------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
-- --
-- S Y S T E M . S T R I N G S . S T R E A M _ O P S --
-- --
-- B o d y --
-- --
-- Copyright (C) 2008-2010, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
pragma Compiler_Unit;
with Ada.Streams; use Ada.Streams;
with Ada.Streams.Stream_IO; use Ada.Streams.Stream_IO;
with Ada.Unchecked_Conversion;
with System.Stream_Attributes; use System;
package body System.Strings.Stream_Ops is
-- The following type describes the low-level IO mechanism used in package
-- Stream_Ops_Internal.
type IO_Kind is (Byte_IO, Block_IO);
-- The following package provides an IO framework for strings. Depending
-- on the version of System.Stream_Attributes as well as the size of
-- formal parameter Character_Type, the package will either utilize block
-- IO or character-by-character IO.
generic
type Character_Type is private;
type String_Type is array (Positive range <>) of Character_Type;
package Stream_Ops_Internal is
function Input
(Strm : access Root_Stream_Type'Class;
IO : IO_Kind) return String_Type;
procedure Output
(Strm : access Root_Stream_Type'Class;
Item : String_Type;
IO : IO_Kind);
procedure Read
(Strm : access Root_Stream_Type'Class;
Item : out String_Type;
IO : IO_Kind);
procedure Write
(Strm : access Root_Stream_Type'Class;
Item : String_Type;
IO : IO_Kind);
end Stream_Ops_Internal;
-------------------------
-- Stream_Ops_Internal --
-------------------------
package body Stream_Ops_Internal is
-- The following value represents the number of BITS allocated for the
-- default block used in string IO. The sizes of all other types are
-- calculated relative to this value.
Default_Block_Size : constant := 512 * 8;
-- Shorthand notation for stream element and character sizes
C_Size : constant Integer := Character_Type'Size;
SE_Size : constant Integer := Stream_Element'Size;
-- The following constants describe the number of stream elements or
-- characters that can fit into a default block.
C_In_Default_Block : constant Integer := Default_Block_Size / C_Size;
SE_In_Default_Block : constant Integer := Default_Block_Size / SE_Size;
-- Buffer types
subtype Default_Block is Stream_Element_Array
(1 .. Stream_Element_Offset (SE_In_Default_Block));
subtype String_Block is String_Type (1 .. C_In_Default_Block);
-- Conversions to and from Default_Block
function To_Default_Block is
new Ada.Unchecked_Conversion (String_Block, Default_Block);
function To_String_Block is
new Ada.Unchecked_Conversion (Default_Block, String_Block);
-----------
-- Input --
-----------
function Input
(Strm : access Root_Stream_Type'Class;
IO : IO_Kind) return String_Type
is
begin
if Strm = null then
raise Constraint_Error;
end if;
declare
Low : Positive;
High : Positive;
begin
-- Read the bounds of the string
Positive'Read (Strm, Low);
Positive'Read (Strm, High);
declare
Item : String_Type (Low .. High);
begin
-- Read the character content of the string
Read (Strm, Item, IO);
return Item;
end;
end;
end Input;
------------
-- Output --
------------
procedure Output
(Strm : access Root_Stream_Type'Class;
Item : String_Type;
IO : IO_Kind)
is
begin
if Strm = null then
raise Constraint_Error;
end if;
-- Write the bounds of the string
Positive'Write (Strm, Item'First);
Positive'Write (Strm, Item'Last);
-- Write the character content of the string
Write (Strm, Item, IO);
end Output;
----------
-- Read --
----------
procedure Read
(Strm : access Root_Stream_Type'Class;
Item : out String_Type;
IO : IO_Kind)
is
begin
if Strm = null then
raise Constraint_Error;
end if;
-- Nothing to do if the desired string is empty
if Item'Length = 0 then
return;
end if;
-- Block IO
if IO = Block_IO
and then Stream_Attributes.Block_IO_OK
then
declare
-- Determine the size in BITS of the block necessary to contain
-- the whole string.
Block_Size : constant Natural :=
(Item'Last - Item'First + 1) * C_Size;
-- Item can be larger than what the default block can store,
-- determine the number of whole reads necessary to read the
-- string.
