[857] | 1 | // (C) Copyright Jonathan Turkanis 2003.
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| 2 | // Distributed under the Boost Software License, Version 1.0. (See accompanying
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| 3 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
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| 4 |
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| 5 | // See http://www.boost.org/libs/iostreams for documentation.
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| 6 |
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| 7 | // Contains the definitions of the class templates gzip_compressor and
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| 8 | // gzip_decompressor for reading and writing files in the gzip file format
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| 9 | // (RFC 1952). Based in part on work of Jonathan de Halleux; see [...]
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| 10 |
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| 11 | #ifndef BOOST_IOSTREAMS_GZIP_HPP_INCLUDED
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| 12 | #define BOOST_IOSTREAMS_GZIP_HPP_INCLUDED
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| 13 |
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| 14 | #if defined(_MSC_VER) && (_MSC_VER >= 1020)
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| 15 | # pragma once
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| 16 | #endif
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| 17 |
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| 18 | #include <boost/config.hpp> // STATIC_CONSTANT, STDC_NAMESPACE,
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| 19 | // DINKUMWARE_STDLIB, __STL_CONFIG_H.
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| 20 | #include <algorithm> // min.
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| 21 | #include <cstdio> // EOF.
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| 22 | #include <cstddef> // size_t.
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| 23 | #include <ctime> // std::time_t.
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| 24 | #include <memory> // allocator.
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| 25 | #include <boost/config.hpp> // Put size_t in std.
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| 26 | #include <boost/detail/workaround.hpp>
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| 27 | #include <boost/cstdint.hpp> // uint8_t, uint32_t.
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| 28 | #include <boost/iostreams/constants.hpp> // buffer size.
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| 29 | #include <boost/iostreams/detail/adapter/non_blocking_adapter.hpp>
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| 30 | #include <boost/iostreams/detail/adapter/range_adapter.hpp>
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| 31 | #include <boost/iostreams/detail/char_traits.hpp>
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| 32 | #include <boost/iostreams/detail/ios.hpp> // failure.
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| 33 | #include <boost/iostreams/operations.hpp>
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| 34 | #include <boost/iostreams/device/back_inserter.hpp>
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| 35 | #include <boost/iostreams/filter/zlib.hpp>
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| 36 | #include <boost/iostreams/pipeline.hpp>
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| 37 |
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| 38 | // Must come last.
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| 39 | #if defined(BOOST_MSVC)
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| 40 | # pragma warning(push)
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| 41 | # pragma warning(disable: 4309) // Truncation of constant value.
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| 42 | #endif
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| 43 |
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| 44 | #ifdef BOOST_NO_STDC_NAMESPACE
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| 45 | namespace std { using ::time_t; }
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| 46 | #endif
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| 47 |
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| 48 | namespace boost { namespace iostreams {
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| 49 |
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| 50 | namespace gzip {
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| 51 |
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| 52 | using namespace boost::iostreams::zlib;
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| 53 |
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| 54 | // Error codes used by gzip_error.
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| 55 |
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| 56 | const int zlib_error = 1;
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| 57 | const int bad_crc = 2; // Recorded crc doesn't match data.
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| 58 | const int bad_length = 3; // Recorded length doesn't match data.
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| 59 | const int bad_header = 4; // Malformed header.
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| 60 | const int bad_footer = 5; // Malformed footer.
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| 61 |
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| 62 | namespace magic {
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| 63 |
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| 64 | // Magic numbers used by gzip header.
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| 65 |
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| 66 | const int id1 = 0x1f;
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| 67 | const int id2 = 0x8b;
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| 68 |
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| 69 | } // End namespace magic.
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| 70 |
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| 71 | namespace method {
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| 72 |
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| 73 | // Codes used for the 'CM' byte of the gzip header.
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| 74 |
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| 75 | const int deflate = 8;
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| 76 |
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| 77 | } // End namespace method.
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| 78 |
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| 79 | namespace flags {
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| 80 |
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| 81 | // Codes used for the 'FLG' byte of the gzip header.
