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| <li class="navelem"><a class="el" href="dir_82f3a10095a8f2296c0cf5c491a57b02.html">cpc</a></li><li class="navelem"><a class="el" href="dir_fabb7854c43508dcbf81254d1daad42f.html">include</a></li> </ul> |
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| <div class="title">cpc_compressor_impl.hpp</div> </div> |
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| <div class="fragment"><div class="line"><a name="l00001"></a><span class="lineno"> 1</span> <span class="comment">/*</span></div> |
| <div class="line"><a name="l00002"></a><span class="lineno"> 2</span> <span class="comment"> * Licensed to the Apache Software Foundation (ASF) under one</span></div> |
| <div class="line"><a name="l00003"></a><span class="lineno"> 3</span> <span class="comment"> * or more contributor license agreements. See the NOTICE file</span></div> |
| <div class="line"><a name="l00004"></a><span class="lineno"> 4</span> <span class="comment"> * distributed with this work for additional information</span></div> |
| <div class="line"><a name="l00005"></a><span class="lineno"> 5</span> <span class="comment"> * regarding copyright ownership. The ASF licenses this file</span></div> |
| <div class="line"><a name="l00006"></a><span class="lineno"> 6</span> <span class="comment"> * to you under the Apache License, Version 2.0 (the</span></div> |
| <div class="line"><a name="l00007"></a><span class="lineno"> 7</span> <span class="comment"> * "License"); you may not use this file except in compliance</span></div> |
| <div class="line"><a name="l00008"></a><span class="lineno"> 8</span> <span class="comment"> * with the License. You may obtain a copy of the License at</span></div> |
| <div class="line"><a name="l00009"></a><span class="lineno"> 9</span> <span class="comment"> *</span></div> |
| <div class="line"><a name="l00010"></a><span class="lineno"> 10</span> <span class="comment"> * http://www.apache.org/licenses/LICENSE-2.0</span></div> |
| <div class="line"><a name="l00011"></a><span class="lineno"> 11</span> <span class="comment"> *</span></div> |
| <div class="line"><a name="l00012"></a><span class="lineno"> 12</span> <span class="comment"> * Unless required by applicable law or agreed to in writing,</span></div> |
| <div class="line"><a name="l00013"></a><span class="lineno"> 13</span> <span class="comment"> * software distributed under the License is distributed on an</span></div> |
| <div class="line"><a name="l00014"></a><span class="lineno"> 14</span> <span class="comment"> * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY</span></div> |
| <div class="line"><a name="l00015"></a><span class="lineno"> 15</span> <span class="comment"> * KIND, either express or implied. See the License for the</span></div> |
| <div class="line"><a name="l00016"></a><span class="lineno"> 16</span> <span class="comment"> * specific language governing permissions and limitations</span></div> |
| <div class="line"><a name="l00017"></a><span class="lineno"> 17</span> <span class="comment"> * under the License.</span></div> |
| <div class="line"><a name="l00018"></a><span class="lineno"> 18</span> <span class="comment"> */</span></div> |
| <div class="line"><a name="l00019"></a><span class="lineno"> 19</span>  </div> |
| <div class="line"><a name="l00020"></a><span class="lineno"> 20</span> <span class="comment">// author Kevin Lang, Oath Research</span></div> |
| <div class="line"><a name="l00021"></a><span class="lineno"> 21</span>  </div> |
| <div class="line"><a name="l00022"></a><span class="lineno"> 22</span> <span class="preprocessor">#ifndef CPC_COMPRESSOR_IMPL_HPP_</span></div> |
| <div class="line"><a name="l00023"></a><span class="lineno"> 23</span> <span class="preprocessor">#define CPC_COMPRESSOR_IMPL_HPP_</span></div> |
| <div class="line"><a name="l00024"></a><span class="lineno"> 24</span>  </div> |
| <div class="line"><a name="l00025"></a><span class="lineno"> 25</span> <span class="preprocessor">#include <memory></span></div> |
| <div class="line"><a name="l00026"></a><span class="lineno"> 26</span> <span class="preprocessor">#include <stdexcept></span></div> |
| <div class="line"><a name="l00027"></a><span class="lineno"> 27</span>  </div> |
| <div class="line"><a name="l00028"></a><span class="lineno"> 28</span> <span class="preprocessor">#include "compression_data.hpp"</span></div> |
| <div class="line"><a name="l00029"></a><span class="lineno"> 29</span> <span class="preprocessor">#include "cpc_util.hpp"</span></div> |
| <div class="line"><a name="l00030"></a><span class="lineno"> 30</span> <span class="preprocessor">#include "cpc_common.hpp"</span></div> |
| <div class="line"><a name="l00031"></a><span class="lineno"> 31</span> <span class="preprocessor">#include "count_zeros.hpp"</span></div> |
| <div class="line"><a name="l00032"></a><span class="lineno"> 32</span>  </div> |
| <div class="line"><a name="l00033"></a><span class="lineno"> 33</span> <span class="keyword">namespace </span><a class="code" href="namespacedatasketches.html">datasketches</a> {</div> |
| <div class="line"><a name="l00034"></a><span class="lineno"> 34</span>  </div> |
| <div class="line"><a name="l00035"></a><span class="lineno"> 35</span> <span class="comment">// construct on first use</span></div> |
| <div class="line"><a name="l00036"></a><span class="lineno"> 36</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00037"></a><span class="lineno"> 37</span> cpc_compressor<A>& get_compressor() {</div> |
| <div class="line"><a name="l00038"></a><span class="lineno"> 38</span>  <span class="keyword">static</span> cpc_compressor<A>* instance = <span class="keyword">new</span> cpc_compressor<A>(); <span class="comment">// use new for global initialization</span></div> |
| <div class="line"><a name="l00039"></a><span class="lineno"> 39</span>  <span class="keywordflow">return</span> *instance;</div> |
| <div class="line"><a name="l00040"></a><span class="lineno"> 40</span> }</div> |
| <div class="line"><a name="l00041"></a><span class="lineno"> 41</span>  </div> |
| <div class="line"><a name="l00042"></a><span class="lineno"> 42</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00043"></a><span class="lineno"> 43</span> cpc_compressor<A>::cpc_compressor() {</div> |
| <div class="line"><a name="l00044"></a><span class="lineno"> 44</span>  make_decoding_tables();</div> |
| <div class="line"><a name="l00045"></a><span class="lineno"> 45</span> }</div> |
| <div class="line"><a name="l00046"></a><span class="lineno"> 46</span>  </div> |
| <div class="line"><a name="l00047"></a><span class="lineno"> 47</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00048"></a><span class="lineno"> 48</span> cpc_compressor<A>::~cpc_compressor() {</div> |
| <div class="line"><a name="l00049"></a><span class="lineno"> 49</span>  free_decoding_tables();</div> |
| <div class="line"><a name="l00050"></a><span class="lineno"> 50</span> }</div> |
| <div class="line"><a name="l00051"></a><span class="lineno"> 51</span>  </div> |
| <div class="line"><a name="l00052"></a><span class="lineno"> 52</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00053"></a><span class="lineno"> 53</span> uint8_t* cpc_compressor<A>::make_inverse_permutation(<span class="keyword">const</span> uint8_t* permu, <span class="keywordtype">unsigned</span> length) {</div> |
| <div class="line"><a name="l00054"></a><span class="lineno"> 54</span>  uint8_t* inverse = <span class="keyword">new</span> uint8_t[length]; <span class="comment">// use new for global initialization</span></div> |
| <div class="line"><a name="l00055"></a><span class="lineno"> 55</span>  <span class="keywordflow">for</span> (<span class="keywordtype">unsigned</span> i = 0; i < length; i++) {</div> |
| <div class="line"><a name="l00056"></a><span class="lineno"> 56</span>  inverse[permu[i]] = <span class="keyword">static_cast<</span>uint8_t<span class="keyword">></span>(i);</div> |
| <div class="line"><a name="l00057"></a><span class="lineno"> 57</span>  }</div> |
| <div class="line"><a name="l00058"></a><span class="lineno"> 58</span>  <span class="keywordflow">for</span> (<span class="keywordtype">unsigned</span> i = 0; i < length; i++) {</div> |
| <div class="line"><a name="l00059"></a><span class="lineno"> 59</span>  <span class="keywordflow">if</span> (permu[inverse[i]] != i) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"inverse permutation error"</span>);</div> |
| <div class="line"><a name="l00060"></a><span class="lineno"> 60</span>  }</div> |
| <div class="line"><a name="l00061"></a><span class="lineno"> 61</span>  <span class="keywordflow">return</span> inverse;</div> |
| <div class="line"><a name="l00062"></a><span class="lineno"> 62</span> }</div> |
| <div class="line"><a name="l00063"></a><span class="lineno"> 63</span>  </div> |
| <div class="line"><a name="l00064"></a><span class="lineno"> 64</span> <span class="comment">/* Given an encoding table that maps unsigned bytes to codewords</span></div> |
| <div class="line"><a name="l00065"></a><span class="lineno"> 65</span> <span class="comment"> of length at most 12, this builds a size-4096 decoding table */</span></div> |
| <div class="line"><a name="l00066"></a><span class="lineno"> 66</span> <span class="comment">// The second argument is typically 256, but can be other values such as 65.</span></div> |
