aboutsummaryrefslogtreecommitdiffstats
path: root/lib/mnesia/src/mnesia_dumper.erl
blob: 9a0a2c4dcc861ddb3b2ae850234c3c97a405a1fc (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
%%
%% %CopyrightBegin%
%% 
%% Copyright Ericsson AB 1996-2010. 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%
%%

%%
-module(mnesia_dumper).

%% The InitBy arg may be one of the following:
%% scan_decisions     Initial scan for decisions
%% startup	      Initial dump during startup
%% schema_prepare     Dump initiated during schema transaction preparation
%% schema_update      Dump initiated during schema transaction commit
%% fast_schema_update A schema_update, but ignores the log file
%% user		      Dump initiated by user
%% write_threshold    Automatic dump caused by too many log writes
%% time_threshold     Automatic dump caused by timeout

%% Public interface
-export([
	 get_log_writes/0,
	 incr_log_writes/0,
	 raw_dump_table/2,
	 raw_named_dump_table/2,
	 start_regulator/0,
	 opt_dump_log/1,
	 update/3
	]).

 %% Internal stuff
-export([regulator_init/1]).
	
-include("mnesia.hrl").
-include_lib("kernel/include/file.hrl").

-import(mnesia_lib, [fatal/2, dbg_out/2]).

-define(REGULATOR_NAME, mnesia_dumper_load_regulator).
-define(DumpToEtsMultiplier, 4).

get_log_writes() ->
    Max = mnesia_monitor:get_env(dump_log_write_threshold),
    Prev = mnesia_lib:read_counter(trans_log_writes),
    Left = mnesia_lib:read_counter(trans_log_writes_left),
    Diff = Max - Left,
    Prev + Diff.

incr_log_writes() ->
    Left = mnesia_lib:incr_counter(trans_log_writes_left, -1),
    if
	Left > 0 ->
	    ignore;
	true ->
	    adjust_log_writes(true)
    end.

adjust_log_writes(DoCast) ->
    Token = {mnesia_adjust_log_writes, self()},
    case global:set_lock(Token, [node()], 1) of 
	false ->
	    ignore; %% Somebody else is sending a dump request
	true -> 
	    case DoCast of 
		false ->
		    ignore;
		true -> 
		    mnesia_controller:async_dump_log(write_threshold)
	    end,
	    Max = mnesia_monitor:get_env(dump_log_write_threshold),
	    Left = mnesia_lib:read_counter(trans_log_writes_left),
	    %% Don't care if we lost a few writes
	    mnesia_lib:set_counter(trans_log_writes_left, Max),
	    Diff = Max - Left,
	    mnesia_lib:incr_counter(trans_log_writes, Diff),
	    global:del_lock(Token, [node()])
    end.

%% Returns 'ok' or exits
opt_dump_log(InitBy) ->
    Reg = case whereis(?REGULATOR_NAME) of
	      undefined ->
		  nopid; 
	      Pid when is_pid(Pid) ->
		  Pid 
	  end,
    perform_dump(InitBy, Reg).

%% Scan for decisions
perform_dump(InitBy, Regulator) when InitBy == scan_decisions ->
    ?eval_debug_fun({?MODULE, perform_dump}, [InitBy]),
    
    dbg_out("Transaction log dump initiated by ~w~n", [InitBy]),
    scan_decisions(mnesia_log:previous_log_file(), InitBy, Regulator),
    scan_decisions(mnesia_log:latest_log_file(), InitBy, Regulator);