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| 82 |
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| 83 | const int text = 1;
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| 84 | const int header_crc = 2;
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| 85 | const int extra = 4;
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| 86 | const int name = 8;
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| 87 | const int comment = 16;
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| 88 |
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| 89 | } // End namespace flags.
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| 90 |
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| 91 | namespace extra_flags {
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| 92 |
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| 93 | // Codes used for the 'XFL' byte of the gzip header.
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| 94 |
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| 95 | const int best_compression = 2;
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| 96 | const int best_speed = 4;
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| 97 |
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| 98 | } // End namespace extra_flags.
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| 99 |
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| 100 | // Codes used for the 'OS' byte of the gzip header.
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| 101 |
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| 102 | const int os_fat = 0;
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| 103 | const int os_amiga = 1;
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| 104 | const int os_vms = 2;
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| 105 | const int os_unix = 3;
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| 106 | const int os_vm_cms = 4;
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| 107 | const int os_atari = 5;
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| 108 | const int os_hpfs = 6;
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| 109 | const int os_macintosh = 7;
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| 110 | const int os_z_system = 8;
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| 111 | const int os_cp_m = 9;
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| 112 | const int os_tops_20 = 10;
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| 113 | const int os_ntfs = 11;
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| 114 | const int os_qdos = 12;
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| 115 | const int os_acorn = 13;
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| 116 | const int os_unknown = 255;
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| 117 |
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| 118 | } // End namespace gzip.
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| 119 |
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| 120 | //
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| 121 | // Class name: gzip_params.
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| 122 | // Description: Subclass of zlib_params with an additional field
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| 123 | // representing a file name.
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| 124 | //
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| 125 | struct gzip_params : zlib_params {
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| 126 |
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| 127 | // Non-explicit constructor.
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| 128 | gzip_params( int level = gzip::default_compression,
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| 129 | int method = gzip::deflated,
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| 130 | int window_bits = gzip::default_window_bits,
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| 131 | int mem_level = gzip::default_mem_level,
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| 132 | int strategy = gzip::default_strategy,
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| 133 | std::string file_name = "",
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| 134 | std::string comment = "",
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| 135 | std::time_t mtime = 0 )
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| 136 | : zlib_params(level, method, window_bits, mem_level, strategy),
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| 137 | file_name(file_name), mtime(mtime)
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| 138 | { }
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| 139 | std::string file_name;
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| 140 | std::string comment;
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| 141 | std::time_t mtime;
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| 142 | };
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| 143 |
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| 144 | //
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| 145 | // Class name: gzip_error.
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| 146 | // Description: Subclass of std::ios_base::failure thrown to indicate
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| 147 | // zlib errors other than out-of-memory conditions.
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| 148 | //
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| 149 | class gzip_error : public BOOST_IOSTREAMS_FAILURE {
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| 150 | public:
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| 151 | explicit gzip_error(int error)
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| 152 | : BOOST_IOSTREAMS_FAILURE("gzip error"),
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| 153 | error_(error), zlib_error_code_(zlib::okay) { }
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| 154 | explicit gzip_error(const zlib_error& e)
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| 155 | : BOOST_IOSTREAMS_FAILURE("gzip error"),
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| 156 | error_(gzip::zlib_error), zlib_error_code_(e.error())
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| 157 | { }
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| 158 | int error() const { return error_; }
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| 159 | int zlib_error_code() const { return zlib_error_code_; }
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| 160 | private:
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| 161 | int error_;
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| 162 | int zlib_error_code_;
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| 163 | };
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| 164 |
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| 165 | //
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| 166 | // Template name: gzip_compressor
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| 167 | // Description: Model of OutputFilter implementing compression in the
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| 168 | // gzip format.
