File : asgc-list-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.List.Dynamic_Managed is
procedure Free_Node is new Ada.Unchecked_Deallocation(Node,
Node_Ptr);
procedure Free_Iterator is new Ada.Unchecked_Deallocation(Iterator,
Iterator_Ptr);
------------------------------------------------------------------------
-- Allocate a free node for the list.
procedure Alloc_Node (O : in out Object'Class;
Item : out Node_Ptr) is
begin
Item := new Node;
end Alloc_Node;
------------------------------------------------------------------------
-- Free a node for the list.
procedure Free_Node (O : in out Object'Class;
Item : in out Node_Ptr) is
begin
Free_Node(Item);
end Free_Node;
------------------------------------------------------------------------
-- Check that an object is valid, that is has not been freed. This is
-- not a perfect check, but will hopefully help find some bugs.
procedure Check_Object (O : in Object'Class) is
begin
if (O.Is_Free) then
raise Object_Free;
end if;
end Check_Object;
------------------------------------------------------------------------
-- Check that an iterator is valid. It must not have been freed, it
-- must be initialized, its object must be valid, and it must not have
-- been modified since the last time the iterator was positioned.
procedure Check_Iterator (Iter : in Iterator'Class) is
begin
if (Iter.Is_Free) then
raise Iterator_Free;
end if;
if (Iter.Robj = null) then
raise Invalid_Iterator;
end if;
Check_Object(Iter.Robj.all);
if (Iter.Update /= Iter.Robj.Update) then
raise Object_Updated;
end if;
if (Iter.Pos = null) then
raise Invalid_Iterator;
end if;
end Check_Iterator;
------------------------------------------------------------------------
-- Check an iterator, but don't bother checking its positions. This is
-- primarily for methods that set some the position of the iterator.
procedure Check_Iterator_Null_Ok (Iter : in Iterator'Class) is
begin
if (Iter.Is_Free) then
raise Iterator_Free;
end if;
if (Iter.Robj = null) then
raise Invalid_Iterator;
end if;
Check_Object(Iter.Robj.all);
if (Iter.Update /= Iter.Robj.Update) then
raise Object_Updated;
end if;
end Check_Iterator_Null_Ok;
------------------------------------------------------------------------
-- Search the list for the given position. Return the value that is
-- previous to the found entry and the found entry if found. The Prev
-- value will be null if the found value is first in the list.
procedure Local_Search(O : in Object;
Val : in Contained_Type;
Prev : out Node_Ptr;
Curr : out Node_Ptr;
Found : out Boolean) is
LPrev : Node_Ptr;
LCurr : Node_Ptr;
begin
LCurr := O.Head;
LPrev := null;
while ((LCurr /= null)
and then (LCurr.Val /= Val))
loop
Prev := LCurr;
LCurr := LCurr.Next;
end loop;
if (LCurr = null) then
Found := False;
else
Found := True;
Curr := LCurr;
Prev := LPrev;
end if;
end Local_Search;
------------------------------------------------------------------------
-- This is a controlled type, so we have those methods to handle.
------------------------------------------------------------------------
procedure Initialize (O : in out Object) is
begin
null;
end Initialize;
------------------------------------------------------------------------
procedure Adjust (O : in out Object) is
New_List : Node_Ptr := null;
New_Curr : Node_Ptr;
Old_Curr : Node_Ptr := O.Head;
begin
if (O.Head = null) then
O.Head := null;
O.Tail := null;
else
-- Copy the list.
New_List := new Node;
New_List.Val := Old_Curr.Val;
New_Curr := New_List;
while (Old_Curr.Next /= null) loop
New_Curr.Next := new Node;
New_Curr.Next.Val := Old_Curr.Next.Val;
Old_Curr := Old_Curr.Next;
New_Curr := New_Curr.Next;
end loop;
O.Head := New_List;
O.Tail := New_Curr;
end if;
-- Call the Copied callback method for every item in the new list.
if (O.Cb /= null) then
New_Curr := O.Head;
while (New_Curr /= null) loop
Copied(O.Cb, O, New_Curr.Val);
New_Curr := New_Curr.Next;
end loop;
end if;
end Adjust;
------------------------------------------------------------------------
procedure Finalize (O : in out Object) is
Curr : Node_Ptr := O.Head;
Temp : Node_Ptr;
begin
while (Curr /= null) loop
if (O.Cb /= null) then
Deleted(O.Cb, O, Curr.Val);
end if;
Temp := Curr.Next;
Free_Node(Curr);
Curr := Temp;
end loop;
O.Is_Free := True;
end Finalize;
------------------------------------------------------------------------
procedure Finalize (Iter : in out Iterator) is
begin
Iter.Is_Free := True;
end Finalize;
------------------------------------------------------------------------
-- The functions that follow are defined as abstract in previous
-- packages. See those packages for descriptions of what these
-- methods do.