%% Propagate the log into the DAT-files
perform_dump(InitBy, Regulator) ->
    ?eval_debug_fun({?MODULE, perform_dump}, [InitBy]),
    LogState = mnesia_log:prepare_log_dump(InitBy),
    dbg_out("Transaction log dump initiated by ~w: ~w~n",
	    [InitBy, LogState]), 
    adjust_log_writes(false),    
    case LogState of
	already_dumped ->
	    mnesia_recover:allow_garb(),
	    dumped;
	{needs_dump, Diff} ->
	    U = mnesia_monitor:get_env(dump_log_update_in_place),
	    Cont = mnesia_log:init_log_dump(),
	    mnesia_recover:sync(),
	    case catch do_perform_dump(Cont, U, InitBy, Regulator, undefined) of
		ok ->
		    ?eval_debug_fun({?MODULE, post_dump}, [InitBy]),
		    case mnesia_monitor:use_dir() of
			true ->
			    mnesia_recover:dump_decision_tab();
			false ->
			    mnesia_log:purge_some_logs()
		    end,
		    mnesia_recover:allow_garb(),
		    %% And now to the crucial point...
		    mnesia_log:confirm_log_dump(Diff);
		{error, Reason} ->
		    {error, Reason};
 		{'EXIT', {Desc, Reason}} ->
		    case mnesia_monitor:get_env(auto_repair) of
			true ->
			    mnesia_lib:important(Desc, Reason),
			    %% Ignore rest of the log
			    mnesia_log:confirm_log_dump(Diff);
			false -> 
			    fatal(Desc, Reason)
		    end
	    end;
	{error, Reason} ->
	    {error, {"Cannot prepare log dump", Reason}}
    end.

scan_decisions(Fname, InitBy, Regulator) ->
    Exists = mnesia_lib:exists(Fname),
    case Exists of
	false ->
	    ok;
	true ->
	    Header = mnesia_log:trans_log_header(),
	    Name = previous_log,
	    mnesia_log:open_log(Name, Header, Fname, Exists,
				mnesia_monitor:get_env(auto_repair), read_only),
	    Cont = start,
	    Res = (catch do_perform_dump(Cont, false, InitBy, Regulator, undefined)),
	    mnesia_log:close_log(Name),
	    case Res of
		ok -> ok;
		{'EXIT', Reason} -> {error, Reason}
	    end
    end.

do_perform_dump(Cont, InPlace, InitBy, Regulator, OldVersion) ->
    case mnesia_log:chunk_log(Cont) of
	{C2, Recs} ->
	    case catch insert_recs(Recs, InPlace, InitBy, Regulator, OldVersion) of
		{'EXIT', R} ->
		    Reason = {"Transaction log dump error: ~p~n", [R]},
		    close_files(InPlace, {error, Reason}, InitBy),
		    exit(Reason);
		Version ->
		    do_perform_dump(C2, InPlace, InitBy, Regulator, Version)
	    end;
	eof ->
	    close_files(InPlace, ok, InitBy),
	    erase(mnesia_dumper_dets),
	    ok
    end.

insert_recs([Rec | Recs], InPlace, InitBy, Regulator, LogV) ->
    regulate(Regulator),
    case insert_rec(Rec, InPlace, InitBy, LogV) of
 	LogH when is_record(LogH, log_header) ->	    
	    insert_recs(Recs, InPlace, InitBy, Regulator, LogH#log_header.log_version);
	_ -> 
	    insert_recs(Recs, InPlace, InitBy, Regulator, LogV)
    end;

insert_recs([], _InPlace, _InitBy, _Regulator, Version) ->
    Version.

insert_rec(Rec, _InPlace, scan_decisions, _LogV) ->
    if 
	is_record(Rec, commit) ->
	    ignore;
	is_record(Rec, log_header) ->
	    ignore;
	true ->
	    mnesia_recover:note_log_decision(Rec, scan_decisions)
    end;
insert_rec(Rec, InPlace, InitBy, LogV) when is_record(Rec, commit) ->
    %% Determine the Outcome of the transaction and recover it
    D = Rec#commit.decision,
    case mnesia_recover:wait_for_decision(D, InitBy) of
	{Tid, committed} ->
	    do_insert_rec(Tid, Rec, InPlace, InitBy, LogV);
	{Tid, aborted} ->
	    mnesia_schema:undo_prepare_commit(Tid, Rec)
    end;
insert_rec(H, _InPlace, _InitBy, _LogV) when is_record(H, log_header) ->
    CurrentVersion = mnesia_log:version(),
    if
        H#log_header.log_kind /= trans_log ->
	    exit({"Bad kind of transaction log", H});
	H#log_header.log_version == CurrentVersion ->
	    ok; 
	H#log_header.log_version == "4.2" ->
	    ok;
	H#log_header.log_version == "4.1" ->
	    ok;
	H#log_header.log_version == "4.0" ->
	    ok;
	true ->
	    fatal("Bad version of transaction log: ~p~n", [H])
    end,
    H;

insert_rec(_Rec, _InPlace, _InitBy, _LogV) ->
    ok.

