File : asgc-graph-links-dynamic_managed.adb
-- The Ada Structured Library - A set of container classes and general
-- tools for use with Ada95.
-- Copyright (C) 1998-1999 Corey Minyard (minyard@acm.org)
--
-- This library 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 of the License, or (at your
-- option) any later version.
--
-- This library 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 this library; if not, write to the Free Software Foundation, Inc.,
-- 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.
--
with Ada.Unchecked_Deallocation;
package body Asgc.Graph.Links.Dynamic_Managed is
procedure Free_Dynamic_Graph_Edge is new Ada.Unchecked_Deallocation
(Dynamic_Graph_Edge, Dynamic_Graph_Edge_Ptr);
------------------------------------------------------------------------
-- Check that an iterator is valid. An iterator is not valid if
-- it has not been initialized of if the Link container has been
-- modified since the last time the iterator's position was set.
procedure Check_Iterator (Iter : in Graph_Link_It'Class) is
begin
if (Iter.Robj = null) then
raise Invalid_Iterator;
end if;
if (Iter.Update /= Iter.Robj.Update) then
raise Invalid_Iterator;
end if;
end Check_Iterator;
------------------------------------------------------------------------
-- Check an iterator, but don't require it to have a valid position.
-- It still must be initialized properly.
procedure Check_Iterator_No_Pos (Iter : in Graph_Link_It'Class) is
begin
if (Iter.Robj = null) then
raise Invalid_Iterator;
end if;
end Check_Iterator_No_Pos;
------------------------------------------------------------------------
-- The rest of the methods below are are external definitions whose
-- functions are defined in the spec file for this package.
---------------------------------------------------------------------
procedure Free_Graph_Link (Node : in out Graph_Link) is
To_Free : Dynamic_Graph_Edge_Ptr;
begin
while (Node.Edges /= null) loop
To_Free := Node.Edges;
Node.Edges := To_Free.Next;
Free_Dynamic_Graph_Edge(To_Free);
end loop;
end Free_Graph_Link;
------------------------------------------------------------------------
procedure Copied_Graph_Link (Node : in out Graph_Link) is
New_Curr : Dynamic_Graph_Edge_Ptr;
Curr : Dynamic_Graph_Edge_Ptr;
begin
Curr := Node.Edges;
if (Curr /= null) then
Node.Edges := new Dynamic_Graph_Edge'(Val => Curr.Val,
Contents => Curr.Contents,
Next => null);
New_Curr := Node.Edges;
Curr := Curr.Next;
while (Curr /= null) loop
New_Curr.Next := new Dynamic_Graph_Edge'(Val => Curr.Val,
Contents => Curr.Contents,
Next => null);
New_Curr := New_Curr.Next;
Curr := Curr.Next;
end loop;
end if;
end Copied_Graph_Link;
------------------------------------------------------------------------
procedure Set_Node (Iter : in out Graph_Link_It;
Node : in Links.Graph_Link_Class) is
begin
Iter.Robj := Graph_Link_Class(Node);
Iter.Update := Iter.Robj.Update - 1;
end Set_Node;
------------------------------------------------------------------------
procedure Add (Node : in out Graph_Link;
Val : in Link_Type;
Contents : in Link_Contained_Type) is
New_Edge : Dynamic_Graph_Edge_Ptr;
begin
New_Edge := new Dynamic_Graph_Edge'(Val => Val,
Contents => Contents,
Next => Node.Edges);
Node.Edges := New_Edge;
Node.Update := Node.Update + 1;
Node.Link_Count := Node.Link_Count + 1;
end Add;
------------------------------------------------------------------------