Blocks : constant Natural := Block_Size / Default_Block_Size;
-- The size of Item may not be a multiple of the default block
-- size, determine the size of the remaining chunk in BITS.
Rem_Size : constant Natural :=
Block_Size mod Default_Block_Size;
-- String indexes
Low : Positive := Item'First;
High : Positive := Low + C_In_Default_Block - 1;
-- End of stream error detection
Last : Stream_Element_Offset := 0;
Sum : Stream_Element_Offset := 0;
begin
-- Step 1: If the string is too large, read in individual
-- chunks the size of the default block.
if Blocks > 0 then
declare
Block : Default_Block;
begin
for Counter in 1 .. Blocks loop
Read (Strm.all, Block, Last);
Item (Low .. High) := To_String_Block (Block);
Low := High + 1;
High := Low + C_In_Default_Block - 1;
Sum := Sum + Last;
Last := 0;
end loop;
end;
end if;
-- Step 2: Read in any remaining elements
if Rem_Size > 0 then
declare
subtype Rem_Block is Stream_Element_Array
(1 .. Stream_Element_Offset (Rem_Size / SE_Size));
subtype Rem_String_Block is
String_Type (1 .. Rem_Size / C_Size);
function To_Rem_String_Block is new
Ada.Unchecked_Conversion (Rem_Block, Rem_String_Block);
Block : Rem_Block;
begin
Read (Strm.all, Block, Last);
Item (Low .. Item'Last) := To_Rem_String_Block (Block);
Sum := Sum + Last;
end;
end if;
-- Step 3: Potential error detection. The sum of all the
-- chunks is less than we initially wanted to read. In other
-- words, the stream does not contain enough elements to fully
-- populate Item.
if (Integer (Sum) * SE_Size) / C_Size < Item'Length then
raise End_Error;
end if;
end;
-- Byte IO
else
declare
C : Character_Type;
begin
for Index in Item'First .. Item'Last loop
Character_Type'Read (Strm, C);
Item (Index) := C;
end loop;
end;
end if;
end Read;
-----------
-- Write --
-----------
procedure Write
(Strm : access Root_Stream_Type'Class;
Item : String_Type;
IO : IO_Kind)
is
begin
if Strm = null then
raise Constraint_Error;
end if;
-- Nothing to do if the input string is empty
if Item'Length = 0 then
return;
end if;
-- Block IO
if IO = Block_IO
and then Stream_Attributes.Block_IO_OK
then
declare
-- Determine the size in BITS of the block necessary to contain
-- the whole string.
Block_Size : constant Natural := Item'Length * C_Size;
-- Item can be larger than what the default block can store,
-- determine the number of whole writes necessary to output the
-- string.
Blocks : constant Natural := Block_Size / Default_Block_Size;
-- The size of Item may not be a multiple of the default block
-- size, determine the size of the remaining chunk.
Rem_Size : constant Natural :=
Block_Size mod Default_Block_Size;
-- String indexes
Low : Positive := Item'First;
High : Positive := Low + C_In_Default_Block - 1;
begin
-- Step 1: If the string is too large, write out individual
-- chunks the size of the default block.
