| [1096] | 1 | ------------------------------------------------------------------------------
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| 2 | -- ZLib for Ada thick binding. --
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| 3 | -- --
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| 4 | -- Copyright (C) 2002-2004 Dmitriy Anisimkov --
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| 5 | -- --
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| 6 | -- This library is free software; you can redistribute it and/or modify --
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| 7 | -- it under the terms of the GNU General Public License as published by --
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| 8 | -- the Free Software Foundation; either version 2 of the License, or (at --
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| 9 | -- your option) any later version. --
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| 10 | -- --
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| 11 | -- This library is distributed in the hope that it will be useful, but --
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| 12 | -- WITHOUT ANY WARRANTY; without even the implied warranty of --
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| 13 | -- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU --
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| 14 | -- General Public License for more details. --
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| 15 | -- --
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| 16 | -- You should have received a copy of the GNU General Public License --
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| 17 | -- along with this library; if not, write to the Free Software Foundation, --
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| 18 | -- Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. --
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| 19 | -- --
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| 20 | -- As a special exception, if other files instantiate generics from this --
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| 21 | -- unit, or you link this unit with other files to produce an executable, --
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| 22 | -- this unit does not by itself cause the resulting executable to be --
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| 23 | -- covered by the GNU General Public License. This exception does not --
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| 24 | -- however invalidate any other reasons why the executable file might be --
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| 25 | -- covered by the GNU Public License. --
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| 26 | ------------------------------------------------------------------------------
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| 27 |
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| 28 | -- $Id: zlib.ads,v 1.26 2004/09/06 06:53:19 vagul Exp $
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| 29 |
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| 30 | with Ada.Streams;
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| 31 |
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| 32 | with Interfaces;
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| 33 |
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| 34 | package ZLib is
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| 35 |
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| 36 | ZLib_Error : exception;
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| 37 | Status_Error : exception;
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| 38 |
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| 39 | type Compression_Level is new Integer range -1 .. 9;
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| 40 |
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| 41 | type Flush_Mode is private;
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| 42 |
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| 43 | type Compression_Method is private;
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| 44 |
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| 45 | type Window_Bits_Type is new Integer range 8 .. 15;
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| 46 |
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| 47 | type Memory_Level_Type is new Integer range 1 .. 9;
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| 48 |
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| 49 | type Unsigned_32 is new Interfaces.Unsigned_32;
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| 50 |
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| 51 | type Strategy_Type is private;
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| 52 |
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| 53 | type Header_Type is (None, Auto, Default, GZip);
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| 54 | -- Header type usage have a some limitation for inflate.
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| 55 | -- See comment for Inflate_Init.
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| 56 |
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| 57 | subtype Count is Ada.Streams.Stream_Element_Count;
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| 58 |
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| 59 | Default_Memory_Level : constant Memory_Level_Type := 8;
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| 60 | Default_Window_Bits : constant Window_Bits_Type := 15;
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| 61 |
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| 62 | ----------------------------------
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| 63 | -- Compression method constants --
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| 64 | ----------------------------------
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| 65 |
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| 66 | Deflated : constant Compression_Method;
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| 67 | -- Only one method allowed in this ZLib version
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| 68 |
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| 69 | ---------------------------------
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| 70 | -- Compression level constants --
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| 71 | ---------------------------------
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| 72 |
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| 73 | No_Compression : constant Compression_Level := 0;
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| 74 | Best_Speed : constant Compression_Level := 1;
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| 75 | Best_Compression : constant Compression_Level := 9;
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| 76 | Default_Compression : constant Compression_Level := -1;
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| 77 |
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| 78 | --------------------------
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| 79 | -- Flush mode constants --
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| 80 | --------------------------
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| 81 |
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| 82 | No_Flush : constant Flush_Mode;
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| 83 | -- Regular way for compression, no flush
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| 84 |
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| 85 | Partial_Flush : constant Flush_Mode;
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| 86 | -- Will be removed, use Z_SYNC_FLUSH instead
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| 87 |
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| 88 | Sync_Flush : constant Flush_Mode;
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| 89 | -- All pending output is flushed to the output buffer and the output
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| 90 | -- is aligned on a byte boundary, so that the decompressor can get all
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| 91 | -- input data available so far. (In particular avail_in is zero after the
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| 92 | -- call if enough output space has been provided before the call.)