------------------------------------------------------------------------
procedure Delete (O : in out Object;
Val : in Contained_Type) is
To_Free : Node_Ptr;
Next_Val : Node_Ptr;
Prev : Node_Ptr;
Found : Boolean;
begin
Check_Object(O);
Local_Search(O, Val, Prev, To_Free, Found);
if (not Found) then
raise Item_Not_Found;
end if;
Next_Val := To_Free.Next;
if (Prev /= null) then
-- Not deleting the first item, modify the prev's next ref.
Prev.Next := Next_Val;
else
-- Deleting the first item, change the head.
O.Head := Next_Val;
if (Next_Val = null) then
-- Deleting the only item.
O.Tail := null;
end if;
end if;
O.Count := O.Count - 1;
O.Update := O.Update + 1;
if (O.Cb /= null) then
Deleted(O.Cb,O, To_Free.Val);
end if;
Free_Node(O, To_Free);
end Delete;
------------------------------------------------------------------------
function Value_Exists (O : in Object;
Val : in Contained_Type)
return Boolean is
Curr : Node_Ptr;
Prev : Node_Ptr;
Found : Boolean;
begin
Check_Object(O);
Local_Search(O, Val, Prev, Curr, Found);
return Found;
end Value_Exists;
------------------------------------------------------------------------
procedure Add_Head (O : in out Object; Val : in Contained_Type) is
New_Node : Node_Ptr;
begin
Check_Object(O);
Alloc_Node(O, New_Node);
New_Node.Val := Val;
New_Node.Next := O.Head;
O.Head := New_Node;
if (O.Tail = null) then
O.Tail := New_Node;
end if;
O.Count := O.Count + 1;
O.Update := O.Update + 1;
if (O.Cb /= null) then
Added(O.Cb, O, New_Node.Val);
end if;
end Add_Head;
------------------------------------------------------------------------
procedure Add_Tail (O : in out Object; Val : in Contained_Type) is
New_Node : Node_Ptr;
begin
Check_Object(O);
Alloc_Node(O, New_Node);
New_Node.Val := Val;
New_Node.Next := null;
if (O.Tail = null) then
O.Head := New_Node;
else
O.Tail.Next := New_Node;
end if;
O.Tail := New_Node;
O.Count := O.Count + 1;
O.Update := O.Update + 1;
if (O.Cb /= null) then
Added(O.Cb, O, New_Node.Val);
end if;
end Add_Tail;
------------------------------------------------------------------------
function "=" (O1, O2 : in Object) return Boolean is
Curr1 : Node_Ptr;
Curr2 : Node_Ptr;
begin
Check_Object(O1);
Check_Object(O2);
if (O1.Count /= O2.Count) then
return False;
else
Curr1 := O1.Head;
Curr2 := O2.Head;
while (Curr1 /= null) loop
if (Curr2 = null) then
raise Internal_List_Error;
end if;
if (Curr1.Val /= Curr2.Val) then
return False;
end if;
Curr1 := Curr1.Next;
Curr2 := Curr2.Next;
end loop;
if (Curr2 /= null) then
raise Internal_List_Error;
end if;
return True;
end if;
end "=";
------------------------------------------------------------------------
function Member_Count (O : in Object)
return Natural is
begin
Check_Object(O);
return O.Count;
end Member_Count;
------------------------------------------------------------------------
procedure Verify_Integrity (O : in Object) is
Curr : Node_Ptr;
Count : Natural;
begin
Check_Object(O);
if (O.Count = 0) then
if ((O.Head /= null) or (O.Tail /= null)) then
raise Internal_List_Error;
end if;
else
Curr := O.Head;
Count := 1;
while (Curr.Next /= null) loop
if (Count > O.Count) then
raise Internal_List_Error;
end if;
Curr := Curr.Next;
Count := Count + 1;
end loop;
if (Count /= O.Count) then
raise Internal_List_Error;
end if;
if (Curr /= O.Tail) then
raise Internal_List_Error;
end if;
end if;
end Verify_Integrity;
------------------------------------------------------------------------
function Copy (O : in Object) return Asgc.Object_Class is
Retval : Object_Ptr;
begin
Retval := new Object;
Retval.all := O;
return Asgc.Object_Class(Retval);
end Copy;
------------------------------------------------------------------------
procedure Add_Before (Iter : in out Iterator; Val : in Contained_Type) is
New_Node : Node_Ptr;
begin
Check_Iterator_Null_Ok(Iter);
Alloc_Node(Iter.Robj.all, New_Node);
New_Node.Val := Val;
New_Node.Next := Iter.Pos;
if (Iter.Robj.Tail = null) then
-- The list is empty, this becomes the only member.
