------------------------------------------------------------------------------ -- -- -- GNAT LIBRARY COMPONENTS -- -- -- -- A D A . C O N T A I N E R S . -- -- I N D E F I N I T E _ H A S H E D _ S E T S -- -- -- -- B o d y -- -- -- -- Copyright (C) 2004-2006, Free Software Foundation, Inc. -- -- -- -- This specification is derived from the Ada Reference Manual for use with -- -- GNAT. The copyright notice above, and the license provisions that follow -- -- apply solely to the contents of the part following the private keyword. -- -- -- -- 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 2, 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. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING. If not, write -- -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, -- -- Boston, MA 02110-1301, USA. -- -- -- -- As a special exception, if other files instantiate generics from this -- -- unit, or you link this unit with other files to produce an executable, -- -- this unit does not by itself cause the resulting executable to be -- -- covered by the GNU General Public License. This exception does not -- -- however invalidate any other reasons why the executable file might be -- -- covered by the GNU Public License. -- -- -- -- This unit has originally being developed by Matthew J Heaney. -- ------------------------------------------------------------------------------ with Ada.Unchecked_Deallocation; with Ada.Containers.Hash_Tables.Generic_Operations; pragma Elaborate_All (Ada.Containers.Hash_Tables.Generic_Operations); with Ada.Containers.Hash_Tables.Generic_Keys; pragma Elaborate_All (Ada.Containers.Hash_Tables.Generic_Keys); with Ada.Containers.Prime_Numbers; with System; use type System.Address; package body Ada.Containers.Indefinite_Hashed_Sets is ----------------------- -- Local Subprograms -- ----------------------- function Copy_Node (Source : Node_Access) return Node_Access; pragma Inline (Copy_Node); function Equivalent_Keys (Key : Element_Type; Node : Node_Access) return Boolean; pragma Inline (Equivalent_Keys); function Find_Equal_Key (R_HT : Hash_Table_Type; L_Node : Node_Access) return Boolean; function Find_Equivalent_Key (R_HT : Hash_Table_Type; L_Node : Node_Access) return Boolean; procedure Free (X : in out Node_Access); function Hash_Node (Node : Node_Access) return Hash_Type; pragma Inline (Hash_Node); procedure Insert (HT : in out Hash_Table_Type; New_Item : Element_Type; Node : out Node_Access; Inserted : out Boolean); function Is_In (HT : Hash_Table_Type; Key : Node_Access) return Boolean; pragma Inline (Is_In); function Next (Node : Node_Access) return Node_Access; pragma Inline (Next); function Read_Node (Stream : access Root_Stream_Type'Class) return Node_Access; pragma Inline (Read_Node); procedure Replace_Element (HT : in out Hash_Table_Type; Node : Node_Access; New_Item : Element_Type); procedure Set_Next (Node : Node_Access; Next : Node_Access); pragma Inline (Set_Next); function Vet (Position : Cursor) return Boolean; procedure Write_Node (Stream : access Root_Stream_Type'Class; Node : Node_Access); pragma Inline (Write_Node); -------------------------- -- Local Instantiations -- -------------------------- procedure Free_Element is new Ada.Unchecked_Deallocation (Element_Type, Element_Access); package HT_Ops is new Hash_Tables.Generic_Operations (HT_Types => HT_Types, Hash_Node => Hash_Node, Next => Next, Set_Next => Set_Next, Copy_Node => Copy_Node, Free => Free); package Element_Keys is new Hash_Tables.Generic_Keys (HT_Types => HT_Types, Next => Next, Set_Next => Set_Next, Key_Type => Element_Type, Hash => Hash, Equivalent_Keys => Equivalent_Keys); function Is_Equal is new HT_Ops.Generic_Equal (Find_Equal_Key); function Is_Equivalent is new HT_Ops.Generic_Equal (Find_Equivalent_Key); procedure Read_Nodes is new HT_Ops.Generic_Read (Read_Node); procedure Write_Nodes is new HT_Ops.Generic_Write (Write_Node); --------- -- "=" -- --------- function "=" (Left, Right : Set) return Boolean is begin return Is_Equal (Left.HT, Right.HT); end "="; ------------ -- Adjust -- ------------ procedure Adjust (Container : in out Set) is begin HT_Ops.Adjust (Container.HT); end Adjust; -------------- -- Capacity -- -------------- function Capacity (Container : Set) return Count_Type is begin return HT_Ops.Capacity (Container.HT); end Capacity; ----------- -- Clear -- ----------- procedure Clear (Container : in out Set) is begin HT_Ops.Clear (Container.HT); end Clear; -------------- -- Contains -- -------------- function Contains (Container : Set; Item : Element_Type) return Boolean is begin return Find (Container, Item) /= No_Element; end Contains; --------------- -- Copy_Node -- --------------- function Copy_Node (Source : Node_Access) return Node_Access is E : Element_Access := new Element_Type'(Source.Element.all); begin return new Node_Type'(Element => E, Next => null); exception when others => Free_Element (E); raise; end Copy_Node; ------------ -- Delete -- ------------ procedure Delete (Container : in out Set; Item : Element_Type) is X : Node_Access; begin Element_Keys.Delete_Key_Sans_Free (Container.HT, Item, X); if X = null then raise Constraint_Error with "attempt to delete element not in set"; end if; Free (X); end Delete; procedure Delete (Container : in out Set; Position : in out Cursor) is begin if Position.Node = null then raise Constraint_Error with "Position cursor equals No_Element"; end if; if Position.Node.Element = null then raise Program_Error with "Position cursor is bad"; end if; if Position.Container /= Container'Unrestricted_Access then raise Program_Error with "Position cursor designates wrong set"; end if; if Container.HT.Busy > 0 then raise Program_Error with "attempt to tamper with elements (set is busy)"; end if; pragma Assert (Vet (Position), "Position cursor is bad"); HT_Ops.Delete_Node_Sans_Free (Container.HT, Position.Node); Free (Position.Node); Position.Container := null; end Delete; ---------------- -- Difference -- ---------------- procedure Difference (Target : in out Set; Source : Set) is Tgt_Node : Node_Access; begin if Target'Address = Source'Address then Clear (Target); return; end if; if Source.Length = 0 then return; end if; if Target.HT.Busy > 0 then raise Program_Error with "attempt to tamper with elements (set is busy)"; end if; -- TODO: This can be written in terms of a loop instead as -- active-iterator style, sort of like a passive iterator. Tgt_Node := HT_Ops.First (Target.HT); while Tgt_Node /= null loop if Is_In (Source.HT, Tgt_Node) then declare X : Node_Access := Tgt_Node; begin Tgt_Node := HT_Ops.Next (Target.HT, Tgt_Node); HT_Ops.Delete_Node_Sans_Free (Target.HT, X); Free (X); end; else Tgt_Node := HT_Ops.Next (Target.HT, Tgt_Node); end if; end loop; end Difference; function Difference (Left, Right : Set) return Set is Buckets : HT_Types.Buckets_Access; Length : Count_Type; begin if Left'Address = Right'Address then return Empty_Set; end if; if Left.Length = 0 then return Empty_Set; end if; if Right.Length = 0 then return Left; end if; declare Size : constant Hash_Type := Prime_Numbers.To_Prime (Left.Length); begin Buckets := new Buckets_Type (0 .. Size - 1); end; Length := 0; Iterate_Left : declare procedure Process (L_Node : Node_Access); procedure Iterate is new HT_Ops.Generic_Iteration (Process); ------------- -- Process -- ------------- procedure Process (L_Node : Node_Access) is begin if not Is_In (Right.HT, L_Node) then declare Src : Element_Type renames L_Node.Element.all; Indx : constant Hash_Type := Hash (Src) mod Buckets'Length; Bucket : Node_Access renames Buckets (Indx); Tgt : Element_Access := new Element_Type'(Src); begin Bucket := new Node_Type'(Tgt, Bucket); exception when others => Free_Element (Tgt); raise; end; Length := Length + 1; end if; end Process; -- Start of processing for Iterate_Left begin Iterate (Left.HT); exception when others => HT_Ops.Free_Hash_Table (Buckets); raise; end Iterate_Left; return (Controlled with HT => (Buckets, Length, 0, 0)); end Difference; ------------- -- Element -- ------------- function Element (Position : Cursor) return Element_Type is begin if Position.Node = null then raise Constraint_Error with "Position cursor of equals No_Element"; end if; if Position.Node.Element = null then -- handle dangling reference raise Program_Error with "Position cursor is bad"; end if; pragma Assert (Vet (Position), "bad cursor in function Element"); return Position.Node.Element.all; end Element; --------------------- -- Equivalent_Sets -- --------------------- function Equivalent_Sets (Left, Right : Set) return Boolean is begin return Is_Equivalent (Left.HT, Right.HT); end Equivalent_Sets; ------------------------- -- Equivalent_Elements -- ------------------------- function Equivalent_Elements (Left, Right : Cursor) return Boolean is begin if Left.Node = null then raise Constraint_Error with "Left cursor of Equivalent_Elements equals No_Element"; end if; if Right.Node = null then raise Constraint_Error with "Right cursor of Equivalent_Elements equals No_Element"; end if; if Left.Node.Element = null then raise Program_Error with "Left cursor of Equivalent_Elements is bad"; end if; if Right.Node.Element = null then raise Program_Error with "Right cursor of Equivalent_Elements is bad"; end if; pragma Assert (Vet (Left), "bad Left cursor in Equivalent_Elements"); pragma Assert (Vet (Right), "bad Right cursor in Equivalent_Elements"); return Equivalent_Elements (Left.Node.Element.all, Right.Node.Element.all); end Equivalent_Elements; function Equivalent_Elements (Left : Cursor; Right : Element_Type) return Boolean is begin if Left.Node = null then raise Constraint_Error with "Left cursor of Equivalent_Elements equals No_Element"; end if; if Left.Node.Element = null then raise Program_Error with "Left cursor of