summaryrefslogtreecommitdiff
path: root/gcc/ada/a-cbhama.adb
blob: 942007cde5d13346118e3aa3069c0f63be68566a (plain)
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
------------------------------------------------------------------------------
--                                                                          --
--                         GNAT LIBRARY COMPONENTS                          --
--                                                                          --
--   A D A . C O N T A I N E R S . B O U N D E D _ H A S H E D _ M A P S    --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--          Copyright (C) 2004-2010, Free Software Foundation, Inc.         --
--                                                                          --
-- GNAT is free software;  you can  redistribute it  and/or modify it under --
-- terms of the  GNU General Public License as published  by the Free Soft- --
-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
--                                                                          --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception,   --
-- version 3.1, as published by the Free Software Foundation.               --
--                                                                          --
-- You should have received a copy of the GNU General Public License and    --
-- a copy of the GCC Runtime Library Exception along with this program;     --
-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
-- <http://www.gnu.org/licenses/>.                                          --
--                                                                          --
-- This unit was originally developed by Matthew J Heaney.                  --
------------------------------------------------------------------------------

with Ada.Containers.Hash_Tables.Generic_Bounded_Operations;
pragma Elaborate_All (Ada.Containers.Hash_Tables.Generic_Bounded_Operations);

with Ada.Containers.Hash_Tables.Generic_Bounded_Keys;
pragma Elaborate_All (Ada.Containers.Hash_Tables.Generic_Bounded_Keys);

with Ada.Containers.Prime_Numbers;  use Ada.Containers.Prime_Numbers;
with System;  use type System.Address;

package body Ada.Containers.Bounded_Hashed_Maps is

   -----------------------
   -- Local Subprograms --
   -----------------------

   function Equivalent_Key_Node
     (Key  : Key_Type;
      Node : Node_Type) return Boolean;
   pragma Inline (Equivalent_Key_Node);

   function Hash_Node (Node : Node_Type) return Hash_Type;
   pragma Inline (Hash_Node);

   function Next (Node : Node_Type) return Count_Type;
   pragma Inline (Next);

   procedure Set_Next (Node : in out Node_Type; Next : Count_Type);
   pragma Inline (Set_Next);

   function Vet (Position : Cursor) return Boolean;

   --------------------------
   -- Local Instantiations --
   --------------------------

   package HT_Ops is new Hash_Tables.Generic_Bounded_Operations
     (HT_Types  => HT_Types,
      Hash_Node => Hash_Node,
      Next      => Next,
      Set_Next  => Set_Next);

   package Key_Ops is new Hash_Tables.Generic_Bounded_Keys
     (HT_Types        => HT_Types,
      Next            => Next,
      Set_Next        => Set_Next,
      Key_Type        => Key_Type,
      Hash            => Hash,
      Equivalent_Keys => Equivalent_Key_Node);

   ---------
   -- "=" --
   ---------

   function "=" (Left, Right : Map) return Boolean is
      function Find_Equal_Key
        (R_HT   : Hash_Table_Type'Class;
         L_Node : Node_Type) return Boolean;

      function Is_Equal is new HT_Ops.Generic_Equal (Find_Equal_Key);

      --------------------
      -- Find_Equal_Key --
      --------------------

      function Find_Equal_Key
        (R_HT   : Hash_Table_Type'Class;
         L_Node : Node_Type) return Boolean
      is
         R_Index : constant Hash_Type := Key_Ops.Index (R_HT, L_Node.Key);
         R_Node  : Count_Type := R_HT.Buckets (R_Index);

      begin
         while R_Node /= 0 loop
            if Equivalent_Keys (L_Node.Key, R_HT.Nodes (R_Node).Key) then
               return L_Node.Element = R_HT.Nodes (R_Node).Element;
            end if;

            R_Node := R_HT.Nodes (R_Node).Next;
         end loop;

         return False;
      end Find_Equal_Key;

   --  Start of processing for "="

   begin
      return Is_Equal (Left, Right);
   end "=";

   ------------
   -- Assign --
   ------------

   procedure Assign (Target : in out Map; Source : Map) is
      procedure Insert_Element (Source_Node : Count_Type);

      procedure Insert_Elements is
         new HT_Ops.Generic_Iteration (Insert_Element);