do_insert_rec(Tid, Rec, InPlace, InitBy, LogV) ->
    case Rec#commit.schema_ops of
	[] ->
	    ignore;
	SchemaOps ->
	    case val({schema, storage_type}) of 
		ram_copies -> 
		    insert_ops(Tid, schema_ops, SchemaOps, InPlace, InitBy, LogV);
	        Storage ->
		    true = open_files(schema, Storage, InPlace, InitBy),
		    insert_ops(Tid, schema_ops, SchemaOps, InPlace, InitBy, LogV)
	    end
    end,
    D = Rec#commit.disc_copies,
    insert_ops(Tid, disc_copies, D, InPlace, InitBy, LogV),
    case InitBy of
	startup ->
	    DO = Rec#commit.disc_only_copies,
	    insert_ops(Tid, disc_only_copies, DO, InPlace, InitBy, LogV);
	_ ->
	    ignore
    end.
    

update(_Tid, [], _DumperMode) ->
    dumped;
update(Tid, SchemaOps, DumperMode) ->
    UseDir = mnesia_monitor:use_dir(),
    Res = perform_update(Tid, SchemaOps, DumperMode, UseDir),    
    mnesia_controller:release_schema_commit_lock(),
    Res.

perform_update(_Tid, _SchemaOps, mandatory, true) ->
    %% Force a dump of the transaction log in order to let the
    %% dumper perform needed updates

    InitBy = schema_update,
    ?eval_debug_fun({?MODULE, dump_schema_op}, [InitBy]),    
    opt_dump_log(InitBy);
perform_update(Tid, SchemaOps, _DumperMode, _UseDir) ->
    %% No need for a full transaction log dump.
    %% Ignore the log file and perform only perform
    %% the corresponding updates.

    InitBy = fast_schema_update, 
    InPlace = mnesia_monitor:get_env(dump_log_update_in_place),
    ?eval_debug_fun({?MODULE, dump_schema_op}, [InitBy]),
    case catch insert_ops(Tid, schema_ops, SchemaOps, InPlace, InitBy, 
			  mnesia_log:version()) of
	{'EXIT', Reason} ->
	    Error = {error, {"Schema update error", Reason}},
	    close_files(InPlace, Error, InitBy),
            fatal("Schema update error ~p ~p", [Reason, SchemaOps]);
	_ ->		    
	    ?eval_debug_fun({?MODULE, post_dump}, [InitBy]),
	    close_files(InPlace, ok, InitBy),
	    ok
    end.

insert_ops(_Tid, _Storage, [], _InPlace, _InitBy, _) ->    ok;
insert_ops(Tid, Storage, [Op], InPlace, InitBy, Ver)  when Ver >= "4.3"->
    insert_op(Tid, Storage, Op, InPlace, InitBy),
    ok;
insert_ops(Tid, Storage, [Op | Ops], InPlace, InitBy, Ver)  when Ver >= "4.3"->
    insert_op(Tid, Storage, Op, InPlace, InitBy),
    insert_ops(Tid, Storage, Ops, InPlace, InitBy, Ver);
insert_ops(Tid, Storage, [Op | Ops], InPlace, InitBy, Ver) when Ver < "4.3" ->
    insert_ops(Tid, Storage, Ops, InPlace, InitBy, Ver),
    insert_op(Tid, Storage, Op, InPlace, InitBy).

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Normal ops

disc_insert(_Tid, Storage, Tab, Key, Val, Op, InPlace, InitBy) ->
    case open_files(Tab, Storage, InPlace, InitBy) of
	true ->
	    case Storage of 
		disc_copies when Tab /= schema ->
		    mnesia_log:append({?MODULE,Tab}, {{Tab, Key}, Val, Op}),
		    ok;
		_ ->
		    dets_insert(Op,Tab,Key,Val)
	    end;
	false ->
	    ignore
    end.

