mnesia_dumper.erl

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		    mnesia_lib:del({schema, local_tables}, Tab),
		    mnesia_lib:set({Tab, storage_type}, unknown),
		    insert_cstruct(Tid, Cs, true, InPlace, InitBy),
		    disc_delete_table(Tab, Storage),
		    disc_delete_indecies(Tab, Cs, Storage),
		    mnesia_schema:ram_delete_table(Tab, Storage),
		    mnesia_checkpoint:tm_del_copy(Tab, Node);
		true ->
		    case val({Tab, where_to_read}) of
			Node ->
			    mnesia_lib:set_remote_where_to_read(Tab);
			_  ->
			    ignore
		    end,
		    insert_cstruct(Tid, Cs, true, InPlace, InitBy)
	    end
    end;

insert_op(Tid, _, {op, add_table_copy, _Storage, _Node, TabDef}, InPlace, InitBy) ->
    %% During prepare commit, the files was created
    %% and the replica was announced
    Cs = mnesia_schema:list2cs(TabDef),
    insert_cstruct(Tid, Cs, true, InPlace, InitBy);

insert_op(Tid, _, {op, add_snmp, _Us, TabDef}, InPlace, InitBy) ->
    Cs = mnesia_schema:list2cs(TabDef),
    insert_cstruct(Tid, Cs, true, InPlace, InitBy);

insert_op(Tid, _, {op, del_snmp, TabDef}, InPlace, InitBy) ->
    Cs = mnesia_schema:list2cs(TabDef),
    Tab = Cs#cstruct.name,
    Storage = mnesia_lib:cs_to_storage_type(node(), Cs),
    if
	InitBy /= startup,
	Storage /= unknown ->
	    case ?catch_val({Tab, {index, snmp}}) of
		{'EXIT', _} -> 
		    ignore;
		Stab -> 
		    mnesia_snmp_hook:delete_table(Tab, Stab),
		    mnesia_lib:unset({Tab, {index, snmp}})
	    end;
	true ->
	    ignore
    end,
    insert_cstruct(Tid, Cs, true, InPlace, InitBy);

insert_op(Tid, _, {op, add_index, Pos, TabDef}, InPlace, InitBy) ->
    Cs = mnesia_schema:list2cs(TabDef),
    Tab = insert_cstruct(Tid, Cs, true, InPlace, InitBy),
    Storage = mnesia_lib:cs_to_storage_type(node(), Cs),
    case InitBy of
	startup when Storage == disc_only_copies ->
	    true = open_files(Tab, Storage, InPlace, InitBy),
	    mnesia_index:init_indecies(Tab, Storage, [Pos]);
	startup ->
	    ignore; 
	_  ->
	    mnesia_index:init_indecies(Tab, Storage, [Pos])
    end;

insert_op(Tid, _, {op, del_index, Pos, TabDef}, InPlace, InitBy) ->
    Cs = mnesia_schema:list2cs(TabDef),
    Tab = Cs#cstruct.name,
    Storage = mnesia_lib:cs_to_storage_type(node(), Cs),
    case InitBy of
	startup when Storage == disc_only_copies ->
	    mnesia_index:del_index_table(Tab, Storage, Pos);
	startup -> 
	    ignore;
	_ ->
	    mnesia_index:del_index_table(Tab, Storage, Pos)
    end,
    insert_cstruct(Tid, Cs, true, InPlace, InitBy);

insert_op(Tid, _, {op, change_table_access_mode,TabDef, _OldAccess, _Access}, InPlace, InitBy) ->
    Cs = mnesia_schema:list2cs(TabDef),
    case InitBy of
	startup -> ignore;
	_ -> mnesia_controller:change_table_access_mode(Cs)
    end,
    insert_cstruct(Tid, Cs, true, InPlace, InitBy);

insert_op(Tid, _, {op, change_table_load_order, TabDef, _OldLevel, _Level}, InPlace, InitBy) ->
    Cs = mnesia_schema:list2cs(TabDef),
    insert_cstruct(Tid, Cs, true, InPlace, InitBy);