Iter.Robj.Head := New_Node;
Iter.Robj.Tail := New_Node;
elsif (Iter.Robj.Head = Iter.Pos) then
-- If we are at the head, the new item becomes the new head.
Iter.Robj.Head := New_Node;
else
Iter.Prev.Next := New_Node;
end if;
Iter.Pos := New_Node;
Iter.Robj.Count := Iter.Robj.Count + 1;
Iter.Robj.Update := Iter.Robj.Update + 1;
Iter.Update := Iter.Robj.Update;
if (Iter.Robj.Cb /= null) then
Added(Iter.Robj.Cb,
Iter.Robj.all,
New_Node.Val);
end if;
end Add_Before;
------------------------------------------------------------------------
procedure Add_After (Iter : in out Iterator; Val : in Contained_Type) is
New_Node : Node_Ptr;
begin
Check_Iterator_Null_Ok(Iter);
Alloc_Node(Iter.Robj.all, New_Node);
New_Node.Val := Val;
if (Iter.Robj.Tail = null) then
-- The list is empty, this becomes the only member.
Iter.Robj.Head := New_Node;
Iter.Robj.Tail := New_Node;
else
New_Node.Next := Iter.Pos.Next;
Iter.Pos.Next := New_Node;
if (Iter.Robj.Tail = Iter.Pos) then
-- If we are at the tail, the new item becomes the new tail.
Iter.Robj.Tail := New_Node;
end if;
end if;
Iter.Prev := Iter.Pos;
Iter.Pos := New_Node;
Iter.Robj.Count := Iter.Robj.Count + 1;
Iter.Robj.Update := Iter.Robj.Update + 1;
Iter.Update := Iter.Robj.Update;
if (Iter.Robj.Cb /= null) then
Added(Iter.Robj.Cb,
Iter.Robj.all,
New_Node.Val);
end if;
end Add_After;
------------------------------------------------------------------------
procedure Set (Iter : in Iterator; Val : in Contained_Type) is
begin
Check_Iterator(Iter);
Iter.Pos.Val := Val;
end Set;
------------------------------------------------------------------------
function New_Iterator (O : access Object) return Asgc.Iterator_Class is
Retval : Iterator_Ptr;
begin
Check_Object(O.all);
Retval := new Iterator;
Retval.Robj := Object_Class(O);
Retval.Update := Invalid_Update;
return Asgc.Iterator_Class(Retval);
end New_Iterator;
------------------------------------------------------------------------
function New_Iterator (O : in Object_Class) return Iterator is
Retval : Iterator;
begin
Retval.Robj := O;
Retval.Update := Invalid_Update;
return Retval;
end New_Iterator;
------------------------------------------------------------------------
procedure Free (Iter : access Iterator) is
To_Free : Iterator_Ptr := Iterator_Ptr(Iter);
begin
if (Iter.Is_Free) then
raise Iterator_Free;
end if;
Free_Iterator(To_Free);
end Free;
------------------------------------------------------------------------
procedure Set_Container (Iter : in out Iterator;
O : in Asgc.Object_Class) is
begin
Check_Object(Object'Class(O.all));
Iter.Robj := Object_Class(O);
Iter.Update := Invalid_Update;
end Set_Container;
------------------------------------------------------------------------
procedure Add (Iter : in out Iterator;
Val : in Contained_Type) is
New_Node : Node_Ptr;
begin
Check_Iterator_Null_Ok(Iter);
Alloc_Node(Iter.Robj.all, New_Node);
New_Node.Val := Val;
Iter.Prev := Iter.Robj.Tail;
if (Iter.Robj.Tail = null) then
-- The list is empty, this becomes the only member.
