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-------------------------------------------------------------------------------
-- (C) Altran Praxis Limited
-------------------------------------------------------------------------------
--
-- The SPARK toolset is free software; you can redistribute it and/or modify it
-- under terms of the GNU General Public License as published by the Free
-- Software Foundation; either version 3, or (at your option) any later
-- version. The SPARK toolset 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 distributed with the SPARK toolset; see file
-- COPYING3. If not, go to http://www.gnu.org/licenses for a complete copy of
-- the license.
--
--=============================================================================
with FatalErrors, HeapIndex;
use type HeapIndex.IndexType;
package body FileHeap
--# own State is StartOfPointersList,
--# TheDetails,
--# ThePointers;
is
ThePointers : Heap.HeapRecord;
TheDetails : FileDetails.DataType;
StartOfPointersList : Heap.Atom;
function FirstEntry return Heap.Atom
--# global in StartOfPointersList;
is
begin
return StartOfPointersList;
end FirstEntry;
------------------------------------------------------------------------
procedure Add (StartIndex : in Heap.Atom;
NewName : in E_Strings.T;
NewFileType : in FileDetails.FileTypes)
--# global in out FatalErrors.State;
--# in out TheDetails;
--# in out ThePointers;
--# derives FatalErrors.State,
--# TheDetails,
--# ThePointers from *,
--# NewFileType,
--# NewName,
--# StartIndex,
--# TheDetails,
--# ThePointers;
is
Dummy : Boolean;
ExistingName : E_Strings.T;
ExistingFileType : FileDetails.FileTypes;
ListIndex : Heap.Atom;
LoopFinished : Boolean := False;
NextEntryInList : Heap.Atom;
OrderResult : E_Strings.Order_Types;
OrderSuccess : Boolean;
RetrieveSuccess : Boolean;
------------------------------------------------------------------------
procedure InsertInList
(ListIndex : in Heap.Atom;
NextEntryInList : in Heap.Atom;
Name : in E_Strings.T;
FileType : in FileDetails.FileTypes)
--# global in out FatalErrors.State;
--# in out TheDetails;
--# in out ThePointers;
--# derives FatalErrors.State from *,
--# TheDetails,
--# ThePointers &
--# TheDetails from *,
--# FileType,
--# Name &
--# ThePointers from *,
--# ListIndex,
--# NextEntryInList,
--# TheDetails;
is
CreateAtomSuccess : Boolean;
DetailsAddSuccess : Boolean;
NewDetailsIndex : HeapIndex.IndexType;
NewPointersIndex : Heap.Atom;
begin -- InsertInList
-- allocate heap atom
Heap.CreateAtom (ThePointers, NewPointersIndex, CreateAtomSuccess);
-- allocate file details entry
FileDetails.Add (TheDetails, NewDetailsIndex, DetailsAddSuccess, Name, FileType);
if not (CreateAtomSuccess and DetailsAddSuccess) then
FatalErrors.Process (FatalErrors.File_Heap_Full, E_Strings.Empty_String);
end if;
-- point heap atom to file details entry
Heap.UpdateAValue (ThePointers, NewPointersIndex, NewDetailsIndex);
-- link heap atom into list
Heap.UpdateAPointer (ThePointers, ListIndex, NewPointersIndex);
Heap.UpdateAPointer (ThePointers, NewPointersIndex, NextEntryInList);
end InsertInList;
-------------------------------------------------------------------------
begin -- Add
-- start at point specified in linked list
ListIndex := StartIndex;
while not LoopFinished loop
-- if current item is last then add after it
NextEntryInList := Heap.APointer (ThePointers, ListIndex);
if NextEntryInList = 0 then
InsertInList (ListIndex, NextEntryInList, NewName, NewFileType);
LoopFinished := True;
else
-- otherwise get relative order of next item in list and the new item
--# accept F, 10, Dummy, "Dummy unused here";
FileDetails.Retrieve
(TheDetails,
Heap.AValue (ThePointers, NextEntryInList),
RetrieveSuccess,
ExistingName,
ExistingFileType,
Dummy);
--# end accept;
if not RetrieveSuccess then
FatalErrors.Process (FatalErrors.Data_Structure_Inconsistency, E_Strings.Empty_String);