procedure Delete_First (Node : in out Graph_Link) is
Curr : Dynamic_Graph_Edge_Ptr;
begin
Curr := Node.Edges;
Node.Edges := Curr.Next;
Free_Dynamic_Graph_Edge(Curr);
Node.Update := Node.Update + 1;
Node.Link_Count := Node.Link_Count - 1;
end Delete_First;
------------------------------------------------------------------------
procedure Delete_Val (Node : in out Graph_Link;
Val : in Link_Type;
Instance : in Positive := 1) is
Curr : Dynamic_Graph_Edge_Ptr;
Prev : Dynamic_Graph_Edge_Ptr;
Count : Positive := 1;
begin
Curr := Node.Edges;
Prev := null;
while (Curr /= null) loop
if (Curr.Val = Val) then
if (Count = Instance) then
if (Prev = null) then
Node.Edges := Curr.Next;
else
Prev.Next := Curr.Next;
end if;
Free_Dynamic_Graph_Edge(Curr);
Node.Update := Node.Update + 1;
Node.Link_Count := Node.Link_Count - 1;
return;
else
Count := Count + 1;
end if;
end if;
Prev := Curr;
Curr := Curr.Next;
end loop;
raise Item_Not_Found;
end Delete_Val;
------------------------------------------------------------------------
function Get_Pos (Node : in Graph_Link;
Pos : in Positive)
return Link_Type is
Curr : Dynamic_Graph_Edge_Ptr;
begin
Curr := Node.Edges;
for I in 2 .. Pos loop
Curr := Curr.Next;
end loop;
return Curr.Val;
end Get_Pos;
------------------------------------------------------------------------
function Val_Exists (Node : in Graph_Link;
Val : in Link_Type;
Instance : in Positive := 1)
return Boolean is
Curr : Dynamic_Graph_Edge_Ptr;
Count : Positive := 1;
begin
Curr := Node.Edges;
while (Curr /= null) loop
if (Curr.Val = Val) then
if (Count = Instance) then
return True;
else
Count := Count + 1;
end if;
end if;
Curr := Curr.Next;
end loop;
return False;
end Val_Exists;
------------------------------------------------------------------------
function Get_Contents (Iter : in Graph_Link_It)
return Link_Contained_Type is
begin
Check_Iterator(Iter);
return Iter.Curr.Contents;
end Get_Contents;
------------------------------------------------------------------------
function Get_Contents (Node : in Graph_Link;
Val : in Link_Type;
Instance : in Positive := 1)
return Link_Contained_Type is
Curr : Dynamic_Graph_Edge_Ptr;
Count : Positive := 1;
begin
Curr := Node.Edges;
while (Curr /= null) loop
if (Curr.Val = Val) then
if (Count = Instance) then
return Curr.Contents;
else
Count := Count + 1;
end if;
end if;
Curr := Curr.Next;
end loop;
raise Item_Not_Found;
end Get_Contents;
------------------------------------------------------------------------
function Get_First_Contents (Node : in Graph_Link)
return Link_Contained_Type is
begin
return Node.Edges.Contents;
end Get_First_Contents;
------------------------------------------------------------------------
procedure Set_Contents (Iter : in out Graph_Link_It;
Contents : in Link_Contained_Type) is
begin
Check_Iterator(Iter);
Iter.Curr.Contents := Contents;
end Set_Contents;
------------------------------------------------------------------------
procedure Delete (Iter : in out Graph_Link_It;
Is_End : out End_Marker) is
To_Free : Dynamic_Graph_Edge_Ptr;
begin
Check_Iterator(Iter);
To_Free := Iter.Curr;
Iter.Curr := Iter.Curr.Next;
if (Iter.Prev = null) then
Iter.Robj.Edges := To_Free.Next;
else
Iter.Prev.Next := To_Free.Next;
end if;
Free_Dynamic_Graph_Edge(To_Free);
Iter.Robj.Update := Iter.Robj.Update + 1;
Iter.Robj.Link_Count := Iter.Robj.Link_Count - 1;
if (Iter.Curr = null) then
