everything is exported.
+
+-module(mnesia_lib).
+
+-include("mnesia.hrl").
+-include_lib("kernel/include/file.hrl").
+
+-export([core_file/0]).
+
+-export([
+	 active_tables/0,
+	 add/2,
+	 add_list/2,
+	 add_lsort/2,
+	 all_nodes/0,
+%%	 catch_val/1,
+	 copy_file/2,
+	 copy_holders/1,
+	 coredump/0,
+	 coredump/1,
+	 create_counter/1,
+	 cs_to_nodes/1,
+	 cs_to_storage_type/2,
+	 dets_to_ets/6,
+	 db_chunk/2,
+	 db_init_chunk/1,
+	 db_init_chunk/2,
+	 db_init_chunk/3,
+	 db_erase/2,
+	 db_erase/3,
+	 db_erase_tab/1,
+	 db_erase_tab/2,
+	 db_first/1,
+	 db_first/2,
+	 db_last/1,
+	 db_last/2,
+	 db_fixtable/3,
+	 db_get/2,
+	 db_get/3,
+	 db_match_erase/2,
+	 db_match_erase/3,
+	 db_match_object/2,
+	 db_match_object/3,
+	 db_next_key/2,
+	 db_next_key/3,
+	 db_prev_key/2,
+	 db_prev_key/3,
+	 db_put/2,
+	 db_put/3,
+	 db_select/2,	 
+	 db_select/3,
+	 db_select_init/4,
+	 db_select_cont/3,
+	 db_slot/2,
+	 db_slot/3,
+	 db_update_counter/3,
+	 db_update_counter/4,
+	 dbg_out/2,
+	 del/2,
+	 dets_sync_close/1,
+	 dets_sync_open/2,
+	 dets_sync_open/3,
+	 dir/0,
+	 dir/1,
+	 dir_info/0,
+	 dirty_rpc_error_tag/1,
+	 dist_coredump/0,
+	 disk_type/1,
+	 disk_type/2,	 
+	 elems/2,
+	 ensure_loaded/1,
+	 error/2,
+	 error_desc/1,
+	 etype/1,
+	 exists/1,
+	 fatal/2,
+	 get_node_number/0,
+	 fix_error/1,
+	 important/2,
+	 incr_counter/1,
+	 incr_counter/2,
+	 intersect/2,
+	 is_running/0,
+	 is_running/1,
+	 is_running_remote/0,
+	 is_string/1,
+	 key_search_delete/3,
+	 key_search_all/3,
+	 last_error/0,
+	 local_active_tables/0,
+	 lock_table/1,
+	 mkcore/1,
+	 not_active_here/1,
+	 other_val/2,
+	 pad_name/3,
+	 random_time/2,
+	 read_counter/1,
+	 readable_indecies/1,
+	 remote_copy_holders/1,
+	 report_fatal/2,
+	 report_system_event/1,
+	 running_nodes/0,
+	 running_nodes/1,
+	 schema_cs_to_storage_type/2,
+	 search_delete/2,
+	 set/2,
+	 set_counter/2,
+	 set_local_content_whereabouts/1,
+	 set_remote_where_to_read/1,
+	 set_remote_where_to_read/2,
+	 show/1,
+	 show/2,
+	 sort_commit/1,
+	 storage_type_at_node/2,
+	 tab2dat/1,
+	 tab2dmp/1,
+	 tab2tmp/1,
+	 tab2dcd/1,
+	 tab2dcl/1,
+	 to_list/1,
+	 union/2,
+	 uniq/1,
+	 unlock_table/1,
+	 unset/1,
+	 %% update_counter/2,
+	 val/1,
+	 vcore/0,
+	 vcore/1,
+	 verbose/2,
+	 view/0,
+	 view/1,
+	 view/2,
+	 warning/2,
+
+	 is_debug_compiled/0,
+	 activate_debug_fun/5,
+	 deactivate_debug_fun/3,
+	 eval_debug_fun/4,
+	 scratch_debug_fun/0
+	]).
+ 
+
+search_delete(Obj, List) ->
+    search_delete(Obj, List, [], none).
+search_delete(Obj, [Obj|Tail], Ack, _Res) ->
+    search_delete(Obj, Tail, Ack, Obj);
+search_delete(Obj, [H|T], Ack, Res) ->
+    search_delete(Obj, T, [H|Ack], Res);
+search_delete(_, [], Ack, Res) ->
+    {Res, Ack}.
+
+key_search_delete(Key, Pos, TupleList) ->
+    key_search_delete(Key, Pos, TupleList, none, []).
+key_search_delete(Key, Pos, [H|T], _Obj, Ack) when element(Pos, H) == Key ->
+    key_search_delete(Key, Pos, T, H, Ack);
+key_search_delete(Key, Pos, [H|T], Obj, Ack) ->
+    key_search_delete(Key, Pos, T, Obj, [H|Ack]);
+key_search_delete(_, _, [], Obj, Ack) ->
+    {Obj, Ack}.
+
+key_search_all(Key, Pos, TupleList) -> 
+    key_search_all(Key, Pos, TupleList, []).
+key_search_all(Key, N, [H|T], Ack) when element(N, H) == Key ->
+    key_search_all(Key, N, T, [H|Ack]);
+key_search_all(Key, N, [_|T], Ack) ->
+    key_search_all(Key, N, T, Ack);
+key_search_all(_, _, [], Ack) -> Ack.
+
+intersect(L1, L2) ->
+    L2 -- (L2 -- L1).
+
+elems(I, [H|T]) ->
+    [element(I, H) | elems(I, T)];
+elems(_, []) ->
+    [].
+
+%%  sort_commit see to that checkpoint info is always first in 
+%%  commit_work structure the other info don't need to be sorted.
+sort_commit(List) ->
+    sort_commit2(List, []).
+
+sort_commit2([{checkpoints, ChkpL}| Rest], Acc) ->
+    [{checkpoints, ChkpL}| Rest] ++ Acc;
+sort_commit2([H | R], Acc) ->
+    sort_commit2(R, [H | Acc]);
+sort_commit2([], Acc) -> Acc.
