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346 | --
-- Copyright (C) 2020-2023, AdaCore
--
-- SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
--
with Ada.Unchecked_Deallocation;
with System.Storage_Elements;
with VSS.Implementation.Character_Codes;
with VSS.Implementation.String_Handlers;
with VSS.Unicode;
package body VSS.Implementation.String_Vectors is
procedure Free is
new Ada.Unchecked_Deallocation
(VSS.Implementation.String_Vectors.String_Vector_Data,
VSS.Implementation.String_Vectors.String_Vector_Data_Access);
Line_Terminator_To_Code_Point : constant
array (VSS.Strings.Line_Terminator) of VSS.Unicode.Code_Point :=
[VSS.Strings.CR => VSS.Implementation.Character_Codes.Carriage_Return,
VSS.Strings.LF => VSS.Implementation.Character_Codes.Line_Feed,
VSS.Strings.CRLF => VSS.Implementation.Character_Codes.Carriage_Return,
VSS.Strings.NEL => VSS.Implementation.Character_Codes.Next_Line,
VSS.Strings.VT => VSS.Implementation.Character_Codes.Line_Tabulation,
VSS.Strings.FF => VSS.Implementation.Character_Codes.Form_Feed,
VSS.Strings.LS => VSS.Implementation.Character_Codes.Line_Separator,
VSS.Strings.PS =>
VSS.Implementation.Character_Codes.Paragraph_Separator];
-- Mapping from Line_Terminator to code point of first character of the
-- line terminator sequence. Only CRLF case requires longer sequence and
-- it is processed separately.
Growth_Factor : constant := 2;
-- The growth factor controls how much extra space is allocated when
-- we have to increase the size of an allocated vector storage. By
-- allocating extra space, we avoid the need to reallocate on every
-- append, particularly important when a vector is built up by repeated
-- append operations of an individual items. This is expressed as a
-- factor so 2 means add 1/2 of the length of the vector as growth space.
Min_Mul_Alloc : constant := Standard'Maximum_Alignment;
-- Allocation will be done by a multiple of Min_Mul_Alloc. This causes
-- no memory loss as most (all?) malloc implementations are obliged to
-- align the returned memory on the maximum alignment as malloc does not
-- know the target alignment.
procedure Mutate
(Self : in out String_Vector_Data_Access;
Required : Natural;
Reserved : Natural);
-- Prepare object to be modified and reserve space for at least Required
-- number of items and up to additional Reserved number of items.
-- Parameters Required and Reserve are separated to prevent potential
-- integer overflow at the caller side.
function Aligned_Length
(Required : Natural;
Reserved : Natural) return Natural;
-- Return recommended length of the vector storage which is enough to
-- store at least Required number of items and up to Reserved number of
-- items additionally. Calculation takes into account alignment of the
-- allocated memory segments to use memory effectively by
-- Append/Insert/etc operations.
--------------------
-- Aligned_Length --
--------------------
function Aligned_Length
(Required : Natural;
Reserved : Natural) return Natural
is
use type System.Storage_Elements.Storage_Offset;
subtype Empty_String_Vector_Data is String_Vector_Data (0);
Element_Size : constant System.Storage_Elements.Storage_Count :=
VSS.Implementation.Strings.String_Data'Max_Size_In_Storage_Elements;
Static_Size : constant System.Storage_Elements.Storage_Count :=
Empty_String_Vector_Data'Max_Size_In_Storage_Elements;
begin
if Required > Natural'Last - Reserved then
-- Total requested number of items is large than maximum number,
-- so limit it to maximum number of items.
