1 | /* |
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2 | * Copyright (c) 2012, Chris Johns <chrisj@rtems.org> |
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3 | * |
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4 | * Permission to use, copy, modify, and/or distribute this software for any |
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5 | * purpose with or without fee is hereby granted, provided that the above |
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6 | * copyright notice and this permission notice appear in all copies. |
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7 | * |
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8 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
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9 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
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10 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
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11 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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12 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
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13 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
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14 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
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15 | */ |
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16 | /** |
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17 | * @file |
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18 | * |
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19 | * @ingroup rtems-ld |
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20 | * |
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21 | * @brief RTEMS Linker compression handles compressed images. |
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22 | * |
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23 | */ |
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24 | |
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25 | #if !defined (_RLD_COMPRESSION_H_) |
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26 | #define _RLD_COMPRESSION_H_ |
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27 | |
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28 | #include <rld-files.h> |
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29 | |
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30 | namespace rld |
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31 | { |
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32 | namespace compress |
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33 | { |
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34 | /** |
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35 | * A compressor. |
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36 | */ |
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37 | class compressor |
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38 | { |
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39 | public: |
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40 | /** |
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41 | * Construct the compressor for the given image. |
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42 | * |
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43 | * @param image The image to read or write to. |
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44 | * @param size The size of the input and output buffers. |
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45 | * @param out The compressor is compressing. |
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46 | * @param compress Set to false to disable compression. |
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47 | */ |
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48 | compressor (files::image& image, |
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49 | size_t size, |
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50 | bool out = true, |
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51 | bool compress = true); |
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52 | |
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53 | /** |
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54 | * Destruct the compressor. |
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55 | */ |
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56 | ~compressor (); |
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57 | |
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58 | /** |
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59 | * Write the data to the output buffer and once the image buffer is full |
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60 | * compress and write the compressed data to the image. |
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61 | * |
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62 | * @param data The data to write to the image compressed |
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63 | * @param length The mount of data in bytes to write. |
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64 | */ |
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65 | void write (const void* data, size_t length); |
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66 | |
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67 | /** |
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68 | * Write the section of the input image file to the output buffer and |
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69 | * once the image buffer is full compress and write the compressed data |
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70 | * to the image. |
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71 | * |
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72 | * @param input The input image. |
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73 | * @param offset The input image offset to read from. |
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74 | * @param length The mount of data in bytes to write. |
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75 | */ |
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76 | void write (files::image& input, off_t offset, size_t length); |
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77 | |
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78 | /** |
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79 | * Flush the output buffer is data is present. |
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80 | */ |
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81 | void flush (); |
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82 | |
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83 | /** |
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84 | * Read the compressed data into the input buffer and return the section |
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85 | * requested. |
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86 | * |
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87 | * @param data Write the decompressed data here. |
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88 | * @param length The mount of data in bytes to read. |
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89 | * @return size_t The amount of data read. |
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90 | */ |
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91 | size_t read (void* data, size_t length); |
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92 | |
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93 | /** |
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94 | * Read the decompressed data writing it to the image. |
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95 | * |
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96 | * @param output_ The output image. |
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97 | * @param offset The output image offset to write from. |
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98 | * @param length The mount of data in bytes to read. |
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99 | * @return size_t The amount of data read. |
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100 | */ |
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101 | size_t read (files::image& output_, off_t offset, size_t length); |
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102 | |
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103 | /** |
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104 | * Read the decompressed data writing it to the image. |
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105 | * |
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106 | * @param output_ The output image. |
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107 | * @param length The mount of data in bytes to read. |
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108 | * @return size_t The amount of data read. |
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109 | */ |
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110 | size_t read (files::image& output_, size_t length); |
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111 | |
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112 | /** |
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113 | * The amount of uncompressed data transferred. |