      --------------------
      -- Insert_Element --
      --------------------

      procedure Insert_Element (Source_Node : Count_Type) is
         N : Node_Type renames Source.Nodes (Source_Node);
         C : Cursor;
         B : Boolean;

      begin
         Insert (Target, N.Key, N.Element, C, B);
         pragma Assert (B);
      end Insert_Element;

   --  Start of processing for Assign

   begin
      if Target'Address = Source'Address then
         return;
      end if;

      if Target.Capacity < Source.Length then
         raise Capacity_Error
           with "Target capacity is less than Source length";
      end if;

      HT_Ops.Clear (Target);
      Insert_Elements (Source);
   end Assign;

   --------------
   -- Capacity --
   --------------

   function Capacity (Container : Map) return Count_Type is
   begin
      return Container.Capacity;
   end Capacity;

   -----------
   -- Clear --
   -----------

   procedure Clear (Container : in out Map) is
   begin
      HT_Ops.Clear (Container);
   end Clear;

   --------------
   -- Contains --
   --------------

   function Contains (Container : Map; Key : Key_Type) return Boolean is
   begin
      return Find (Container, Key) /= No_Element;
   end Contains;

   ----------
   -- Copy --
   ----------

   function Copy
     (Source   : Map;
      Capacity : Count_Type := 0;
      Modulus  : Hash_Type := 0) return Map
   is
      C : Count_Type;
      M : Hash_Type;

   begin
      if Capacity = 0 then
         C := Source.Length;

      elsif Capacity >= Source.Length then
         C := Capacity;

      else
         raise Capacity_Error with "Capacity value too small";
      end if;

      if Modulus = 0 then
         M := Default_Modulus (C);
      else
         M := Modulus;
      end if;

      return Target : Map (Capacity => C, Modulus => M) do
         Assign (Target => Target, Source => Source);
      end return;
   end Copy;

   ---------------------
   -- Default_Modulus --
   ---------------------

   function Default_Modulus (Capacity : Count_Type) return Hash_Type is
   begin
      return To_Prime (Capacity);
   end Default_Modulus;

   ------------
   -- Delete --
   ------------

   procedure Delete (Container : in out Map; Key : Key_Type) is
      X : Count_Type;

   begin
      Key_Ops.Delete_Key_Sans_Free (Container, Key, X);

      if X = 0 then
         raise Constraint_Error with "attempt to delete key not in map";
      end if;

      HT_Ops.Free (Container, X);
   end Delete;

   procedure Delete (Container : in out Map; Position : in out Cursor) is
   begin
      if Position.Node = 0 then
         raise Constraint_Error with
           "Position cursor of Delete equals No_Element";
      end if;

      if Position.Container /= Container'Unrestricted_Access then
         raise Program_Error with
           "Position cursor of Delete designates wrong map";
      end if;

      if Container.Busy > 0 then
         raise Program_Error with
           "Delete attempted to tamper with cursors (map is busy)";
      end if;

      pragma Assert (Vet (Position), "bad cursor in Delete");

      HT_Ops.Delete_Node_Sans_Free (Container, Position.Node);
      HT_Ops.Free (Container, Position.Node);

      Position := No_Element;
   end Delete;

   -------------
   -- Element --
   -------------

   function Element (Container : Map; Key : Key_Type) return Element_Type is
      Node : constant Count_Type := Key_Ops.Find (Container, Key);

   begin
      if Node = 0 then
         raise Constraint_Error with
           "no element available because key not in map";
      end if;

      return Container.Nodes (Node).Element;
   end Element;

   function Element (Position : Cursor) return Element_Type is
   begin
      if Position.Node = 0 then
         raise Constraint_Error with
           "Position cursor of function Element equals No_Element";
      end if;

      pragma Assert (Vet (Position), "bad cursor in function Element");

      return Position.Container.Nodes (Position.Node).Element;
   end Element;

   -------------------------
   -- Equivalent_Key_Node --
   -------------------------

   function Equivalent_Key_Node
     (Key  : Key_Type;
      Node : Node_Type) return Boolean is
   begin
      return Equivalent_Keys (Key, Node.Key);
   end Equivalent_Key_Node;