+    
+is_string([H|T]) ->
+    if
+	0 =< H, H < 256, is_integer(H)  -> is_string(T);
+	true -> false
+    end;
+is_string([]) -> true.
+
+%%%
+
+union([H|L1], L2) ->
+    case lists:member(H, L2) of
+	true -> union(L1, L2);
+	false -> [H | union(L1, L2)]
+    end;
+union([], L2) -> L2.
+
+uniq([]) ->
+    [];
+uniq(List) ->
+    [H|T] = lists:sort(List),
+    uniq1(H, T, []).
+
+uniq1(H, [H|R], Ack) ->
+    uniq1(H, R, Ack);
+uniq1(Old, [H|R], Ack) ->
+    uniq1(H, R, [Old|Ack]);
+uniq1(Old, [], Ack) ->
+    [Old| Ack].
+
+to_list(X) when is_list(X) -> X;
+to_list(X) -> atom_to_list(X).
+
+all_nodes() ->
+    Ns = mnesia:system_info(db_nodes) ++
+	mnesia:system_info(extra_db_nodes),
+    mnesia_lib:uniq(Ns).
+
+running_nodes() ->
+    running_nodes(all_nodes()).
+
+running_nodes(Ns) ->
+    {Replies, _BadNs} = rpc:multicall(Ns, ?MODULE, is_running_remote, []),
+    [N || {GoodState, N} <- Replies, GoodState == true].
+
+is_running_remote() ->
+    IsRunning = is_running(),
+    {IsRunning == yes, node()}.
+
+is_running(Node) when is_atom(Node) ->
+    case rpc:call(Node, ?MODULE, is_running, []) of
+	{badrpc, _} -> no;
+	X -> X
+    end.
+
+is_running() ->
+    case ?catch_val(mnesia_status) of
+	{'EXIT', _} -> no;
+	running -> yes;
+	starting -> starting;
+	stopping -> stopping
+    end.
+
+show(X) ->
+    show(X, []).
+show(F, A) ->
+    io:format(user, F, A).
+
+
+pad_name([Char | Chars], Len, Tail) ->
+    [Char | pad_name(Chars, Len - 1, Tail)];
+pad_name([], Len, Tail) when Len =< 0 ->
+    Tail;
+pad_name([], Len, Tail) ->
+    [$ | pad_name([], Len - 1, Tail)].
+    
+%% Some utility functions .....
+active_here(Tab) ->
+    case val({Tab, where_to_read}) of
+	Node when Node == node() -> true;
+	_ -> false
+    end.
+
+not_active_here(Tab) ->
+    not active_here(Tab).
+
+exists(Fname) ->
+    case file:open(Fname, [raw,read]) of
+	{ok, F} ->file:close(F), true;
+	_ -> false
+    end.
+
+dir() -> mnesia_monitor:get_env(dir).
+
+dir(Fname) ->
+    filename:join([dir(), to_list(Fname)]).
+
+tab2dat(Tab) ->  %% DETS files 
+    dir(lists:concat([Tab, ".DAT"])).
+
+tab2tmp(Tab) ->
+    dir(lists:concat([Tab, ".TMP"])).
+
+tab2dmp(Tab) ->  %% Dumped ets tables
+    dir(lists:concat([Tab, ".DMP"])).
+
+tab2dcd(Tab) ->  %% Disc copies data
+    dir(lists:concat([Tab, ".DCD"])).
+
+tab2dcl(Tab) ->  %% Disc copies log
+    dir(lists:concat([Tab, ".DCL"])).
+
+storage_type_at_node(Node, Tab) ->
+    search_key(Node, [{disc_copies, val({Tab, disc_copies})},
+		      {ram_copies, val({Tab, ram_copies})},
+		      {disc_only_copies, val({Tab, disc_only_copies})}]).
+
+cs_to_storage_type(Node, Cs) ->
+    search_key(Node, [{disc_copies, Cs#cstruct.disc_copies},
+		      {ram_copies, Cs#cstruct.ram_copies},
+		      {disc_only_copies, Cs#cstruct.disc_only_copies}]).
+
+schema_cs_to_storage_type(Node, Cs) ->
+    case cs_to_storage_type(Node, Cs) of
+	unknown when Cs#cstruct.name == schema -> ram_copies;
+	Other -> Other
+    end.
+
+
+search_key(Key, [{Val, List} | Tail]) ->
+    case lists:member(Key, List) of
+	true -> Val;
+	false -> search_key(Key, Tail)
+    end;
+search_key(_Key, []) ->
+    unknown.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% ops, we've got some global variables here :-)
+
+%% They are
+%%
+%%   {Tab, setorbag}, -> set | bag
+%%   {Tab, storage_type}       -> disc_copies |ram_copies | unknown (**)
+%%   {Tab, disc_copies}        -> node list  (from schema)
+%%   {Tab, ram_copies}, -> node list  (from schema)
+%%   {Tab, arity}, -> number
+%%   {Tab, attributes}, -> atom list
+%%   {Tab, wild_pattern}, -> record tuple with '_'s
+%%   {Tab, {index, Pos}}       -> ets table
+%%   {Tab, index}              -> integer list
+%%   {Tab, cstruct}            -> cstruct  structure
+%%
+
+%%   The following fields are dynamic according to the
+%%   the current node/table situation
+
+%%   {Tab, where_to_write}      -> node list
+%%   {Tab, where_to_read}       -> node | nowhere
+%%
+%%   {schema, tables}                    -> tab list
+%%   {schema, local_tables}              -> tab list  (**)
+%%
+%%   {current, db_nodes}                  -> node list
+%%
+%%   dir                                  -> directory path (**)
+%%   mnesia_status                        -> status | running | stopping (**)
+%%   (**) ==   (Different on all nodes)
+%%
+
+val(Var) ->
+    case ?catch_val(Var) of
+	{'EXIT', _ReASoN_} -> mnesia_lib:other_val(Var, _ReASoN_); 
+	_VaLuE_ -> _VaLuE_ 
+    end.
+
+set(Var, Val) ->
+    ?ets_insert(mnesia_gvar, {Var, Val}).