| <div class="line"><a name="l00067"></a><span class="lineno"> 67</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00068"></a><span class="lineno"> 68</span> uint16_t* cpc_compressor<A>::make_decoding_table(<span class="keyword">const</span> uint16_t* encoding_table, <span class="keywordtype">unsigned</span> num_byte_values) {</div> |
| <div class="line"><a name="l00069"></a><span class="lineno"> 69</span>  uint16_t* decoding_table = <span class="keyword">new</span> uint16_t[4096]; <span class="comment">// use new for global initialization</span></div> |
| <div class="line"><a name="l00070"></a><span class="lineno"> 70</span>  <span class="keywordflow">for</span> (<span class="keywordtype">unsigned</span> byte_value = 0; byte_value < num_byte_values; byte_value++) {</div> |
| <div class="line"><a name="l00071"></a><span class="lineno"> 71</span>  <span class="keyword">const</span> uint16_t encoding_entry = encoding_table[byte_value];</div> |
| <div class="line"><a name="l00072"></a><span class="lineno"> 72</span>  <span class="keyword">const</span> uint16_t code_value = encoding_entry & 0xfff;</div> |
| <div class="line"><a name="l00073"></a><span class="lineno"> 73</span>  <span class="keyword">const</span> uint8_t code_length = encoding_entry >> 12;</div> |
| <div class="line"><a name="l00074"></a><span class="lineno"> 74</span>  <span class="keyword">const</span> uint16_t decoding_entry = <span class="keyword">static_cast<</span>uint16_t<span class="keyword">></span>((code_length << 8) | byte_value);</div> |
| <div class="line"><a name="l00075"></a><span class="lineno"> 75</span>  <span class="keyword">const</span> uint8_t garbage_length = 12 - code_length;</div> |
| <div class="line"><a name="l00076"></a><span class="lineno"> 76</span>  <span class="keyword">const</span> uint32_t num_copies = 1 << garbage_length;</div> |
| <div class="line"><a name="l00077"></a><span class="lineno"> 77</span>  <span class="keywordflow">for</span> (uint32_t garbage_bits = 0; garbage_bits < num_copies; garbage_bits++) {</div> |
| <div class="line"><a name="l00078"></a><span class="lineno"> 78</span>  <span class="keyword">const</span> uint16_t extended_code_value = <span class="keyword">static_cast<</span>uint16_t<span class="keyword">></span>(code_value | (garbage_bits << code_length));</div> |
| <div class="line"><a name="l00079"></a><span class="lineno"> 79</span>  decoding_table[extended_code_value & 0xfff] = decoding_entry;</div> |
| <div class="line"><a name="l00080"></a><span class="lineno"> 80</span>  }</div> |
| <div class="line"><a name="l00081"></a><span class="lineno"> 81</span>  }</div> |
| <div class="line"><a name="l00082"></a><span class="lineno"> 82</span>  <span class="keywordflow">return</span> decoding_table;</div> |
| <div class="line"><a name="l00083"></a><span class="lineno"> 83</span> }</div> |
| <div class="line"><a name="l00084"></a><span class="lineno"> 84</span>  </div> |
| <div class="line"><a name="l00085"></a><span class="lineno"> 85</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00086"></a><span class="lineno"> 86</span> <span class="keywordtype">void</span> cpc_compressor<A>::validate_decoding_table(<span class="keyword">const</span> uint16_t* decoding_table, <span class="keyword">const</span> uint16_t* encoding_table)<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00087"></a><span class="lineno"> 87</span>  <span class="keywordflow">for</span> (<span class="keywordtype">int</span> decode_this = 0; decode_this < 4096; decode_this++) {</div> |
| <div class="line"><a name="l00088"></a><span class="lineno"> 88</span>  <span class="keyword">const</span> <span class="keywordtype">int</span> tmp_d = decoding_table[decode_this];</div> |
| <div class="line"><a name="l00089"></a><span class="lineno"> 89</span>  <span class="keyword">const</span> <span class="keywordtype">int</span> decoded_byte = tmp_d & 0xff;</div> |
| <div class="line"><a name="l00090"></a><span class="lineno"> 90</span>  <span class="keyword">const</span> <span class="keywordtype">int</span> decoded_length = tmp_d >> 8;</div> |
| <div class="line"><a name="l00091"></a><span class="lineno"> 91</span>  </div> |
| <div class="line"><a name="l00092"></a><span class="lineno"> 92</span>  <span class="keyword">const</span> <span class="keywordtype">int</span> tmp_e = encoding_table[decoded_byte];</div> |
| <div class="line"><a name="l00093"></a><span class="lineno"> 93</span>  <span class="keyword">const</span> <span class="keywordtype">int</span> encoded_bit_pattern = tmp_e & 0xfff;</div> |
| <div class="line"><a name="l00094"></a><span class="lineno"> 94</span>  <span class="keyword">const</span> <span class="keywordtype">int</span> encoded_length = tmp_e >> 12;</div> |
| <div class="line"><a name="l00095"></a><span class="lineno"> 95</span>  </div> |
| <div class="line"><a name="l00096"></a><span class="lineno"> 96</span>  <span class="keywordflow">if</span> (decoded_length != encoded_length) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"decoded length error"</span>);</div> |
| <div class="line"><a name="l00097"></a><span class="lineno"> 97</span>  <span class="keywordflow">if</span> (encoded_bit_pattern != (decode_this & ((1 << decoded_length) - 1))) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"bit pattern error"</span>);</div> |
| <div class="line"><a name="l00098"></a><span class="lineno"> 98</span>  }</div> |
| <div class="line"><a name="l00099"></a><span class="lineno"> 99</span> }</div> |
| <div class="line"><a name="l00100"></a><span class="lineno"> 100</span>  </div> |
| <div class="line"><a name="l00101"></a><span class="lineno"> 101</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00102"></a><span class="lineno"> 102</span> <span class="keywordtype">void</span> cpc_compressor<A>::make_decoding_tables() {</div> |
| <div class="line"><a name="l00103"></a><span class="lineno"> 103</span>  length_limited_unary_decoding_table65 = make_decoding_table(length_limited_unary_encoding_table65, 65);</div> |
| <div class="line"><a name="l00104"></a><span class="lineno"> 104</span>  validate_decoding_table(</div> |
| <div class="line"><a name="l00105"></a><span class="lineno"> 105</span>  length_limited_unary_decoding_table65,</div> |
| <div class="line"><a name="l00106"></a><span class="lineno"> 106</span>  length_limited_unary_encoding_table65</div> |
| <div class="line"><a name="l00107"></a><span class="lineno"> 107</span>  );</div> |
| <div class="line"><a name="l00108"></a><span class="lineno"> 108</span>  </div> |
| <div class="line"><a name="l00109"></a><span class="lineno"> 109</span>  <span class="keywordflow">for</span> (<span class="keywordtype">int</span> i = 0; i < (16 + 6); i++) {</div> |
| <div class="line"><a name="l00110"></a><span class="lineno"> 110</span>  decoding_tables_for_high_entropy_byte[i] = make_decoding_table(encoding_tables_for_high_entropy_byte[i], 256);</div> |
| <div class="line"><a name="l00111"></a><span class="lineno"> 111</span>  validate_decoding_table(</div> |
| <div class="line"><a name="l00112"></a><span class="lineno"> 112</span>  decoding_tables_for_high_entropy_byte[i],</div> |
| <div class="line"><a name="l00113"></a><span class="lineno"> 113</span>  encoding_tables_for_high_entropy_byte[i]</div> |
| <div class="line"><a name="l00114"></a><span class="lineno"> 114</span>  );</div> |
| <div class="line"><a name="l00115"></a><span class="lineno"> 115</span>  }</div> |
| <div class="line"><a name="l00116"></a><span class="lineno"> 116</span>  </div> |
| <div class="line"><a name="l00117"></a><span class="lineno"> 117</span>  <span class="keywordflow">for</span> (<span class="keywordtype">int</span> i = 0; i < 16; i++) {</div> |
| <div class="line"><a name="l00118"></a><span class="lineno"> 118</span>  column_permutations_for_decoding[i] = make_inverse_permutation(column_permutations_for_encoding[i], 56);</div> |
| <div class="line"><a name="l00119"></a><span class="lineno"> 119</span>  }</div> |
| <div class="line"><a name="l00120"></a><span class="lineno"> 120</span> }</div> |
| <div class="line"><a name="l00121"></a><span class="lineno"> 121</span>  </div> |
| <div class="line"><a name="l00122"></a><span class="lineno"> 122</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00123"></a><span class="lineno"> 123</span> <span class="keywordtype">void</span> cpc_compressor<A>::free_decoding_tables() {</div> |
| <div class="line"><a name="l00124"></a><span class="lineno"> 124</span>  <span class="keyword">delete</span>[] length_limited_unary_decoding_table65;</div> |
| <div class="line"><a name="l00125"></a><span class="lineno"> 125</span>  <span class="keywordflow">for</span> (<span class="keywordtype">int</span> i = 0; i < (16 + 6); i++) {</div> |
| <div class="line"><a name="l00126"></a><span class="lineno"> 126</span>  <span class="keyword">delete</span>[] decoding_tables_for_high_entropy_byte[i];</div> |
| <div class="line"><a name="l00127"></a><span class="lineno"> 127</span>  }</div> |
| <div class="line"><a name="l00128"></a><span class="lineno"> 128</span>  <span class="keywordflow">for</span> (<span class="keywordtype">int</span> i = 0; i < 16; i++) {</div> |
| <div class="line"><a name="l00129"></a><span class="lineno"> 129</span>  <span class="keyword">delete</span>[] column_permutations_for_decoding[i];</div> |
| <div class="line"><a name="l00130"></a><span class="lineno"> 130</span>  }</div> |
| <div class="line"><a name="l00131"></a><span class="lineno"> 131</span> }</div> |