for Counter in 1 .. Blocks loop
Write (Strm.all, To_Default_Block (Item (Low .. High)));
Low := High + 1;
High := Low + C_In_Default_Block - 1;
end loop;
-- Step 2: Write out any remaining elements
if Rem_Size > 0 then
declare
subtype Rem_Block is Stream_Element_Array
(1 .. Stream_Element_Offset (Rem_Size / SE_Size));
subtype Rem_String_Block is
String_Type (1 .. Rem_Size / C_Size);
function To_Rem_Block is new
Ada.Unchecked_Conversion (Rem_String_Block, Rem_Block);
begin
Write (Strm.all, To_Rem_Block (Item (Low .. Item'Last)));
end;
end if;
end;
-- Byte IO
else
for Index in Item'First .. Item'Last loop
Character_Type'Write (Strm, Item (Index));
end loop;
end if;
end Write;
end Stream_Ops_Internal;
-- Specific instantiations for all Ada string types
package String_Ops is
new Stream_Ops_Internal
(Character_Type => Character,
String_Type => String);
package Wide_String_Ops is
new Stream_Ops_Internal
(Character_Type => Wide_Character,
String_Type => Wide_String);
package Wide_Wide_String_Ops is
new Stream_Ops_Internal
(Character_Type => Wide_Wide_Character,
String_Type => Wide_Wide_String);
------------------
-- String_Input --
------------------
function String_Input
(Strm : access Ada.Streams.Root_Stream_Type'Class) return String
is
begin
return String_Ops.Input (Strm, Byte_IO);
end String_Input;
-------------------------
-- String_Input_Blk_IO --
-------------------------
function String_Input_Blk_IO
(Strm : access Ada.Streams.Root_Stream_Type'Class) return String
is
begin
return String_Ops.Input (Strm, Block_IO);
end String_Input_Blk_IO;
-------------------
-- String_Output --
-------------------
procedure String_Output
(Strm : access Ada.Streams.Root_Stream_Type'Class;
Item : String)
is
begin
String_Ops.Output (Strm, Item, Byte_IO);
end String_Output;
--------------------------
-- String_Output_Blk_IO --
--------------------------
procedure String_Output_Blk_IO
(Strm : access Ada.Streams.Root_Stream_Type'Class;
Item : String)
is
begin
String_Ops.Output (Strm, Item, Block_IO);
end String_Output_Blk_IO;
-----------------
-- String_Read --
-----------------
procedure String_Read
(Strm : access Ada.Streams.Root_Stream_Type'Class;
Item : out String)
is
begin
String_Ops.Read (Strm, Item, Byte_IO);
end String_Read;
------------------------
-- String_Read_Blk_IO --
------------------------
procedure String_Read_Blk_IO
(Strm : access Ada.Streams.Root_Stream_Type'Class;
Item : out String)
is
begin
String_Ops.Read (Strm, Item, Block_IO);
end String_Read_Blk_IO;
------------------
-- String_Write --
------------------
procedure String_Write
(Strm : access Ada.Streams.Root_Stream_Type'Class;
Item : String)
is
begin
String_Ops.Write (Strm, Item, Byte_IO);
end String_Write;
-------------------------
-- String_Write_Blk_IO --
-------------------------
procedure String_Write_Blk_IO
(Strm : access Ada.Streams.Root_Stream_Type'Class;
Item : String)
is
begin
String_Ops.Write (Strm, Item, Block_IO);
end String_Write_Blk_IO;
-----------------------
-- Wide_String_Input --
-----------------------
function Wide_String_Input
(Strm : access Ada.Streams.Root_Stream_Type'Class) return Wide_String
is
begin
return Wide_String_Ops.Input (Strm, Byte_IO);
end Wide_String_Input;
------------------------------
-- Wide_String_Input_Blk_IO --
------------------------------
function Wide_String_Input_Blk_IO
(Strm : access Ada.Streams.Root_Stream_Type'Class) return Wide_String
is
begin
return Wide_String_Ops.Input (Strm, Block_IO);
end Wide_String_Input_Blk_IO;
------------------------
-- Wide_String_Output --
------------------------
procedure Wide_String_Output
(Strm : access Ada.Streams.Root_Stream_Type'Class;
Item : Wide_String)
is
begin
Wide_String_Ops.Output (Strm, Item, Byte_IO);
end Wide_String_Output;
-------------------------------