+
+unset(Var) ->
+    ?ets_delete(mnesia_gvar, Var).
+
+other_val(Var, Other) ->
+    case Var of
+	{_, where_to_read} -> nowhere;
+	{_, where_to_write} -> [];
+	{_, active_replicas} -> [];
+	_ ->
+	    pr_other(Var, Other)
+    end.
+
+-spec(pr_other/2 :: (_,_) -> no_return()).
+
+pr_other(Var, Other) ->
+    Why = 
+	case is_running() of
+	    no -> {node_not_running, node()};
+	    _ -> {no_exists, Var}
+	end,
+    verbose("~p (~p) val(mnesia_gvar, ~w) -> ~p ~p ~n",
+	    [self(), process_info(self(), registered_name),
+	     Var, Other, Why]),
+    case Other of
+	{badarg, [{ets, lookup_element, _}|_]} ->
+	    exit(Why);
+	_ ->
+	    erlang:error(Why)
+    end.
+
+%% Some functions for list valued variables
+add(Var, Val) ->
+    L = val(Var),
+    set(Var, [Val | lists:delete(Val, L)]).
+
+add_list(Var, List) ->
+    L = val(Var),
+    set(Var, union(L, List)).
+
+del(Var, Val) ->
+    L = val(Var),
+    set(Var, lists:delete(Val, L)).
+
+%% LSort -> [node()| Sorted] == Locker sorted
+
+add_lsort(Var, Val) when node() == Val ->
+    L = val(Var),
+    set(Var, [Val | lists:delete(Val, L)]);
+add_lsort(Var,Val) ->
+    case val(Var) of
+	[Head|Rest] when Head == node() ->
+	    set(Var,[Head|lsort_add(Val,Rest)]);
+	List ->
+	    set(Var,lsort_add(Val,List))
+    end.
+
+lsort_add(Val,List) ->
+    case ordsets:is_element(Val,List) of
+	true -> List;
+	false -> ordsets:add_element(Val,List)
+    end.
+	    
+%% This function is needed due to the fact
+%% that the application_controller enters
+%% a deadlock now and then. ac is implemented
+%% as a rather naive server.
+ensure_loaded(Appl) ->
+    case application_controller:get_loaded(Appl) of
+	{true, _} -> 
+	    ok;
+	false ->
+	    case application:load(Appl) of
+		ok ->
+		    ok;
+		{error, {already_loaded, Appl}} ->
+		    ok;
+		{error, Reason} ->
+		    {error, {application_load_error, Reason}}
+	    end
+    end.
+
+local_active_tables() ->
+    Tabs = val({schema, local_tables}),
+    lists:zf(fun(Tab) -> active_here(Tab) end, Tabs).
+
+active_tables() ->
+    Tabs = val({schema, tables}),
+    F = fun(Tab) ->
+		case val({Tab, where_to_read}) of
+		    nowhere -> false;
+		    _ -> {true, Tab}
+		end
+	end,
+    lists:zf(F, Tabs).
+
+etype(X) when is_integer(X) -> integer;
+etype([]) -> nil;
+etype(X) when is_list(X) -> list;
+etype(X) when is_tuple(X) -> tuple;
+etype(X) when is_atom(X) -> atom;
+etype(_) -> othertype.
+
+remote_copy_holders(Cs) ->
+    copy_holders(Cs) -- [node()].
+
+copy_holders(Cs) when Cs#cstruct.local_content == false ->
+    cs_to_nodes(Cs);
+copy_holders(Cs) when Cs#cstruct.local_content == true ->
+    case lists:member(node(), cs_to_nodes(Cs)) of
+	true -> [node()];
+	false -> []
+    end.
+
+
+set_remote_where_to_read(Tab) ->
+    set_remote_where_to_read(Tab, []).
+
+set_remote_where_to_read(Tab, Ignore) ->
+    Active = val({Tab, active_replicas}),
+    Valid = 
+	case mnesia_recover:get_master_nodes(Tab) of
+	    [] ->  Active;
+	    Masters -> mnesia_lib:intersect(Masters, Active)
+	end,    
+    Available = mnesia_lib:intersect(val({current, db_nodes}), Valid -- Ignore),    
+    DiscOnlyC = val({Tab, disc_only_copies}),
+    Prefered  = Available -- DiscOnlyC,
+    if
+	Prefered /= [] ->
+	    set({Tab, where_to_read}, hd(Prefered));
+	Available /= [] ->
+	    set({Tab, where_to_read}, hd(Available));
+	true ->
+	    set({Tab, where_to_read}, nowhere)
+    end.
+
+%%% Local only
+set_local_content_whereabouts(Tab) ->
+    add({schema, local_tables}, Tab),
+    add({Tab, active_replicas}, node()),
+    set({Tab, where_to_write}, [node()]),
+    set({Tab, where_to_read}, node()).
+
+%%% counter routines
+
+create_counter(Name) ->
+    set_counter(Name, 0).
+
+set_counter(Name, Val) ->
+    ?ets_insert(mnesia_stats, {Name, Val}).
+
+incr_counter(Name) ->
+    ?ets_update_counter(mnesia_stats, Name, 1).
+
+incr_counter(Name, I) ->
+    ?ets_update_counter(mnesia_stats, Name, I).
+
+%% update_counter(Name, Val) ->
+%%     ?ets_update_counter(mnesia_stats, Name, Val).
+
+read_counter(Name) ->
+    ?ets_lookup_element(mnesia_stats, Name, 2).
+
+cs_to_nodes(Cs) ->
+    Cs#cstruct.disc_only_copies ++
+    Cs#cstruct.disc_copies ++
+    Cs#cstruct.ram_copies.
+ 
+dist_coredump() ->
+    dist_coredump(all_nodes()).
+dist_coredump(Ns) ->
+    {Replies, _} = rpc:multicall(Ns, ?MODULE, coredump, []),
+    Replies.
+
+coredump() ->
+    coredump({crashinfo, {"user initiated~n", []}}).
+coredump(CrashInfo) ->
+    Core = mkcore(CrashInfo),
+    Out = core_file(),
+    important("Writing Mnesia core to file: ~p...~p~n", [Out, CrashInfo]),
+    file:write_file(Out, Core),
+    Out.
