701 lines
20 KiB
Ada
701 lines
20 KiB
Ada
----------------------------------------------------------------
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-- ZLib for Ada thick binding. --
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-- --
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-- Copyright (C) 2002-2004 Dmitriy Anisimkov --
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-- --
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-- Open source license information is in the zlib.ads file. --
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----------------------------------------------------------------
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-- $Id: zlib.adb,v 1.31 2004/09/06 06:53:19 vagul Exp $
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with Ada.Exceptions;
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with Ada.Unchecked_Conversion;
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with Ada.Unchecked_Deallocation;
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with Interfaces.C.Strings;
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with ZLib.Thin;
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package body ZLib is
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use type Thin.Int;
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type Z_Stream is new Thin.Z_Stream;
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type Return_Code_Enum is
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(OK,
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STREAM_END,
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NEED_DICT,
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ERRNO,
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STREAM_ERROR,
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DATA_ERROR,
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MEM_ERROR,
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BUF_ERROR,
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VERSION_ERROR);
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type Flate_Step_Function is access
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function (Strm : in Thin.Z_Streamp; Flush : in Thin.Int) return Thin.Int;
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pragma Convention (C, Flate_Step_Function);
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type Flate_End_Function is access
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function (Ctrm : in Thin.Z_Streamp) return Thin.Int;
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pragma Convention (C, Flate_End_Function);
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type Flate_Type is record
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Step : Flate_Step_Function;
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Done : Flate_End_Function;
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end record;
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subtype Footer_Array is Stream_Element_Array (1 .. 8);
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Simple_GZip_Header : constant Stream_Element_Array (1 .. 10)
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:= (16#1f#, 16#8b#, -- Magic header
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16#08#, -- Z_DEFLATED
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16#00#, -- Flags
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16#00#, 16#00#, 16#00#, 16#00#, -- Time
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16#00#, -- XFlags
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16#03# -- OS code
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);
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-- The simplest gzip header is not for informational, but just for
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-- gzip format compatibility.
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-- Note that some code below is using assumption
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-- Simple_GZip_Header'Last > Footer_Array'Last, so do not make
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-- Simple_GZip_Header'Last <= Footer_Array'Last.
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Return_Code : constant array (Thin.Int range <>) of Return_Code_Enum
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:= (0 => OK,
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1 => STREAM_END,
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2 => NEED_DICT,
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-1 => ERRNO,
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-2 => STREAM_ERROR,
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-3 => DATA_ERROR,
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-4 => MEM_ERROR,
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-5 => BUF_ERROR,
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-6 => VERSION_ERROR);
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Flate : constant array (Boolean) of Flate_Type
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:= (True => (Step => Thin.Deflate'Access,
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Done => Thin.DeflateEnd'Access),
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False => (Step => Thin.Inflate'Access,
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Done => Thin.InflateEnd'Access));
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Flush_Finish : constant array (Boolean) of Flush_Mode
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:= (True => Finish, False => No_Flush);
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procedure Raise_Error (Stream : in Z_Stream);
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pragma Inline (Raise_Error);
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procedure Raise_Error (Message : in String);
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pragma Inline (Raise_Error);
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procedure Check_Error (Stream : in Z_Stream; Code : in Thin.Int);
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procedure Free is new Ada.Unchecked_Deallocation
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(Z_Stream, Z_Stream_Access);
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function To_Thin_Access is new Ada.Unchecked_Conversion
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(Z_Stream_Access, Thin.Z_Streamp);
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procedure Translate_GZip
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(Filter : in out Filter_Type;
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In_Data : in Ada.Streams.Stream_Element_Array;
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In_Last : out Ada.Streams.Stream_Element_Offset;
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Out_Data : out Ada.Streams.Stream_Element_Array;
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Out_Last : out Ada.Streams.Stream_Element_Offset;
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Flush : in Flush_Mode);
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-- Separate translate routine for make gzip header.
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procedure Translate_Auto
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(Filter : in out Filter_Type;
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In_Data : in Ada.Streams.Stream_Element_Array;
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In_Last : out Ada.Streams.Stream_Element_Offset;
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Out_Data : out Ada.Streams.Stream_Element_Array;
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Out_Last : out Ada.Streams.Stream_Element_Offset;
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Flush : in Flush_Mode);
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-- translate routine without additional headers.