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| 93 | -- Flushing may degrade compression for some compression algorithms and so
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| 94 | -- it should be used only when necessary.
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| 95 |
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| 96 | Block_Flush : constant Flush_Mode;
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| 97 | -- Z_BLOCK requests that inflate() stop
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| 98 | -- if and when it get to the next deflate block boundary. When decoding the
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| 99 | -- zlib or gzip format, this will cause inflate() to return immediately
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| 100 | -- after the header and before the first block. When doing a raw inflate,
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| 101 | -- inflate() will go ahead and process the first block, and will return
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| 102 | -- when it gets to the end of that block, or when it runs out of data.
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| 103 |
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| 104 | Full_Flush : constant Flush_Mode;
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| 105 | -- All output is flushed as with SYNC_FLUSH, and the compression state
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| 106 | -- is reset so that decompression can restart from this point if previous
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| 107 | -- compressed data has been damaged or if random access is desired. Using
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| 108 | -- Full_Flush too often can seriously degrade the compression.
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| 109 |
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| 110 | Finish : constant Flush_Mode;
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| 111 | -- Just for tell the compressor that input data is complete.
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| 112 |
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| 113 | ------------------------------------
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| 114 | -- Compression strategy constants --
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| 115 | ------------------------------------
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| 116 |
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| 117 | -- RLE stategy could be used only in version 1.2.0 and later.
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| 118 |
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| 119 | Filtered : constant Strategy_Type;
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| 120 | Huffman_Only : constant Strategy_Type;
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| 121 | RLE : constant Strategy_Type;
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| 122 | Default_Strategy : constant Strategy_Type;
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| 123 |
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| 124 | Default_Buffer_Size : constant := 4096;
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| 125 |
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| 126 | type Filter_Type is tagged limited private;
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| 127 | -- The filter is for compression and for decompression.
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| 128 | -- The usage of the type is depend of its initialization.
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| 129 |
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| 130 | function Version return String;
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| 131 | pragma Inline (Version);
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| 132 | -- Return string representation of the ZLib version.
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| 133 |
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| 134 | procedure Deflate_Init
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| 135 | (Filter : in out Filter_Type;
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| 136 | Level : in Compression_Level := Default_Compression;
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| 137 | Strategy : in Strategy_Type := Default_Strategy;
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| 138 | Method : in Compression_Method := Deflated;
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| 139 | Window_Bits : in Window_Bits_Type := Default_Window_Bits;
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| 140 | Memory_Level : in Memory_Level_Type := Default_Memory_Level;
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| 141 | Header : in Header_Type := Default);
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| 142 | -- Compressor initialization.
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| 143 | -- When Header parameter is Auto or Default, then default zlib header
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| 144 | -- would be provided for compressed data.
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| 145 | -- When Header is GZip, then gzip header would be set instead of
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| 146 | -- default header.
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| 147 | -- When Header is None, no header would be set for compressed data.
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| 148 |
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| 149 | procedure Inflate_Init
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| 150 | (Filter : in out Filter_Type;
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| 151 | Window_Bits : in Window_Bits_Type := Default_Window_Bits;
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| 152 | Header : in Header_Type := Default);
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| 153 | -- Decompressor initialization.
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| 154 | -- Default header type mean that ZLib default header is expecting in the
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| 155 | -- input compressed stream.
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| 156 | -- Header type None mean that no header is expecting in the input stream.
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| 157 | -- GZip header type mean that GZip header is expecting in the
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| 158 | -- input compressed stream.
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| 159 | -- Auto header type mean that header type (GZip or Native) would be
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| 160 | -- detected automatically in the input stream.
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| 161 | -- Note that header types parameter values None, GZip and Auto are
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| 162 | -- supported for inflate routine only in ZLib versions 1.2.0.2 and later.
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| 163 | -- Deflate_Init is supporting all header types.
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| 164 |
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| 165 | function Is_Open (Filter : in Filter_Type) return Boolean;
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| 166 | pragma Inline (Is_Open);
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| 167 | -- Is the filter opened for compression or decompression.