+
+core_file() ->
+    Integers = tuple_to_list(date()) ++ tuple_to_list(time()),
+    Fun = fun(I) when I < 10 -> ["_0", I];
+	     (I) -> ["_", I]
+	  end,
+    List = lists:append([Fun(I) || I <- Integers]),
+    case mnesia_monitor:get_env(core_dir) of
+	Dir when is_list(Dir) ->
+	    filename:absname(lists:concat(["MnesiaCore.", node()] ++ List), Dir);
+	_ ->
+	    filename:absname(lists:concat(["MnesiaCore.", node()] ++ List))
+    end.
+   
+mkcore(CrashInfo) ->
+%   dbg_out("Making a Mnesia core dump...~p~n", [CrashInfo]),
+    Nodes = [node() |nodes()],
+    %%TidLocks = (catch ets:tab2list(mnesia_tid_locks)),
+    HeldLocks = (catch mnesia:system_info(held_locks)),
+    Core = [
+	    CrashInfo,
+	    {time, {date(), time()}},
+	    {self, catch process_info(self())},
+	    {nodes, catch rpc:multicall(Nodes, ?MODULE, get_node_number, [])},
+	    {applications, catch lists:sort(application:loaded_applications())},
+	    {flags, catch init:get_arguments()},
+	    {code_path, catch code:get_path()},
+	    {code_loaded, catch lists:sort(code:all_loaded())},
+	    {etsinfo, catch ets_info(ets:all())},
+
+	    {version, catch mnesia:system_info(version)},
+	    {schema, catch ets:tab2list(schema)},
+	    {gvar, catch ets:tab2list(mnesia_gvar)},
+	    {master_nodes, catch mnesia_recover:get_master_node_info()},
+
+	    {processes, catch procs()},
+	    {relatives, catch relatives()},
+	    {workers, catch workers(mnesia_controller:get_workers(2000))},
+	    {locking_procs, catch locking_procs(HeldLocks)},
+
+	    {held_locks, HeldLocks},
+	    {lock_queue, catch mnesia:system_info(lock_queue)},
+	    {load_info, catch mnesia_controller:get_info(2000)},
+	    {trans_info, catch mnesia_tm:get_info(2000)},
+	    	    
+	    {schema_file, catch file:read_file(tab2dat(schema))},
+	    {dir_info, catch dir_info()},
+	    {logfile, catch {ok, read_log_files()}}
+	   ],
+    term_to_binary(Core).
+
+procs() ->
+    Fun = fun(P) -> {P, (catch lists:zf(fun proc_info/1, process_info(P)))} end,
+    lists:map(Fun, processes()).
+
+proc_info({registered_name, Val}) -> {true, Val};
+proc_info({message_queue_len, Val}) -> {true, Val};
+proc_info({status, Val}) -> {true, Val};
+proc_info({current_function, Val}) -> {true, Val};
+proc_info(_) -> false.
+
+get_node_number() ->
+    {node(), self()}.
+
+read_log_files() ->
+    [{F, catch file:read_file(F)} || F <- mnesia_log:log_files()].
+
+dir_info() ->
+    {ok, Cwd} = file:get_cwd(),
+    Dir = dir(),
+    [{cwd, Cwd, file:read_file_info(Cwd)},
+     {mnesia_dir, Dir, file:read_file_info(Dir)}] ++
+    case file:list_dir(Dir) of
+	{ok, Files} ->
+	    [{mnesia_file, F, catch file:read_file_info(dir(F))} || F <- Files];
+	Other ->
+	    [Other]
+    end.
+
+ets_info([H|T]) ->
+    [{table, H, mk_info_tuple(ets:info(H))} | ets_info(T)];
+ets_info([]) -> [].
+
+mk_info_tuple(T) when is_list(T) ->
+    list_to_tuple(T);
+mk_info_tuple(T) -> T.
+
+relatives() ->
+    Info = fun(Name) ->
+		   case whereis(Name) of
+		       undefined -> false;
+		       Pid -> {true, {Name, Pid, catch process_info(Pid)}}
+		   end
+	   end,
+    lists:zf(Info, mnesia:ms()).
+
+workers({workers, Loaders, Senders, Dumper}) ->
+    Info = fun({Pid, {send_table, Tab, _Receiver, _St}}) ->
+		   case Pid of
+		       undefined -> false;
+		       Pid -> {true, {Pid, Tab, catch process_info(Pid)}}
+		   end;
+	      ({Pid, What}) when is_pid(Pid) ->
+		   {true, {Pid, What, catch process_info(Pid)}};
+	      ({Name, Pid}) ->
+		   case Pid of
+		       undefined -> false;
+		       Pid -> {true, {Name, Pid, catch process_info(Pid)}}
+		   end
+	   end,
+    SInfo = lists:zf(Info, Senders),
+    Linfo = lists:zf(Info, Loaders),
+    [{senders, SInfo},{loader, Linfo}|lists:zf(Info, [{dumper, Dumper}])].
+
+locking_procs(LockList) when is_list(LockList) ->
+    Tids = [element(3, Lock) || Lock <- LockList],
+    UT = uniq(Tids),    
+    Info = fun(Tid) ->
+		   Pid = Tid#tid.pid,
+		   case node(Pid) == node() of
+		       true -> 
+			   {true, {Pid, catch process_info(Pid)}};
+		       _ ->
+			   false
+		   end
+	   end,
+    lists:zf(Info, UT).
+
+view() ->
+    Bin = mkcore({crashinfo, {"view only~n", []}}),
+    vcore(Bin).
+
+%% Displays a Mnesia file on the tty. The file may be repaired.
+view(File) ->
+    case suffix([".DAT", ".RET", ".DMP", ".TMP"], File) of
+	true ->
+	    view(File, dat);
+	false ->
+	    case suffix([".LOG", ".BUP", ".ETS"], File) of
+		true ->
+		    view(File, log);
+		false ->
+		    case lists:prefix("MnesiaCore.", File) of
+			true ->
+			    view(File, core);
+			false ->
+			    {error, "Unknown file name"}
+		    end
+	    end
+    end.