%% To fix update_counter so that it behaves better.
%% i.e. if nothing have changed in tab except update_counter
%% trust that the value in the dets file is correct. 
%% Otherwise we will get a double increment.
%% This is perfect but update_counter is a dirty op.

dets_insert(Op,Tab,Key,Val) ->
    case Op of
	write ->
	    dets_updated(Tab,Key),
	    ok = dets:insert(Tab, Val);
	delete ->
	    dets_updated(Tab,Key),
	    ok = dets:delete(Tab, Key);
	update_counter ->
	    case dets_incr_counter(Tab,Key) of
		true ->
		    {RecName, Incr} = Val,
		    case catch dets:update_counter(Tab, Key, Incr) of
			CounterVal when is_integer(CounterVal) ->
			    ok;
			_ when Incr < 0 ->
			    Zero = {RecName, Key, 0},
			    ok = dets:insert(Tab, Zero);
			_ -> 
			    Init = {RecName, Key, Incr},
			    ok = dets:insert(Tab, Init)
		    end;
		false ->  ok
	    end;				    
	delete_object ->
	    dets_updated(Tab,Key),
	    ok = dets:delete_object(Tab, Val);
	clear_table ->
	    dets_cleared(Tab),
	    ok = dets:match_delete(Tab, '_')
    end.
	    
dets_updated(Tab,Key) -> 
    case get(mnesia_dumper_dets) of
	undefined -> 
	    Empty = gb_trees:empty(),
	    Tree = gb_trees:insert(Tab, gb_sets:singleton(Key), Empty),
	    put(mnesia_dumper_dets, Tree);
	Tree ->
	    case gb_trees:lookup(Tab,Tree) of
		{value, cleared} -> ignore;
		{value, Set} -> 
		    T = gb_trees:update(Tab, gb_sets:add(Key, Set), Tree),
		    put(mnesia_dumper_dets, T);
		none ->
		    T = gb_trees:insert(Tab, gb_sets:singleton(Key), Tree),
		    put(mnesia_dumper_dets, T)
	    end
    end.

dets_incr_counter(Tab,Key) ->
    case get(mnesia_dumper_dets) of
	undefined -> false;
	Tree ->
	    case gb_trees:lookup(Tab,Tree) of
		{value, cleared} -> true;
		{value, Set} -> gb_sets:is_member(Key, Set);
		none -> false
	    end
    end.

dets_cleared(Tab) ->
    case get(mnesia_dumper_dets) of
	undefined -> 
	    Empty = gb_trees:empty(),
	    Tree = gb_trees:insert(Tab, cleared, Empty),
	    put(mnesia_dumper_dets, Tree);
	Tree ->
	    case gb_trees:lookup(Tab,Tree) of
		{value, cleared} -> ignore;
		_ -> 
		    T = gb_trees:enter(Tab, cleared, Tree),
		    put(mnesia_dumper_dets, T)
	    end
    end.

insert(Tid, Storage, Tab, Key, [Val | Tail], Op, InPlace, InitBy) ->
    insert(Tid, Storage, Tab, Key, Val, Op, InPlace, InitBy),
    insert(Tid, Storage, Tab, Key, Tail, Op, InPlace, InitBy);

insert(_Tid, _Storage, _Tab, _Key, [], _Op, _InPlace, _InitBy) ->
    ok;
    
insert(Tid, Storage, Tab, Key, Val, Op, InPlace, InitBy) ->
    Item = {{Tab, Key}, Val, Op},
    case InitBy of
	startup ->
	    disc_insert(Tid, Storage, Tab, Key, Val, Op, InPlace, InitBy);

	_ when Storage == ram_copies ->
	    mnesia_tm:do_update_op(Tid, Storage, Item),
	    Snmp = mnesia_tm:prepare_snmp(Tab, Key, [Item]),
	    mnesia_tm:do_snmp(Tid, Snmp);