Equivalent_Elements is bad"; end if; pragma Assert (Vet (Left), "bad Left cursor in Equivalent_Elements"); return Equivalent_Elements (Left.Node.Element.all, Right); end Equivalent_Elements; function Equivalent_Elements (Left : Element_Type; Right : Cursor) return Boolean is begin if Right.Node = null then raise Constraint_Error with "Right cursor of Equivalent_Elements equals No_Element"; end if; if Right.Node.Element = null then raise Program_Error with "Right cursor of Equivalent_Elements is bad"; end if; pragma Assert (Vet (Right), "bad Right cursor in Equivalent_Elements"); return Equivalent_Elements (Left, Right.Node.Element.all); end Equivalent_Elements; --------------------- -- Equivalent_Keys -- --------------------- function Equivalent_Keys (Key : Element_Type; Node : Node_Access) return Boolean is begin return Equivalent_Elements (Key, Node.Element.all); end Equivalent_Keys; ------------- -- Exclude -- ------------- procedure Exclude (Container : in out Set; Item : Element_Type) is X : Node_Access; begin Element_Keys.Delete_Key_Sans_Free (Container.HT, Item, X); Free (X); end Exclude; -------------- -- Finalize -- -------------- procedure Finalize (Container : in out Set) is begin HT_Ops.Finalize (Container.HT); end Finalize; ---------- -- Find -- ---------- function Find (Container : Set; Item : Element_Type) return Cursor is Node : constant Node_Access := Element_Keys.Find (Container.HT, Item); begin if Node = null then return No_Element; end if; return Cursor'(Container'Unrestricted_Access, Node); end Find; -------------------- -- Find_Equal_Key -- -------------------- function Find_Equal_Key (R_HT : Hash_Table_Type; L_Node : Node_Access) return Boolean is R_Index : constant Hash_Type := Element_Keys.Index (R_HT, L_Node.Element.all); R_Node : Node_Access := R_HT.Buckets (R_Index); begin loop if R_Node = null then return False; end if; if L_Node.Element.all = R_Node.Element.all then return True; end if; R_Node := Next (R_Node); end loop; end Find_Equal_Key; ------------------------- -- Find_Equivalent_Key -- ------------------------- function Find_Equivalent_Key (R_HT : Hash_Table_Type; L_Node : Node_Access) return Boolean is R_Index : constant Hash_Type := Element_Keys.Index (R_HT, L_Node.Element.all); R_Node : Node_Access := R_HT.Buckets (R_Index); begin loop if R_Node = null then return False; end if; if Equivalent_Elements (L_Node.Element.all, R_Node.Element.all) then return True; end if; R_Node := Next (R_Node); end loop; end Find_Equivalent_Key; ----------- -- First -- ----------- function First (Container : Set) return Cursor is Node : constant Node_Access := HT_Ops.First (Container.HT); begin if Node = null then return No_Element; end if; return Cursor'(Container'Unrestricted_Access, Node); end First; ---------- -- Free -- ---------- procedure Free (X : in out Node_Access) is procedure Deallocate is new Ada.Unchecked_Deallocation (Node_Type, Node_Access); begin if X = null then return; end if; X.Next := X; -- detect mischief (in Vet) begin Free_Element (X.Element); exception when others => X.Element := null; Deallocate (X); raise; end; Deallocate (X); end Free; ----------------- -- Has_Element -- ----------------- function Has_Element (Position : Cursor) return Boolean is begin pragma Assert (Vet (Position), "bad cursor in Has_Element"); return Position.Node /= null; end Has_Element; --------------- -- Hash_Node -- --------------- function Hash_Node (Node : Node_Access) return Hash_Type is begin return Hash (Node.Element.all); end Hash_Node; ------------- -- Include -- ------------- procedure Include (Container : in out Set; New_Item : Element_Type) is Position : Cursor; Inserted : Boolean; X : Element_Access; begin Insert (Container, New_Item, Position, Inserted); if not Inserted then if Container.HT.Lock > 0 then raise Program_Error with "attempt to tamper with cursors (set is locked)"; end if; X := Position.Node.Element; Position.Node.Element := new Element_Type'(New_Item); Free_Element (X); end if; end Include; ------------ -- Insert -- ------------ procedure Insert (Container : in out Set; New_Item : Element_Type; Position : out Cursor; Inserted : out Boolean) is begin Insert (Container.HT, New_Item, Position.Node, Inserted); Position.Container := Container'Unchecked_Access; end Insert; procedure Insert (Container : in out Set; New_Item : Element_Type) is Position : Cursor; Inserted : Boolean; begin Insert (Container, New_Item, Position, Inserted); if not Inserted then raise Constraint_Error with "attempt to insert element already in set"; end if; end Insert; procedure Insert (HT : in out Hash_Table_Type; New_Item : Element_Type; Node : out Node_Access; Inserted : out Boolean) is function New_Node (Next : Node_Access) return Node_Access; pragma Inline (New_Node); procedure Local_Insert is new Element_Keys.Generic_Conditional_Insert (New_Node); -------------- -- New_Node -- -------------- function