+
+view(File, dat) ->
+    dets:view(File);
+view(File, log) ->
+    mnesia_log:view(File);
+view(File, core) ->
+    vcore(File).
+
+suffix(Suffixes, File) ->
+    Fun = fun(S) -> lists:suffix(S, File) end,
+    lists:any(Fun, Suffixes).
+
+%% View a core file
+
+vcore() ->
+    Prefix = lists:concat(["MnesiaCore.", node()]),
+    Filter = fun(F) -> lists:prefix(Prefix, F) end,
+    {ok, Cwd} = file:get_cwd(),
+    case file:list_dir(Cwd) of
+	{ok, Files}->
+	    CoreFiles = lists:sort(lists:zf(Filter, Files)),
+	    show("Mnesia core files: ~p~n", [CoreFiles]),
+	    vcore(lists:last(CoreFiles));
+	Error ->
+	    Error
+    end.
+
+vcore(Bin) when is_binary(Bin) ->
+    Core = binary_to_term(Bin),
+    Fun = fun({Item, Info}) ->
+		  show("***** ~p *****~n", [Item]),
+		  case catch vcore_elem({Item, Info}) of
+		      {'EXIT', Reason} ->
+			  show("{'EXIT', ~p}~n", [Reason]);
+		      _ -> ok
+		  end
+	  end,
+    lists:foreach(Fun, Core);
+    
+vcore(File) ->
+    show("~n***** Mnesia core: ~p *****~n", [File]),
+    case file:read_file(File) of
+	{ok, Bin} ->
+	    vcore(Bin);
+	_ ->
+	    nocore
+    end.
+
+vcore_elem({schema_file, {ok, B}}) ->
+    Fname = "/tmp/schema.DAT",
+    file:write_file(Fname, B),
+    dets:view(Fname),
+    file:delete(Fname);
+
+vcore_elem({logfile, {ok, BinList}}) ->
+    Fun = fun({F, Info}) ->
+		  show("----- logfile: ~p -----~n", [F]),
+		  case Info of
+		      {ok, B} ->
+			  Fname = "/tmp/mnesia_vcore_elem.TMP",
+			  file:write_file(Fname, B),
+			  mnesia_log:view(Fname),
+			  file:delete(Fname);
+		      _ ->
+			  show("~p~n", [Info])
+		  end
+	  end,
+    lists:foreach(Fun, BinList);
+
+vcore_elem({crashinfo, {Format, Args}}) ->
+    show(Format, Args);
+vcore_elem({gvar, L}) ->
+    show("~p~n", [lists:sort(L)]);
+vcore_elem({transactions, Info}) ->
+    mnesia_tm:display_info(user, Info);
+
+vcore_elem({_Item, Info}) ->
+    show("~p~n", [Info]).
+
+fix_error(X) ->
+    set(last_error, X), %% for debugabililty
+    case X of
+	{aborted, Reason} -> Reason;
+	{abort, Reason} -> Reason;
+	Y when is_atom(Y) -> Y;
+	{'EXIT', {_Reason, {Mod, _, _}}} when is_atom(Mod) ->
+	    save(X),
+	    case atom_to_list(Mod) of
+		[$m, $n, $e|_] -> badarg;
+		_ -> X
+	    end;
+	_ -> X
+    end.
+
+last_error() ->
+    val(last_error).
+
+%% The following is a list of possible mnesia errors and what they
+%% actually mean
+
+error_desc(nested_transaction) -> "Nested transactions are not allowed";
+error_desc(badarg) -> "Bad or invalid argument, possibly bad type";
+error_desc(no_transaction) -> "Operation not allowed outside transactions";
+error_desc(combine_error)  -> "Table options were ilegally combined";
+error_desc(bad_index)  -> "Index already exists or was out of bounds";
+error_desc(already_exists) -> "Some schema option we try to set is already on";
+error_desc(index_exists)-> "Some ops can not  be performed on tabs with index";
+error_desc(no_exists)-> "Tried to perform op on non-existing (non alive) item";
+error_desc(system_limit) -> "Some system_limit was exhausted";
+error_desc(mnesia_down) -> "A transaction involving objects at some remote "
+                           "node which died while transaction was executing"
+                           "*and* object(s) are no longer available elsewhere"
+                           "in the network";
+error_desc(not_a_db_node) -> "A node which is non existant in "
+                              "the schema was mentioned";
+error_desc(bad_type)            -> "Bad type on some provided arguments";
+error_desc(node_not_running)    -> "Node not running";
+error_desc(truncated_binary_file) -> "Truncated binary in file";
+error_desc(active)     -> "Some delete ops require that "
+                           "all active objects are removed";
+error_desc(illegal) -> "Operation not supported on object";
+error_desc({'EXIT', Reason}) ->
+    error_desc(Reason);
+error_desc({error, Reason}) ->
+    error_desc(Reason);
+error_desc({aborted, Reason}) ->
+    error_desc(Reason);
+error_desc(Reason) when is_tuple(Reason), size(Reason) > 0 ->
+    setelement(1, Reason, error_desc(element(1, Reason)));
+error_desc(Reason) ->
+    Reason.
+
+dirty_rpc_error_tag(Reason) ->
+    case Reason of
+	{'EXIT', _} -> badarg;
+	no_variable -> badarg;
+	_           -> no_exists
+    end.
+
+fatal(Format, Args) ->
+    catch set(mnesia_status, stopping),
+    Core = mkcore({crashinfo, {Format, Args}}),
+    report_fatal(Format, Args, Core),
+    timer:sleep(10000), % Enough to write the core dump to disc?
+    mnesia:lkill(),
+    exit(fatal).
+
+report_fatal(Format, Args) ->
+    report_fatal(Format, Args, nocore).
+
+report_fatal(Format, Args, Core) ->
+    report_system_event({mnesia_fatal, Format, Args, Core}),
+    catch exit(whereis(mnesia_monitor), fatal).