	_ when Storage == disc_copies ->
	    disc_insert(Tid, Storage, Tab, Key, Val, Op, InPlace, InitBy),
	    mnesia_tm:do_update_op(Tid, Storage, Item),
	    Snmp = mnesia_tm:prepare_snmp(Tab, Key, [Item]),
	    mnesia_tm:do_snmp(Tid, Snmp);

	_ when Storage == disc_only_copies ->
	    mnesia_tm:do_update_op(Tid, Storage, Item),
	    Snmp = mnesia_tm:prepare_snmp(Tab, Key, [Item]),
	    mnesia_tm:do_snmp(Tid, Snmp);

	_ when Storage == unknown ->
	    ignore
    end.

disc_delete_table(Tab, Storage) ->
    case mnesia_monitor:use_dir() of
	true ->
	    if 		
		Storage == disc_only_copies; Tab == schema ->  
		    mnesia_monitor:unsafe_close_dets(Tab),
		    Dat = mnesia_lib:tab2dat(Tab),
		    file:delete(Dat);		
		true -> 
		    DclFile = mnesia_lib:tab2dcl(Tab),
		    case get({?MODULE,Tab}) of
			{opened_dumper, dcl} ->
			    del_opened_tab(Tab),
			    mnesia_log:unsafe_close_log(Tab);
			_ -> 
			    ok
		    end,
		    file:delete(DclFile),
		    DcdFile = mnesia_lib:tab2dcd(Tab),
		    file:delete(DcdFile),
		    ok
	    end,
	    erase({?MODULE, Tab});
	false ->
	    ignore
    end.

disc_delete_indecies(_Tab, _Cs, Storage) when Storage /= disc_only_copies ->
    ignore;
disc_delete_indecies(Tab, Cs, disc_only_copies) ->
    Indecies = Cs#cstruct.index,
    mnesia_index:del_transient(Tab, Indecies, disc_only_copies).

insert_op(Tid, Storage, {{Tab, Key}, Val, Op}, InPlace, InitBy) ->
    %% Propagate to disc only
    disc_insert(Tid, Storage, Tab, Key, Val, Op, InPlace, InitBy);

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% NOTE that all operations below will only
%% be performed if the dump is initiated by
%% startup or fast_schema_update
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

insert_op(_Tid, schema_ops, _OP, _InPlace, Initby)
  when Initby /= startup,
       Initby /= fast_schema_update,
       Initby /= schema_update -> 
    ignore;

insert_op(Tid, _, {op, rec, Storage, Item}, InPlace, InitBy) ->
    {{Tab, Key}, ValList, Op} = Item,
    insert(Tid, Storage, Tab, Key, ValList, Op, InPlace, InitBy);

