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end loop;
end Prepend;
Ret : Status_Code;
D_Entry : FAT_Directory_Entry;
V_Entry : VFAT_Directory_Entry;
function To_VFAT_Entry is new Ada.Unchecked_Conversion
(FAT_Directory_Entry, VFAT_Directory_Entry);
C : Unsigned_8;
Last_Seq : VFAT_Sequence_Number := 0;
CRC : Unsigned_8 := 0;
Matches : Boolean;
Current_CRC : Unsigned_8;
L_Name : String (1 .. MAX_FILENAME_LENGTH);
L_Name_First : Natural;
begin
L_Name_First := L_Name'Last + 1;
loop
Ret := Next_Entry
(FS,
Current_Cluster => Current_Cluster,
Current_Block => Current_Block,
Current_Index => Current_Index,
DEntry => D_Entry);
if Ret /= OK then
return Ret;
end if;
-- Check if we have a VFAT entry here by checking that the
-- attributes are 16#0F# (e.g. all attributes set except
-- subdirectory and archive)
if D_Entry.Attributes = VFAT_Directory_Entry_Attribute then
V_Entry := To_VFAT_Entry (D_Entry);
if V_Entry.VFAT_Attr.Stop_Bit then
L_Name_First := L_Name'Last + 1;
else
if Last_Seq = 0
or else Last_Seq - 1 /= V_Entry.VFAT_Attr.Sequence
then
L_Name_First := L_Name'Last + 1;
end if;
end if;
Last_Seq := V_Entry.VFAT_Attr.Sequence;
Prepend (V_Entry.Name_3, L_Name, L_Name_First);
Prepend (V_Entry.Name_2, L_Name, L_Name_First);
Prepend (V_Entry.Name_1, L_Name, L_Name_First);
if V_Entry.VFAT_Attr.Sequence = 1 then
CRC := V_Entry.Checksum;
end if;
-- Ignore Volumes and deleted files
elsif not D_Entry.Attributes.Volume_Label
and then Character'Pos (D_Entry.Filename (1)) /= 16#E5#
then
if L_Name_First not in L_Name'Range then
Matches := False;
else
Current_CRC := 0;
Last_Seq := 0;
for Ch of String'(D_Entry.Filename & D_Entry.Extension) loop
C := Character'Enum_Rep (Ch);
Current_CRC := Shift_Right (Current_CRC and 16#FE#, 1)
or Shift_Left (Current_CRC and 16#01#, 7);
-- Modulo addition
Current_CRC := Current_CRC + C;
end loop;
Matches := Current_CRC = CRC;
end if;
DEntry :=
(FS => FAT_Filesystem_Access (FS),
L_Name => <>,
S_Name => D_Entry.Filename,
S_Name_Ext => D_Entry.Extension,
Attributes => D_Entry.Attributes,
Start_Cluster => (if FS.Version = FAT16
then Cluster_Type (D_Entry.Cluster_L)
else Cluster_Type (D_Entry.Cluster_L) or
Shift_Left
(Cluster_Type (D_Entry.Cluster_H), 16)),
Size => D_Entry.Size,
Index => Current_Index - 1,
Is_Root => False,
Is_Dirty => False);
if Matches then
DEntry.L_Name := -L_Name (L_Name_First .. L_Name'Last);
else
DEntry.L_Name.Len := 0;