+
+%% We sleep longer and longer the more we try
+%% Made some testing and came up with the following constants
+random_time(Retries, _Counter0) ->    
+%    UpperLimit = 2000,
+%    MaxIntv = trunc(UpperLimit * (1-(4/((Retries*Retries)+4)))),
+    UpperLimit = 500,
+    Dup = Retries * Retries,
+    MaxIntv = trunc(UpperLimit * (1-(50/((Dup)+50)))),
+    
+    case get(random_seed) of
+	undefined ->
+	    {X, Y, Z} = erlang:now(), %% time()
+	    random:seed(X, Y, Z),
+	    Time = Dup + random:uniform(MaxIntv),
+	    %%	    dbg_out("---random_test rs ~w max ~w val ~w---~n", [Retries, MaxIntv, Time]),
+	    Time;
+	_ ->
+	    Time = Dup + random:uniform(MaxIntv),
+	    %%	    dbg_out("---random_test rs ~w max ~w val ~w---~n", [Retries, MaxIntv, Time]),
+	    Time	    
+    end.
+
+report_system_event(Event0) ->
+    Event = {mnesia_system_event, Event0},
+    report_system_event(catch_notify(Event), Event),
+    case ?catch_val(subscribers) of
+	{'EXIT', _} -> ignore;
+	Pids -> lists:foreach(fun(Pid) -> Pid ! Event end, Pids)
+    end,
+    ok.
+
+catch_notify(Event) ->
+    case whereis(mnesia_event) of
+	undefined ->
+	    {'EXIT', {badarg, {mnesia_event, Event}}};
+	Pid ->
+	    gen_event:notify(Pid, Event)
+    end.
+
+report_system_event({'EXIT', Reason}, Event) ->
+    Mod = mnesia_monitor:get_env(event_module),
+    case mnesia_sup:start_event() of
+	{ok, Pid} ->
+	    link(Pid),
+	    gen_event:call(mnesia_event, Mod, Event, infinity),
+	    unlink(Pid),
+
+            %% We get an exit signal if server dies
+            receive
+                {'EXIT', Pid, _Reason} ->
+                    {error, {node_not_running, node()}}
+            after 0 ->
+		    gen_event:stop(mnesia_event),
+                    ok
+            end;
+
+	Error ->
+	    Msg = "Mnesia(~p): Cannot report event ~p: ~p (~p)~n",
+	    error_logger:format(Msg, [node(), Event, Reason, Error])
+    end;
+report_system_event(_Res, _Event) ->
+    ignore.
+
+%% important messages are reported regardless of debug level
+important(Format, Args) ->
+    save({Format, Args}),
+    report_system_event({mnesia_info, Format, Args}).
+
+%% Warning messages are reported regardless of debug level
+warning(Format, Args) ->
+    save({Format, Args}),
+    report_system_event({mnesia_warning, Format, Args}).
+
+%% error messages are reported regardless of debug level
+error(Format, Args) ->
+    save({Format, Args}),
+    report_system_event({mnesia_error, Format, Args}).
+
+%% verbose messages are reported if debug level == debug or verbose
+verbose(Format, Args) ->
+    case mnesia_monitor:get_env(debug) of
+	none ->    save({Format, Args});
+	verbose -> important(Format, Args);
+	debug ->   important(Format, Args);
+	trace ->   important(Format, Args)
+    end.
+
+%% debug message are display if debug level == 2
+dbg_out(Format, Args) ->
+    case mnesia_monitor:get_env(debug) of
+	none ->    ignore;
+	verbose -> save({Format, Args});
+	_ ->  report_system_event({mnesia_info, Format, Args})
+    end.
+
+%% Keep the last 10 debug print outs
+save(DbgInfo) ->
+    catch save2(DbgInfo).
+
+save2(DbgInfo) ->
+    Key = {'$$$_report', current_pos},
+    P =
+	case ?ets_lookup_element(mnesia_gvar, Key, 2) of
+	    30 -> -1;
+	    I -> I
+	end,
+    set({'$$$_report', current_pos}, P+1),
+    set({'$$$_report', P+1}, {date(), time(), DbgInfo}).
+
+copy_file(From, To) ->
+    case file:open(From, [raw, binary, read]) of
+	{ok, F} ->
+	    case file:open(To, [raw, binary, write]) of
+		{ok, T} ->
+		    Res = copy_file_loop(F, T, 8000),
+		    file:close(F),
+		    file:close(T),
+		    Res;
+		{error, Reason} ->
+		    {error, Reason}
+	    end;
+	{error, Reason} ->
+	    {error, Reason}
+    end.
+
+copy_file_loop(F, T, ChunkSize) ->
+    case file:read(F, ChunkSize) of
+	{ok, Bin} ->
+	    file:write(T, Bin),
+	    copy_file_loop(F, T, ChunkSize);
+	eof ->
+	    ok;
+	{error, Reason} ->
+	    {error, Reason}
+    end.
+
+
+%%%%%%%%%%%%
+%% versions of all the lowlevel db funcs that determine whether we
+%% shall go to disc or ram to do the actual operation.
+
+db_get(Tab, Key) ->
+    db_get(val({Tab, storage_type}), Tab, Key).
+db_get(ram_copies, Tab, Key) -> ?ets_lookup(Tab, Key);
+db_get(disc_copies, Tab, Key) -> ?ets_lookup(Tab, Key);
+db_get(disc_only_copies, Tab, Key) -> dets:lookup(Tab, Key).
+
+db_init_chunk(Tab) ->
+    db_init_chunk(val({Tab, storage_type}), Tab, 1000).
+db_init_chunk(Tab, N) ->
+    db_init_chunk(val({Tab, storage_type}), Tab, N).
+
+db_init_chunk(disc_only_copies, Tab, N) ->
+    dets:select(Tab, [{'_', [], ['$_']}], N);
+db_init_chunk(_, Tab, N) ->
+    ets:select(Tab, [{'_', [], ['$_']}], N).
+
+db_chunk(disc_only_copies, State) ->
+    dets:select(State);
+db_chunk(_, State) ->
+    ets:select(State).
+
+db_put(Tab, Val) ->
+    db_put(val({Tab, storage_type}), Tab, Val).