   ---------------------
   -- Equivalent_Keys --
   ---------------------

   function Equivalent_Keys (Left, Right : Cursor)
     return Boolean is
   begin
      if Left.Node = 0 then
         raise Constraint_Error with
           "Left cursor of Equivalent_Keys equals No_Element";
      end if;

      if Right.Node = 0 then
         raise Constraint_Error with
           "Right cursor of Equivalent_Keys equals No_Element";
      end if;

      pragma Assert (Vet (Left), "Left cursor of Equivalent_Keys is bad");
      pragma Assert (Vet (Right), "Right cursor of Equivalent_Keys is bad");

      declare
         LN : Node_Type renames Left.Container.Nodes (Left.Node);
         RN : Node_Type renames Right.Container.Nodes (Right.Node);

      begin
         return Equivalent_Keys (LN.Key, RN.Key);
      end;
   end Equivalent_Keys;

   function Equivalent_Keys (Left : Cursor; Right : Key_Type) return Boolean is
   begin
      if Left.Node = 0 then
         raise Constraint_Error with
           "Left cursor of Equivalent_Keys equals No_Element";
      end if;

      pragma Assert (Vet (Left), "Left cursor in Equivalent_Keys is bad");

      declare
         LN : Node_Type renames Left.Container.Nodes (Left.Node);

      begin
         return Equivalent_Keys (LN.Key, Right);
      end;
   end Equivalent_Keys;

   function Equivalent_Keys (Left : Key_Type; Right : Cursor) return Boolean is
   begin
      if Right.Node = 0 then
         raise Constraint_Error with
           "Right cursor of Equivalent_Keys equals No_Element";
      end if;

      pragma Assert (Vet (Right), "Right cursor of Equivalent_Keys is bad");

      declare
         RN : Node_Type renames Right.Container.Nodes (Right.Node);

      begin
         return Equivalent_Keys (Left, RN.Key);
      end;
   end Equivalent_Keys;

   -------------
   -- Exclude --
   -------------

   procedure Exclude (Container : in out Map; Key : Key_Type) is
      X : Count_Type;
   begin
      Key_Ops.Delete_Key_Sans_Free (Container, Key, X);
      HT_Ops.Free (Container, X);
   end Exclude;

   ----------
   -- Find --
   ----------

   function Find (Container : Map; Key : Key_Type) return Cursor is
      Node : constant Count_Type := Key_Ops.Find (Container, Key);

   begin
      if Node = 0 then
         return No_Element;
      end if;

      return Cursor'(Container'Unrestricted_Access, Node);
   end Find;

   -----------
   -- First --
   -----------

   function First (Container : Map) return Cursor is
      Node : constant Count_Type := HT_Ops.First (Container);

   begin
      if Node = 0 then
         return No_Element;
      end if;

      return Cursor'(Container'Unrestricted_Access, Node);
   end First;

   -----------------
   -- Has_Element --
   -----------------

   function Has_Element (Position : Cursor) return Boolean is
   begin
      pragma Assert (Vet (Position), "bad cursor in Has_Element");
      return Position.Node /= 0;
   end Has_Element;

   ---------------
   -- Hash_Node --
   ---------------

   function Hash_Node (Node : Node_Type) return Hash_Type is
   begin
      return Hash (Node.Key);
   end Hash_Node;

   -------------
   -- Include --
   -------------

   procedure Include
     (Container : in out Map;
      Key       : Key_Type;
      New_Item  : Element_Type)
   is
      Position : Cursor;
      Inserted : Boolean;

   begin
      Insert (Container, Key, New_Item, Position, Inserted);

      if not Inserted then
         if Container.Lock > 0 then
            raise Program_Error with
              "Include attempted to tamper with elements (map is locked)";
         end if;

         declare
            N : Node_Type renames Container.Nodes (Position.Node);

         begin
            N.Key := Key;
            N.Element := New_Item;
         end;
      end if;
   end Include;

   ------------
   -- Insert --
   ------------

   procedure Insert
     (Container : in out Map;
      Key       : Key_Type;
      Position  : out Cursor;
      Inserted  : out Boolean)
   is
      procedure Assign_Key (Node : in out Node_Type);
      pragma Inline (Assign_Key);

      function New_Node return Count_Type;
      pragma Inline (New_Node);

      procedure Local_Insert is
        new Key_Ops.Generic_Conditional_Insert (New_Node);

      procedure Allocate is
         new HT_Ops.Generic_Allocate (Assign_Key);