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-----------------
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-- Check_Error --
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-----------------
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procedure Check_Error (Stream : in Z_Stream; Code : in Thin.Int) is
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use type Thin.Int;
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begin
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if Code /= Thin.Z_OK then
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Raise_Error
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(Return_Code_Enum'Image (Return_Code (Code))
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& ": " & Last_Error_Message (Stream));
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end if;
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end Check_Error;
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-----------
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-- Close --
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-----------
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procedure Close
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(Filter : in out Filter_Type;
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Ignore_Error : in Boolean := False)
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is
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Code : Thin.Int;
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begin
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if not Ignore_Error and then not Is_Open (Filter) then
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raise Status_Error;
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end if;
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Code := Flate (Filter.Compression).Done (To_Thin_Access (Filter.Strm));
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if Ignore_Error or else Code = Thin.Z_OK then
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Free (Filter.Strm);
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else
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declare
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Error_Message : constant String
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:= Last_Error_Message (Filter.Strm.all);
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begin
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Free (Filter.Strm);
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Ada.Exceptions.Raise_Exception
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(ZLib_Error'Identity,
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Return_Code_Enum'Image (Return_Code (Code))
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& ": " & Error_Message);
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end;
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end if;
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end Close;
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-----------
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-- CRC32 --
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-----------
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function CRC32
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(CRC : in Unsigned_32;
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Data : in Ada.Streams.Stream_Element_Array)
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return Unsigned_32
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is
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use Thin;
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begin
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return Unsigned_32 (crc32 (ULong (CRC),
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Data'Address,
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Data'Length));
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end CRC32;
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procedure CRC32
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(CRC : in out Unsigned_32;
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Data : in Ada.Streams.Stream_Element_Array) is
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begin
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CRC := CRC32 (CRC, Data);
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end CRC32;
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------------------
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-- Deflate_Init --
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------------------
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procedure Deflate_Init
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(Filter : in out Filter_Type;
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Level : in Compression_Level := Default_Compression;
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Strategy : in Strategy_Type := Default_Strategy;
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Method : in Compression_Method := Deflated;
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Window_Bits : in Window_Bits_Type := Default_Window_Bits;
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Memory_Level : in Memory_Level_Type := Default_Memory_Level;
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Header : in Header_Type := Default)
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is
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use type Thin.Int;
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Win_Bits : Thin.Int := Thin.Int (Window_Bits);
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begin
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if Is_Open (Filter) then
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raise Status_Error;
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end if;
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-- We allow ZLib to make header only in case of default header type.
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-- Otherwise we would either do header by ourselfs, or do not do
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-- header at all.
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if Header = None or else Header = GZip then
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Win_Bits := -Win_Bits;
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end if;
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-- For the GZip CRC calculation and make headers.
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if Header = GZip then
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Filter.CRC := 0;
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Filter.Offset := Simple_GZip_Header'First;
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else
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Filter.Offset := Simple_GZip_Header'Last + 1;
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end if;
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Filter.Strm := new Z_Stream;
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Filter.Compression := True;
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Filter.Stream_End := False;
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Filter.Header := Header;
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if Thin.Deflate_Init
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(To_Thin_Access (Filter.Strm),
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Level => Thin.Int (Level),
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method => Thin.Int (Method),
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windowBits => Win_Bits,
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memLevel => Thin.Int (Memory_Level),
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strategy => Thin.Int (Strategy)) /= Thin.Z_OK
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then
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Raise_Error (Filter.Strm.all);
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end if;
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end Deflate_Init;
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-----------
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-- Flush --
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-----------
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procedure Flush
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(Filter : in out Filter_Type;
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Out_Data : out Ada.Streams.Stream_Element_Array;
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Out_Last : out Ada.Streams.Stream_Element_Offset;
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Flush : in Flush_Mode)
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is
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No_Data : Stream_Element_Array := (1 .. 0 => 0);
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Last : Stream_Element_Offset;
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begin
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Translate (Filter, No_Data, Last, Out_Data, Out_Last, Flush);
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end Flush;
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-----------------------
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-- Generic_Translate --
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-----------------------
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procedure Generic_Translate
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(Filter : in out ZLib.Filter_Type;
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In_Buffer_Size : in Integer := Default_Buffer_Size;
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Out_Buffer_Size : in Integer := Default_Buffer_Size)
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is
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In_Buffer : Stream_Element_Array
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(1 .. Stream_Element_Offset (In_Buffer_Size));
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Out_Buffer : Stream_Element_Array
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(1 .. Stream_Element_Offset (Out_Buffer_Size));
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Last : Stream_Element_Offset;
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In_Last : Stream_Element_Offset;
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In_First : Stream_Element_Offset;
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Out_Last : Stream_Element_Offset;
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begin
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Main : loop
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Data_In (In_Buffer, Last);
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In_First := In_Buffer'First;
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loop
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Translate
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(Filter => Filter,
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In_Data => In_Buffer (In_First .. Last),
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In_Last => In_Last,
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Out_Data => Out_Buffer,
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Out_Last => Out_Last,
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Flush => Flush_Finish (Last < In_Buffer'First));
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if Out_Buffer'First <= Out_Last then
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Data_Out (Out_Buffer (Out_Buffer'First .. Out_Last));
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end if;
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exit Main when Stream_End (Filter);
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-- The end of in buffer.