+
+db_put(ram_copies, Tab, Val) -> ?ets_insert(Tab, Val), ok;
+db_put(disc_copies, Tab, Val) -> ?ets_insert(Tab, Val), ok;
+db_put(disc_only_copies, Tab, Val) -> dets:insert(Tab, Val).
+
+db_match_object(Tab, Pat) ->
+    db_match_object(val({Tab, storage_type}), Tab, Pat).
+db_match_object(Storage, Tab, Pat) ->
+    db_fixtable(Storage, Tab, true),
+    Res = catch_match_object(Storage, Tab, Pat),
+    db_fixtable(Storage, Tab, false),
+    case Res of
+	{'EXIT', Reason} -> exit(Reason);
+	_ -> Res
+    end.
+
+catch_match_object(disc_only_copies, Tab, Pat) ->
+    catch dets:match_object(Tab, Pat);
+catch_match_object(_, Tab, Pat) ->
+    catch ets:match_object(Tab, Pat).
+
+db_select(Tab, Pat) ->
+    db_select(val({Tab, storage_type}), Tab, Pat).
+
+db_select(Storage, Tab, Pat) ->
+    db_fixtable(Storage, Tab, true),
+    Res = catch_select(Storage, Tab, Pat),
+    db_fixtable(Storage, Tab, false),
+    case Res of
+	{'EXIT', Reason} -> exit(Reason);
+	_ -> Res
+    end.
+
+catch_select(disc_only_copies, Tab, Pat) ->
+    catch dets:select(Tab, Pat);
+catch_select(_, Tab, Pat) ->
+    catch ets:select(Tab, Pat).
+
+db_select_init(disc_only_copies, Tab, Pat, Limit) ->
+    dets:select(Tab, Pat, Limit);
+db_select_init(_, Tab, Pat, Limit) ->
+    ets:select(Tab, Pat, Limit).
+
+db_select_cont(disc_only_copies, Cont0, Ms) ->
+    Cont = dets:repair_continuation(Cont0, Ms),
+    dets:select(Cont);
+db_select_cont(_, Cont0, Ms) ->
+    Cont = ets:repair_continuation(Cont0, Ms),
+    ets:select(Cont).
+
+db_fixtable(ets, Tab, Bool) ->
+    ets:safe_fixtable(Tab, Bool);
+db_fixtable(ram_copies, Tab, Bool) ->
+    ets:safe_fixtable(Tab, Bool);
+db_fixtable(disc_copies, Tab, Bool) ->
+    ets:safe_fixtable(Tab, Bool);
+db_fixtable(dets, Tab, Bool) ->
+    dets:safe_fixtable(Tab, Bool);
+db_fixtable(disc_only_copies, Tab, Bool) ->
+    dets:safe_fixtable(Tab, Bool).
+
+db_erase(Tab, Key) ->
+    db_erase(val({Tab, storage_type}), Tab, Key).
+db_erase(ram_copies, Tab, Key) -> ?ets_delete(Tab, Key), ok;
+db_erase(disc_copies, Tab, Key) -> ?ets_delete(Tab, Key), ok;
+db_erase(disc_only_copies, Tab, Key) -> dets:delete(Tab, Key).
+
+db_match_erase(Tab, Pat) ->
+    db_match_erase(val({Tab, storage_type}), Tab, Pat).
+db_match_erase(ram_copies, Tab, Pat) -> ?ets_match_delete(Tab, Pat), ok;
+db_match_erase(disc_copies, Tab, Pat) -> ?ets_match_delete(Tab, Pat), ok;
+db_match_erase(disc_only_copies, Tab, Pat) -> dets:match_delete(Tab, Pat).
+
+db_first(Tab) ->
+    db_first(val({Tab, storage_type}), Tab).
+db_first(ram_copies, Tab) -> ?ets_first(Tab);
+db_first(disc_copies, Tab) -> ?ets_first(Tab);
+db_first(disc_only_copies, Tab) -> dets:first(Tab).
+
+db_next_key(Tab, Key) ->
+    db_next_key(val({Tab, storage_type}), Tab, Key).
+db_next_key(ram_copies, Tab, Key) -> ?ets_next(Tab, Key);
+db_next_key(disc_copies, Tab, Key) -> ?ets_next(Tab, Key);
+db_next_key(disc_only_copies, Tab, Key) -> dets:next(Tab, Key).
+
+db_last(Tab) ->
+    db_last(val({Tab, storage_type}), Tab).
+db_last(ram_copies, Tab) -> ?ets_last(Tab);
+db_last(disc_copies, Tab) -> ?ets_last(Tab);
+db_last(disc_only_copies, Tab) -> dets:first(Tab). %% Dets don't have order
+
+db_prev_key(Tab, Key) ->
+    db_prev_key(val({Tab, storage_type}), Tab, Key).
+db_prev_key(ram_copies, Tab, Key) -> ?ets_prev(Tab, Key);
+db_prev_key(disc_copies, Tab, Key) -> ?ets_prev(Tab, Key);
+db_prev_key(disc_only_copies, Tab, Key) -> dets:next(Tab, Key). %% Dets don't have order
+
+db_slot(Tab, Pos) ->
+    db_slot(val({Tab, storage_type}), Tab, Pos).
+db_slot(ram_copies, Tab, Pos) -> ?ets_slot(Tab, Pos);
+db_slot(disc_copies, Tab, Pos) -> ?ets_slot(Tab, Pos);
+db_slot(disc_only_copies, Tab, Pos) -> dets:slot(Tab, Pos).
+
+db_update_counter(Tab, C, Val) ->
+    db_update_counter(val({Tab, storage_type}), Tab, C, Val).
+db_update_counter(ram_copies, Tab, C, Val) ->
+    ?ets_update_counter(Tab, C, Val);
+db_update_counter(disc_copies, Tab, C, Val) ->
+    ?ets_update_counter(Tab, C, Val);
+db_update_counter(disc_only_copies, Tab, C, Val) ->
+    dets:update_counter(Tab, C, Val).
+
+db_erase_tab(Tab) ->
+    db_erase_tab(val({Tab, storage_type}), Tab).