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| 169 | //
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| 170 | template<typename Alloc = std::allocator<char> >
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| 171 | class basic_gzip_compressor : basic_zlib_compressor<Alloc> {
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| 172 | private:
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| 173 | typedef basic_zlib_compressor<Alloc> base_type;
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| 174 | public:
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| 175 | typedef char char_type;
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| 176 | struct category
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| 177 | : dual_use,
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| 178 | filter_tag,
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| 179 | multichar_tag,
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| 180 | closable_tag
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| 181 | { };
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| 182 | basic_gzip_compressor( const gzip_params& = gzip::default_compression,
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| 183 | int buffer_size = default_device_buffer_size );
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| 184 |
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| 185 | template<typename Source>
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| 186 | std::streamsize read(Source& src, char_type* s, std::streamsize n)
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| 187 | {
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| 188 | using namespace std;
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| 189 | streamsize result = 0;
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| 190 |
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| 191 | // Read header.
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| 192 | if (!(flags_ & f_header_done))
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| 193 | result += read_string(s, n, header_);
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| 194 |
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| 195 | // Read body.
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| 196 | if (!(flags_ & f_body_done)) {
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| 197 |
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| 198 | // Read from basic_zlib_filter.
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| 199 | streamsize amt = base_type::read(src, s + result, n - result);
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| 200 | if (amt != -1) {
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| 201 | result += amt;
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| 202 | if (amt < n - result) { // Double-check for EOF.
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| 203 | amt = base_type::read(src, s + result, n - result);
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| 204 | if (amt != -1)
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| 205 | result += amt;
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| 206 | }
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| 207 | }
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| 208 | if (amt == -1)
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| 209 | prepare_footer();
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| 210 | }
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| 211 |
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| 212 | // Read footer.
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| 213 | if ((flags_ & f_body_done) != 0 && result < n)
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| 214 | result += read_string(s + result, n - result, footer_);
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| 215 |
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| 216 | return result != 0 ? result : -1;
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| 217 | }
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| 218 |
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| 219 | template<typename Sink>
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| 220 | std::streamsize write(Sink& snk, const char_type* s, std::streamsize n)
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| 221 | {
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| 222 | if (!(flags_ & f_header_done)) {
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| 223 | std::streamsize amt =
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| 224 | static_cast<std::streamsize>(header_.size() - offset_);
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| 225 | offset_ += boost::iostreams::write(snk, header_.data() + offset_, amt);
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| 226 | if (offset_ == header_.size())
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| 227 | flags_ |= f_header_done;
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| 228 | else
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| 229 | return 0;
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| 230 | }
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| 231 | return base_type::write(snk, s, n);
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| 232 | }
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| 233 |
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| 234 | template<typename Sink>
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| 235 | void close(Sink& snk, BOOST_IOS::openmode m)
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| 236 | {
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| 237 | namespace io = boost::iostreams;
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| 238 |
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| 239 | if (m & BOOST_IOS::out) {
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| 240 |
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| 241 | // Close zlib compressor.
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| 242 | base_type::close(snk, BOOST_IOS::out);
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| 243 |
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| 244 | if (flags_ & f_header_done) {
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| 245 |
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| 246 | // Write final fields of gzip file format.
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| 247 | write_long(this->crc(), snk);
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| 248 | write_long(this->total_in(), snk);
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| 249 | }
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| 250 |
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| 251 | }
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| 252 | #if BOOST_WORKAROUND(__GNUC__, == 2) && defined(__STL_CONFIG_H) || \
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| 253 | BOOST_WORKAROUND(BOOST_DINKUMWARE_STDLIB, == 1) \
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| 254 | /**/
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| 255 | footer_.erase(0, std::string::npos);
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| 256 | #else
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| 257 | footer_.clear();
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| 258 | #endif
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| 259 | offset_ = 0;
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| 260 | flags_ = 0;
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| 261 | }
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| 262 | private:
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| 263 | static gzip_params normalize_params(gzip_params p);
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| 264 | void prepare_footer();
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| 265 | std::streamsize read_string(char* s, std::streamsize n, std::string& str);
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| 266 |
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| 267 | template<typename Sink>
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| 268 | static void write_long(long n, Sink& next)
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| 269 | {
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| 270 | boost::iostreams::put(next, static_cast<char>(0xFF & n));
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| 271 | boost::iostreams::put(next, static_cast<char>(0xFF & (n >> 8)));
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| 272 | boost::iostreams::put(next, static_cast<char>(0xFF & (n >> 16)));
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| 273 | boost::iostreams::put(next, static_cast<char>(0xFF & (n >> 24)));
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| 274 | }
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| 275 |
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| 276 | enum flag_type {
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| 277 | f_header_done = 1,
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| 278 | f_body_done = f_header_done << 1,
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| 279 | f_footer_done = f_body_done << 1
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| 280 | };
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| 281 | std::string header_;
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| 282 | std::string footer_;
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| 283 | std::size_t offset_;
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| 284 | int flags_;
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| 285 | };
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| 286 | BOOST_IOSTREAMS_PIPABLE(basic_gzip_compressor, 1)
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| 287 |
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| 288 | typedef basic_gzip_compressor<> gzip_compressor;
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| 289 |
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| 290 | //
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| 291 | // Template name: basic_gzip_decompressor
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| 292 | // Description: Model of InputFilter implementing compression in the
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| 293 | // gzip format.
