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Diffstat (limited to 'src/dyn_maps.ads')
-rw-r--r-- | src/dyn_maps.ads | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/src/dyn_maps.ads b/src/dyn_maps.ads new file mode 100644 index 000000000..2fb7485db --- /dev/null +++ b/src/dyn_maps.ads @@ -0,0 +1,102 @@ +-- Maps - association of unique object with a value. +-- Copyright (C) 2019-2020 Tristan Gingold +-- +-- GHDL is free software; you can redistribute it and/or modify it under +-- the terms of the GNU General Public License as published by the Free +-- Software Foundation; either version 2, or (at your option) any later +-- version. +-- +-- GHDL is distributed in the hope that it will be useful, but WITHOUT 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 +-- along with GHDL; see the file COPYING. If not, write to the Free +-- Software Foundation, 59 Temple Place - Suite 330, Boston, MA +-- 02111-1307, USA. + +with Types; use Types; +with Hash; use Hash; +with Dyn_Tables; + +-- This generic package provides a factory to build unique objects. +-- Get will return an existing object or create a new one. +generic + -- Parameters of the object to be created. + type Params_Type (<>) is private; + + -- Object to be built and stored. + type Object_Type is private; + + -- Value associated to the object. Could be modified but not used + -- for comparision. + type Value_Type is private; + + -- Reduce PARAMS to a small value. + -- The required property is: Hash(P1) /= Hash(P2) => P1 /= P2. + with function Hash (Params : Params_Type) return Hash_Value_Type; + + -- Create an object from PARAMS. + with function Build (Params : Params_Type) return Object_Type; + + -- Initial value of the object. Called when an object is created. + with function Build_Value (Obj : Object_Type) return Value_Type; + + -- Return True iff OBJ is the object corresponding to PARAMS. + with function Equal (Obj : Object_Type; Params : Params_Type) + return Boolean; +package Dyn_Maps is + type Instance is limited private; + + -- Initialize. Required before any other operation. + procedure Init (Inst : out Instance); + + procedure Free (Inst : in out Instance); + + type Index_Type is new Uns32; + No_Index : constant Index_Type := 0; + First_Index : constant Index_Type := 1; + + -- If there is already an existing object for PARAMS, return its index. + -- Otherwise create it. + -- The index is doesn't change over the lifetime of the map. + procedure Get_Index + (Inst : in out Instance; Params : Params_Type; Idx : out Index_Type); + + -- Get the number of elements in the table. + function Last_Index (Inst : Instance) return Index_Type; + + -- Get an element by index. The index has no real meaning, but the + -- current implementation allocates index incrementally. + function Get_By_Index (Inst : Instance; Index : Index_Type) + return Object_Type; + + -- Get/Set the value. + function Get_Value (Inst : Instance; Index : Index_Type) return Value_Type; + procedure Set_Value + (Inst : in out Instance; Index : Index_Type; Val : Value_Type); +private + type Element_Wrapper is record + Hash : Hash_Value_Type; + Next : Index_Type := No_Index; + Obj : Object_Type; + Val : Value_Type; + end record; + + package Wrapper_Tables is new Dyn_Tables + (Table_Index_Type => Index_Type, + Table_Component_Type => Element_Wrapper, + Table_Low_Bound => No_Index + 1); + + type Hash_Array is array (Hash_Value_Type range <>) of Index_Type; + type Hash_Array_Acc is access Hash_Array; + + Initial_Size : constant Hash_Value_Type := 1024; + + type Instance is record + Els : Wrapper_Tables.Instance; + Size : Hash_Value_Type; + Hash_Table : Hash_Array_Acc; + end record; +end Dyn_Maps; |