-- Wide_String_Output_Blk_IO --
-------------------------------
procedure Wide_String_Output_Blk_IO
(Strm : access Ada.Streams.Root_Stream_Type'Class;
Item : Wide_String)
is
begin
Wide_String_Ops.Output (Strm, Item, Block_IO);
end Wide_String_Output_Blk_IO;
----------------------
-- Wide_String_Read --
----------------------
procedure Wide_String_Read
(Strm : access Ada.Streams.Root_Stream_Type'Class;
Item : out Wide_String)
is
begin
Wide_String_Ops.Read (Strm, Item, Byte_IO);
end Wide_String_Read;
-----------------------------
-- Wide_String_Read_Blk_IO --
-----------------------------
procedure Wide_String_Read_Blk_IO
(Strm : access Ada.Streams.Root_Stream_Type'Class;
Item : out Wide_String)
is
begin
Wide_String_Ops.Read (Strm, Item, Block_IO);
end Wide_String_Read_Blk_IO;
-----------------------
-- Wide_String_Write --
-----------------------
procedure Wide_String_Write
(Strm : access Ada.Streams.Root_Stream_Type'Class;
Item : Wide_String)
is
begin
Wide_String_Ops.Write (Strm, Item, Byte_IO);
end Wide_String_Write;
------------------------------
-- Wide_String_Write_Blk_IO --
------------------------------
procedure Wide_String_Write_Blk_IO
(Strm : access Ada.Streams.Root_Stream_Type'Class;
Item : Wide_String)
is
begin
Wide_String_Ops.Write (Strm, Item, Block_IO);
end Wide_String_Write_Blk_IO;
----------------------------
-- Wide_Wide_String_Input --
----------------------------
function Wide_Wide_String_Input
(Strm : access Ada.Streams.Root_Stream_Type'Class) return Wide_Wide_String
is
begin
return Wide_Wide_String_Ops.Input (Strm, Byte_IO);
end Wide_Wide_String_Input;
-----------------------------------
-- Wide_Wide_String_Input_Blk_IO --
-----------------------------------
function Wide_Wide_String_Input_Blk_IO
(Strm : access Ada.Streams.Root_Stream_Type'Class) return Wide_Wide_String
is
begin
return Wide_Wide_String_Ops.Input (Strm, Block_IO);
end Wide_Wide_String_Input_Blk_IO;
-----------------------------
-- Wide_Wide_String_Output --
-----------------------------
procedure Wide_Wide_String_Output
(Strm : access Ada.Streams.Root_Stream_Type'Class;
Item : Wide_Wide_String)
is
begin
Wide_Wide_String_Ops.Output (Strm, Item, Byte_IO);
end Wide_Wide_String_Output;
------------------------------------
-- Wide_Wide_String_Output_Blk_IO --
------------------------------------
procedure Wide_Wide_String_Output_Blk_IO
(Strm : access Ada.Streams.Root_Stream_Type'Class;
Item : Wide_Wide_String)
is
begin
Wide_Wide_String_Ops.Output (Strm, Item, Block_IO);
end Wide_Wide_String_Output_Blk_IO;
---------------------------
-- Wide_Wide_String_Read --
---------------------------
procedure Wide_Wide_String_Read
(Strm : access Ada.Streams.Root_Stream_Type'Class;
Item : out Wide_Wide_String)
is
begin
Wide_Wide_String_Ops.Read (Strm, Item, Byte_IO);
end Wide_Wide_String_Read;
----------------------------------
-- Wide_Wide_String_Read_Blk_IO --
----------------------------------
procedure Wide_Wide_String_Read_Blk_IO
(Strm : access Ada.Streams.Root_Stream_Type'Class;
Item : out Wide_Wide_String)
is
begin
Wide_Wide_String_Ops.Read (Strm, Item, Block_IO);
end Wide_Wide_String_Read_Blk_IO;
----------------------------
-- Wide_Wide_String_Write --
----------------------------
procedure Wide_Wide_String_Write
(Strm : access Ada.Streams.Root_Stream_Type'Class;
Item : Wide_Wide_String)
is
begin
Wide_Wide_String_Ops.Write (Strm, Item, Byte_IO);
end Wide_Wide_String_Write;
-----------------------------------
-- Wide_Wide_String_Write_Blk_IO --
-----------------------------------
procedure Wide_Wide_String_Write_Blk_IO
(Strm : access Ada.Streams.Root_Stream_Type'Class;
Item : Wide_Wide_String)
is
begin
Wide_Wide_String_Ops.Write (Strm, Item, Block_IO);
end Wide_Wide_String_Write_Blk_IO;
end System.Strings.Stream_Ops;