      -----------------
      --  Assign_Key --
      -----------------

      procedure Assign_Key (Node : in out Node_Type) is
      begin
         Node.Key := Key;
         --  Node.Element := New_Item;
      end Assign_Key;

      --------------
      -- New_Node --
      --------------

      function New_Node return Count_Type is
         Result : Count_Type;
      begin
         Allocate (Container, Result);
         return Result;
      end New_Node;

   --  Start of processing for Insert

   begin
      --  ???
      --  if HT_Ops.Capacity (HT) = 0 then
      --     HT_Ops.Reserve_Capacity (HT, 1);
      --  end if;

      Local_Insert (Container, Key, Position.Node, Inserted);

      --  ???
      --  if Inserted
      --    and then HT.Length > HT_Ops.Capacity (HT)
      --  then
      --     HT_Ops.Reserve_Capacity (HT, HT.Length);
      --  end if;

      Position.Container := Container'Unchecked_Access;
   end Insert;

   procedure Insert
     (Container : in out Map;
      Key       : Key_Type;
      New_Item  : Element_Type;
      Position  : out Cursor;
      Inserted  : out Boolean)
   is
      procedure Assign_Key (Node : in out Node_Type);
      pragma Inline (Assign_Key);

      function New_Node return Count_Type;
      pragma Inline (New_Node);

      procedure Local_Insert is
        new Key_Ops.Generic_Conditional_Insert (New_Node);

      procedure Allocate is
         new HT_Ops.Generic_Allocate (Assign_Key);

      -----------------
      --  Assign_Key --
      -----------------

      procedure Assign_Key (Node : in out Node_Type) is
      begin
         Node.Key := Key;
         Node.Element := New_Item;
      end Assign_Key;

      --------------
      -- New_Node --
      --------------

      function New_Node return Count_Type is
         Result : Count_Type;
      begin
         Allocate (Container, Result);
         return Result;
      end New_Node;

   --  Start of processing for Insert

   begin
      --  ??
      --  if HT_Ops.Capacity (HT) = 0 then
      --     HT_Ops.Reserve_Capacity (HT, 1);
      --  end if;

      Local_Insert (Container, Key, Position.Node, Inserted);

      --  ???
      --  if Inserted
      --    and then HT.Length > HT_Ops.Capacity (HT)
      --  then
      --     HT_Ops.Reserve_Capacity (HT, HT.Length);
      --  end if;

      Position.Container := Container'Unchecked_Access;
   end Insert;

   procedure Insert
     (Container : in out Map;
      Key       : Key_Type;
      New_Item  : Element_Type)
   is
      Position : Cursor;
      pragma Unreferenced (Position);

      Inserted : Boolean;

   begin
      Insert (Container, Key, New_Item, Position, Inserted);

      if not Inserted then
         raise Constraint_Error with
           "attempt to insert key already in map";
      end if;
   end Insert;

   --------------
   -- Is_Empty --
   --------------

   function Is_Empty (Container : Map) return Boolean is
   begin
      return Container.Length = 0;
   end Is_Empty;

   -------------
   -- Iterate --
   -------------

   procedure Iterate
     (Container : Map;
      Process   : not null access procedure (Position : Cursor))
   is
      procedure Process_Node (Node : Count_Type);
      pragma Inline (Process_Node);

      procedure Local_Iterate is new HT_Ops.Generic_Iteration (Process_Node);

      ------------------
      -- Process_Node --
      ------------------

      procedure Process_Node (Node : Count_Type) is
      begin
         Process (Cursor'(Container'Unrestricted_Access, Node));
      end Process_Node;

      B : Natural renames Container'Unrestricted_Access.Busy;

   --  Start of processing for Iterate

   begin
      B := B + 1;

      begin
         Local_Iterate (Container);
      exception
         when others =>
            B := B - 1;
            raise;
      end;

      B := B - 1;
   end Iterate;

   ---------
   -- Key --
   ---------

   function Key (Position : Cursor) return Key_Type is
   begin
      if Position.Node = 0 then
         raise Constraint_Error with
           "Position cursor of function Key equals No_Element";
      end if;

      pragma Assert (Vet (Position), "bad cursor in function Key");

      return Position.Container.Nodes (Position.Node).Key;
   end Key;