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| 168 |
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| 169 | procedure Close
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| 170 | (Filter : in out Filter_Type;
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| 171 | Ignore_Error : in Boolean := False);
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| 172 | -- Closing the compression or decompressor.
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| 173 | -- If stream is closing before the complete and Ignore_Error is False,
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| 174 | -- The exception would be raised.
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| 175 |
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| 176 | generic
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| 177 | with procedure Data_In
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| 178 | (Item : out Ada.Streams.Stream_Element_Array;
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| 179 | Last : out Ada.Streams.Stream_Element_Offset);
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| 180 | with procedure Data_Out
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| 181 | (Item : in Ada.Streams.Stream_Element_Array);
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| 182 | procedure Generic_Translate
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| 183 | (Filter : in out Filter_Type;
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| 184 | In_Buffer_Size : in Integer := Default_Buffer_Size;
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| 185 | Out_Buffer_Size : in Integer := Default_Buffer_Size);
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| 186 | -- Compress/decompress data fetch from Data_In routine and pass the result
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| 187 | -- to the Data_Out routine. User should provide Data_In and Data_Out
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| 188 | -- for compression/decompression data flow.
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| 189 | -- Compression or decompression depend on Filter initialization.
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| 190 |
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| 191 | function Total_In (Filter : in Filter_Type) return Count;
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| 192 | pragma Inline (Total_In);
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| 193 | -- Returns total number of input bytes read so far
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| 194 |
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| 195 | function Total_Out (Filter : in Filter_Type) return Count;
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| 196 | pragma Inline (Total_Out);
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| 197 | -- Returns total number of bytes output so far
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| 198 |
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| 199 | function CRC32
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| 200 | (CRC : in Unsigned_32;
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| 201 | Data : in Ada.Streams.Stream_Element_Array)
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| 202 | return Unsigned_32;
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| 203 | pragma Inline (CRC32);
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| 204 | -- Compute CRC32, it could be necessary for make gzip format
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| 205 |
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| 206 | procedure CRC32
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| 207 | (CRC : in out Unsigned_32;
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| 208 | Data : in Ada.Streams.Stream_Element_Array);
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| 209 | pragma Inline (CRC32);
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| 210 | -- Compute CRC32, it could be necessary for make gzip format
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| 211 |
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| 212 | -------------------------------------------------
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| 213 | -- Below is more complex low level routines. --
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| 214 | -------------------------------------------------
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| 215 |
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| 216 | procedure Translate
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| 217 | (Filter : in out Filter_Type;
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| 218 | In_Data : in Ada.Streams.Stream_Element_Array;
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| 219 | In_Last : out Ada.Streams.Stream_Element_Offset;
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| 220 | Out_Data : out Ada.Streams.Stream_Element_Array;
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| 221 | Out_Last : out Ada.Streams.Stream_Element_Offset;
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| 222 | Flush : in Flush_Mode);
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| 223 | -- Compress/decompress the In_Data buffer and place the result into
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| 224 | -- Out_Data. In_Last is the index of last element from In_Data accepted by
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| 225 | -- the Filter. Out_Last is the last element of the received data from
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| 226 | -- Filter. To tell the filter that incoming data are complete put the
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| 227 | -- Flush parameter to Finish.
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| 228 |
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| 229 | function Stream_End (Filter : in Filter_Type) return Boolean;
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| 230 | pragma Inline (Stream_End);
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| 231 | -- Return the true when the stream is complete.
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| 232 |
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| 233 | procedure Flush
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| 234 | (Filter : in out Filter_Type;
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| 235 | Out_Data : out Ada.Streams.Stream_Element_Array;
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| 236 | Out_Last : out Ada.Streams.Stream_Element_Offset;
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| 237 | Flush : in Flush_Mode);
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| 238 | pragma Inline (Flush);
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| 239 | -- Flushing the data from the compressor.
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| 240 |
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| 241 | generic
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| 242 | with procedure Write
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| 243 | (Item : in Ada.Streams.Stream_Element_Array);
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| 244 | -- User should provide this routine for accept
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| 245 | -- compressed/decompressed data.