New_Node (Next : Node_Access) return Node_Access is Element : Element_Access := new Element_Type'(New_Item); begin return new Node_Type'(Element, Next); exception when others => Free_Element (Element); raise; 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 (HT, New_Item, Node, Inserted); if Inserted and then HT.Length > HT_Ops.Capacity (HT) then HT_Ops.Reserve_Capacity (HT, HT.Length); end if; end Insert; ------------------ -- Intersection -- ------------------ procedure Intersection (Target : in out Set; Source : Set) is Tgt_Node : Node_Access; begin if Target'Address = Source'Address then return; end if; if Source.Length = 0 then Clear (Target); return; end if; if Target.HT.Busy > 0 then raise Program_Error with "attempt to tamper with elements (set is busy)"; end if; -- TODO: optimize this to use an explicit -- loop instead of an active iterator -- (similar to how a passive iterator is -- implemented). -- -- Another possibility is to test which -- set is smaller, and iterate over the -- smaller set. Tgt_Node := HT_Ops.First (Target.HT); while Tgt_Node /= null loop if Is_In (Source.HT, Tgt_Node) then Tgt_Node := HT_Ops.Next (Target.HT, Tgt_Node); else declare X : Node_Access := Tgt_Node; begin Tgt_Node := HT_Ops.Next (Target.HT, Tgt_Node); HT_Ops.Delete_Node_Sans_Free (Target.HT, X); Free (X); end; end if; end loop; end Intersection; function Intersection (Left, Right : Set) return Set is Buckets : HT_Types.Buckets_Access; Length : Count_Type; begin if Left'Address = Right'Address then return Left; end if; Length := Count_Type'Min (Left.Length, Right.Length); if Length = 0 then return Empty_Set; end if; declare Size : constant Hash_Type := Prime_Numbers.To_Prime (Length); begin Buckets := new Buckets_Type (0 .. Size - 1); end; Length := 0; Iterate_Left : declare procedure Process (L_Node : Node_Access); procedure Iterate is new HT_Ops.Generic_Iteration (Process); ------------- -- Process -- ------------- procedure Process (L_Node : Node_Access) is begin if Is_In (Right.HT, L_Node) then declare Src : Element_Type renames L_Node.Element.all; Indx : constant Hash_Type := Hash (Src) mod Buckets'Length; Bucket : Node_Access renames Buckets (Indx); Tgt : Element_Access := new Element_Type'(Src); begin Bucket := new Node_Type'(Tgt, Bucket); exception when others => Free_Element (Tgt); raise; end; Length := Length + 1; end if; end Process; -- Start of processing for Iterate_Left begin Iterate (Left.HT); exception when others => HT_Ops.Free_Hash_Table (Buckets); raise; end Iterate_Left; return (Controlled with HT => (Buckets, Length, 0, 0)); end Intersection; -------------- -- Is_Empty -- -------------- function Is_Empty (Container : Set) return Boolean is begin return Container.HT.Length = 0; end Is_Empty; ----------- -- Is_In -- ----------- function Is_In (HT : Hash_Table_Type; Key : Node_Access) return Boolean is begin return Element_Keys.Find (HT, Key.Element.all) /= null; end Is_In; --------------- -- Is_Subset -- --------------- function Is_Subset (Subset : Set; Of_Set : Set) return Boolean is Subset_Node : Node_Access; begin if Subset'Address = Of_Set'Address then return True; end if; if Subset.Length > Of_Set.Length then return False; end if; -- TODO: rewrite this to loop in the -- style of a passive iterator. Subset_Node := HT_Ops.First (Subset.HT); while Subset_Node /= null loop if not Is_In (Of_Set.HT, Subset_Node) then return False; end if; Subset_Node := HT_Ops.Next (Subset.HT, Subset_Node); end loop; return True; end Is_Subset; ------------- -- Iterate -- ------------- procedure Iterate (Container : Set; Process : not null access procedure (Position : Cursor)) is procedure Process_Node (Node : Node_Access); pragma Inline (Process_Node); procedure Iterate is new HT_Ops.Generic_Iteration (Process_Node); ------------------ -- Process_Node -- ------------------ procedure Process_Node (Node : Node_Access) is begin Process (Cursor'(Container'Unrestricted_Access, Node)); end Process_Node; HT : Hash_Table_Type renames Container'Unrestricted_Access.all.HT; -- Start of processing for Iterate begin -- TODO: resolve whether HT_Ops.Generic_Iteration should -- manipulate busy bit. Iterate (HT); end Iterate; ------------ -- Length -- ------------ function Length (Container : Set) return Count_Type is begin return Container.HT.Length; end Length; ---------- -- Move -- ---------- procedure Move (Target : in out Set; Source : in out Set) is begin HT_Ops.Move (Target => Target.HT, Source => Source.HT); end Move; ---------- -- Next -- ---------- function Next (Node : Node_Access) return Node_Access is begin return Node.Next; end Next; function Next (Position : Cursor) return Cursor is begin if Position.Node = null then return No_Element; end if; if Position.Node.Element = null then raise Program_Error with "bad cursor in Next"; end if; pragma Assert (Vet (Position), "bad cursor in Next"); declare HT : Hash_Table_Type renames