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exit when In_Last = Last;
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In_First := In_Last + 1;
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end loop;
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end loop Main;
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end Generic_Translate;
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------------------
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-- Inflate_Init --
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------------------
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procedure Inflate_Init
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(Filter : in out Filter_Type;
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Window_Bits : in Window_Bits_Type := Default_Window_Bits;
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Header : in Header_Type := Default)
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is
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use type Thin.Int;
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Win_Bits : Thin.Int := Thin.Int (Window_Bits);
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procedure Check_Version;
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-- Check the latest header types compatibility.
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procedure Check_Version is
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begin
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if Version <= "1.1.4" then
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Raise_Error
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("Inflate header type " & Header_Type'Image (Header)
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& " incompatible with ZLib version " & Version);
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end if;
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end Check_Version;
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begin
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if Is_Open (Filter) then
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raise Status_Error;
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end if;
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case Header is
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when None =>
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Check_Version;
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-- Inflate data without headers determined
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-- by negative Win_Bits.
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Win_Bits := -Win_Bits;
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when GZip =>
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Check_Version;
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-- Inflate gzip data defined by flag 16.
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Win_Bits := Win_Bits + 16;
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when Auto =>
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Check_Version;
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-- Inflate with automatic detection
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-- of gzip or native header defined by flag 32.
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Win_Bits := Win_Bits + 32;
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when Default => null;
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end case;
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Filter.Strm := new Z_Stream;
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Filter.Compression := False;
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Filter.Stream_End := False;
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Filter.Header := Header;
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if Thin.Inflate_Init
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(To_Thin_Access (Filter.Strm), Win_Bits) /= Thin.Z_OK
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then
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Raise_Error (Filter.Strm.all);
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end if;
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end Inflate_Init;
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-------------
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-- Is_Open --
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-------------
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function Is_Open (Filter : in Filter_Type) return Boolean is
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begin
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return Filter.Strm /= null;
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end Is_Open;
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-----------------
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-- Raise_Error --
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-----------------
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procedure Raise_Error (Message : in String) is
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begin
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Ada.Exceptions.Raise_Exception (ZLib_Error'Identity, Message);
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end Raise_Error;
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procedure Raise_Error (Stream : in Z_Stream) is
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begin
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Raise_Error (Last_Error_Message (Stream));
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end Raise_Error;
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----------
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-- Read --
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----------
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procedure Read
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(Filter : in out Filter_Type;
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Item : out Ada.Streams.Stream_Element_Array;
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Last : out Ada.Streams.Stream_Element_Offset;
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Flush : in Flush_Mode := No_Flush)
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is
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In_Last : Stream_Element_Offset;
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Item_First : Ada.Streams.Stream_Element_Offset := Item'First;
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V_Flush : Flush_Mode := Flush;
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begin
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pragma Assert (Rest_First in Buffer'First .. Buffer'Last + 1);
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pragma Assert (Rest_Last in Buffer'First - 1 .. Buffer'Last);
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loop
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if Rest_Last = Buffer'First - 1 then
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V_Flush := Finish;
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elsif Rest_First > Rest_Last then
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Read (Buffer, Rest_Last);
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Rest_First := Buffer'First;
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if Rest_Last < Buffer'First then
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V_Flush := Finish;
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end if;
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end if;
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Translate
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(Filter => Filter,
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In_Data => Buffer (Rest_First .. Rest_Last),
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In_Last => In_Last,
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Out_Data => Item (Item_First .. Item'Last),
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Out_Last => Last,
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Flush => V_Flush);
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Rest_First := In_Last + 1;
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exit when Stream_End (Filter)
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or else Last = Item'Last
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or else (Last >= Item'First and then Allow_Read_Some);