| <div class="line"><a name="l00132"></a><span class="lineno"> 132</span>  </div> |
| <div class="line"><a name="l00133"></a><span class="lineno"> 133</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00134"></a><span class="lineno"> 134</span> <span class="keywordtype">void</span> cpc_compressor<A>::compress(<span class="keyword">const</span> cpc_sketch_alloc<A>& source, compressed_state<A>& result)<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00135"></a><span class="lineno"> 135</span>  <span class="keywordflow">switch</span> (source.determine_flavor()) {</div> |
| <div class="line"><a name="l00136"></a><span class="lineno"> 136</span>  <span class="keywordflow">case</span> cpc_sketch_alloc<A>::flavor::EMPTY:</div> |
| <div class="line"><a name="l00137"></a><span class="lineno"> 137</span>  <span class="keywordflow">break</span>;</div> |
| <div class="line"><a name="l00138"></a><span class="lineno"> 138</span>  <span class="keywordflow">case</span> cpc_sketch_alloc<A>::flavor::SPARSE:</div> |
| <div class="line"><a name="l00139"></a><span class="lineno"> 139</span>  compress_sparse_flavor(source, result);</div> |
| <div class="line"><a name="l00140"></a><span class="lineno"> 140</span>  <span class="keywordflow">if</span> (result.window_data.size() > 0) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"window is not expected"</span>);</div> |
| <div class="line"><a name="l00141"></a><span class="lineno"> 141</span>  <span class="keywordflow">if</span> (result.table_data.size() == 0) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"table is expected"</span>);</div> |
| <div class="line"><a name="l00142"></a><span class="lineno"> 142</span>  <span class="keywordflow">break</span>;</div> |
| <div class="line"><a name="l00143"></a><span class="lineno"> 143</span>  <span class="keywordflow">case</span> cpc_sketch_alloc<A>::flavor::HYBRID:</div> |
| <div class="line"><a name="l00144"></a><span class="lineno"> 144</span>  compress_hybrid_flavor(source, result);</div> |
| <div class="line"><a name="l00145"></a><span class="lineno"> 145</span>  <span class="keywordflow">if</span> (result.window_data.size() > 0) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"window is not expected"</span>);</div> |
| <div class="line"><a name="l00146"></a><span class="lineno"> 146</span>  <span class="keywordflow">if</span> (result.table_data.size() == 0) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"table is expected"</span>);</div> |
| <div class="line"><a name="l00147"></a><span class="lineno"> 147</span>  <span class="keywordflow">break</span>;</div> |
| <div class="line"><a name="l00148"></a><span class="lineno"> 148</span>  <span class="keywordflow">case</span> cpc_sketch_alloc<A>::flavor::PINNED:</div> |
| <div class="line"><a name="l00149"></a><span class="lineno"> 149</span>  compress_pinned_flavor(source, result);</div> |
| <div class="line"><a name="l00150"></a><span class="lineno"> 150</span>  <span class="keywordflow">if</span> (result.window_data.size() == 0) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"window is not expected"</span>);</div> |
| <div class="line"><a name="l00151"></a><span class="lineno"> 151</span>  <span class="keywordflow">break</span>;</div> |
| <div class="line"><a name="l00152"></a><span class="lineno"> 152</span>  <span class="keywordflow">case</span> cpc_sketch_alloc<A>::flavor::SLIDING:</div> |
| <div class="line"><a name="l00153"></a><span class="lineno"> 153</span>  compress_sliding_flavor(source, result);</div> |
| <div class="line"><a name="l00154"></a><span class="lineno"> 154</span>  <span class="keywordflow">if</span> (result.window_data.size() == 0) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"window is expected"</span>);</div> |
| <div class="line"><a name="l00155"></a><span class="lineno"> 155</span>  <span class="keywordflow">break</span>;</div> |
| <div class="line"><a name="l00156"></a><span class="lineno"> 156</span>  <span class="keywordflow">default</span>: <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"Unknown sketch flavor"</span>);</div> |
| <div class="line"><a name="l00157"></a><span class="lineno"> 157</span>  }</div> |
| <div class="line"><a name="l00158"></a><span class="lineno"> 158</span> }</div> |
| <div class="line"><a name="l00159"></a><span class="lineno"> 159</span>  </div> |
| <div class="line"><a name="l00160"></a><span class="lineno"> 160</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00161"></a><span class="lineno"> 161</span> <span class="keywordtype">void</span> cpc_compressor<A>::uncompress(<span class="keyword">const</span> compressed_state<A>& source, uncompressed_state<A>& target, uint8_t lg_k, uint32_t num_coupons)<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00162"></a><span class="lineno"> 162</span>  <span class="keywordflow">switch</span> (cpc_sketch_alloc<A>::determine_flavor(lg_k, num_coupons)) {</div> |
| <div class="line"><a name="l00163"></a><span class="lineno"> 163</span>  <span class="keywordflow">case</span> cpc_sketch_alloc<A>::flavor::EMPTY:</div> |
| <div class="line"><a name="l00164"></a><span class="lineno"> 164</span>  target.table = u32_table<A>(2, 6 + lg_k, source.table_data.get_allocator());</div> |
| <div class="line"><a name="l00165"></a><span class="lineno"> 165</span>  <span class="keywordflow">break</span>;</div> |
| <div class="line"><a name="l00166"></a><span class="lineno"> 166</span>  <span class="keywordflow">case</span> cpc_sketch_alloc<A>::flavor::SPARSE:</div> |
| <div class="line"><a name="l00167"></a><span class="lineno"> 167</span>  uncompress_sparse_flavor(source, target, lg_k);</div> |
| <div class="line"><a name="l00168"></a><span class="lineno"> 168</span>  <span class="keywordflow">break</span>;</div> |
| <div class="line"><a name="l00169"></a><span class="lineno"> 169</span>  <span class="keywordflow">case</span> cpc_sketch_alloc<A>::flavor::HYBRID:</div> |
| <div class="line"><a name="l00170"></a><span class="lineno"> 170</span>  uncompress_hybrid_flavor(source, target, lg_k);</div> |
| <div class="line"><a name="l00171"></a><span class="lineno"> 171</span>  <span class="keywordflow">break</span>;</div> |
| <div class="line"><a name="l00172"></a><span class="lineno"> 172</span>  <span class="keywordflow">case</span> cpc_sketch_alloc<A>::flavor::PINNED:</div> |
| <div class="line"><a name="l00173"></a><span class="lineno"> 173</span>  <span class="keywordflow">if</span> (source.window_data.size() == 0) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"window is expected"</span>);</div> |
| <div class="line"><a name="l00174"></a><span class="lineno"> 174</span>  uncompress_pinned_flavor(source, target, lg_k, num_coupons);</div> |
| <div class="line"><a name="l00175"></a><span class="lineno"> 175</span>  <span class="keywordflow">break</span>;</div> |
| <div class="line"><a name="l00176"></a><span class="lineno"> 176</span>  <span class="keywordflow">case</span> cpc_sketch_alloc<A>::flavor::SLIDING:</div> |
| <div class="line"><a name="l00177"></a><span class="lineno"> 177</span>  uncompress_sliding_flavor(source, target, lg_k, num_coupons);</div> |
| <div class="line"><a name="l00178"></a><span class="lineno"> 178</span>  <span class="keywordflow">break</span>;</div> |
| <div class="line"><a name="l00179"></a><span class="lineno"> 179</span>  <span class="keywordflow">default</span>: std::logic_error(<span class="stringliteral">"Unknown sketch flavor"</span>);</div> |
| <div class="line"><a name="l00180"></a><span class="lineno"> 180</span>  }</div> |
| <div class="line"><a name="l00181"></a><span class="lineno"> 181</span> }</div> |
| <div class="line"><a name="l00182"></a><span class="lineno"> 182</span>  </div> |
| <div class="line"><a name="l00183"></a><span class="lineno"> 183</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00184"></a><span class="lineno"> 184</span> <span class="keywordtype">void</span> cpc_compressor<A>::compress_sparse_flavor(<span class="keyword">const</span> cpc_sketch_alloc<A>& source, compressed_state<A>& result)<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00185"></a><span class="lineno"> 185</span>  <span class="keywordflow">if</span> (source.sliding_window.size() > 0) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"unexpected sliding window"</span>);</div> |
| <div class="line"><a name="l00186"></a><span class="lineno"> 186</span>  vector_u32 pairs = source.surprising_value_table.unwrapping_get_items();</div> |
| <div class="line"><a name="l00187"></a><span class="lineno"> 187</span>  u32_table<A>::introspective_insertion_sort(pairs.data(), 0, pairs.size());</div> |
| <div class="line"><a name="l00188"></a><span class="lineno"> 188</span>  compress_surprising_values(pairs, source.get_lg_k(), result);</div> |
| <div class="line"><a name="l00189"></a><span class="lineno"> 189</span> }</div> |
| <div class="line"><a name="l00190"></a><span class="lineno"> 190</span>  </div> |
| <div class="line"><a name="l00191"></a><span class="lineno"> 191</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00192"></a><span class="lineno"> 192</span> <span class="keywordtype">void</span> cpc_compressor<A>::uncompress_sparse_flavor(<span class="keyword">const</span> compressed_state<A>& source, uncompressed_state<A>& target, uint8_t lg_k)<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00193"></a><span class="lineno"> 193</span>  <span class="keywordflow">if</span> (source.window_data.size() > 0) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"unexpected sliding window"</span>);</div> |