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| 294 | //
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| 295 | template<typename Alloc = std::allocator<char> >
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| 296 | class basic_gzip_decompressor : basic_zlib_decompressor<Alloc> {
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| 297 | public:
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| 298 | typedef char char_type;
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| 299 | struct category
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| 300 | : multichar_input_filter_tag,
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| 301 | closable_tag
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| 302 | { };
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| 303 | basic_gzip_decompressor( int window_bits = gzip::default_window_bits,
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| 304 | int buffer_size = default_device_buffer_size );
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| 305 |
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| 306 | template<typename Source>
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| 307 | std::streamsize read(Source& src, char_type* s, std::streamsize n)
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| 308 | {
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| 309 | if ((flags_ & f_header_read) == 0) {
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| 310 | non_blocking_adapter<Source> nb(src);
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| 311 | read_header(nb);
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| 312 | flags_ |= f_header_read;
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| 313 | }
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| 314 |
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| 315 | if ((flags_ & f_footer_read) != 0)
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| 316 | return -1;
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| 317 |
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| 318 | try {
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| 319 | std::streamsize result = 0;
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| 320 | std::streamsize amt;
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| 321 | if ((amt = base_type::read(src, s, n)) != -1) {
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| 322 | result += amt;
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| 323 | if (amt < n) { // Double check for EOF.
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| 324 | amt = base_type::read(src, s + result, n - result);
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| 325 | if (amt != -1)
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| 326 | result += amt;
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| 327 | }
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| 328 | }
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| 329 | if (amt == -1) {
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| 330 | non_blocking_adapter<Source> nb(src);
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| 331 | read_footer(nb);
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| 332 | flags_ |= f_footer_read;
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| 333 | }
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| 334 | return result;
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| 335 | } catch (const zlib_error& e) {
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| 336 | throw gzip_error(e);
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| 337 | }
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| 338 | }
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| 339 |
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| 340 | template<typename Source>
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| 341 | void close(Source& src)
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| 342 | {
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| 343 | try {
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| 344 | base_type::close(src, BOOST_IOS::in);
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| 345 | flags_ = 0;
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| 346 | } catch (const zlib_error& e) {
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| 347 | throw gzip_error(e);
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| 348 | }
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| 349 | }
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| 350 |
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| 351 | std::string file_name() const { return file_name_; }
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| 352 | std::string comment() const { return comment_; }
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| 353 | bool text() const { return (flags_ & gzip::flags::text) != 0; }
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| 354 | int os() const { return os_; }
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| 355 | std::time_t mtime() const { return mtime_; }
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| 356 | private:
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| 357 | typedef basic_zlib_decompressor<Alloc> base_type;
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| 358 | typedef BOOST_IOSTREAMS_CHAR_TRAITS(char) traits_type;
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| 359 | static bool is_eof(int c) { return traits_type::eq_int_type(c, EOF); }
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| 360 | static gzip_params make_params(int window_bits);
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| 361 |
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| 362 | template<typename Source>
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| 363 | static uint8_t read_uint8(Source& src, int error)
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| 364 | {
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| 365 | int c;
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| 366 | if ((c = boost::iostreams::get(src)) == EOF || c == WOULD_BLOCK)
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| 367 | throw gzip_error(error);