Position.Container.HT; Node : constant Node_Access := HT_Ops.Next (HT, Position.Node); begin if Node = null 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; ------------- -- Overlap -- ------------- function Overlap (Left, Right : Set) return Boolean is Left_Node : Node_Access; begin if Right.Length = 0 then return False; end if; if Left'Address = Right'Address then return True; end if; Left_Node := HT_Ops.First (Left.HT); while Left_Node /= null loop if Is_In (Right.HT, Left_Node) then return True; end if; Left_Node := HT_Ops.Next (Left.HT, Left_Node); end loop; return False; end Overlap; ------------------- -- Query_Element -- ------------------- procedure Query_Element (Position : Cursor; Process : not null access procedure (Element : Element_Type)) is begin if Position.Node = null then raise Constraint_Error with "Position cursor of Query_Element equals No_Element"; end if; if Position.Node.Element = null then raise Program_Error with "bad cursor in Query_Element"; end if; pragma Assert (Vet (Position), "bad cursor in Query_Element"); declare HT : Hash_Table_Type renames Position.Container'Unrestricted_Access.all.HT; B : Natural renames HT.Busy; L : Natural renames HT.Lock; begin B := B + 1; L := L + 1; begin Process (Position.Node.Element.all); 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 : access Root_Stream_Type'Class; Container : out Set) is begin Read_Nodes (Stream, Container.HT); end Read; procedure Read (Stream : access Root_Stream_Type'Class; Item : out Cursor) is begin raise Program_Error with "attempt to stream set cursor"; end Read; --------------- -- Read_Node -- --------------- function Read_Node (Stream : access Root_Stream_Type'Class) return Node_Access is X : Element_Access := new Element_Type'(Element_Type'Input (Stream)); begin return new Node_Type'(X, null); exception when others => Free_Element (X); raise; end Read_Node; ------------- -- Replace -- ------------- procedure Replace (Container : in out Set; New_Item : Element_Type) is Node : constant Node_Access := Element_Keys.Find (Container.HT, New_Item); X : Element_Access; begin if Node = null then raise Constraint_Error with "attempt to replace element not in set"; end if; if Container.HT.Lock > 0 then raise Program_Error with "attempt to tamper with cursors (set is locked)"; end if; X := Node.Element; Node.Element := new Element_Type'(New_Item); Free_Element (X); end Replace; --------------------- -- Replace_Element -- --------------------- procedure Replace_Element (HT : in out Hash_Table_Type; Node : Node_Access; New_Item : Element_Type) is begin if Equivalent_Elements (Node.Element.all, New_Item) then pragma Assert (Hash (Node.Element.all) = Hash (New_Item)); if HT.Lock > 0 then raise Program_Error with "attempt to tamper with cursors (set is locked)"; end if; declare X : Element_Access := Node.Element; begin Node.Element := new Element_Type'(New_Item); -- OK if fails Free_Element (X); end; return; end if; if HT.Busy > 0 then raise Program_Error with "attempt to tamper with elements (set is busy)"; end if; HT_Ops.Delete_Node_Sans_Free (HT, Node); Insert_New_Element : declare function New_Node (Next : Node_Access) return Node_Access; pragma Inline (New_Node); procedure Insert is new Element_Keys.Generic_Conditional_Insert (New_Node); ------------------------ -- Insert_New_Element -- ------------------------ function New_Node (Next : Node_Access) return Node_Access is begin Node.Element := new Element_Type'(New_Item); -- OK if fails Node.Next := Next; return Node; end New_Node; Result : Node_Access; Inserted : Boolean; X : Element_Access := Node.Element; -- Start of processing for Insert_New_Element begin Attempt_Insert : begin Insert (HT => HT, Key => New_Item, Node => Result, Inserted => Inserted); exception when others => Inserted := False; -- Assignment failed end Attempt_Insert; if Inserted then Free_Element (X); -- Just propagate if fails return; end if; end Insert_New_Element; Reinsert_Old_Element : declare function New_Node (Next : Node_Access) return Node_Access; pragma Inline (New_Node); procedure Insert is new Element_Keys.Generic_Conditional_Insert (New_Node); -------------- -- New_Node -- -------------- function New_Node (Next : Node_Access) return Node_Access is begin Node.Next := Next; return Node; end New_Node; Result : Node_Access; Inserted : Boolean; -- Start of processing for Reinsert_Old_Element begin Insert (HT => HT, Key => Node.Element.all, Node => Result, Inserted => Inserted); exception when others => null; end Reinsert_Old_Element; raise Program_Error with "attempt to replace existing element"; end Replace_Element; procedure Replace_Element (Container : in out Set; Position : Cursor; New_Item : Element_Type) is begin if Position.Node = null then raise Constraint_Error with "Position cursor equals No_Element"; end if; if Position.Node.Element = null then raise Program_Error with "bad cursor in