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114 | * |
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115 | * @return size_t The amount of data tranferred. |
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116 | */ |
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117 | size_t transferred () const; |
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118 | |
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119 | /** |
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120 | * The amount of compressed data transferred. |
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121 | * |
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122 | * @return size_t The amount of compressed data tranferred. |
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123 | */ |
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124 | size_t compressed () const; |
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125 | |
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126 | /** |
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127 | * The current offset in the stream. |
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128 | * |
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129 | * @return off_t The current uncompressed offset. |
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130 | */ |
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131 | off_t offset () const; |
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132 | |
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133 | private: |
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134 | |
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135 | /** |
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136 | * Output the block of data to the output file with the block header. |
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137 | * |
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138 | * @param forced If true output the buffer. |
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139 | */ |
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140 | void output (bool forced = false); |
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141 | |
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142 | /** |
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143 | * Input a block of compressed data and decompress it. |
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144 | */ |
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145 | void input (); |
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146 | |
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147 | files::image& image; //< The image to read or write to or from. |
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148 | size_t size; //< The size of the buffer. |
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149 | bool out; //< If true the it is compression. |
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150 | bool compress; //< If true compress the data. |
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151 | uint8_t* buffer; //< The decompressed buffer |
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152 | uint8_t* io; //< The I/O buffer. |
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153 | size_t level; //< The amount of data in the buffer. |
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154 | size_t total; //< The amount of uncompressed data |
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155 | // transferred. |
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156 | size_t total_compressed; //< The amount of compressed data |
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157 | // transferred. |
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158 | }; |
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159 | |
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160 | /** |
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161 | * Compressor template function for writing data to the compressor. |
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162 | */ |
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163 | template < typename T > |
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164 | void write (compressor& comp, const T value) |
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165 | { |
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166 | uint8_t bytes[sizeof (T)]; |
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167 | T v = value; |
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168 | int b = sizeof (T) - 1; |
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169 | while (b >= 0) |
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170 | { |
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171 | bytes[b--] = (uint8_t) v; |
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172 | v >>= 8; |
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173 | } |
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174 | comp.write (bytes, sizeof (T)); |
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175 | } |
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176 | |
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177 | /** |
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178 | * Compressor template function for reading data from the compressor. |
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179 | */ |
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180 | template < typename T > |
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181 | T read (compressor& comp) |
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182 | { |
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183 | uint8_t bytes[sizeof (T)]; |
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184 | T v = 0; |
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185 | uint32_t b = 0; |
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186 | if (comp.read (bytes, sizeof (T)) != sizeof (T)) |
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187 | throw rld::error ("Reading of value failed", "compression"); |
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188 | while (b < sizeof (T)) |
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189 | { |
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190 | v = (v << 8) | ((T) bytes[b++]); |
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191 | } |
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192 | return v; |
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193 | } |
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194 | |
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195 | } |
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196 | } |
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197 | |
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198 | static inline rld::compress::compressor& operator<< (rld::compress::compressor& comp, |
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199 | const uint64_t value) { |
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200 | rld::compress::write < uint64_t > (comp, value); |
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201 | return comp; |
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202 | } |
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203 | |
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204 | static inline rld::compress::compressor& operator<< (rld::compress::compressor& comp, |
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205 | const uint32_t value) { |
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206 | rld::compress::write < uint32_t > (comp, value); |
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207 | return comp; |
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208 | } |
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209 | |
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210 | static inline rld::compress::compressor& operator<< (rld::compress::compressor& comp, |
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211 | const std::string& str) { |
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212 | comp.write (str.c_str (), str.size ()); |
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213 | return comp; |
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214 | } |
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215 | |
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216 | static inline rld::compress::compressor& operator>> (rld::compress::compressor& comp, |
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217 | uint64_t& value) { |
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218 | value = rld::compress::read < uint64_t > (comp); |
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219 | return comp; |
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220 | } |
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221 | |
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222 | static inline rld::compress::compressor& operator>> (rld::compress::compressor& comp, |
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223 | uint32_t& value) { |
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224 | value = rld::compress::read < uint32_t > (comp); |
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225 | return comp; |
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226 | } |
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227 | |
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228 | #endif |
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