| <div class="line"><a name="l00194"></a><span class="lineno"> 194</span>  <span class="keywordflow">if</span> (source.table_data.size() == 0) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"table is expected"</span>);</div> |
| <div class="line"><a name="l00195"></a><span class="lineno"> 195</span>  vector_u32 pairs = uncompress_surprising_values(source.table_data.data(), source.table_data_words, source.table_num_entries,</div> |
| <div class="line"><a name="l00196"></a><span class="lineno"> 196</span>  lg_k, source.table_data.get_allocator());</div> |
| <div class="line"><a name="l00197"></a><span class="lineno"> 197</span>  target.table = u32_table<A>::make_from_pairs(pairs.data(), source.table_num_entries, lg_k, pairs.get_allocator());</div> |
| <div class="line"><a name="l00198"></a><span class="lineno"> 198</span> }</div> |
| <div class="line"><a name="l00199"></a><span class="lineno"> 199</span>  </div> |
| <div class="line"><a name="l00200"></a><span class="lineno"> 200</span> <span class="comment">// This is complicated because it effectively builds a Sparse version</span></div> |
| <div class="line"><a name="l00201"></a><span class="lineno"> 201</span> <span class="comment">// of a Pinned sketch before compressing it. Hence the name Hybrid.</span></div> |
| <div class="line"><a name="l00202"></a><span class="lineno"> 202</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00203"></a><span class="lineno"> 203</span> <span class="keywordtype">void</span> cpc_compressor<A>::compress_hybrid_flavor(<span class="keyword">const</span> cpc_sketch_alloc<A>& source, compressed_state<A>& result)<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00204"></a><span class="lineno"> 204</span>  <span class="keywordflow">if</span> (source.sliding_window.size() == 0) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"no sliding window"</span>);</div> |
| <div class="line"><a name="l00205"></a><span class="lineno"> 205</span>  <span class="keywordflow">if</span> (source.window_offset != 0) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"window_offset != 0"</span>);</div> |
| <div class="line"><a name="l00206"></a><span class="lineno"> 206</span>  <span class="keyword">const</span> uint32_t k = 1 << source.get_lg_k();</div> |
| <div class="line"><a name="l00207"></a><span class="lineno"> 207</span>  vector_u32 pairs_from_table = source.surprising_value_table.unwrapping_get_items();</div> |
| <div class="line"><a name="l00208"></a><span class="lineno"> 208</span>  <span class="keyword">const</span> uint32_t num_pairs_from_table = <span class="keyword">static_cast<</span>uint32_t<span class="keyword">></span>(pairs_from_table.size());</div> |
| <div class="line"><a name="l00209"></a><span class="lineno"> 209</span>  <span class="keywordflow">if</span> (num_pairs_from_table > 0) u32_table<A>::introspective_insertion_sort(pairs_from_table.data(), 0, num_pairs_from_table);</div> |
| <div class="line"><a name="l00210"></a><span class="lineno"> 210</span>  <span class="keyword">const</span> uint32_t num_pairs_from_window = source.get_num_coupons() - num_pairs_from_table; <span class="comment">// because the window offset is zero</span></div> |
| <div class="line"><a name="l00211"></a><span class="lineno"> 211</span>  </div> |
| <div class="line"><a name="l00212"></a><span class="lineno"> 212</span>  vector_u32 all_pairs = tricky_get_pairs_from_window(source.sliding_window.data(), k, num_pairs_from_window, num_pairs_from_table, source.get_allocator());</div> |
| <div class="line"><a name="l00213"></a><span class="lineno"> 213</span>  </div> |
| <div class="line"><a name="l00214"></a><span class="lineno"> 214</span>  u32_table<A>::merge(</div> |
| <div class="line"><a name="l00215"></a><span class="lineno"> 215</span>  pairs_from_table.data(), 0, pairs_from_table.size(),</div> |
| <div class="line"><a name="l00216"></a><span class="lineno"> 216</span>  all_pairs.data(), num_pairs_from_table, num_pairs_from_window,</div> |
| <div class="line"><a name="l00217"></a><span class="lineno"> 217</span>  all_pairs.data(), 0</div> |
| <div class="line"><a name="l00218"></a><span class="lineno"> 218</span>  ); <span class="comment">// note the overlapping subarray trick</span></div> |
| <div class="line"><a name="l00219"></a><span class="lineno"> 219</span>  </div> |
| <div class="line"><a name="l00220"></a><span class="lineno"> 220</span>  compress_surprising_values(all_pairs, source.get_lg_k(), result);</div> |
| <div class="line"><a name="l00221"></a><span class="lineno"> 221</span> }</div> |
| <div class="line"><a name="l00222"></a><span class="lineno"> 222</span>  </div> |
| <div class="line"><a name="l00223"></a><span class="lineno"> 223</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00224"></a><span class="lineno"> 224</span> <span class="keywordtype">void</span> cpc_compressor<A>::uncompress_hybrid_flavor(<span class="keyword">const</span> compressed_state<A>& source, uncompressed_state<A>& target, uint8_t lg_k)<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00225"></a><span class="lineno"> 225</span>  <span class="keywordflow">if</span> (source.window_data.size() > 0) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"window is not expected"</span>);</div> |
| <div class="line"><a name="l00226"></a><span class="lineno"> 226</span>  <span class="keywordflow">if</span> (source.table_data.size() == 0) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"table is expected"</span>);</div> |
| <div class="line"><a name="l00227"></a><span class="lineno"> 227</span>  vector_u32 pairs = uncompress_surprising_values(source.table_data.data(), source.table_data_words, source.table_num_entries,</div> |
| <div class="line"><a name="l00228"></a><span class="lineno"> 228</span>  lg_k, source.table_data.get_allocator());</div> |
| <div class="line"><a name="l00229"></a><span class="lineno"> 229</span>  </div> |
| <div class="line"><a name="l00230"></a><span class="lineno"> 230</span>  <span class="comment">// In the hybrid flavor, some of these pairs actually</span></div> |
| <div class="line"><a name="l00231"></a><span class="lineno"> 231</span>  <span class="comment">// belong in the window, so we will separate them out,</span></div> |
| <div class="line"><a name="l00232"></a><span class="lineno"> 232</span>  <span class="comment">// moving the "true" pairs to the bottom of the array.</span></div> |
| <div class="line"><a name="l00233"></a><span class="lineno"> 233</span>  <span class="keyword">const</span> uint32_t k = 1 << lg_k;</div> |
| <div class="line"><a name="l00234"></a><span class="lineno"> 234</span>  target.window.resize(k, 0); <span class="comment">// important: zero the memory</span></div> |
| <div class="line"><a name="l00235"></a><span class="lineno"> 235</span>  uint32_t next_true_pair = 0;</div> |
| <div class="line"><a name="l00236"></a><span class="lineno"> 236</span>  <span class="keywordflow">for</span> (uint32_t i = 0; i < source.table_num_entries; i++) {</div> |
| <div class="line"><a name="l00237"></a><span class="lineno"> 237</span>  <span class="keyword">const</span> uint32_t row_col = pairs[i];</div> |
| <div class="line"><a name="l00238"></a><span class="lineno"> 238</span>  <span class="keywordflow">if</span> (row_col == UINT32_MAX) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"empty marker is not expected"</span>);</div> |
| <div class="line"><a name="l00239"></a><span class="lineno"> 239</span>  <span class="keyword">const</span> uint8_t col = row_col & 63;</div> |
| <div class="line"><a name="l00240"></a><span class="lineno"> 240</span>  <span class="keywordflow">if</span> (col < 8) {</div> |
| <div class="line"><a name="l00241"></a><span class="lineno"> 241</span>  <span class="keyword">const</span> uint32_t row = row_col >> 6;</div> |
| <div class="line"><a name="l00242"></a><span class="lineno"> 242</span>  target.window[row] |= 1 << col; <span class="comment">// set the window bit</span></div> |
| <div class="line"><a name="l00243"></a><span class="lineno"> 243</span>  } <span class="keywordflow">else</span> {</div> |
| <div class="line"><a name="l00244"></a><span class="lineno"> 244</span>  pairs[next_true_pair++] = row_col; <span class="comment">// move true pair down</span></div> |
| <div class="line"><a name="l00245"></a><span class="lineno"> 245</span>  }</div> |
| <div class="line"><a name="l00246"></a><span class="lineno"> 246</span>  }</div> |
| <div class="line"><a name="l00247"></a><span class="lineno"> 247</span>  target.table = u32_table<A>::make_from_pairs(pairs.data(), next_true_pair, lg_k, pairs.get_allocator());</div> |
| <div class="line"><a name="l00248"></a><span class="lineno"> 248</span> }</div> |
| <div class="line"><a name="l00249"></a><span class="lineno"> 249</span>  </div> |
| <div class="line"><a name="l00250"></a><span class="lineno"> 250</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00251"></a><span class="lineno"> 251</span> <span class="keywordtype">void</span> cpc_compressor<A>::compress_pinned_flavor(<span class="keyword">const</span> cpc_sketch_alloc<A>& source, compressed_state<A>& result)<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00252"></a><span class="lineno"> 252</span>  compress_sliding_window(source.sliding_window.data(), source.get_lg_k(), source.get_num_coupons(), result);</div> |
