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Diffstat (limited to 'gcc/ada/a-chtgke.adb')
| -rw-r--r-- | gcc/ada/a-chtgke.adb | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/gcc/ada/a-chtgke.adb b/gcc/ada/a-chtgke.adb new file mode 100644 index 00000000000..9a21ad0c9eb --- /dev/null +++ b/gcc/ada/a-chtgke.adb @@ -0,0 +1,178 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT LIBRARY COMPONENTS -- +-- -- +-- ADA.CONTAINERS.HASH_TABLES.GENERIC_KEYS -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 2004 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, 59 Temple Place - Suite 330, Boston, -- +-- MA 02111-1307, 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 was originally developed by Matthew J Heaney. -- +------------------------------------------------------------------------------ + +package body Ada.Containers.Hash_Tables.Generic_Keys is + + -------------------------- + -- Delete_Key_Sans_Free -- + -------------------------- + + procedure Delete_Key_Sans_Free + (HT : in out HT_Type; + Key : Key_Type; + X : out Node_Access) + is + Indx : Hash_Type; + Prev : Node_Access; + + begin + if HT.Length = 0 then + X := Null_Node; + return; + end if; + + Indx := Index (HT, Key); + X := HT.Buckets (Indx); + + if X = Null_Node then + return; + end if; + + if Equivalent_Keys (Key, X) then + HT.Buckets (Indx) := Next (X); + HT.Length := HT.Length - 1; + return; + end if; + + loop + Prev := X; + X := Next (Prev); + + if X = Null_Node then + return; + end if; + + if Equivalent_Keys (Key, X) then + Set_Next (Node => Prev, Next => Next (X)); + HT.Length := HT.Length - 1; + return; + end if; + end loop; + end Delete_Key_Sans_Free; + + ---------- + -- Find -- + ---------- + + function Find + (HT : HT_Type; + Key : Key_Type) return Node_Access is + + Indx : Hash_Type; + Node : Node_Access; + + begin + if HT.Length = 0 then + return Null_Node; + end if; + + Indx := Index (HT, Key); + + Node := HT.Buckets (Indx); + while Node /= Null_Node loop + if Equivalent_Keys (Key, Node) then + return Node; + end if; + Node := Next (Node); + end loop; + + return Null_Node; + end Find; + + -------------------------------- + -- Generic_Conditional_Insert -- + -------------------------------- + + procedure Generic_Conditional_Insert + (HT : in out HT_Type; + Key : Key_Type; + Node : out Node_Access; + Success : out Boolean) + is + Indx : constant Hash_Type := Index (HT, Key); + B : Node_Access renames HT.Buckets (Indx); + + subtype Length_Subtype is Count_Type range 0 .. Count_Type'Last - 1; + + begin + if B = Null_Node then + declare + Length : constant Length_Subtype := HT.Length; + begin + Node := New_Node (Next => Null_Node); + Success := True; + + B := Node; + HT.Length := Length + 1; + end; + + return; + end if; + + Node := B; + loop + if Equivalent_Keys (Key, Node) then + Success := False; + return; + end if; + + Node := Next (Node); + + exit when Node = Null_Node; + end loop; + + declare + Length : constant Length_Subtype := HT.Length; + begin + Node := New_Node (Next => B); + Success := True; + + B := Node; + HT.Length := Length + 1; + end; + end Generic_Conditional_Insert; + + ----------- + -- Index -- + ----------- + + function Index + (HT : HT_Type; + Key : Key_Type) return Hash_Type is + begin + return Hash (Key) mod HT.Buckets'Length; + end Index; + +end Ada.Containers.Hash_Tables.Generic_Keys; |