   ------------
   -- Length --
   ------------

   function Length (Container : Map) return Count_Type is
   begin
      return Container.Length;
   end Length;

   ----------
   -- Move --
   ----------

   procedure Move
     (Target : in out Map;
      Source : in out Map)
   is
   begin
      if Target'Address = Source'Address then
         return;
      end if;

      if Source.Busy > 0 then
         raise Program_Error with
           "attempt to tamper with cursors (container is busy)";
      end if;

      Assign (Target => Target, Source => Source);
   end Move;

   ----------
   -- Next --
   ----------

   function Next (Node : Node_Type) return Count_Type is
   begin
      return Node.Next;
   end Next;

   function Next (Position : Cursor) return Cursor is
   begin
      if Position.Node = 0 then
         return No_Element;
      end if;

      pragma Assert (Vet (Position), "bad cursor in function Next");

      declare
         M    : Map renames Position.Container.all;
         Node : constant Count_Type := HT_Ops.Next (M, Position.Node);

      begin
         if Node = 0 then
            return No_Element;
         end if;

         return Cursor'(Position.Container, Node);
      end;
   end Next;

   procedure Next (Position : in out Cursor) is
   begin
      Position := Next (Position);
   end Next;

   -------------------
   -- Query_Element --
   -------------------

   procedure Query_Element
     (Position : Cursor;
      Process  : not null access
                   procedure (Key : Key_Type; Element : Element_Type))
   is
   begin
      if Position.Node = 0 then
         raise Constraint_Error with
           "Position cursor of Query_Element equals No_Element";
      end if;

      pragma Assert (Vet (Position), "bad cursor in Query_Element");

      declare
         M : Map renames Position.Container.all;
         N : Node_Type renames M.Nodes (Position.Node);
         B : Natural renames M.Busy;
         L : Natural renames M.Lock;

      begin
         B := B + 1;
         L := L + 1;

         declare

         begin
            Process (N.Key, N.Element);
         exception
            when others =>
               L := L - 1;
               B := B - 1;
               raise;
         end;

         L := L - 1;
         B := B - 1;
      end;
   end Query_Element;

   ----------
   -- Read --
   ----------

   procedure Read
     (Stream    : not null access Root_Stream_Type'Class;
      Container : out Map)
   is
      function Read_Node
        (Stream : not null access Root_Stream_Type'Class) return Count_Type;
      --  pragma Inline (Read_Node);  ???

      procedure Read_Nodes is new HT_Ops.Generic_Read (Read_Node);

      ---------------
      -- Read_Node --
      ---------------

      function Read_Node
        (Stream : not null access Root_Stream_Type'Class) return Count_Type
      is
         procedure Read_Element (Node : in out Node_Type);
         --  pragma Inline (Read_Element);  ???

         procedure Allocate is
            new HT_Ops.Generic_Allocate (Read_Element);

         procedure Read_Element (Node : in out Node_Type) is
         begin
            Key_Type'Read (Stream, Node.Key);
            Element_Type'Read (Stream, Node.Element);
         end Read_Element;

         Node : Count_Type;

      --  Start of processing for Read_Node

      begin
         Allocate (Container, Node);
         return Node;
      end Read_Node;

   --  Start of processing for Read

   begin
      Read_Nodes (Stream, Container);
   end Read;

   procedure Read
     (Stream : not null access Root_Stream_Type'Class;
      Item   : out Cursor)
   is
   begin
      raise Program_Error with "attempt to stream map cursor";
   end Read;

   -------------
   -- Replace --
   -------------

   procedure Replace
     (Container : in out Map;
      Key       : Key_Type;
      New_Item  : Element_Type)
   is
      Node : constant Count_Type := Key_Ops.Find (Container, Key);

   begin
      if Node = 0 then
         raise Constraint_Error with
           "attempt to replace key not in map";
      end if;

      if Container.Lock > 0 then
         raise Program_Error with
           "Replace attempted to tamper with elements (map is locked)";
      end if;

      declare
         N : Node_Type renames Container.Nodes (Node);

      begin
         N.Key := Key;
         N.Element := New_Item;
      end;
   end Replace;

