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-- Copyright (c) 2014, Natacha Porté --
-- --
-- Permission to use, copy, modify, and distribute this software for any --
-- purpose with or without fee is hereby granted, provided that the above --
-- copyright notice and this permission notice appear in all copies. --
-- --
-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES --
-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF --
-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR --
-- ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES --
-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN --
-- ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF --
-- OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. --
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-- Natools.S_Expressions.File_Readers provides types that read into files --
-- on disk (using Stream_IO) and expose their data as S-expressions or as --
-- atoms. --
------------------------------------------------------------------------------
with Natools.S_Expressions.Atom_Buffers;
with Natools.S_Expressions.Lockable;
private with Ada.Finalization;
private with Ada.Streams.Stream_IO;
private with Natools.S_Expressions.Parsers;
package Natools.S_Expressions.File_Readers is
type S_Reader is limited new Lockable.Descriptor with private;
-- Make a disk file available as a S-expression
function Reader (Name : String) return S_Reader;
-- Create a S_Reader associated with file Name
procedure Set_Filename (Object : in out S_Reader; Name : in String);
-- Reset Object with the new file Name
procedure Rewind (Object : in out S_Reader);
-- Return to the beginning of the file
type Atom_Reader is tagged limited private;
-- Make a disk file available as a single atom
function Reader (Name : String) return Atom_Reader;
-- Create an Atom_Reader associated with file Name;
procedure Set_Filename (Object : in out Atom_Reader; Name : in String);
-- Reset Object with the new file Name
function Length (Object : Atom_Reader) return Count;
-- Return the file length
function Read (Object : Atom_Reader) return Atom;
-- Read the whole file and return it as a single atom
procedure Read
(Object : in Atom_Reader;
Data : out Atom;
Length : out Count);
-- Read the whole file and store it in Data, along with its Length.
-- If Data is too small, only the file prefix is read.
procedure Read
(Object : in Atom_Reader;
Buffer : out Atom_Buffers.Atom_Buffer;
Block_Size : in Count := 1024);
-- Read the whole file into Buffer
generic
type Atom_Access is access Atom;
with procedure Unchecked_Deallocation (X : in out Atom_Access);
procedure Query
(Object : in Atom_Reader;
Process : not null access procedure (Data : in Atom));
-- Read the whole file into a memory zone allocated through Atom_Access,
-- and call Process on it.
procedure Block_Query
(Object : in Atom_Reader;
Block_Size : in Count;
Process : not null access procedure (Block : in Atom));
-- Read file block by block, and call Process on each of them
private
type Autoclose is new Ada.Finalization.Limited_Controlled with record
File : Ada.Streams.Stream_IO.File_Type;
end record;
overriding procedure Finalize (Object : in out Autoclose);
-- Close the underlying file if it was opened.
-- Used because a compiler bug in GNAT prevents adding
-- Ada.Finalization.Limited_Controlled as an ancestor of Parser,
-- so close-on-finalization has to be provided through composition.
type S_Reader is limited new Parsers.Parser with record
Holder : Autoclose;
end record;
overriding procedure Read_More
(Object : in out S_Reader;
Buffer : out Atom_Buffers.Atom_Buffer);
type Atom_Reader is new Ada.Finalization.Limited_Controlled with record
File : Ada.Streams.Stream_IO.File_Type;
end record;
overriding procedure Finalize (Object : in out Atom_Reader);
end Natools.S_Expressions.File_Readers;