Is_End := Past_End;
else
Is_End := Not_Past_End;
Iter.Update := Iter.Robj.Update;
end if;
end Delete;
------------------------------------------------------------------------
procedure First (Iter : in out Graph_Link_It;
Is_End : out End_Marker) is
begin
Check_Iterator_No_Pos(Iter);
if (Iter.Robj.Edges = null) then
Is_End := Past_End;
else
Is_End := Not_Past_End;
Iter.Prev := null;
Iter.Curr := Iter.Robj.Edges;
Iter.Update := Iter.Robj.Update;
end if;
end First;
------------------------------------------------------------------------
procedure Next (Iter : in out Graph_Link_It;
Is_End : out End_Marker) is
begin
Check_Iterator(Iter);
if (Iter.Curr.Next = null) then
Is_End := Past_End;
else
Is_End := Not_Past_End;
Iter.Prev := Iter.Curr;
Iter.Curr := Iter.Curr.Next;
end if;
end Next;
------------------------------------------------------------------------
procedure Find (Iter : in out Graph_Link_It;
Val : in Link_Type;
Found : out Boolean;
Instance : in Positive := 1) is
Curr : Dynamic_Graph_Edge_Ptr;
Prev : Dynamic_Graph_Edge_Ptr;
Count : Positive := 1;
begin
Check_Iterator_No_Pos(Iter);
Curr := Iter.Robj.Edges;
Prev := null;
while (Curr /= null) loop
if (Curr.Val = Val) then
if (Count = Instance) then
exit;
else
Count := Count + 1;
end if;
end if;
Prev := Curr;
Curr := Curr.Next;
end loop;
if (Curr = null) then
Found := False;
else
Found := True;
Iter.Prev := Prev;
Iter.Curr := Curr;
Iter.Update := Iter.Robj.Update;
end if;
end Find;
------------------------------------------------------------------------
procedure Find_Again (Iter : in out Graph_Link_It;
Found : out Boolean) is
Orig : Dynamic_Graph_Edge_Ptr;
Curr : Dynamic_Graph_Edge_Ptr;
Prev : Dynamic_Graph_Edge_Ptr;
begin
Check_Iterator(Iter);
Orig := Iter.Curr;
Prev := Iter.Curr;
Curr := Iter.Curr.Next;
while ((Curr /= null)
and then (Curr.Val /= Orig.Val))
loop
Prev := Curr;
Curr := Curr.Next;
end loop;
if (Curr = null) then
Found := False;
else
Found := True;
Iter.Prev := Prev;
Iter.Curr := Curr;
end if;
end Find_Again;
------------------------------------------------------------------------
function Get_Instance_Number (Iter : in Graph_Link_It)
return Positive is
Curr : Dynamic_Graph_Edge_Ptr;
Retval : Positive := 1;
begin
Check_Iterator(Iter);
Curr := Iter.Robj.Edges;
while (Curr /= Iter.Curr) loop
if (Curr.Val = Iter.Curr.Val) then
Retval := Retval + 1;
end if;
Curr := Curr.Next;
end loop;
return Retval;
end Get_Instance_Number;
------------------------------------------------------------------------
function Get_Instance_Number (Node : in Graph_Link;
Pos : in Positive)
return Positive is
Curr : Dynamic_Graph_Edge_Ptr;
Ref : Dynamic_Graph_Edge_Ptr;
Retval : Positive := 1;
begin
if (Pos > Node.Link_Count) then
raise Constraint_Error;
end if;
Ref := Node.Edges;
for I in 2 .. Pos loop
Ref := Ref.Next;
end loop;
Curr := Node.Edges;
for I in 1 .. (Pos - 1) loop
if (Curr.Val = Ref.Val) then
Retval := Retval + 1;
end if;
Curr := Curr.Next;
end loop;
return Retval;
end Get_Instance_Number;
------------------------------------------------------------------------
function Get (Iter : in Graph_Link_It)
return Link_Type is
begin
Check_Iterator(Iter);
return Iter.Curr.Val;
end Get;
------------------------------------------------------------------------
function Link_Count (Node : in Graph_Link) return Natural is
begin
return Node.Link_Count;
end Link_Count;
end Asgc.Graph.Links.Dynamic_Managed;