Replace_Element"; end if; if Position.Container /= Container'Unrestricted_Access then raise Program_Error with "Position cursor designates wrong set"; end if; pragma Assert (Vet (Position), "bad cursor in Replace_Element"); Replace_Element (Container.HT, Position.Node, New_Item); end Replace_Element; ---------------------- -- Reserve_Capacity -- ---------------------- procedure Reserve_Capacity (Container : in out Set; Capacity : Count_Type) is begin HT_Ops.Reserve_Capacity (Container.HT, Capacity); end Reserve_Capacity; -------------- -- Set_Next -- -------------- procedure Set_Next (Node : Node_Access; Next : Node_Access) is begin Node.Next := Next; end Set_Next; -------------------------- -- Symmetric_Difference -- -------------------------- procedure Symmetric_Difference (Target : in out Set; Source : Set) is begin if Target'Address = Source'Address then Clear (Target); return; end if; if Target.HT.Busy > 0 then raise Program_Error with "attempt to tamper with elements (set is busy)"; end if; declare N : constant Count_Type := Target.Length + Source.Length; begin if N > HT_Ops.Capacity (Target.HT) then HT_Ops.Reserve_Capacity (Target.HT, N); end if; end; if Target.Length = 0 then Iterate_Source_When_Empty_Target : declare procedure Process (Src_Node : Node_Access); procedure Iterate is new HT_Ops.Generic_Iteration (Process); ------------- -- Process -- ------------- procedure Process (Src_Node : Node_Access) is E : Element_Type renames Src_Node.Element.all; B : Buckets_Type renames Target.HT.Buckets.all; J : constant Hash_Type := Hash (E) mod B'Length; N : Count_Type renames Target.HT.Length; begin declare X : Element_Access := new Element_Type'(E); begin B (J) := new Node_Type'(X, B (J)); exception when others => Free_Element (X); raise; end; N := N + 1; end Process; -- Start of processing for Iterate_Source_When_Empty_Target begin Iterate (Source.HT); end Iterate_Source_When_Empty_Target; else Iterate_Source : declare procedure Process (Src_Node : Node_Access); procedure Iterate is new HT_Ops.Generic_Iteration (Process); ------------- -- Process -- ------------- procedure Process (Src_Node : Node_Access) is E : Element_Type renames Src_Node.Element.all; B : Buckets_Type renames Target.HT.Buckets.all; J : constant Hash_Type := Hash (E) mod B'Length; N : Count_Type renames Target.HT.Length; begin if B (J) = null then declare X : Element_Access := new Element_Type'(E); begin B (J) := new Node_Type'(X, null); exception when others => Free_Element (X); raise; end; N := N + 1; elsif Equivalent_Elements (E, B (J).Element.all) then declare X : Node_Access := B (J); begin B (J) := B (J).Next; N := N - 1; Free (X); end; else declare Prev : Node_Access := B (J); Curr : Node_Access := Prev.Next; begin while Curr /= null loop if Equivalent_Elements (E, Curr.Element.all) then Prev.Next := Curr.Next; N := N - 1; Free (Curr); return; end if; Prev := Curr; Curr := Prev.Next; end loop; declare X : Element_Access := new Element_Type'(E); begin B (J) := new Node_Type'(X, B (J)); exception when others => Free_Element (X); raise; end; N := N + 1; end; end if; end Process; -- Start of processing for Iterate_Source begin Iterate (Source.HT); end Iterate_Source; end if; end Symmetric_Difference; function Symmetric_Difference (Left, Right : Set) return Set is Buckets : HT_Types.Buckets_Access; Length : Count_Type; begin if Left'Address = Right'Address then return Empty_Set; end if; if Right.Length = 0 then return Left; end if; if Left.Length = 0 then return Right; end if; declare Size : constant Hash_Type := Prime_Numbers.To_Prime (Left.Length + Right.Length); begin Buckets := new Buckets_Type (0 .. Size - 1); end; Length := 0; Iterate_Left : declare procedure Process (L_Node : Node_Access); procedure Iterate is new HT_Ops.Generic_Iteration (Process); ------------- -- Process -- ------------- procedure Process (L_Node : Node_Access) is begin if not Is_In (Right.HT, L_Node) then declare E : Element_Type renames L_Node.Element.all; J : constant Hash_Type := Hash (E) mod Buckets'Length; begin declare X : Element_Access := new Element_Type'(E); begin Buckets (J) := new Node_Type'(X, Buckets (J)); exception when others => Free_Element (X); raise; end; Length := Length + 1; end; end if; end Process; -- Start of processing for Iterate_Left begin Iterate (Left.HT); exception when others => HT_Ops.Free_Hash_Table (Buckets); raise; end Iterate_Left; Iterate_Right : declare procedure Process (R_Node : Node_Access); procedure Iterate is new HT_Ops.Generic_Iteration (Process); ------------- -- Process -- ------------- procedure Process (R_Node : Node_Access) is begin if not Is_In (Left.HT, R_Node) then declare E : Element_Type renames R_Node.Element.all; J : constant Hash_Type := Hash (E) mod Buckets'Length; begin declare X : Element_Access := new Element_Type'(E); begin Buckets (J) := new Node_Type'(X, Buckets (J)); exception when others => Free_Element (X); raise; end; Length := Length + 1; end; end if; end Process; -- Start of processing for Iterate_Right begin Iterate (Right.HT); exception when others => HT_Ops.Free_Hash_Table (Buckets); raise; end Iterate_Right; return (Controlled with HT => (Buckets, Length, 0, 0)); end Symmetric_Difference; ------------ -- To_Set -- ------------ function To_Set (New_Item : Element_Type) return Set is HT : Hash_Table_Type; Node : Node_Access; Inserted : Boolean; begin Insert (HT, New_Item, Node, Inserted); return Set'(Controlled with HT); end To_Set; ----------- -- Union -- ----------- procedure Union (Target : in out Set; Source : Set) is procedure Process (Src_Node : Node_Access); procedure Iterate is new HT_Ops.Generic_Iteration (Process); ------------- -- Process -- ------------- procedure Process (Src_Node : Node_Access) is Src : Element_Type renames Src_Node.Element.all; function New_Node (Next : Node_Access) return Node_Access; pragma Inline (New_Node); procedure Insert is new Element_Keys.Generic_Conditional_Insert (New_Node); -------------- -- New_Node -- -------------- function New_Node (Next : Node_Access) return Node_Access is Tgt : Element_Access := new Element_Type'(Src); begin return new Node_Type'(Tgt, Next); exception when others => Free_Element (Tgt); raise; end New_Node; Tgt_Node : Node_Access; Success : Boolean; -- Start of processing for Process begin Insert (Target.HT, Src, Tgt_Node, Success); end Process; -- Start of processing for Union begin if Target'Address = Source'Address then return; end if; if Target.HT.Busy > 0 then raise Program_Error with "attempt to tamper with elements (set is busy)"; end if; declare N : constant Count_Type := Target.Length + Source.Length; begin if N > HT_Ops.Capacity (Target.HT) then HT_Ops.Reserve_Capacity (Target.HT, N); end if; end; Iterate (Source.HT); end Union; function Union (Left, Right : Set) return Set is Buckets : HT_Types.Buckets_Access; Length : Count_Type; begin if Left'Address = Right'Address then return Left; end if; if Right.Length = 0 then return Left; end if; if Left.Length = 0 then return Right; end if; declare Size : constant Hash_Type := Prime_Numbers.To_Prime (Left.Length + Right.Length); begin Buckets := new Buckets_Type (0 .. Size - 1); end; Iterate_Left : declare procedure Process (L_Node : Node_Access); procedure Iterate is new HT_Ops.Generic_Iteration (Process); ------------- -- Process -- ------------- procedure Process (L_Node : Node_Access) is Src : Element_Type renames L_Node.Element.all; J : constant Hash_Type := Hash (Src) mod Buckets'Length; Bucket : Node_Access renames Buckets (J); Tgt : Element_Access := new Element_Type'(Src); begin Bucket := new Node_Type'(Tgt, Bucket); exception when others => Free_Element (Tgt); raise; end Process; -- Start of processing for Process begin Iterate (Left.HT); exception when others => HT_Ops.Free_Hash_Table (Buckets); raise; end Iterate_Left; Length := Left.Length; Iterate_Right : declare procedure Process (Src_Node : Node_Access); procedure Iterate is new HT_Ops.Generic_Iteration (Process); ------------- -- Process -- ------------- procedure Process (Src_Node : Node_Access) is Src : Element_Type renames Src_Node.Element.all; Idx : constant Hash_Type := Hash (Src) mod Buckets'Length; Tgt_Node : Node_Access := Buckets (Idx); begin while Tgt_Node /= null loop if Equivalent_Elements (Src, Tgt_Node.Element.all) then return; end if; Tgt_Node := Next (Tgt_Node); end loop; declare Tgt : Element_Access := new Element_Type'(Src); begin Buckets (Idx) := new Node_Type'(Tgt, Buckets (Idx)); exception when others => Free_Element (Tgt); raise; end; Length := Length + 1; end Process; -- Start of processing for Iterate_Right begin Iterate (Right.HT); exception when others => HT_Ops.Free_Hash_Table (Buckets); raise; end Iterate_Right; return (Controlled with HT => (Buckets, Length, 0, 0)); end Union; --------- -- Vet -- --------- function Vet (Position : Cursor) return Boolean is begin if Position.Node = null then return Position.Container = null; end if; if Position.Container = null then return False; end if; if Position.Node.Next = Position.Node then return False; end if; if Position.Node.Element = null then return False; end if; declare HT : Hash_Table_Type renames Position.Container.HT; X : Node_Access; begin if HT.Length = 0 then return False; end if; if HT.Buckets = null or else HT.Buckets'Length = 0 then return False; end if; X := HT.Buckets (Element_Keys.Index (HT, Position.Node.Element.all)); for J in 1 .. HT.Length loop if X = Position.Node then return True; end if; if X = null then return False; end if; if X = X.Next then -- to prevent unnecessary looping return False; end if; X := X.Next; end loop; return False; end; end Vet; ----------- -- Write -- ----------- procedure Write (Stream : access Root_Stream_Type'Class; Container : Set) is begin Write_Nodes (Stream, Container.HT); end Write; procedure