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);
|
---|
447 | }
|
---|
448 | }
|
---|
449 |
|
---|
450 | template<typename Source>
|
---|
451 | void read_footer(Source& src)
|
---|
452 | {
|
---|
453 | typename base_type::string_type footer =
|
---|
454 | this->unconsumed_input();
|
---|
455 | int c;
|
---|
456 | while (!is_eof(c = boost::iostreams::get(src)))
|
---|
457 | footer += c;
|
---|
458 | detail::range_adapter<input, std::string>
|
---|
459 | rng(footer.begin(), footer.end());
|
---|
460 | if (read_uint32(rng, gzip::bad_footer) != this->crc())
|
---|
461 | throw gzip_error(gzip::bad_crc);
|
---|
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
|
---|