| <div class="line"><a name="l00253"></a><span class="lineno"> 253</span>  vector_u32 pairs = source.surprising_value_table.unwrapping_get_items();</div> |
| <div class="line"><a name="l00254"></a><span class="lineno"> 254</span>  <span class="keywordflow">if</span> (pairs.size() > 0) {</div> |
| <div class="line"><a name="l00255"></a><span class="lineno"> 255</span>  <span class="comment">// Here we subtract 8 from the column indices. Because they are stored in the low 6 bits</span></div> |
| <div class="line"><a name="l00256"></a><span class="lineno"> 256</span>  <span class="comment">// of each row_col pair, and because no column index is less than 8 for a "Pinned" sketch,</span></div> |
| <div class="line"><a name="l00257"></a><span class="lineno"> 257</span>  <span class="comment">// we can simply subtract 8 from the pairs themselves.</span></div> |
| <div class="line"><a name="l00258"></a><span class="lineno"> 258</span>  </div> |
| <div class="line"><a name="l00259"></a><span class="lineno"> 259</span>  <span class="comment">// shift the columns over by 8 positions before compressing (because of the window)</span></div> |
| <div class="line"><a name="l00260"></a><span class="lineno"> 260</span>  <span class="keywordflow">for</span> (<span class="keywordtype">size_t</span> i = 0; i < pairs.size(); i++) {</div> |
| <div class="line"><a name="l00261"></a><span class="lineno"> 261</span>  <span class="keywordflow">if</span> ((pairs[i] & 63) < 8) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"(pairs[i] & 63) < 8"</span>);</div> |
| <div class="line"><a name="l00262"></a><span class="lineno"> 262</span>  pairs[i] -= 8;</div> |
| <div class="line"><a name="l00263"></a><span class="lineno"> 263</span>  }</div> |
| <div class="line"><a name="l00264"></a><span class="lineno"> 264</span>  </div> |
| <div class="line"><a name="l00265"></a><span class="lineno"> 265</span>  <span class="keywordflow">if</span> (pairs.size() > 0) u32_table<A>::introspective_insertion_sort(pairs.data(), 0, pairs.size());</div> |
| <div class="line"><a name="l00266"></a><span class="lineno"> 266</span>  compress_surprising_values(pairs, source.get_lg_k(), result);</div> |
| <div class="line"><a name="l00267"></a><span class="lineno"> 267</span>  }</div> |
| <div class="line"><a name="l00268"></a><span class="lineno"> 268</span> }</div> |
| <div class="line"><a name="l00269"></a><span class="lineno"> 269</span>  </div> |
| <div class="line"><a name="l00270"></a><span class="lineno"> 270</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00271"></a><span class="lineno"> 271</span> <span class="keywordtype">void</span> cpc_compressor<A>::uncompress_pinned_flavor(<span class="keyword">const</span> compressed_state<A>& source, uncompressed_state<A>& target,</div> |
| <div class="line"><a name="l00272"></a><span class="lineno"> 272</span>  uint8_t lg_k, uint32_t num_coupons)<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00273"></a><span class="lineno"> 273</span>  <span class="keywordflow">if</span> (source.window_data.size() == 0) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"window is expected"</span>);</div> |
| <div class="line"><a name="l00274"></a><span class="lineno"> 274</span>  uncompress_sliding_window(source.window_data.data(), source.window_data_words, target.window, lg_k, num_coupons);</div> |
| <div class="line"><a name="l00275"></a><span class="lineno"> 275</span>  <span class="keyword">const</span> uint32_t num_pairs = source.table_num_entries;</div> |
| <div class="line"><a name="l00276"></a><span class="lineno"> 276</span>  <span class="keywordflow">if</span> (num_pairs == 0) {</div> |
| <div class="line"><a name="l00277"></a><span class="lineno"> 277</span>  target.table = u32_table<A>(2, 6 + lg_k, source.table_data.get_allocator());</div> |
| <div class="line"><a name="l00278"></a><span class="lineno"> 278</span>  } <span class="keywordflow">else</span> {</div> |
| <div class="line"><a name="l00279"></a><span class="lineno"> 279</span>  <span class="keywordflow">if</span> (source.table_data.size() == 0) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"table is expected"</span>);</div> |
| <div class="line"><a name="l00280"></a><span class="lineno"> 280</span>  vector_u32 pairs = uncompress_surprising_values(source.table_data.data(), source.table_data_words, num_pairs,</div> |
| <div class="line"><a name="l00281"></a><span class="lineno"> 281</span>  lg_k, source.table_data.get_allocator());</div> |
| <div class="line"><a name="l00282"></a><span class="lineno"> 282</span>  <span class="comment">// undo the compressor's 8-column shift</span></div> |
| <div class="line"><a name="l00283"></a><span class="lineno"> 283</span>  <span class="keywordflow">for</span> (uint32_t i = 0; i < num_pairs; i++) {</div> |
| <div class="line"><a name="l00284"></a><span class="lineno"> 284</span>  <span class="keywordflow">if</span> ((pairs[i] & 63) >= 56) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"(pairs[i] & 63) >= 56"</span>);</div> |
| <div class="line"><a name="l00285"></a><span class="lineno"> 285</span>  pairs[i] += 8;</div> |
| <div class="line"><a name="l00286"></a><span class="lineno"> 286</span>  }</div> |
| <div class="line"><a name="l00287"></a><span class="lineno"> 287</span>  target.table = u32_table<A>::make_from_pairs(pairs.data(), num_pairs, lg_k, pairs.get_allocator());</div> |
| <div class="line"><a name="l00288"></a><span class="lineno"> 288</span>  }</div> |
| <div class="line"><a name="l00289"></a><span class="lineno"> 289</span> }</div> |
| <div class="line"><a name="l00290"></a><span class="lineno"> 290</span>  </div> |
| <div class="line"><a name="l00291"></a><span class="lineno"> 291</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00292"></a><span class="lineno"> 292</span> <span class="keywordtype">void</span> cpc_compressor<A>::compress_sliding_flavor(<span class="keyword">const</span> cpc_sketch_alloc<A>& source, compressed_state<A>& result)<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00293"></a><span class="lineno"> 293</span>  compress_sliding_window(source.sliding_window.data(), source.get_lg_k(), source.get_num_coupons(), result);</div> |
| <div class="line"><a name="l00294"></a><span class="lineno"> 294</span>  vector_u32 pairs = source.surprising_value_table.unwrapping_get_items();</div> |
| <div class="line"><a name="l00295"></a><span class="lineno"> 295</span>  <span class="keywordflow">if</span> (pairs.size() > 0) {</div> |
| <div class="line"><a name="l00296"></a><span class="lineno"> 296</span>  <span class="comment">// Here we apply a complicated transformation to the column indices, which</span></div> |
| <div class="line"><a name="l00297"></a><span class="lineno"> 297</span>  <span class="comment">// changes the implied ordering of the pairs, so we must do it before sorting.</span></div> |
| <div class="line"><a name="l00298"></a><span class="lineno"> 298</span>  </div> |
| <div class="line"><a name="l00299"></a><span class="lineno"> 299</span>  <span class="keyword">const</span> uint8_t pseudo_phase = determine_pseudo_phase(source.get_lg_k(), source.get_num_coupons());</div> |
| <div class="line"><a name="l00300"></a><span class="lineno"> 300</span>  <span class="keywordflow">if</span> (pseudo_phase >= 16) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"unexpected pseudo phase for sliding flavor"</span>);</div> |
| <div class="line"><a name="l00301"></a><span class="lineno"> 301</span>  <span class="keyword">const</span> uint8_t* permutation = column_permutations_for_encoding[pseudo_phase];</div> |
| <div class="line"><a name="l00302"></a><span class="lineno"> 302</span>  </div> |
| <div class="line"><a name="l00303"></a><span class="lineno"> 303</span>  <span class="keyword">const</span> uint8_t offset = source.window_offset;</div> |
| <div class="line"><a name="l00304"></a><span class="lineno"> 304</span>  <span class="keywordflow">if</span> (offset > 56) <span class="keywordflow">throw</span> std::out_of_range(<span class="stringliteral">"offset out of range"</span>);</div> |
| <div class="line"><a name="l00305"></a><span class="lineno"> 305</span>  </div> |
| <div class="line"><a name="l00306"></a><span class="lineno"> 306</span>  <span class="keywordflow">for</span> (<span class="keywordtype">size_t</span> i = 0; i < pairs.size(); i++) {</div> |
| <div class="line"><a name="l00307"></a><span class="lineno"> 307</span>  <span class="keyword">const</span> uint32_t row_col = pairs[i];</div> |
| <div class="line"><a name="l00308"></a><span class="lineno"> 308</span>  <span class="keyword">const</span> uint32_t row = row_col >> 6;</div> |
| <div class="line"><a name="l00309"></a><span class="lineno"> 309</span>  uint8_t col = row_col & 63;</div> |
| <div class="line"><a name="l00310"></a><span class="lineno"> 310</span>  <span class="comment">// first rotate the columns into a canonical configuration: new = ((old - (offset+8)) + 64) mod 64</span></div> |
| <div class="line"><a name="l00311"></a><span class="lineno"> 311</span>  col = (col + 56 - offset) & 63;</div> |
| <div class="line"><a name="l00312"></a><span class="lineno"> 312</span>  <span class="keywordflow">if</span> (col >= 56) <span class="keywordflow">throw</span> std::out_of_range(<span class="stringliteral">"col out of range"</span>);</div> |