Write (Stream : access Root_Stream_Type'Class; Item : Cursor) is begin raise Program_Error with "attempt to stream set cursor"; end Write; ---------------- -- Write_Node -- ---------------- procedure Write_Node (Stream : access Root_Stream_Type'Class; Node : Node_Access) is begin Element_Type'Output (Stream, Node.Element.all); end Write_Node; package body Generic_Keys is ----------------------- -- Local Subprograms -- ----------------------- function Equivalent_Key_Node (Key : Key_Type; Node : Node_Access) return Boolean; pragma Inline (Equivalent_Key_Node); -------------------------- -- Local Instantiations -- -------------------------- package Key_Keys is new Hash_Tables.Generic_Keys (HT_Types => HT_Types, Next => Next, Set_Next => Set_Next, Key_Type => Key_Type, Hash => Hash, Equivalent_Keys => Equivalent_Key_Node); -------------- -- Contains -- -------------- function Contains (Container : Set; Key : Key_Type) return Boolean is begin return Find (Container, Key) /= No_Element; end Contains; ------------ -- Delete -- ------------ procedure Delete (Container : in out Set; Key : Key_Type) is X : Node_Access; begin Key_Keys.Delete_Key_Sans_Free (Container.HT, Key, X); if X = null then raise Constraint_Error with "key not in map"; end if; Free (X); end Delete; ------------- -- Element -- ------------- function Element (Container : Set; Key : Key_Type) return Element_Type is Node : constant Node_Access := Key_Keys.Find (Container.HT, Key); begin if Node = null then raise Constraint_Error with "key not in map"; end if; return Node.Element.all; end Element; ------------------------- -- Equivalent_Key_Node -- ------------------------- function Equivalent_Key_Node (Key : Key_Type; Node : Node_Access) return Boolean is begin return Equivalent_Keys (Key, Generic_Keys.Key (Node.Element.all)); end Equivalent_Key_Node; ------------- -- Exclude -- ------------- procedure Exclude (Container : in out Set; Key : Key_Type) is X : Node_Access; begin Key_Keys.Delete_Key_Sans_Free (Container.HT, Key, X); Free (X); end Exclude; ---------- -- Find -- ---------- function Find (Container : Set; Key : Key_Type) return Cursor is Node : constant Node_Access := Key_Keys.Find (Container.HT, Key); begin if Node = null then return No_Element; end if; return Cursor'(Container'Unrestricted_Access, Node); end Find; --------- -- Key -- --------- function Key (Position : Cursor) return Key_Type is begin if Position.Node = null then raise Constraint_Error with "Position cursor equals No_Element"; end if; if Position.Node.Element = null then raise Program_Error with "Position cursor is bad"; end if; pragma Assert (Vet (Position), "bad cursor in function Key"); return Key (Position.Node.Element.all); end Key; ------------- -- Replace -- ------------- procedure Replace (Container : in out Set; Key : Key_Type; New_Item : Element_Type) is Node : constant Node_Access := Key_Keys.Find (Container.HT, Key); begin if Node = null then raise Constraint_Error with "attempt to replace key not in set"; end if; Replace_Element (Container.HT, Node, New_Item); end Replace; procedure Update_Element_Preserving_Key (Container : in out Set; Position : Cursor; Process : not null access procedure (Element : in out Element_Type)) is HT : Hash_Table_Type renames Container.HT; Indx : Hash_Type; begin if Position.Node = null then raise Constraint_Error with "Position cursor equals No_Element"; end if; if Position.Node.Element = null or else Position.Node.Next = Position.Node then raise Program_Error with "Position cursor is bad"; end if; if Position.Container /= Container'Unrestricted_Access then raise Program_Error with "Position cursor designates wrong set"; end if; if HT.Buckets = null or else HT.Buckets'Length = 0 or else HT.Length = 0 then raise Program_Error with "Position cursor is bad (set is empty)"; end if; pragma Assert (Vet (Position), "bad cursor in Update_Element_Preserving_Key"); Indx := HT_Ops.Index (HT, Position.Node); declare E : Element_Type renames Position.Node.Element.all; K : constant Key_Type := Key (E); B : Natural renames HT.Busy; L : Natural renames HT.Lock; begin B := B + 1; L := L + 1; begin Process (E); exception when others => L := L - 1; B := B - 1; raise; end; L := L - 1; B := B - 1; if Equivalent_Keys (K, Key (E)) then pragma Assert (Hash (K) = Hash (E)); return; end if; end; if HT.Buckets (Indx) = Position.Node then HT.Buckets (Indx) := Position.Node.Next; else declare Prev : Node_Access := HT.Buckets (Indx); begin while Prev.Next /= Position.Node loop Prev := Prev.Next; if Prev = null then raise Program_Error with "Position cursor is bad (node not found)"; end if; end loop; Prev.Next := Position.Node.Next; end; end if; HT.Length := HT.Length - 1; declare X : Node_Access := Position.Node; begin Free (X); end; raise Program_Error with "key was modified"; end Update_Element_Preserving_Key; end Generic_Keys; end Ada.Containers.Indefinite_Hashed_Sets;