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Item_First := Last + 1;
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end loop;
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end Read;
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----------------
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-- Stream_End --
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----------------
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function Stream_End (Filter : in Filter_Type) return Boolean is
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begin
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if Filter.Header = GZip and Filter.Compression then
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return Filter.Stream_End
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and then Filter.Offset = Footer_Array'Last + 1;
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else
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return Filter.Stream_End;
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end if;
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end Stream_End;
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--------------
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-- Total_In --
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--------------
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function Total_In (Filter : in Filter_Type) return Count is
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begin
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return Count (Thin.Total_In (To_Thin_Access (Filter.Strm).all));
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end Total_In;
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---------------
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-- Total_Out --
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---------------
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function Total_Out (Filter : in Filter_Type) return Count is
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begin
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return Count (Thin.Total_Out (To_Thin_Access (Filter.Strm).all));
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end Total_Out;
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---------------
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-- Translate --
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---------------
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procedure Translate
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(Filter : in out Filter_Type;
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In_Data : in Ada.Streams.Stream_Element_Array;
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In_Last : out Ada.Streams.Stream_Element_Offset;
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Out_Data : out Ada.Streams.Stream_Element_Array;
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Out_Last : out Ada.Streams.Stream_Element_Offset;
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Flush : in Flush_Mode) is
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begin
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if Filter.Header = GZip and then Filter.Compression then
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Translate_GZip
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(Filter => Filter,
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In_Data => In_Data,
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In_Last => In_Last,
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Out_Data => Out_Data,
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Out_Last => Out_Last,
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Flush => Flush);
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else
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Translate_Auto
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(Filter => Filter,
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In_Data => In_Data,
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In_Last => In_Last,
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Out_Data => Out_Data,
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Out_Last => Out_Last,
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Flush => Flush);
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end if;
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end Translate;
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--------------------
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-- Translate_Auto --
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--------------------
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procedure Translate_Auto
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(Filter : in out Filter_Type;
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In_Data : in Ada.Streams.Stream_Element_Array;
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In_Last : out Ada.Streams.Stream_Element_Offset;
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Out_Data : out Ada.Streams.Stream_Element_Array;
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Out_Last : out Ada.Streams.Stream_Element_Offset;
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Flush : in Flush_Mode)
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is
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use type Thin.Int;
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Code : Thin.Int;
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begin
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if not Is_Open (Filter) then
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raise Status_Error;
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end if;
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if Out_Data'Length = 0 and then In_Data'Length = 0 then
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raise Constraint_Error;
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end if;
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Set_Out (Filter.Strm.all, Out_Data'Address, Out_Data'Length);
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Set_In (Filter.Strm.all, In_Data'Address, In_Data'Length);
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Code := Flate (Filter.Compression).Step
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(To_Thin_Access (Filter.Strm),
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Thin.Int (Flush));
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if Code = Thin.Z_STREAM_END then
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Filter.Stream_End := True;
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else
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Check_Error (Filter.Strm.all, Code);
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end if;
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In_Last := In_Data'Last
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- Stream_Element_Offset (Avail_In (Filter.Strm.all));
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Out_Last := Out_Data'Last
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- Stream_Element_Offset (Avail_Out (Filter.Strm.all));
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end Translate_Auto;
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--------------------
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-- Translate_GZip --
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--------------------
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procedure Translate_GZip
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(Filter : in out Filter_Type;
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In_Data : in Ada.Streams.Stream_Element_Array;
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In_Last : out Ada.Streams.Stream_Element_Offset;
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Out_Data : out Ada.Streams.Stream_Element_Array;
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Out_Last : out Ada.Streams.Stream_Element_Offset;
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Flush : in Flush_Mode)
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is
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Out_First : Stream_Element_Offset;
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procedure Add_Data (Data : in Stream_Element_Array);
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-- Add data to stream from the Filter.Offset till necessary,
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-- used for add gzip headr/footer.