insert_op(Tid, _, {op, delete_property, TabDef, PropKey}, InPlace, InitBy) ->
    Cs = mnesia_schema:list2cs(TabDef),
    Tab = Cs#cstruct.name,
    mnesia_lib:unset({Tab, user_property, PropKey}),
    insert_cstruct(Tid, Cs, true, InPlace, InitBy);

insert_op(Tid, _, {op, write_property, TabDef, _Prop}, InPlace, InitBy) ->
    Cs = mnesia_schema:list2cs(TabDef),
    insert_cstruct(Tid, Cs, true, InPlace, InitBy);

insert_op(Tid, _, {op, change_table_frag, _Change, TabDef}, InPlace, InitBy) ->
    Cs = mnesia_schema:list2cs(TabDef),
    insert_cstruct(Tid, Cs, true, InPlace, InitBy).

open_files(Tab, Storage, UpdateInPlace, InitBy)
  when Storage /= unknown, Storage /= ram_copies ->
    case get({?MODULE, Tab}) of
	undefined ->
	    case ?catch_val({Tab, setorbag}) of
		{'EXIT', _} ->
		    false;
		Type ->
		    case Storage of 
			disc_copies when Tab /= schema ->
			    Bool = open_disc_copies(Tab, InitBy),
			    Bool;
			_ ->
			    Fname = prepare_open(Tab, UpdateInPlace),
			    Args = [{file, Fname},
				    {keypos, 2},
				    {repair, mnesia_monitor:get_env(auto_repair)},
				    {type, mnesia_lib:disk_type(Tab, Type)}],
			    {ok, _} = mnesia_monitor:open_dets(Tab, Args),
			    put({?MODULE, Tab}, {opened_dumper, dat}),
			    true
		    end
	    end;
	already_dumped ->
	    false;
	{opened_dumper, _} ->
	    true
    end;
open_files(_Tab, _Storage, _UpdateInPlace, _InitBy) ->
    false.

open_disc_copies(Tab, InitBy) ->
    DclF = mnesia_lib:tab2dcl(Tab),
    DumpEts = 
	case file:read_file_info(DclF) of
	    {error, enoent} ->
		false;
	    {ok, DclInfo} ->
		DcdF =  mnesia_lib:tab2dcd(Tab),
		case file:read_file_info(DcdF) of
		    {error, Reason} ->
			mnesia_lib:dbg_out("File ~p info_error ~p ~n",
					   [DcdF, Reason]),
			true;
		    {ok, DcdInfo} -> 
			Mul = case ?catch_val(dc_dump_limit) of
				  {'EXIT', _} -> ?DumpToEtsMultiplier;
				  Val -> Val
			      end,
			DcdInfo#file_info.size =< (DclInfo#file_info.size * Mul)
		end
	end,
    if 
	DumpEts == false; InitBy == startup ->	    
	    mnesia_log:open_log({?MODULE,Tab}, 
				mnesia_log:dcl_log_header(), 
				DclF, 
				mnesia_lib:exists(DclF), 
				mnesia_monitor:get_env(auto_repair),
				read_write),
	    put({?MODULE, Tab}, {opened_dumper, dcl}),
	    true;
	true ->
	    mnesia_log:ets2dcd(Tab),
	    put({?MODULE, Tab}, already_dumped),
	    false
    end. 

%% Always opens the dcl file for writing overriding already_dumped 
%% mechanismen, used for schema transactions.
open_dcl(Tab) ->
    case get({?MODULE, Tab}) of
    	{opened_dumper, _} ->
	    true;
	_ -> %% undefined or already_dumped
	    DclF = mnesia_lib:tab2dcl(Tab),
	    mnesia_log:open_log({?MODULE,Tab}, 
				mnesia_log:dcl_log_header(), 
				DclF, 
				mnesia_lib:exists(DclF), 
				mnesia_monitor:get_env(auto_repair),
				read_write),
	    put({?MODULE, Tab}, {opened_dumper, dcl}),
	    true
    end.