Iter.Robj.Head := New_Node;
Iter.Robj.Tail := New_Node;
else
-- Add it on to the end of the list.
New_Node.Next := null;
Iter.Robj.Tail.Next := New_Node;
Iter.Robj.Tail := New_Node;
end if;
Iter.Pos := New_Node;
Iter.Robj.Count := Iter.Robj.Count + 1;
Iter.Robj.Update := Iter.Robj.Update + 1;
Iter.Update := Iter.Robj.Update;
if (Iter.Robj.Cb /= null) then
Added(Iter.Robj.Cb,
Iter.Robj.all,
New_Node.Val);
end if;
end Add;
------------------------------------------------------------------------
procedure First (Iter : in out Iterator; Is_End : out End_Marker) is
begin
Check_Object(Iter.Robj.all);
Iter.Pos := Iter.Robj.Head;
Iter.Prev := null;
Iter.Update := Iter.Robj.Update;
if (Iter.Pos = null) then
Is_End := Past_End;
else
Is_End := Not_Past_End;
end if;
end First;
------------------------------------------------------------------------
procedure Next (Iter : in out Iterator; Is_End : out End_Marker) is
begin
Check_Iterator(Iter);
if (Iter.Pos.Next = null) then
Is_End := Past_End;
else
Iter.Prev := Iter.Pos;
Iter.Pos := Iter.Pos.Next;
Is_End := Not_Past_End;
end if;
end Next;
------------------------------------------------------------------------
procedure Delete (Iter : in out Iterator; Is_End : out End_Marker) is
To_Free : Node_Ptr;
Next_Val : Node_Ptr;
begin
Check_Iterator(Iter);
To_Free := Iter.Pos;
Next_Val := To_Free.Next;
if (Iter.Prev /= null) then
-- Not deleting the first item, modify the prev's next ref.
Iter.Prev.Next := Next_Val;
else
-- Deleting the first item, change the head.
Iter.Robj.Head := Next_Val;
if (Next_Val = null) then
-- Deleting the only item.
Iter.Robj.Tail := null;
end if;
end if;
Iter.Robj.Count := Iter.Robj.Count - 1;
Iter.Robj.Update := Iter.Robj.Update + 1;
if (Next_Val = null) then
-- If we delete the last value, we invalidate the iterator by not
-- updating it.
Iter.Robj.Tail := Iter.Prev;
Iter.Pos := null;
else
Iter.Update := Iter.Robj.Update;
Iter.Pos := Next_Val;
Is_End := Not_Past_End;
end if;
if (Iter.Robj.Cb /= null) then
Deleted(Iter.Robj.Cb,
Iter.Robj.all,
To_Free.Val);
end if;
Free_Node(Iter.Robj.all, To_Free);
end Delete;
------------------------------------------------------------------------
function Is_Same (Iter1, Iter2 : in Iterator) return Boolean is
begin
Check_Iterator(Iter1);
Check_Iterator(Iter2);
if (Iter1.Robj /= Iter2.Robj) then
raise Iterator_Mismatch;
end if;
return (Iter1.Pos = Iter2.Pos);
end Is_Same;
------------------------------------------------------------------------
function Get (Iter : in Iterator) return Contained_Type is
begin
Check_Iterator(Iter);
return Iter.Pos.Val;
end Get;
------------------------------------------------------------------------
procedure Get_Incr (Iter : in out Iterator;
Val : out Contained_Type;
Is_End : out End_Marker) is
begin
Check_Iterator(Iter);
Val := Iter.Pos.Val;
Next(Iter, Is_End);
end Get_Incr;
------------------------------------------------------------------------
function "=" (Iter1, Iter2 : in Iterator) return Boolean is
begin
Check_Iterator(Iter1);
Check_Iterator(Iter2);
return (Iter1.Pos.Val = Iter2.Pos.Val);
end "=";
------------------------------------------------------------------------
function "=" (Iter : in Iterator; Val : in Contained_Type) return Boolean is
begin
Check_Iterator(Iter);
return (Iter.Pos.Val = Val);
end "=";
------------------------------------------------------------------------
function "=" (Val : in Contained_Type; Iter : in Iterator) return Boolean is
begin
Check_Iterator(Iter);
return (Val = Iter.Pos.Val);
end "=";
end Asgc.List.Dynamic_Managed;