+db_erase_tab(ram_copies, Tab) -> ?ets_delete_table(Tab);
+db_erase_tab(disc_copies, Tab) -> ?ets_delete_table(Tab);
+db_erase_tab(disc_only_copies, _Tab) -> ignore.
+
+%% assuming that Tab is a valid ets-table
+dets_to_ets(Tabname, Tab, File, Type, Rep, Lock) ->
+    {Open, Close} = mkfuns(Lock),
+    case Open(Tabname, [{file, File}, {type, disk_type(Tab, Type)},
+			{keypos, 2}, {repair, Rep}]) of
+	{ok, Tabname} ->
+	    Res = dets:to_ets(Tabname, Tab),
+	    Close(Tabname),
+	    trav_ret(Res, Tab);
+	Other ->
+	    Other
+    end.
+
+trav_ret(Tabname, Tabname) -> loaded;
+trav_ret(Other, _Tabname) -> Other.
+
+mkfuns(yes) ->
+    {fun(Tab, Args) -> dets_sync_open(Tab, Args) end,
+     fun(Tab) -> dets_sync_close(Tab) end};
+mkfuns(no) ->
+    {fun(Tab, Args) -> dets:open_file(Tab, Args) end,
+     fun(Tab) -> dets:close(Tab) end}.
+
+disk_type(Tab) ->
+    disk_type(Tab, val({Tab, setorbag})).
+
+disk_type(_Tab, ordered_set) ->
+    set;
+disk_type(_, Type) ->
+    Type.
+
+dets_sync_open(Tab, Ref, File) ->
+    Args = [{file, File},
+	    {keypos, 2},
+	    {repair, mnesia_monitor:get_env(auto_repair)},
+	    {type, disk_type(Tab)}],
+    dets_sync_open(Ref, Args).
+
+lock_table(Tab) ->
+    global:set_lock({{mnesia_table_lock, Tab}, self()}, [node()], infinity).
+%    dbg_out("dets_sync_open: ~p ~p~n", [T, self()]),
+
+unlock_table(Tab) ->
+    global:del_lock({{mnesia_table_lock, Tab}, self()}, [node()]).
+%    dbg_out("unlock_table: ~p ~p~n", [T, self()]),
+
+dets_sync_open(Tab, Args) ->
+    lock_table(Tab),
+    case dets:open_file(Tab, Args) of
+	{ok, Tab} ->
+	    {ok, Tab};
+	Other ->
+	    dets_sync_close(Tab),
+	    Other
+    end.
+
+dets_sync_close(Tab) ->
+    catch dets:close(Tab),
+    unlock_table(Tab),
+    ok.
+
+readable_indecies(Tab) ->
+    val({Tab, index}).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Managing conditional debug functions
+%%
+%% The main idea with the debug_fun's is to allow test programs
+%% to control the internal behaviour of Mnesia. This is needed
+%% to make the test programs independent of system load, swapping
+%% and other circumstances that may affect the behaviour of Mnesia.
+%%
+%% First should calls to ?eval_debug_fun be inserted at well
+%% defined places in Mnesia's code. E.g. in critical situations
+%% of startup, transaction commit, backups etc.
+%%
+%% Then compile Mnesia with the compiler option 'debug'.
+%%
+%% In test programs ?activate_debug_fun should be called
+%% in order to bind a fun to the debug identifier stated
+%% in the call to ?eval_debug_fun.
+%%
+%% If eval_debug_fun finds that the fun is activated it
+%% invokes the fun as NewContext = Fun(PreviousContext, EvalContext)
+%% and replaces the PreviousContext with the NewContext.
+%% The initial context of a debug_fun is given as argument to
+%% activate_debug_fun.
+
+-define(DEBUG_TAB, mnesia_debug).
+-record(debug_info, {id, function, context, file, line}).
+
+scratch_debug_fun() ->
+    dbg_out("scratch_debug_fun(): ~p~n", [?DEBUG_TAB]),
+    (catch ?ets_delete_table(?DEBUG_TAB)),
+    ?ets_new_table(?DEBUG_TAB, [set, public, named_table, {keypos, 2}]).
+
+activate_debug_fun(FunId, Fun, InitialContext, File, Line) ->
+    Info = #debug_info{id = FunId,
+		       function = Fun,
+		       context = InitialContext,
+		       file = File,
+		       line = Line
+		      },
+    update_debug_info(Info).
+
+update_debug_info(Info) ->
+    case catch ?ets_insert(?DEBUG_TAB, Info) of
+	{'EXIT', _} ->
+	    scratch_debug_fun(),
+	    ?ets_insert(?DEBUG_TAB, Info);
+	_ ->
+	    ok
+    end,
+    dbg_out("update_debug_info(~p)~n", [Info]),
+    ok.
+
+deactivate_debug_fun(FunId, _File, _Line) ->
+    catch ?ets_delete(?DEBUG_TAB, FunId),
+    ok.
+
+eval_debug_fun(FunId, EvalContext, EvalFile, EvalLine) ->
+    case catch ?ets_lookup(?DEBUG_TAB, FunId) of
+	[] ->
+	    ok;
+	[Info] ->
+	    OldContext = Info#debug_info.context,
+	    dbg_out("~s(~p): ~w "
+		    "activated in ~s(~p)~n  "
+		    "eval_debug_fun(~w, ~w)~n",
+		    [filename:basename(EvalFile), EvalLine, Info#debug_info.id,
+		     filename:basename(Info#debug_info.file), Info#debug_info.line,
+		     OldContext, EvalContext]),
+	    Fun = Info#debug_info.function,
+	    NewContext = Fun(OldContext, EvalContext),
+	    
+	    case catch ?ets_lookup(?DEBUG_TAB, FunId) of
+		[Info] when NewContext /= OldContext ->
+		    NewInfo = Info#debug_info{context = NewContext},
+		    update_debug_info(NewInfo);
+		_ ->
+		    ok
+	    end;
+	{'EXIT', _} -> ok    
+    end.
+	
+-ifdef(debug).
+    is_debug_compiled() -> true.
+-else.
+    is_debug_compiled() -> false.
+-endif.   
+
+