insert_op(Tid, _, {op, change_table_copy_type, N, FromS, ToS, TabDef}, InPlace, InitBy) ->
    Cs = mnesia_schema:list2cs(TabDef),
    Val = mnesia_schema:insert_cstruct(Tid, Cs, true), % Update ram only
    {schema, Tab, _} = Val,
    case lists:member(N, val({current, db_nodes})) of
	true when InitBy /= startup  ->
	    mnesia_controller:add_active_replica(Tab, N, Cs);
	_ ->
	    ignore
    end,
    if  
	N == node() ->
	    Dmp  = mnesia_lib:tab2dmp(Tab),
	    Dat  = mnesia_lib:tab2dat(Tab),
	    Dcd  = mnesia_lib:tab2dcd(Tab),
	    Dcl  = mnesia_lib:tab2dcl(Tab),
	    case {FromS, ToS} of
		{ram_copies, disc_copies} when Tab == schema ->
		    ok = ensure_rename(Dmp, Dat);
		{ram_copies, disc_copies} ->
		    file:delete(Dcl),
		    ok = ensure_rename(Dmp, Dcd);
		{disc_copies, ram_copies} when Tab == schema ->
		    mnesia_lib:set(use_dir, false),
		    mnesia_monitor:unsafe_close_dets(Tab),
		    file:delete(Dat);
		{disc_copies, ram_copies} ->
		    file:delete(Dcl),
		    file:delete(Dcd);
		{ram_copies, disc_only_copies} ->
		    ok = ensure_rename(Dmp, Dat),
		    true = open_files(Tab, disc_only_copies, InPlace, InitBy),
		    %% ram_delete_table must be done before init_indecies,
		    %% it uses info which is reset in init_indecies,
		    %% it doesn't matter, because init_indecies don't use 
		    %% the ram replica of the table when creating the disc 
		    %% index; Could be improved :)
		    mnesia_schema:ram_delete_table(Tab, FromS),
		    PosList = Cs#cstruct.index,
		    mnesia_index:init_indecies(Tab, disc_only_copies, PosList);
		{disc_only_copies, ram_copies} ->
		    mnesia_monitor:unsafe_close_dets(Tab),
		    disc_delete_indecies(Tab, Cs, disc_only_copies),
		    case InitBy of 
			startup -> 
			    ignore;
			_ -> 
			    mnesia_controller:get_disc_copy(Tab)
		    end,
		    disc_delete_table(Tab, disc_only_copies);
		{disc_copies, disc_only_copies} ->
		    ok = ensure_rename(Dmp, Dat),
		    true = open_files(Tab, disc_only_copies, InPlace, InitBy),
		    mnesia_schema:ram_delete_table(Tab, FromS), 
		    PosList = Cs#cstruct.index,
		    mnesia_index:init_indecies(Tab, disc_only_copies, PosList),
		    file:delete(Dcl),
		    file:delete(Dcd);
		{disc_only_copies, disc_copies} ->
		    mnesia_monitor:unsafe_close_dets(Tab),
		    disc_delete_indecies(Tab, Cs, disc_only_copies),
		    case InitBy of 
			startup -> 
			    ignore;
			_ ->
			    mnesia_log:ets2dcd(Tab),
			    mnesia_controller:get_disc_copy(Tab),
			    disc_delete_table(Tab, disc_only_copies)
		    end
	    end;
	true ->
	    ignore
    end,
    S = val({schema, storage_type}),
    disc_insert(Tid, S, schema, Tab, Val, write, InPlace, InitBy);

insert_op(Tid, _, {op, transform, _Fun, TabDef}, InPlace, InitBy) ->
    Cs = mnesia_schema:list2cs(TabDef),
    case mnesia_lib:cs_to_storage_type(node(), Cs) of
	disc_copies -> 
	    open_dcl(Cs#cstruct.name);
	_ ->
	    ignore
    end,
    insert_cstruct(Tid, Cs, true, InPlace, InitBy);

%%%  Operations below this are handled without using the logg.

insert_op(Tid, _, {op, restore_recreate, TabDef}, InPlace, InitBy) ->
    Cs = mnesia_schema:list2cs(TabDef),
    Tab = Cs#cstruct.name,
    Type = Cs#cstruct.type,
    Storage = mnesia_lib:cs_to_storage_type(node(), Cs),
    %% Delete all possibly existing files and tables
    disc_delete_table(Tab, Storage),
    disc_delete_indecies(Tab, Cs, Storage),
    case InitBy of
	startup ->
	    ignore;
	_ ->
	    case ?catch_val({Tab, cstruct}) of
		{'EXIT', _} -> ignore;
		_ ->
		    mnesia_schema:ram_delete_table(Tab, Storage),
		    mnesia_checkpoint:tm_del_copy(Tab, node())
	    end
    end,
    %% And create new ones..
    if
	(InitBy == startup) or (Storage == unknown) ->
	    ignore;
	Storage == ram_copies ->
	    Args = [{keypos, 2}, public, named_table, Type],
	    mnesia_monitor:mktab(Tab, Args);
	Storage == disc_copies ->
	    Args = [{keypos, 2}, public, named_table, Type],
	    mnesia_monitor:mktab(Tab, Args),
	    File = mnesia_lib:tab2dcd(Tab),	    
	    FArg = [{file, File}, {name, {mnesia,create}}, 
		    {repair, false}, {mode, read_write}],
	    {ok, Log} = mnesia_monitor:open_log(FArg),
	    mnesia_monitor:unsafe_close_log(Log);
	Storage == disc_only_copies ->
	    File = mnesia_lib:tab2dat(Tab),
	    file:delete(File),
	    Args = [{file, mnesia_lib:tab2dat(Tab)},
		    {type, mnesia_lib:disk_type(Tab, Type)},
		    {keypos, 2},
		    {repair, mnesia_monitor:get_env(auto_repair)}],
	    mnesia_monitor:open_dets(Tab, Args)
    end,
    insert_op(Tid, ignore, {op, create_table, TabDef}, InPlace, InitBy);