| <div class="line"><a name="l00313"></a><span class="lineno"> 313</span>  <span class="comment">// then apply the permutation</span></div> |
| <div class="line"><a name="l00314"></a><span class="lineno"> 314</span>  col = permutation[col];</div> |
| <div class="line"><a name="l00315"></a><span class="lineno"> 315</span>  pairs[i] = (row << 6) | col;</div> |
| <div class="line"><a name="l00316"></a><span class="lineno"> 316</span>  }</div> |
| <div class="line"><a name="l00317"></a><span class="lineno"> 317</span>  </div> |
| <div class="line"><a name="l00318"></a><span class="lineno"> 318</span>  <span class="keywordflow">if</span> (pairs.size() > 0) u32_table<A>::introspective_insertion_sort(pairs.data(), 0, pairs.size());</div> |
| <div class="line"><a name="l00319"></a><span class="lineno"> 319</span>  compress_surprising_values(pairs, source.get_lg_k(), result);</div> |
| <div class="line"><a name="l00320"></a><span class="lineno"> 320</span>  }</div> |
| <div class="line"><a name="l00321"></a><span class="lineno"> 321</span> }</div> |
| <div class="line"><a name="l00322"></a><span class="lineno"> 322</span>  </div> |
| <div class="line"><a name="l00323"></a><span class="lineno"> 323</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00324"></a><span class="lineno"> 324</span> <span class="keywordtype">void</span> cpc_compressor<A>::uncompress_sliding_flavor(<span class="keyword">const</span> compressed_state<A>& source, uncompressed_state<A>& target,</div> |
| <div class="line"><a name="l00325"></a><span class="lineno"> 325</span>  uint8_t lg_k, uint32_t num_coupons)<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00326"></a><span class="lineno"> 326</span>  <span class="keywordflow">if</span> (source.window_data.size() == 0) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"window is expected"</span>);</div> |
| <div class="line"><a name="l00327"></a><span class="lineno"> 327</span>  uncompress_sliding_window(source.window_data.data(), source.window_data_words, target.window, lg_k, num_coupons);</div> |
| <div class="line"><a name="l00328"></a><span class="lineno"> 328</span>  <span class="keyword">const</span> uint32_t num_pairs = source.table_num_entries;</div> |
| <div class="line"><a name="l00329"></a><span class="lineno"> 329</span>  <span class="keywordflow">if</span> (num_pairs == 0) {</div> |
| <div class="line"><a name="l00330"></a><span class="lineno"> 330</span>  target.table = u32_table<A>(2, 6 + lg_k, source.table_data.get_allocator());</div> |
| <div class="line"><a name="l00331"></a><span class="lineno"> 331</span>  } <span class="keywordflow">else</span> {</div> |
| <div class="line"><a name="l00332"></a><span class="lineno"> 332</span>  <span class="keywordflow">if</span> (source.table_data.size() == 0) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"table is expected"</span>);</div> |
| <div class="line"><a name="l00333"></a><span class="lineno"> 333</span>  vector_u32 pairs = uncompress_surprising_values(source.table_data.data(), source.table_data_words, num_pairs,</div> |
| <div class="line"><a name="l00334"></a><span class="lineno"> 334</span>  lg_k, source.table_data.get_allocator());</div> |
| <div class="line"><a name="l00335"></a><span class="lineno"> 335</span>  </div> |
| <div class="line"><a name="l00336"></a><span class="lineno"> 336</span>  <span class="keyword">const</span> uint8_t pseudo_phase = determine_pseudo_phase(lg_k, num_coupons);</div> |
| <div class="line"><a name="l00337"></a><span class="lineno"> 337</span>  <span class="keywordflow">if</span> (pseudo_phase >= 16) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"unexpected pseudo phase for sliding flavor"</span>);</div> |
| <div class="line"><a name="l00338"></a><span class="lineno"> 338</span>  <span class="keyword">const</span> uint8_t* permutation = column_permutations_for_decoding[pseudo_phase];</div> |
| <div class="line"><a name="l00339"></a><span class="lineno"> 339</span>  </div> |
| <div class="line"><a name="l00340"></a><span class="lineno"> 340</span>  uint8_t offset = cpc_sketch_alloc<A>::determine_correct_offset(lg_k, num_coupons);</div> |
| <div class="line"><a name="l00341"></a><span class="lineno"> 341</span>  <span class="keywordflow">if</span> (offset > 56) <span class="keywordflow">throw</span> std::out_of_range(<span class="stringliteral">"offset out of range"</span>);</div> |
| <div class="line"><a name="l00342"></a><span class="lineno"> 342</span>  </div> |
| <div class="line"><a name="l00343"></a><span class="lineno"> 343</span>  <span class="keywordflow">for</span> (uint32_t i = 0; i < num_pairs; i++) {</div> |
| <div class="line"><a name="l00344"></a><span class="lineno"> 344</span>  <span class="keyword">const</span> uint32_t row_col = pairs[i];</div> |
| <div class="line"><a name="l00345"></a><span class="lineno"> 345</span>  <span class="keyword">const</span> uint32_t row = row_col >> 6;</div> |
| <div class="line"><a name="l00346"></a><span class="lineno"> 346</span>  uint8_t col = row_col & 63;</div> |
| <div class="line"><a name="l00347"></a><span class="lineno"> 347</span>  <span class="comment">// first undo the permutation</span></div> |
| <div class="line"><a name="l00348"></a><span class="lineno"> 348</span>  col = permutation[col];</div> |
| <div class="line"><a name="l00349"></a><span class="lineno"> 349</span>  <span class="comment">// then undo the rotation: old = (new + (offset+8)) mod 64</span></div> |
| <div class="line"><a name="l00350"></a><span class="lineno"> 350</span>  col = (col + (offset + 8)) & 63;</div> |
| <div class="line"><a name="l00351"></a><span class="lineno"> 351</span>  pairs[i] = (row << 6) | col;</div> |
| <div class="line"><a name="l00352"></a><span class="lineno"> 352</span>  }</div> |
| <div class="line"><a name="l00353"></a><span class="lineno"> 353</span>  </div> |
| <div class="line"><a name="l00354"></a><span class="lineno"> 354</span>  target.table = u32_table<A>::make_from_pairs(pairs.data(), num_pairs, lg_k, pairs.get_allocator());</div> |
| <div class="line"><a name="l00355"></a><span class="lineno"> 355</span>  }</div> |
| <div class="line"><a name="l00356"></a><span class="lineno"> 356</span> }</div> |
| <div class="line"><a name="l00357"></a><span class="lineno"> 357</span>  </div> |
| <div class="line"><a name="l00358"></a><span class="lineno"> 358</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00359"></a><span class="lineno"> 359</span> <span class="keywordtype">void</span> cpc_compressor<A>::compress_surprising_values(<span class="keyword">const</span> vector_u32& pairs, uint8_t lg_k, compressed_state<A>& result)<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00360"></a><span class="lineno"> 360</span>  <span class="keyword">const</span> uint32_t k = 1 << lg_k;</div> |
| <div class="line"><a name="l00361"></a><span class="lineno"> 361</span>  <span class="keyword">const</span> uint32_t num_pairs = <span class="keyword">static_cast<</span>uint32_t<span class="keyword">></span>(pairs.size());</div> |
| <div class="line"><a name="l00362"></a><span class="lineno"> 362</span>  <span class="keyword">const</span> uint8_t num_base_bits = golomb_choose_number_of_base_bits(k + num_pairs, num_pairs);</div> |
| <div class="line"><a name="l00363"></a><span class="lineno"> 363</span>  <span class="keyword">const</span> uint64_t table_len = safe_length_for_compressed_pair_buf(k, num_pairs, num_base_bits);</div> |
| <div class="line"><a name="l00364"></a><span class="lineno"> 364</span>  result.table_data.resize(table_len);</div> |
| <div class="line"><a name="l00365"></a><span class="lineno"> 365</span>  </div> |
| <div class="line"><a name="l00366"></a><span class="lineno"> 366</span>  uint32_t csv_length = low_level_compress_pairs(pairs.data(), <span class="keyword">static_cast<</span>uint32_t<span class="keyword">></span>(pairs.size()), num_base_bits, result.table_data.data());</div> |
| <div class="line"><a name="l00367"></a><span class="lineno"> 367</span>  </div> |
| <div class="line"><a name="l00368"></a><span class="lineno"> 368</span>  <span class="comment">// At this point we could free the unused portion of the compression output buffer,</span></div> |
| <div class="line"><a name="l00369"></a><span class="lineno"> 369</span>  <span class="comment">// but it is not necessary if it is temporary</span></div> |
| <div class="line"><a name="l00370"></a><span class="lineno"> 370</span>  <span class="comment">// Note: realloc caused strange timing spikes for lgK = 11 and 12.</span></div> |
| <div class="line"><a name="l00371"></a><span class="lineno"> 371</span>  </div> |
| <div class="line"><a name="l00372"></a><span class="lineno"> 372</span>  result.table_data_words = csv_length;</div> |
| <div class="line"><a name="l00373"></a><span class="lineno"> 373</span>  result.table_num_entries = num_pairs;</div> |
| <div class="line"><a name="l00374"></a><span class="lineno"> 374</span> }</div> |
| <div class="line"><a name="l00375"></a><span class="lineno"> 375</span>  </div> |
| <div class="line"><a name="l00376"></a><span class="lineno"> 376</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00377"></a><span class="lineno"> 377</span> <span class="keyword">auto</span> cpc_compressor<A>::uncompress_surprising_values(<span class="keyword">const</span> uint32_t* data, uint32_t data_words, uint32_t num_pairs,</div> |
| <div class="line"><a name="l00378"></a><span class="lineno"> 378</span>  uint8_t lg_k, <span class="keyword">const</span> A& allocator) <span class="keyword">const</span> -> vector_u32 {</div> |