   ---------------------
   -- Replace_Element --
   ---------------------

   procedure Replace_Element
     (Container : in out Map;
      Position  : Cursor;
      New_Item  : Element_Type)
   is
   begin
      if Position.Node = 0 then
         raise Constraint_Error with
           "Position cursor of Replace_Element equals No_Element";
      end if;

      if Position.Container /= Container'Unrestricted_Access then
         raise Program_Error with
           "Position cursor of Replace_Element designates wrong map";
      end if;

      if Position.Container.Lock > 0 then
         raise Program_Error with
           "Replace_Element attempted to tamper with elements (map is locked)";
      end if;

      pragma Assert (Vet (Position), "bad cursor in Replace_Element");

      Container.Nodes (Position.Node).Element := New_Item;
   end Replace_Element;

   ----------------------
   -- Reserve_Capacity --
   ----------------------

   procedure Reserve_Capacity
     (Container : in out Map;
      Capacity  : Count_Type)
   is
   begin
      if Capacity > Container.Capacity then
         raise Capacity_Error with "requested capacity is too large";
      end if;
   end Reserve_Capacity;

   --------------
   -- Set_Next --
   --------------

   procedure Set_Next (Node : in out Node_Type; Next : Count_Type) is
   begin
      Node.Next := Next;
   end Set_Next;

   --------------------
   -- Update_Element --
   --------------------

   procedure Update_Element
     (Container : in out Map;
      Position  : Cursor;
      Process   : not null access procedure (Key     : Key_Type;
                                             Element : in out Element_Type))
   is
   begin
      if Position.Node = 0 then
         raise Constraint_Error with
           "Position cursor of Update_Element equals No_Element";
      end if;

      if Position.Container /= Container'Unrestricted_Access then
         raise Program_Error with
           "Position cursor of Update_Element designates wrong map";
      end if;

      pragma Assert (Vet (Position), "bad cursor in Update_Element");

      declare
         N : Node_Type renames Container.Nodes (Position.Node);
         B : Natural renames Container.Busy;
         L : Natural renames Container.Lock;

      begin
         B := B + 1;
         L := L + 1;

         begin
            Process (N.Key, N.Element);
         exception
            when others =>
               L := L - 1;
               B := B - 1;
               raise;
         end;

         L := L - 1;
         B := B - 1;
      end;
   end Update_Element;

   ---------
   -- Vet --
   ---------

   function Vet (Position : Cursor) return Boolean is
   begin
      if Position.Node = 0 then
         return Position.Container = null;
      end if;

      if Position.Container = null then
         return False;
      end if;

      declare
         M : Map renames Position.Container.all;
         X : Count_Type;

      begin
         if M.Length = 0 then
            return False;
         end if;

         if M.Capacity = 0 then
            return False;
         end if;

         if M.Buckets'Length = 0 then
            return False;
         end if;

         if Position.Node > M.Capacity then
            return False;
         end if;

         if M.Nodes (Position.Node).Next = Position.Node then
            return False;
         end if;

         X := M.Buckets (Key_Ops.Index (M, M.Nodes (Position.Node).Key));

         for J in 1 .. M.Length loop
            if X = Position.Node then
               return True;
            end if;

            if X = 0 then
               return False;
            end if;

            if X = M.Nodes (X).Next then  --  to prevent unnecessary looping
               return False;
            end if;

            X := M.Nodes (X).Next;
         end loop;

         return False;
      end;
   end Vet;

   -----------
   -- Write --
   -----------

   procedure Write
     (Stream    : not null access Root_Stream_Type'Class;
      Container : Map)
   is
      procedure Write_Node
        (Stream : not null access Root_Stream_Type'Class;
         Node   : Node_Type);
      pragma Inline (Write_Node);

      procedure Write_Nodes is new HT_Ops.Generic_Write (Write_Node);

      ----------------
      -- Write_Node --
      ----------------

      procedure Write_Node
        (Stream : not null access Root_Stream_Type'Class;
         Node   : Node_Type)
      is
      begin
         Key_Type'Write (Stream, Node.Key);
         Element_Type'Write (Stream, Node.Element);
      end Write_Node;

   --  Start of processing for Write

   begin
      Write_Nodes (Stream, Container);
   end Write;

   procedure Write
     (Stream : not null access Root_Stream_Type'Class;
      Item   : Cursor)
   is
   begin
      raise Program_Error with "attempt to stream map cursor";
   end Write;

end Ada.Containers.Bounded_Hashed_Maps;