insert_op(Tid, _, {op, create_table, TabDef}, InPlace, InitBy) ->
    Cs = mnesia_schema:list2cs(TabDef),
    insert_cstruct(Tid, Cs, false, InPlace, InitBy),
    Tab = Cs#cstruct.name,
    Storage = mnesia_lib:cs_to_storage_type(node(), Cs),
    case InitBy of
	startup ->
	    case Storage of
		unknown ->
		    ignore;
		ram_copies ->
		    ignore;
		disc_copies ->
		    Dcd = mnesia_lib:tab2dcd(Tab),
		    case mnesia_lib:exists(Dcd) of  
			true -> ignore;
			false ->
			    mnesia_log:open_log(temp, 
						mnesia_log:dcd_log_header(),
						Dcd, 
						false, 
						false,
						read_write),
			    mnesia_log:unsafe_close_log(temp)
		    end;
		_ ->
		    Args = [{file, mnesia_lib:tab2dat(Tab)},
			    {type, mnesia_lib:disk_type(Tab, Cs#cstruct.type)},
			    {keypos, 2},
			    {repair, mnesia_monitor:get_env(auto_repair)}],
		    case mnesia_monitor:open_dets(Tab, Args) of
			{ok, _} ->
			    mnesia_monitor:unsafe_close_dets(Tab);
			{error, Error} ->
			    exit({"Failed to create dets table", Error})
		    end
	    end;
	_ ->
	    Copies = mnesia_lib:copy_holders(Cs),
	    Active = mnesia_lib:intersect(Copies, val({current, db_nodes})),
	    [mnesia_controller:add_active_replica(Tab, N, Cs) || N <- Active],

	    case Storage of
		unknown ->
		    mnesia_lib:unset({Tab, create_table}),
		    case Cs#cstruct.local_content of
			true ->
			    ignore;
			false ->
			    mnesia_lib:set_remote_where_to_read(Tab)
		    end;
		_ ->
		    case Cs#cstruct.local_content of
			true ->
			    mnesia_lib:set_local_content_whereabouts(Tab);
			false ->
			    mnesia_lib:set({Tab, where_to_read}, node())
		    end,
		    case Storage of
			ram_copies ->
			    ignore;
			_ ->
			    %% Indecies are still created by loader
			    disc_delete_indecies(Tab, Cs, Storage)
			    %% disc_delete_table(Tab, Storage)
		    end, 
		    
		    %% Update whereabouts and create table
		    mnesia_controller:create_table(Tab),
		    mnesia_lib:unset({Tab, create_table})
	    end
    end;

insert_op(_Tid, _, {op, dump_table, Size, TabDef}, _InPlace, _InitBy) ->
    case Size of
	unknown ->
	    ignore;
	_ ->
	    Cs = mnesia_schema:list2cs(TabDef),
	    Tab = Cs#cstruct.name,
	    Dmp = mnesia_lib:tab2dmp(Tab),
	    Dat = mnesia_lib:tab2dcd(Tab),
	    case Size of
		0 ->
	    	    %% Assume that table files already are closed
		    file:delete(Dmp),
		    file:delete(Dat);
		_ ->
		    ok = ensure_rename(Dmp, Dat)
	    end
    end;