| <div class="line"><a name="l00379"></a><span class="lineno"> 379</span>  <span class="keyword">const</span> uint32_t k = 1 << lg_k;</div> |
| <div class="line"><a name="l00380"></a><span class="lineno"> 380</span>  vector_u32 pairs(num_pairs, 0, allocator);</div> |
| <div class="line"><a name="l00381"></a><span class="lineno"> 381</span>  <span class="keyword">const</span> uint8_t num_base_bits = golomb_choose_number_of_base_bits(k + num_pairs, num_pairs);</div> |
| <div class="line"><a name="l00382"></a><span class="lineno"> 382</span>  low_level_uncompress_pairs(pairs.data(), num_pairs, num_base_bits, data, data_words);</div> |
| <div class="line"><a name="l00383"></a><span class="lineno"> 383</span>  <span class="keywordflow">return</span> pairs;</div> |
| <div class="line"><a name="l00384"></a><span class="lineno"> 384</span> }</div> |
| <div class="line"><a name="l00385"></a><span class="lineno"> 385</span>  </div> |
| <div class="line"><a name="l00386"></a><span class="lineno"> 386</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00387"></a><span class="lineno"> 387</span> <span class="keywordtype">void</span> cpc_compressor<A>::compress_sliding_window(<span class="keyword">const</span> uint8_t* window, uint8_t lg_k, uint32_t num_coupons, compressed_state<A>& target)<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00388"></a><span class="lineno"> 388</span>  <span class="keyword">const</span> uint32_t k = 1 << lg_k;</div> |
| <div class="line"><a name="l00389"></a><span class="lineno"> 389</span>  <span class="keyword">const</span> <span class="keywordtype">size_t</span> window_buf_len = safe_length_for_compressed_window_buf(k);</div> |
| <div class="line"><a name="l00390"></a><span class="lineno"> 390</span>  target.window_data.resize(window_buf_len);</div> |
| <div class="line"><a name="l00391"></a><span class="lineno"> 391</span>  <span class="keyword">const</span> uint8_t pseudo_phase = determine_pseudo_phase(lg_k, num_coupons);</div> |
| <div class="line"><a name="l00392"></a><span class="lineno"> 392</span>  <span class="keywordtype">size_t</span> data_words = low_level_compress_bytes(window, k, encoding_tables_for_high_entropy_byte[pseudo_phase], target.window_data.data());</div> |
| <div class="line"><a name="l00393"></a><span class="lineno"> 393</span>  </div> |
| <div class="line"><a name="l00394"></a><span class="lineno"> 394</span>  <span class="comment">// At this point we could free the unused portion of the compression output buffer,</span></div> |
| <div class="line"><a name="l00395"></a><span class="lineno"> 395</span>  <span class="comment">// but it is not necessary if it is temporary</span></div> |
| <div class="line"><a name="l00396"></a><span class="lineno"> 396</span>  <span class="comment">// Note: realloc caused strange timing spikes for lgK = 11 and 12.</span></div> |
| <div class="line"><a name="l00397"></a><span class="lineno"> 397</span>  </div> |
| <div class="line"><a name="l00398"></a><span class="lineno"> 398</span>  target.window_data_words = <span class="keyword">static_cast<</span>uint32_t<span class="keyword">></span>(data_words);</div> |
| <div class="line"><a name="l00399"></a><span class="lineno"> 399</span> }</div> |
| <div class="line"><a name="l00400"></a><span class="lineno"> 400</span>  </div> |
| <div class="line"><a name="l00401"></a><span class="lineno"> 401</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00402"></a><span class="lineno"> 402</span> <span class="keywordtype">void</span> cpc_compressor<A>::uncompress_sliding_window(<span class="keyword">const</span> uint32_t* data, uint32_t data_words, vector_bytes& window,</div> |
| <div class="line"><a name="l00403"></a><span class="lineno"> 403</span>  uint8_t lg_k, uint32_t num_coupons)<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00404"></a><span class="lineno"> 404</span>  <span class="keyword">const</span> uint32_t k = 1 << lg_k;</div> |
| <div class="line"><a name="l00405"></a><span class="lineno"> 405</span>  window.resize(k); <span class="comment">// zeroing not needed here (unlike the Hybrid Flavor)</span></div> |
| <div class="line"><a name="l00406"></a><span class="lineno"> 406</span>  <span class="keyword">const</span> uint8_t pseudo_phase = determine_pseudo_phase(lg_k, num_coupons);</div> |
| <div class="line"><a name="l00407"></a><span class="lineno"> 407</span>  low_level_uncompress_bytes(window.data(), k, decoding_tables_for_high_entropy_byte[pseudo_phase], data, data_words);</div> |
| <div class="line"><a name="l00408"></a><span class="lineno"> 408</span> }</div> |
| <div class="line"><a name="l00409"></a><span class="lineno"> 409</span>  </div> |
| <div class="line"><a name="l00410"></a><span class="lineno"> 410</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00411"></a><span class="lineno"> 411</span> <span class="keywordtype">size_t</span> cpc_compressor<A>::safe_length_for_compressed_pair_buf(uint32_t k, uint32_t num_pairs, uint8_t num_base_bits) {</div> |
| <div class="line"><a name="l00412"></a><span class="lineno"> 412</span>  <span class="comment">// Long ybits = k + numPairs; // simpler and safer UB</span></div> |
| <div class="line"><a name="l00413"></a><span class="lineno"> 413</span>  <span class="comment">// The following tighter UB on ybits is based on page 198</span></div> |
| <div class="line"><a name="l00414"></a><span class="lineno"> 414</span>  <span class="comment">// of the textbook "Managing Gigabytes" by Witten, Moffat, and Bell.</span></div> |
| <div class="line"><a name="l00415"></a><span class="lineno"> 415</span>  <span class="comment">// Notice that if numBaseBits == 0 it coincides with (k + numPairs).</span></div> |
| <div class="line"><a name="l00416"></a><span class="lineno"> 416</span>  <span class="keyword">const</span> <span class="keywordtype">size_t</span> ybits = num_pairs * (1 + num_base_bits) + (k >> num_base_bits);</div> |
| <div class="line"><a name="l00417"></a><span class="lineno"> 417</span>  <span class="keyword">const</span> <span class="keywordtype">size_t</span> xbits = 12 * num_pairs;</div> |
| <div class="line"><a name="l00418"></a><span class="lineno"> 418</span>  <span class="keyword">const</span> <span class="keywordtype">size_t</span> padding = num_base_bits > 10 ? 0 : 10 - num_base_bits;</div> |
| <div class="line"><a name="l00419"></a><span class="lineno"> 419</span>  <span class="keywordflow">return</span> divide_longs_rounding_up(xbits + ybits + padding, 32);</div> |
| <div class="line"><a name="l00420"></a><span class="lineno"> 420</span> }</div> |
| <div class="line"><a name="l00421"></a><span class="lineno"> 421</span>  </div> |
| <div class="line"><a name="l00422"></a><span class="lineno"> 422</span> <span class="comment">// Explanation of padding: we write</span></div> |
| <div class="line"><a name="l00423"></a><span class="lineno"> 423</span> <span class="comment">// 1) xdelta (huffman, provides at least 1 bit, requires 12-bit lookahead)</span></div> |
| <div class="line"><a name="l00424"></a><span class="lineno"> 424</span> <span class="comment">// 2) ydeltaGolombHi (unary, provides at least 1 bit, requires 8-bit lookahead)</span></div> |
| <div class="line"><a name="l00425"></a><span class="lineno"> 425</span> <span class="comment">// 3) ydeltaGolombLo (straight B bits).</span></div> |
| <div class="line"><a name="l00426"></a><span class="lineno"> 426</span> <span class="comment">// So the 12-bit lookahead is the tight constraint, but there are at least (2 + B) bits emitted,</span></div> |
| <div class="line"><a name="l00427"></a><span class="lineno"> 427</span> <span class="comment">// so we would be safe with max (0, 10 - B) bits of padding at the end of the bitstream.</span></div> |
| <div class="line"><a name="l00428"></a><span class="lineno"> 428</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00429"></a><span class="lineno"> 429</span> <span class="keywordtype">size_t</span> cpc_compressor<A>::safe_length_for_compressed_window_buf(uint32_t k) { <span class="comment">// measured in 32-bit words</span></div> |
| <div class="line"><a name="l00430"></a><span class="lineno"> 430</span>  <span class="keyword">const</span> <span class="keywordtype">size_t</span> bits = 12 * k + 11; <span class="comment">// 11 bits of padding, due to 12-bit lookahead, with 1 bit certainly present.</span></div> |
| <div class="line"><a name="l00431"></a><span class="lineno"> 431</span>  <span class="keywordflow">return</span> divide_longs_rounding_up(bits, 32);</div> |
| <div class="line"><a name="l00432"></a><span class="lineno"> 432</span> }</div> |
| <div class="line"><a name="l00433"></a><span class="lineno"> 433</span>  </div> |
| <div class="line"><a name="l00434"></a><span class="lineno"> 434</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00435"></a><span class="lineno"> 435</span> uint8_t cpc_compressor<A>::determine_pseudo_phase(uint8_t lg_k, uint32_t c) {</div> |
| <div class="line"><a name="l00436"></a><span class="lineno"> 436</span>  <span class="keyword">const</span> uint32_t k = 1 << lg_k;</div> |
| <div class="line"><a name="l00437"></a><span class="lineno"> 437</span>  <span class="comment">// This mid-range logic produces pseudo-phases. They are used to select encoding tables.</span></div> |