prepare_open(Tab, UpdateInPlace) ->
    Dat =  mnesia_lib:tab2dat(Tab),
    case UpdateInPlace of
	true ->
	    Dat;
	false ->
	    Tmp = mnesia_lib:tab2tmp(Tab),
	    case catch mnesia_lib:copy_file(Dat, Tmp) of
		ok ->
		    Tmp;
		Error ->
		    fatal("Cannot copy dets file ~p to ~p: ~p~n",
			  [Dat, Tmp, Error])
	    end
	end.

del_opened_tab(Tab) ->
    erase({?MODULE, Tab}).

close_files(UpdateInPlace, Outcome, InitBy) -> % Update in place
    close_files(UpdateInPlace, Outcome, InitBy, get()).

close_files(InPlace, Outcome, InitBy, [{{?MODULE, Tab}, already_dumped} | Tail]) ->
    erase({?MODULE, Tab}),
    close_files(InPlace, Outcome, InitBy, Tail);
close_files(InPlace, Outcome, InitBy, [{{?MODULE, Tab}, {opened_dumper, Type}} | Tail]) ->
    erase({?MODULE, Tab}),
    case val({Tab, storage_type}) of
	disc_only_copies when InitBy /= startup ->
	    ignore;
	disc_copies when Tab /= schema -> 
	    mnesia_log:close_log({?MODULE,Tab});
	Storage ->
	    do_close(InPlace, Outcome, Tab, Type, Storage)
    end,
    close_files(InPlace, Outcome, InitBy, Tail);

close_files(InPlace, Outcome, InitBy, [_ | Tail]) ->
    close_files(InPlace, Outcome, InitBy, Tail);
close_files(_, _, _InitBy, []) ->
    ok.

%% If storage is unknown during close clean up files, this can happen if timing
%% is right and dirty_write conflicts with schema operations.
do_close(_, _, Tab, dcl, unknown) ->
    mnesia_log:close_log({?MODULE,Tab}),
    file:delete(mnesia_lib:tab2dcl(Tab));
do_close(_, _, Tab, dcl, _) ->  %% To be safe, can it happen?
    mnesia_log:close_log({?MODULE,Tab});

do_close(InPlace, Outcome, Tab, dat, Storage) ->
    mnesia_monitor:close_dets(Tab),
    if
	Storage == unknown, InPlace == true  ->
	    file:delete(mnesia_lib:tab2dat(Tab));
	InPlace == true ->
	    %% Update in place
	    ok;
	Outcome == ok, Storage /= unknown ->
	    %% Success: swap tmp files with dat files
	    TabDat = mnesia_lib:tab2dat(Tab),
	    ok = file:rename(mnesia_lib:tab2tmp(Tab), TabDat);
	true ->
	    file:delete(mnesia_lib:tab2tmp(Tab))
    end.
    

ensure_rename(From, To) ->
    case mnesia_lib:exists(From) of
	true ->
	    file:rename(From, To);
	false ->
	    case mnesia_lib:exists(To) of
		true ->
		    ok;
		false ->
		    {error, {rename_failed, From, To}}
	    end
    end.
    
insert_cstruct(Tid, Cs, KeepWhereabouts, InPlace, InitBy) ->
    Val = mnesia_schema:insert_cstruct(Tid, Cs, KeepWhereabouts),
    {schema, Tab, _} = Val,
    S = val({schema, storage_type}),
    disc_insert(Tid, S, schema, Tab, Val, write, InPlace, InitBy),
    Tab.

delete_cstruct(Tid, Cs, InPlace, InitBy) ->
    Val = mnesia_schema:delete_cstruct(Tid, Cs),
    {schema, Tab, _} = Val,
    S = val({schema, storage_type}),
    disc_insert(Tid, S, schema, Tab, Val, delete, InPlace, InitBy),
    Tab.


temp_set_master_nodes() ->
    Tabs = val({schema, local_tables}),
    Masters = [{Tab, (val({Tab, disc_copies}) ++ 
		      val({Tab, ram_copies}) ++ 
		      val({Tab, disc_only_copies})) -- [node()]} 
	       || Tab <- Tabs],
    %% UseDir = false since we don't want to remember these
    %% masternodes and we are running (really soon anyway) since we want this
    %% to be known during table loading.
    mnesia_recover:log_master_nodes(Masters, false, yes),
    ok.    