insert_op(Tid, _, {op, delete_table, TabDef}, InPlace, InitBy) ->
    Cs = mnesia_schema:list2cs(TabDef),
    Tab = Cs#cstruct.name,
    case mnesia_lib:cs_to_storage_type(node(), Cs) of
	unknown ->
	    ignore;
	Storage ->
	    disc_delete_table(Tab, Storage),
	    disc_delete_indecies(Tab, Cs, Storage),
	    case InitBy of
		startup ->
		    ignore;
		_ ->
		    mnesia_schema:ram_delete_table(Tab, Storage),
		    mnesia_checkpoint:tm_del_copy(Tab, node())
	    end
    end,
    delete_cstruct(Tid, Cs, InPlace, InitBy);

insert_op(Tid, _, {op, clear_table, TabDef}, InPlace, InitBy) ->
    Cs = mnesia_schema:list2cs(TabDef),
    Tab = Cs#cstruct.name,
    case mnesia_lib:cs_to_storage_type(node(), Cs) of
	unknown ->
	    ignore;
	Storage ->
	    Oid = '_', %%val({Tab, wild_pattern}),
	    if Storage == disc_copies ->
		    open_dcl(Cs#cstruct.name);
	       true ->
		    ignore
	    end,
	    %% Need to catch this, it crashes on ram_copies if 
	    %% the op comes before table is loaded at startup.
	    catch insert(Tid, Storage, Tab, '_', Oid, clear_table, InPlace, InitBy)
    end;

insert_op(Tid, _, {op, merge_schema, TabDef}, InPlace, InitBy) ->
    Cs = mnesia_schema:list2cs(TabDef),
    case Cs#cstruct.name of
	schema ->
	    %% If we bootstrap an empty (diskless) mnesia from another node
	    %% we might have changed the storage_type of schema.
	    %% I think this is a good place to do it.
	    Update = fun(NS = {Node,Storage}) -> 
			     case mnesia_lib:cs_to_storage_type(Node, Cs) of
				 Storage -> NS;
				 disc_copies when Node == node() -> 
				     Dir = mnesia_lib:dir(),    
				     ok = mnesia_schema:opt_create_dir(true, Dir),
				     mnesia_schema:purge_dir(Dir, []),
				     mnesia_log:purge_all_logs(),

				     mnesia_lib:set(use_dir, true),	     
				     mnesia_log:init(),
				     Ns = val({current, db_nodes}),
				     F = fun(U) -> mnesia_recover:log_mnesia_up(U) end,
				     lists:foreach(F, Ns),
				     raw_named_dump_table(schema, dat),
				     temp_set_master_nodes(),
				     {Node,disc_copies};
				 CSstorage -> 
				     {Node,CSstorage}
			     end
		     end,
	    
	    W2C0 = val({schema, where_to_commit}),
	    W2C = case W2C0 of
		      {blocked, List} ->
			  {blocked,lists:map(Update,List)};
		      List ->
			  lists:map(Update,List)
		  end,
	    if W2C == W2C0 -> ignore;
	       true -> mnesia_lib:set({schema, where_to_commit}, W2C)
	    end;
	_ ->
	    ignore
    end,
    insert_cstruct(Tid, Cs, false, InPlace, InitBy);

insert_op(Tid, _, {op, del_table_copy, Storage, Node, TabDef}, InPlace, InitBy) ->
    Cs = mnesia_schema:list2cs(TabDef),
    Tab = Cs#cstruct.name,
    if
	Tab == schema, Storage == ram_copies ->
	    insert_cstruct(Tid, Cs, true, InPlace, InitBy);
        Tab /= schema ->
	    mnesia_controller:del_active_replica(Tab, Node),
	    mnesia_lib:del({Tab, Storage}, Node),
	    if
		Node == node() ->
		    case Cs#cstruct.local_content of
			true -> mnesia_lib:set({Tab, where_to_read}, nowhere);
			false -> mnesia_lib:set_remote_where_to_read(Tab)
		    end,
		    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_majority,TabDef, _OldAccess, _Access}, InPlace, InitBy) ->
    Cs = mnesia_schema:list2cs(TabDef),
    case InitBy of
	startup -> ignore;
	_ -> mnesia_controller:change_table_majority(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.