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procedure Put_32
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(Item : in out Stream_Element_Array;
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Data : in Unsigned_32);
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pragma Inline (Put_32);
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|
|
--------------
|
|
-- Add_Data --
|
|
--------------
|
|
|
|
procedure Add_Data (Data : in Stream_Element_Array) is
|
|
Data_First : Stream_Element_Offset renames Filter.Offset;
|
|
Data_Last : Stream_Element_Offset;
|
|
Data_Len : Stream_Element_Offset; -- -1
|
|
Out_Len : Stream_Element_Offset; -- -1
|
|
begin
|
|
Out_First := Out_Last + 1;
|
|
|
|
if Data_First > Data'Last then
|
|
return;
|
|
end if;
|
|
|
|
Data_Len := Data'Last - Data_First;
|
|
Out_Len := Out_Data'Last - Out_First;
|
|
|
|
if Data_Len <= Out_Len then
|
|
Out_Last := Out_First + Data_Len;
|
|
Data_Last := Data'Last;
|
|
else
|
|
Out_Last := Out_Data'Last;
|
|
Data_Last := Data_First + Out_Len;
|
|
end if;
|
|
|
|
Out_Data (Out_First .. Out_Last) := Data (Data_First .. Data_Last);
|
|
|
|
Data_First := Data_Last + 1;
|
|
Out_First := Out_Last + 1;
|
|
end Add_Data;
|
|
|
|
------------
|
|
-- Put_32 --
|
|
------------
|
|
|
|
procedure Put_32
|
|
(Item : in out Stream_Element_Array;
|
|
Data : in Unsigned_32)
|
|
is
|
|
D : Unsigned_32 := Data;
|
|
begin
|
|
for J in Item'First .. Item'First + 3 loop
|
|
Item (J) := Stream_Element (D and 16#FF#);
|
|
D := Shift_Right (D, 8);
|
|
end loop;
|
|
end Put_32;
|
|
|
|
begin
|
|
Out_Last := Out_Data'First - 1;
|
|
|
|
if not Filter.Stream_End then
|
|
Add_Data (Simple_GZip_Header);
|
|
|
|
Translate_Auto
|
|
(Filter => Filter,
|
|
In_Data => In_Data,
|
|
In_Last => In_Last,
|
|
Out_Data => Out_Data (Out_First .. Out_Data'Last),
|
|
Out_Last => Out_Last,
|
|
Flush => Flush);
|
|
|
|
CRC32 (Filter.CRC, In_Data (In_Data'First .. In_Last));
|
|
end if;
|
|
|
|
if Filter.Stream_End and then Out_Last <= Out_Data'Last then
|
|
-- This detection method would work only when
|
|
-- Simple_GZip_Header'Last > Footer_Array'Last
|
|
|
|
if Filter.Offset = Simple_GZip_Header'Last + 1 then
|
|
Filter.Offset := Footer_Array'First;
|
|
end if;
|
|
|
|
declare
|
|
Footer : Footer_Array;
|
|
begin
|
|
Put_32 (Footer, Filter.CRC);
|
|
Put_32 (Footer (Footer'First + 4 .. Footer'Last),
|
|
Unsigned_32 (Total_In (Filter)));
|
|
Add_Data (Footer);
|
|
end;
|
|
end if;
|
|
end Translate_GZip;
|
|
|
|
-------------
|
|
-- Version --
|
|
-------------
|
|
|
|
function Version return String is
|
|
begin
|
|
return Interfaces.C.Strings.Value (Thin.zlibVersion);
|
|
end Version;
|
|
|
|
-----------
|
|
-- Write --
|
|
-----------
|
|
|
|
procedure Write
|
|
(Filter : in out Filter_Type;
|
|
Item : in Ada.Streams.Stream_Element_Array;
|
|
Flush : in Flush_Mode := No_Flush)
|
|
is
|
|
Buffer : Stream_Element_Array (1 .. Buffer_Size);
|
|
In_Last : Stream_Element_Offset;
|
|
Out_Last : Stream_Element_Offset;
|
|
In_First : Stream_Element_Offset := Item'First;
|
|
begin
|
|
if Item'Length = 0 and Flush = No_Flush then
|
|
return;
|
|
end if;
|
|
|
|
loop
|
|
Translate
|
|
(Filter => Filter,
|
|
In_Data => Item (In_First .. Item'Last),
|
|
In_Last => In_Last,
|
|
Out_Data => Buffer,
|
|
Out_Last => Out_Last,
|
|
Flush => Flush);
|
|
|
|
if Out_Last >= Buffer'First then
|
|
Write (Buffer (1 .. Out_Last));
|
|
end if;
|
|
|
|
exit when In_Last = Item'Last or Stream_End (Filter);
|
|
|
|
In_First := In_Last + 1;
|
|
end loop;
|
|
end Write;
|
|
|
|
end ZLib;
|