end if;
FileDetails.Order (ExistingName, ExistingFileType, NewName, NewFileType, OrderSuccess, OrderResult);
if not OrderSuccess then
FatalErrors.Process (FatalErrors.Data_Structure_Inconsistency, E_Strings.Empty_String);
end if;
case OrderResult is
when E_Strings.First_One_First =>
-- next item in list is first, keep going down list
ListIndex := NextEntryInList;
when E_Strings.Second_One_First =>
-- new item is first, insert here
InsertInList (ListIndex, NextEntryInList, NewName, NewFileType);
LoopFinished := True;
when E_Strings.Neither_First =>
-- items identical: do nothing
LoopFinished := True;
end case;
end if;
end loop;
--# accept F, 33, Dummy, "Dummy unused here";
end Add;
----------------------------------------------------------------------------
-- this procedure returns the file details for the specified entry in the
-- linked list. Success if ListIndex points to a heap record which points to
-- a valid set of file details
procedure Details
(ListIndex : in Heap.Atom;
Success : out Boolean;
Name : out E_Strings.T;
FileType : out FileDetails.FileTypes;
DirectoryIsResolved : out Boolean)
--# global in TheDetails;
--# in ThePointers;
--# derives DirectoryIsResolved,
--# FileType,
--# Name,
--# Success from ListIndex,
--# TheDetails,
--# ThePointers;
is
DetailsIndex : HeapIndex.IndexType;
begin -- Details
-- dereference linked list pointer
DetailsIndex := Heap.AValue (ThePointers, ListIndex);
-- if not null pointer then follow it
if DetailsIndex /= 0 then
FileDetails.Retrieve (TheDetails, DetailsIndex, Success, Name, FileType, DirectoryIsResolved);
else
-- if null pointer then return failure
Success := False;
Name := E_Strings.Empty_String;
FileType := FileDetails.Invalid;
DirectoryIsResolved := False;
end if;
end Details;
--------------------------------------------------------------------------
procedure Initialize (TopDirectory : in E_Strings.T)
--# global out StartOfPointersList;
--# out TheDetails;
--# out ThePointers;
--# derives StartOfPointersList,
--# ThePointers from &
--# TheDetails from TopDirectory;
is
Dummy : Boolean;
FirstDetailsIndex : HeapIndex.IndexType;
FirstPointersIndex : Heap.Atom;
begin -- Initialize
Heap.Initialize (ThePointers);
FileDetails.Initialize (TheDetails);
-- insert first item
--# accept F, 10, Dummy, "Dummy unused here";
FileDetails.Add (TheDetails, FirstDetailsIndex, Dummy, TopDirectory, FileDetails.Directory);
Heap.CreateAtom (ThePointers, FirstPointersIndex, Dummy);
--# end accept;
Heap.UpdateAValue (ThePointers, FirstPointersIndex, FirstDetailsIndex);
Heap.UpdateAPointer (ThePointers, FirstPointersIndex, 0);
StartOfPointersList := FirstPointersIndex;
--# accept F, 33, Dummy, "Dummy unused here";
end Initialize;
---------------------------------------------------------------------------
procedure MarkDirectoryResolved (ListIndex : in Heap.Atom)
--# global in ThePointers;
--# in out TheDetails;
--# derives TheDetails from *,
--# ListIndex,
--# ThePointers;
is
DetailsIndex : HeapIndex.IndexType;
begin
DetailsIndex := Heap.AValue (ThePointers, ListIndex);
if DetailsIndex /= 0 then
FileDetails.MarkDirectoryResolved (TheDetails, DetailsIndex);
end if;
end MarkDirectoryResolved;
---------------------------------------------------------------------------
-- this procedure returns the 'NextOne' ordered element in FH after
-- 'AfterThis'. It is successful if the NextOne is not a 'null' pointer
procedure Next (AfterThis : in Heap.Atom;
Success : out Boolean;
NextOne : out Heap.Atom)
--# global in ThePointers;
--# derives NextOne,
--# Success from AfterThis,
--# ThePointers;
is
NextInList : Heap.Atom;
begin -- Next
NextInList := Heap.APointer (ThePointers, AfterThis);
if NextInList = 0 then
Success := False;
NextOne := 0;
else
Success := True;
NextOne := NextInList;
end if;
end Next;
end FileHeap;
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