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| 246 |
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| 247 | Buffer_Size : in Ada.Streams.Stream_Element_Offset
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| 248 | := Default_Buffer_Size;
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| 249 | -- Buffer size for Write user routine.
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| 250 |
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| 251 | procedure Write
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| 252 | (Filter : in out Filter_Type;
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| 253 | Item : in Ada.Streams.Stream_Element_Array;
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| 254 | Flush : in Flush_Mode := No_Flush);
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| 255 | -- Compress/Decompress data from Item to the generic parameter procedure
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| 256 | -- Write. Output buffer size could be set in Buffer_Size generic parameter.
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| 257 |
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| 258 | generic
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| 259 | with procedure Read
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| 260 | (Item : out Ada.Streams.Stream_Element_Array;
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| 261 | Last : out Ada.Streams.Stream_Element_Offset);
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| 262 | -- User should provide data for compression/decompression
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| 263 | -- thru this routine.
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| 264 |
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| 265 | Buffer : in out Ada.Streams.Stream_Element_Array;
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| 266 | -- Buffer for keep remaining data from the previous
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| 267 | -- back read.
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| 268 |
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| 269 | Rest_First, Rest_Last : in out Ada.Streams.Stream_Element_Offset;
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| 270 | -- Rest_First have to be initialized to Buffer'Last + 1
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| 271 | -- Rest_Last have to be initialized to Buffer'Last
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| 272 | -- before usage.
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| 273 |
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| 274 | Allow_Read_Some : in Boolean := False;
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| 275 | -- Is it allowed to return Last < Item'Last before end of data.
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| 276 |
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| 277 | procedure Read
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| 278 | (Filter : in out Filter_Type;
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| 279 | Item : out Ada.Streams.Stream_Element_Array;
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| 280 | Last : out Ada.Streams.Stream_Element_Offset;
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| 281 | Flush : in Flush_Mode := No_Flush);
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| 282 | -- Compress/Decompress data from generic parameter procedure Read to the
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| 283 | -- Item. User should provide Buffer and initialized Rest_First, Rest_Last
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| 284 | -- indicators. If Allow_Read_Some is True, Read routines could return
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| 285 | -- Last < Item'Last only at end of stream.
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| 286 |
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| 287 | private
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| 288 |
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| 289 | use Ada.Streams;
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| 290 |
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| 291 | pragma Assert (Ada.Streams.Stream_Element'Size = 8);
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| 292 | pragma Assert (Ada.Streams.Stream_Element'Modulus = 2**8);
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| 293 |
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| 294 | type Flush_Mode is new Integer range 0 .. 5;
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| 295 |
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| 296 | type Compression_Method is new Integer range 8 .. 8;
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| 297 |
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| 298 | type Strategy_Type is new Integer range 0 .. 3;
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| 299 |
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| 300 | No_Flush : constant Flush_Mode := 0;
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| 301 | Partial_Flush : constant Flush_Mode := 1;
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| 302 | Sync_Flush : constant Flush_Mode := 2;
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| 303 | Full_Flush : constant Flush_Mode := 3;
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| 304 | Finish : constant Flush_Mode := 4;
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| 305 | Block_Flush : constant Flush_Mode := 5;
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| 306 |
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| 307 | Filtered : constant Strategy_Type := 1;
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| 308 | Huffman_Only : constant Strategy_Type := 2;
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| 309 | RLE : constant Strategy_Type := 3;
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| 310 | Default_Strategy : constant Strategy_Type := 0;
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| 311 |
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| 312 | Deflated : constant Compression_Method := 8;
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| 313 |
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| 314 | type Z_Stream;
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| 315 |
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| 316 | type Z_Stream_Access is access all Z_Stream;
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| 317 |
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| 318 | type Filter_Type is tagged limited record
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| 319 | Strm : Z_Stream_Access;
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| 320 | Compression : Boolean;
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| 321 | Stream_End : Boolean;
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| 322 | Header : Header_Type;
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| 323 | CRC : Unsigned_32;
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| 324 | Offset : Stream_Element_Offset;
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| 325 | -- Offset for gzip header/footer output.
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| 326 | end record;
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| 327 |
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| 328 | end ZLib;
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