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Raw dump of table. Dumper must have unique access to the ets table.

raw_named_dump_table(Tab, Ftype) ->
    case mnesia_monitor:use_dir() of
	true ->
	    mnesia_lib:lock_table(Tab),
	    TmpFname = mnesia_lib:tab2tmp(Tab),
	    Fname =
		case Ftype of
		    dat -> mnesia_lib:tab2dat(Tab);
		    dmp -> mnesia_lib:tab2dmp(Tab)
		end,
	    file:delete(TmpFname),
	    file:delete(Fname),
	    TabSize = ?ets_info(Tab, size),
	    TabRef = Tab,
	    DiskType = mnesia_lib:disk_type(Tab),
	    Args = [{file, TmpFname},
		    {keypos, 2},
		    %%		    {ram_file, true},
		    {estimated_no_objects, TabSize + 256},
		    {repair, mnesia_monitor:get_env(auto_repair)},
		    {type, DiskType}],
	    case mnesia_lib:dets_sync_open(TabRef, Args) of
		{ok, TabRef} ->
		    Storage = ram_copies,
		    mnesia_lib:db_fixtable(Storage, Tab, true),
		    
		    case catch raw_dump_table(TabRef, Tab) of
			{'EXIT', Reason} ->
			    mnesia_lib:db_fixtable(Storage, Tab, false),
			    mnesia_lib:dets_sync_close(Tab),
			    file:delete(TmpFname),
			    mnesia_lib:unlock_table(Tab),
			    exit({"Dump of table to disc failed", Reason});
			ok ->
			    mnesia_lib:db_fixtable(Storage, Tab, false),
			    mnesia_lib:dets_sync_close(Tab),
			    mnesia_lib:unlock_table(Tab),
			    ok = file:rename(TmpFname, Fname)
		    end;
		{error, Reason} ->
		    mnesia_lib:unlock_table(Tab),
		    exit({"Open of file before dump to disc failed", Reason})
	    end;
	false ->
	    exit({has_no_disc, node()})
    end.

raw_dump_table(DetsRef, EtsRef) ->
    dets:from_ets(DetsRef, EtsRef).

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Load regulator
%% 
%% This is a poor mans substitute for a fair scheduler algorithm 
%% in the Erlang emulator. The mnesia_dumper process performs many 
%% costly BIF invokations and must pay for this. But since the 
%% Emulator does not handle this properly we must compensate for 
%% this with some form of load regulation of ourselves in order to
%% not steal all computation power in the Erlang Emulator ans make
%% other processes starve. Hopefully this is a temporary solution.

start_regulator() ->
    case mnesia_monitor:get_env(dump_log_load_regulation) of
	false ->
	    nopid;
	true ->
	    N = ?REGULATOR_NAME,
	    case mnesia_monitor:start_proc(N, ?MODULE, regulator_init, [self()]) of
		{ok, Pid} ->
		    Pid;
		{error, Reason} ->
		    fatal("Failed to start ~n: ~p~n", [N, Reason])
	    end
    end.

regulator_init(Parent) ->
    %% No need for trapping exits.
    %% Using low priority causes the regulation
    process_flag(priority, low),
    register(?REGULATOR_NAME, self()),
    proc_lib:init_ack(Parent, {ok, self()}),
    regulator_loop().

regulator_loop() ->
    receive
	{regulate, From} ->
	    From ! {regulated, self()},
	    regulator_loop();
	{stop, From} ->
	    From ! {stopped, self()},
	    exit(normal)
    end.

regulate(nopid) ->
    ok;
regulate(RegulatorPid) ->
    RegulatorPid ! {regulate, self()},
    receive
	{regulated, RegulatorPid} -> ok
    end.

val(Var) ->
    case ?catch_val(Var) of
	{'EXIT', Reason} -> mnesia_lib:other_val(Var, Reason); 
	Value -> Value 
    end.