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| 368 | return static_cast<uint8_t>(traits_type::to_char_type(c));
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| 369 | }
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| 370 |
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| 371 | template<typename Source>
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| 372 | static uint32_t read_uint32(Source& src, int error)
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| 373 | {
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| 374 | uint8_t b1 = read_uint8(src, error);
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| 375 | uint8_t b2 = read_uint8(src, error);
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| 376 | uint8_t b3 = read_uint8(src, error);
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| 377 | uint8_t b4 = read_uint8(src, error);
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| 378 | return b1 + (b2 << 8) + (b3 << 16) + (b4 << 24);
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| 379 | }
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| 380 |
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| 381 | template<typename Source>
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| 382 | std::string read_string(Source& src)
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| 383 | {
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| 384 | std::string result;
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| 385 | while (true) {
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| 386 | int c;
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| 387 | if (is_eof(c = boost::iostreams::get(src)))
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| 388 | throw gzip_error(gzip::bad_header);
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| 389 | else if (c == 0)
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| 390 | return result;
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| 391 | else
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| 392 | result += static_cast<char>(c);
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| 393 | }
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| 394 | }
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| 395 |
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| 396 | template<typename Source>
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| 397 | void read_header(Source& src) // Source is non-blocking.
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| 398 | {
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| 399 | // Reset saved values.
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| 400 | #if BOOST_WORKAROUND(__GNUC__, == 2) && defined(__STL_CONFIG_H) || \
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| 401 | BOOST_WORKAROUND(BOOST_DINKUMWARE_STDLIB, == 1) \
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| 402 | /**/
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| 403 | file_name_.erase(0, std::string::npos);
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| 404 | comment_.erase(0, std::string::npos);
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| 405 | #else
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| 406 | file_name_.clear();
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| 407 | comment_.clear();
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| 408 | #endif
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| 409 | os_ = gzip::os_unknown;
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| 410 | mtime_ = 0;
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| 411 |
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| 412 | int flags;
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| 413 |
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| 414 | // Read header, without checking header crc.
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| 415 | if ( boost::iostreams::get(src) != gzip::magic::id1 || // ID1.
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| 416 | boost::iostreams::get(src) != gzip::magic::id2 || // ID2.
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| 417 | is_eof(boost::iostreams::get(src)) || // CM.
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| 418 | is_eof(flags = boost::iostreams::get(src)) ) // FLG.
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| 419 | {
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| 420 | throw gzip_error(gzip::bad_header);
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| 421 | }
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| 422 | mtime_ = read_uint32(src, gzip::bad_header); // MTIME.
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| 423 | read_uint8(src, gzip::bad_header); // XFL.
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| 424 | os_ = read_uint8(src, gzip::bad_header); // OS.
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| 425 | if (flags & boost::iostreams::gzip::flags::text)
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| 426 | flags_ |= f_text;
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| 427 |
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| 428 | // Skip extra field. (From J. Halleaux; see note at top.)
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| 429 | if (flags & gzip::flags::extra) {
|
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| 430 | int length =
|
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| 431 | static_cast<int>(
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| 432 | read_uint8(src, gzip::bad_header) +
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| 433 | (read_uint8(src, gzip::bad_header) << 8)
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| 434 | );
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| 435 | // length is garbage if EOF but the loop below will quit anyway.
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| 436 | do { }
|
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| 437 | while (length-- != 0 && !is_eof(boost::iostreams::get(src)));
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| 438 | }
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| 439 |
|
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| 440 | if (flags & gzip::flags::name) // Read file name.