return Natural'Last;
else
return
Natural
((((Static_Size
+ System.Storage_Elements.Storage_Count (Required + Reserved)
* Element_Size + Min_Mul_Alloc - 1) / Min_Mul_Alloc)
* Min_Mul_Alloc - Static_Size) / Element_Size);
end if;
end Aligned_Length;
------------
-- Append --
------------
procedure Append
(Self : in out String_Vector_Data_Access;
Item : VSS.Implementation.Strings.String_Data) is
begin
if Self = null then
Mutate (Self, 1, 0);
else
Mutate (Self, Self.Last + 1, Self.Last / Growth_Factor);
end if;
Self.Last := Self.Last + 1;
Self.Data (Self.Last) := Item;
VSS.Implementation.Strings.Reference (Self.Data (Self.Last));
end Append;
-------------------------------
-- Append_And_Move_Ownership --
-------------------------------
procedure Append_And_Move_Ownership
(Self : in out String_Vector_Data_Access;
Item : VSS.Implementation.Strings.String_Data) is
begin
if Self = null then
Mutate (Self, 1, 0);
else
Mutate (Self, Self.Last + 1, Self.Last / Growth_Factor);
end if;
Self.Last := Self.Last + 1;
Self.Data (Self.Last) := Item;
end Append_And_Move_Ownership;
--------------
-- Contains --
--------------
function Contains
(Self : String_Vector_Data_Access;
Item : VSS.Implementation.Strings.String_Data) return Boolean
is
Item_Handler :
VSS.Implementation.String_Handlers.Abstract_String_Handler'Class
renames VSS.Implementation.Strings.Handler (Item).all;
begin
if Self = null then
return False;
end if;
for J in Self.Data'First .. Self.Last loop
declare
Handler :
VSS.Implementation.String_Handlers.Abstract_String_Handler'Class
renames VSS.Implementation.Strings.Handler (Self.Data (J)).all;
begin
if Item_Handler.Is_Equal (Item, Handler, Self.Data (J)) then
return True;
end if;
end;
end loop;
return False;
end Contains;
------------
-- Delete --
------------
procedure Delete
(Self : in out not null String_Vector_Data_Access;
Index : Positive) is
begin
if Index <= Self.Last then
Mutate (Self, Self.Last, 0);
VSS.Implementation.Strings.Unreference (Self.Data (Index));
Self.Data (Index .. Self.Last - 1) :=
Self.Data (Index + 1 .. Self.Last);
Self.Last := Self.Last - 1;
end if;
end Delete;
----------------
-- Join_Lines --
----------------
procedure Join_Lines
(Self : String_Vector_Data_Access;
Result : in out VSS.Implementation.Strings.String_Data;
Terminator : VSS.Strings.Line_Terminator;
Terminate_Last : Boolean)
is
use type VSS.Strings.Line_Terminator;
Offset : VSS.Implementation.Strings.Cursor_Offset;
begin
VSS.Implementation.Strings.Unreference (Result);
if Self = null then
return;
end if;
Result := VSS.Implementation.Strings.Null_String_Data;
for J in 1 .. Self.Last loop
VSS.Implementation.Strings.Handler (Result).Append
(Result, Self.Data (J), Offset);
if J /= Self.Last or Terminate_Last then
VSS.Implementation.Strings.Handler (Result).Append
(Result, Line_Terminator_To_Code_Point (Terminator), Offset);
if Terminator = VSS.Strings.CRLF then
VSS.Implementation.Strings.Handler (Result).Append
(Result,
VSS.Implementation.Character_Codes.Line_Feed,
Offset);
end if;
end if;
end loop;
end Join_Lines;
------------
-- Mutate --
------------
procedure Mutate
(Self : in out String_Vector_Data_Access;
Required : Natural;
Reserved : Natural)
is
begin
if Self = null then
Self := new String_Vector_Data (Aligned_Length (Required, Reserved));
elsif not System.Atomic_Counters.Is_One (Self.Counter)
or else Self.Bulk < Required
then
declare
Old : String_Vector_Data_Access := Self;
begin
Self :=
new String_Vector_Data (Aligned_Length (Required, Reserved));
Self.Last := Old.Last;
Self.Data (1 .. Old.Last) := Old.Data (1 .. Old.Last);
if not System.Atomic_Counters.Is_One (Old.Counter) then
for Data of Self.Data (1 .. Self.Last) loop
VSS.Implementation.Strings.Reference (Data);
end loop;
Unreference (Old);
else
Free (Old);
end if;
end;
end if;
end Mutate;
-------------
-- Prepend --
-------------
procedure Prepend
(Self : in out String_Vector_Data_Access;
Item : VSS.Implementation.Strings.String_Data) is
begin
if Self = null then
Mutate (Self, 1, 0);
else
Mutate (Self, Self.Last + 1, Self.Last / Growth_Factor);
end if;
Self.Data (2 .. Self.Last + 1) := Self.Data (1 .. Self.Last);
Self.Last := Self.Last + 1;
Self.Data (1) := Item;
VSS.Implementation.Strings.Reference (Self.Data (1));
end Prepend;
---------------
-- Reference --
---------------
procedure Reference (Self : String_Vector_Data_Access) is
begin
if Self /= null then
System.Atomic_Counters.Increment (Self.Counter);
end if;
end Reference;
-------------
-- Replace --
-------------
procedure Replace
(Self : in out not null String_Vector_Data_Access;
Index : Positive;
Item : VSS.Implementation.Strings.String_Data) is
begin
Mutate (Self, Self.Last, 0);
VSS.Implementation.Strings.Unreference (Self.Data (Index));
Self.Data (Index) := Item;
VSS.Implementation.Strings.Reference (Self.Data (Index));
end Replace;
-----------------
-- Unreference --
-----------------
procedure Unreference (Self : in out String_Vector_Data_Access) is
begin
if Self /= null then
if System.Atomic_Counters.Decrement (Self.Counter) then
for J in 1 .. Self.Last loop
VSS.Implementation.Strings.Unreference (Self.Data (J));
end loop;
Free (Self);
else
-- Data is shared, reset own pointer to null because counter
-- is decremented.
Self := null;
end if;
end if;
end Unreference;
end VSS.Implementation.String_Vectors;
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