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| 441 | file_name_ = read_string(src);
|
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| 442 | if (flags & gzip::flags::comment) // Read comment.
|
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| 443 | comment_ = read_string(src);
|
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| 444 | if (flags & gzip::flags::header_crc) { // Skip header crc.
|
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| 445 | read_uint8(src, gzip::bad_header);
|
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| 446 | read_uint8(src, gzip::bad_header);
|
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| 447 | }
|
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| 448 | }
|
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| 449 |
|
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| 450 | template<typename Source>
|
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| 451 | void read_footer(Source& src)
|
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| 452 | {
|
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| 453 | typename base_type::string_type footer =
|
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| 454 | this->unconsumed_input();
|
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| 455 | int c;
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| 456 | while (!is_eof(c = boost::iostreams::get(src)))
|
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| 457 | footer += c;
|
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| 458 | detail::range_adapter<input, std::string>
|
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| 459 | rng(footer.begin(), footer.end());
|
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| 460 | if (read_uint32(rng, gzip::bad_footer) != this->crc())
|
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| 461 | throw gzip_error(gzip::bad_crc);
|
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| 462 | if (static_cast<int>(read_uint32(rng, gzip::bad_footer)) != this->total_out())
|
---|
| 463 | throw gzip_error(gzip::bad_length);
|
---|
| 464 | }
|
---|
| 465 | enum flag_type {
|
---|
| 466 | f_header_read = 1,
|
---|
| 467 | f_footer_read = f_header_read << 1,
|
---|
| 468 | f_text = f_footer_read << 1
|
---|
| 469 | };
|
---|
| 470 | std::string file_name_;
|
---|
| 471 | std::string comment_;
|
---|
| 472 | int os_;
|
---|
| 473 | std::time_t mtime_;
|
---|
| 474 | int flags_;
|
---|
| 475 | };
|
---|
| 476 | BOOST_IOSTREAMS_PIPABLE(basic_gzip_decompressor, 1)
|
---|
| 477 |
|
---|
| 478 | typedef basic_gzip_decompressor<> gzip_decompressor;
|
---|
| 479 |
|
---|
| 480 | //------------------Implementation of gzip_compressor-------------------------//
|
---|
| 481 |
|
---|
| 482 | template<typename Alloc>
|
---|
| 483 | basic_gzip_compressor<Alloc>::basic_gzip_compressor
|
---|
| 484 | (const gzip_params& p, int buffer_size)
|
---|
| 485 | : base_type(normalize_params(p), buffer_size),
|
---|
| 486 | offset_(0), flags_(0)
|
---|
| 487 | {
|
---|
| 488 | // Calculate gzip header.
|
---|
| 489 | bool has_name = !p.file_name.empty();
|
---|
| 490 | bool has_comment = !p.comment.empty();
|
---|
| 491 |
|
---|
| 492 | std::string::size_type length =
|
---|
| 493 | 10 +
|
---|
| 494 | (has_name ? p.file_name.size() + 1 : 0) +
|
---|
| 495 | (has_comment ? p.comment.size() + 1 : 0);
|
---|
| 496 | // + 2; // Header crc confuses gunzip.
|
---|
| 497 | int flags =
|
---|
| 498 | //gzip::flags::header_crc +
|
---|
| 499 | (has_name ? gzip::flags::name : 0) +
|
---|
| 500 | (has_comment ? gzip::flags::comment : 0);
|
---|
| 501 | int extra_flags =
|
---|
| 502 | ( p.level == zlib::best_compression ?
|
---|
| 503 | gzip::extra_flags::best_compression :
|
---|
| 504 | 0 ) +
|
---|
| 505 | ( p.level == zlib::best_speed ?
|
---|
| 506 | gzip::extra_flags::best_speed :
|
---|
| 507 | 0 );
|
---|
| 508 | header_.reserve(length);
|
---|
| 509 | header_ += gzip::magic::id1; // ID1.
|
---|
| 510 | header_ += gzip::magic::id2; // ID2.
|
---|
| 511 | header_ += gzip::method::deflate; // CM.
|
---|
| 512 | header_ += static_cast<char>(flags); // FLG.
|
---|
| 513 | header_ += static_cast<char>(0xFF & p.mtime); // MTIME.
|
---|
| 514 | header_ += static_cast<char>(0xFF & (p.mtime >> 8));
|
---|
| 515 | header_ += static_cast<char>(0xFF & (p.mtime >> 16));
|
---|
| 516 | header_ += static_cast<char>(0xFF & (p.mtime >> 24));
|
---|
| 517 | header_ += static_cast<char>(extra_flags); // XFL.
|
---|
| 518 | header_ += static_cast<char>(gzip::os_unknown); // OS.
|
---|
| 519 | if (has_name) {
|
---|
| 520 | header_ += p.file_name;
|
---|
| 521 | header_ += '\0';
|
---|
| 522 | }
|
---|
| 523 | if (has_comment) {
|
---|
| 524 | header_ += p.comment;
|
---|
| 525 | header_ += '\0';
|
---|
| 526 | }
|
---|
| 527 | }
|
---|
| 528 |
|
---|
| 529 | template<typename Alloc>
|
---|
| 530 | gzip_params basic_gzip_compressor<Alloc>::normalize_params(gzip_params p)
|
---|
| 531 | {
|
---|
| 532 | p.noheader = true;
|
---|
| 533 | p.calculate_crc = true;
|
---|
| 534 | return p;
|
---|
| 535 | }
|
---|
| 536 |
|
---|
| 537 | template<typename Alloc>
|
---|
| 538 | void basic_gzip_compressor<Alloc>::prepare_footer()
|
---|
| 539 | {
|
---|
| 540 | boost::iostreams::back_insert_device<std::string> out(footer_);
|
---|
| 541 | write_long(this->crc(), out);
|
---|
| 542 | write_long(this->total_in(), out);
|
---|
| 543 | flags_ |= f_body_done;
|
---|
| 544 | offset_ = 0;
|
---|
| 545 | }
|
---|
| 546 |
|
---|
| 547 | template<typename Alloc>
|
---|
| 548 | std::streamsize basic_gzip_compressor<Alloc>::read_string
|
---|
| 549 | (char* s, std::streamsize n, std::string& str)
|
---|
| 550 | {
|
---|
| 551 | using namespace std;
|
---|
| 552 | streamsize avail =
|
---|
| 553 | static_cast<streamsize>(str.size() - offset_);
|
---|
| 554 | streamsize amt = (std::min)(avail, n);
|
---|
| 555 | std::copy( str.data() + offset_,
|
---|
| 556 | str.data() + offset_ + amt,
|
---|
| 557 | s );
|
---|
| 558 | offset_ += amt;
|
---|
| 559 | if ( !(flags_ & f_header_done) &&
|
---|
| 560 | offset_ == static_cast<std::size_t>(str.size()) )
|
---|
| 561 | {
|
---|
| 562 | flags_ |= f_header_done;
|
---|
| 563 | }
|
---|
| 564 | return amt;
|
---|
| 565 | }
|
---|
| 566 |
|
---|
| 567 | //------------------Implementation of gzip_decompressor-----------------------//
|
---|
| 568 |
|
---|
| 569 | template<typename Alloc>
|
---|
| 570 | basic_gzip_decompressor<Alloc>::basic_gzip_decompressor
|
---|
| 571 | (int window_bits, int buffer_size)
|
---|
| 572 | : base_type(make_params(window_bits), buffer_size),
|
---|
| 573 | os_(gzip::os_unknown), mtime_(0), flags_(0)
|
---|
| 574 | { }
|
---|
| 575 |
|
---|
| 576 | template<typename Alloc>
|
---|
| 577 | gzip_params basic_gzip_decompressor<Alloc>::make_params(int window_bits)
|
---|
| 578 | {
|
---|
| 579 | gzip_params p;
|
---|
| 580 | p.window_bits = window_bits;
|
---|
| 581 | p.noheader = true;
|
---|
| 582 | p.calculate_crc = true;
|
---|
| 583 | return p;
|
---|
| 584 | }
|
---|
| 585 |
|
---|
| 586 | //----------------------------------------------------------------------------//
|
---|
| 587 |
|
---|
| 588 | } } // End namespaces iostreams, boost.
|
---|
| 589 |
|
---|
| 590 | #if defined(BOOST_MSVC)
|
---|
| 591 | # pragma warning(pop)
|
---|
| 592 | #endif
|
---|
| 593 |
|
---|
| 594 | #endif // #ifndef BOOST_IOSTREAMS_GZIP_HPP_INCLUDED
|
---|