| <div class="line"><a name="l00438"></a><span class="lineno"> 438</span>  <span class="comment">// The thresholds were chosen by hand after looking at plots of measured compression.</span></div> |
| <div class="line"><a name="l00439"></a><span class="lineno"> 439</span>  <span class="keywordflow">if</span> (1000 * c < 2375 * k) {</div> |
| <div class="line"><a name="l00440"></a><span class="lineno"> 440</span>  <span class="keywordflow">if</span> ( 4 * c < 3 * k) <span class="keywordflow">return</span> 16 + 0; <span class="comment">// mid-range table</span></div> |
| <div class="line"><a name="l00441"></a><span class="lineno"> 441</span>  <span class="keywordflow">else</span> <span class="keywordflow">if</span> ( 10 * c < 11 * k) <span class="keywordflow">return</span> 16 + 1; <span class="comment">// mid-range table</span></div> |
| <div class="line"><a name="l00442"></a><span class="lineno"> 442</span>  <span class="keywordflow">else</span> <span class="keywordflow">if</span> ( 100 * c < 132 * k) <span class="keywordflow">return</span> 16 + 2; <span class="comment">// mid-range table</span></div> |
| <div class="line"><a name="l00443"></a><span class="lineno"> 443</span>  <span class="keywordflow">else</span> <span class="keywordflow">if</span> ( 3 * c < 5 * k) <span class="keywordflow">return</span> 16 + 3; <span class="comment">// mid-range table</span></div> |
| <div class="line"><a name="l00444"></a><span class="lineno"> 444</span>  <span class="keywordflow">else</span> <span class="keywordflow">if</span> (1000 * c < 1965 * k) <span class="keywordflow">return</span> 16 + 4; <span class="comment">// mid-range table</span></div> |
| <div class="line"><a name="l00445"></a><span class="lineno"> 445</span>  <span class="keywordflow">else</span> <span class="keywordflow">if</span> (1000 * c < 2275 * k) <span class="keywordflow">return</span> 16 + 5; <span class="comment">// mid-range table</span></div> |
| <div class="line"><a name="l00446"></a><span class="lineno"> 446</span>  <span class="keywordflow">else</span> <span class="keywordflow">return</span> 6; <span class="comment">// steady-state table employed before its actual phase</span></div> |
| <div class="line"><a name="l00447"></a><span class="lineno"> 447</span>  } <span class="keywordflow">else</span> { <span class="comment">// This steady-state logic produces true phases. They are used to select</span></div> |
| <div class="line"><a name="l00448"></a><span class="lineno"> 448</span>  <span class="comment">// encoding tables, and also column permutations for the "Sliding" flavor.</span></div> |
| <div class="line"><a name="l00449"></a><span class="lineno"> 449</span>  <span class="keywordflow">if</span> (lg_k < 4) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"lgK < 4"</span>);</div> |
| <div class="line"><a name="l00450"></a><span class="lineno"> 450</span>  <span class="keyword">const</span> <span class="keywordtype">size_t</span> tmp = c >> (lg_k - 4);</div> |
| <div class="line"><a name="l00451"></a><span class="lineno"> 451</span>  <span class="keyword">const</span> uint8_t phase = tmp & 15;</div> |
| <div class="line"><a name="l00452"></a><span class="lineno"> 452</span>  <span class="keywordflow">if</span> (phase >= 16) <span class="keywordflow">throw</span> std::out_of_range(<span class="stringliteral">"wrong phase"</span>);</div> |
| <div class="line"><a name="l00453"></a><span class="lineno"> 453</span>  <span class="keywordflow">return</span> phase;</div> |
| <div class="line"><a name="l00454"></a><span class="lineno"> 454</span>  }</div> |
| <div class="line"><a name="l00455"></a><span class="lineno"> 455</span> }</div> |
| <div class="line"><a name="l00456"></a><span class="lineno"> 456</span>  </div> |
| <div class="line"><a name="l00457"></a><span class="lineno"> 457</span> <span class="keyword">static</span> <span class="keyword">inline</span> <span class="keywordtype">void</span> maybe_flush_bitbuf(uint64_t& bitbuf, uint8_t& bufbits, uint32_t* wordarr, uint32_t& wordindex) {</div> |
| <div class="line"><a name="l00458"></a><span class="lineno"> 458</span>  <span class="keywordflow">if</span> (bufbits >= 32) {</div> |
| <div class="line"><a name="l00459"></a><span class="lineno"> 459</span>  wordarr[wordindex++] = bitbuf & 0xffffffff;</div> |
| <div class="line"><a name="l00460"></a><span class="lineno"> 460</span>  bitbuf = bitbuf >> 32;</div> |
| <div class="line"><a name="l00461"></a><span class="lineno"> 461</span>  bufbits -= 32;</div> |
| <div class="line"><a name="l00462"></a><span class="lineno"> 462</span>  }</div> |
| <div class="line"><a name="l00463"></a><span class="lineno"> 463</span> }</div> |
| <div class="line"><a name="l00464"></a><span class="lineno"> 464</span>  </div> |
| <div class="line"><a name="l00465"></a><span class="lineno"> 465</span> <span class="keyword">static</span> <span class="keyword">inline</span> <span class="keywordtype">void</span> maybe_fill_bitbuf(uint64_t& bitbuf, uint8_t& bufbits, <span class="keyword">const</span> uint32_t* wordarr, uint32_t& wordindex, uint8_t minbits) {</div> |
| <div class="line"><a name="l00466"></a><span class="lineno"> 466</span>  <span class="keywordflow">if</span> (bufbits < minbits) {</div> |
| <div class="line"><a name="l00467"></a><span class="lineno"> 467</span>  bitbuf |= <span class="keyword">static_cast<</span>uint64_t<span class="keyword">></span>(wordarr[wordindex++]) << bufbits;</div> |
| <div class="line"><a name="l00468"></a><span class="lineno"> 468</span>  bufbits += 32;</div> |
| <div class="line"><a name="l00469"></a><span class="lineno"> 469</span>  }</div> |
| <div class="line"><a name="l00470"></a><span class="lineno"> 470</span> }</div> |
| <div class="line"><a name="l00471"></a><span class="lineno"> 471</span>  </div> |
| <div class="line"><a name="l00472"></a><span class="lineno"> 472</span> <span class="comment">// This returns the number of compressed words that were actually used.</span></div> |
| <div class="line"><a name="l00473"></a><span class="lineno"> 473</span> <span class="comment">// It is the caller's responsibility to ensure that the compressed_words array is long enough.</span></div> |
| <div class="line"><a name="l00474"></a><span class="lineno"> 474</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00475"></a><span class="lineno"> 475</span> uint32_t cpc_compressor<A>::low_level_compress_bytes(</div> |
| <div class="line"><a name="l00476"></a><span class="lineno"> 476</span>  <span class="keyword">const</span> uint8_t* byte_array, <span class="comment">// input</span></div> |
| <div class="line"><a name="l00477"></a><span class="lineno"> 477</span>  uint32_t num_bytes_to_encode,</div> |
| <div class="line"><a name="l00478"></a><span class="lineno"> 478</span>  <span class="keyword">const</span> uint16_t* encoding_table,</div> |
| <div class="line"><a name="l00479"></a><span class="lineno"> 479</span>  uint32_t* compressed_words <span class="comment">// output</span></div> |
| <div class="line"><a name="l00480"></a><span class="lineno"> 480</span> )<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00481"></a><span class="lineno"> 481</span>  uint64_t bitbuf = 0; <span class="comment">// bits are packed into this first, then are flushed to compressed_words</span></div> |
| <div class="line"><a name="l00482"></a><span class="lineno"> 482</span>  uint8_t bufbits = 0; <span class="comment">// number of bits currently in bitbuf; must be between 0 and 31</span></div> |
| <div class="line"><a name="l00483"></a><span class="lineno"> 483</span>  uint32_t next_word_index = 0;</div> |
| <div class="line"><a name="l00484"></a><span class="lineno"> 484</span>  </div> |
| <div class="line"><a name="l00485"></a><span class="lineno"> 485</span>  <span class="keywordflow">for</span> (uint32_t byte_index = 0; byte_index < num_bytes_to_encode; byte_index++) {</div> |
| <div class="line"><a name="l00486"></a><span class="lineno"> 486</span>  <span class="keyword">const</span> uint16_t code_info = encoding_table[byte_array[byte_index]];</div> |
| <div class="line"><a name="l00487"></a><span class="lineno"> 487</span>  <span class="keyword">const</span> uint64_t code_val = code_info & 0xfff;</div> |
| <div class="line"><a name="l00488"></a><span class="lineno"> 488</span>  <span class="keyword">const</span> uint8_t code_len = code_info >> 12;</div> |
| <div class="line"><a name="l00489"></a><span class="lineno"> 489</span>  bitbuf |= (code_val << bufbits);</div> |
| <div class="line"><a name="l00490"></a><span class="lineno"> 490</span>  bufbits += code_len;</div> |
| <div class="line"><a name="l00491"></a><span class="lineno"> 491</span>  maybe_flush_bitbuf(bitbuf, bufbits, compressed_words, next_word_index);</div> |
| <div class="line"><a name="l00492"></a><span class="lineno"> 492</span>  }</div> |
| <div class="line"><a name="l00493"></a><span class="lineno"> 493</span>  </div> |
| <div class="line"><a name="l00494"></a><span class="lineno"> 494</span>  <span class="comment">// Pad the bitstream with 11 zero-bits so that the decompressor's 12-bit peek can't overrun its input.</span></div> |
| <div class="line"><a name="l00495"></a><span class="lineno"> 495</span>  bufbits += 11;</div> |
| <div class="line"><a name="l00496"></a><span class="lineno"> 496</span>  maybe_flush_bitbuf(bitbuf, bufbits, compressed_words, next_word_index);</div> |
| <div class="line"><a name="l00497"></a><span class="lineno"> 497</span>  </div> |
| <div class="line"><a name="l00498"></a><span class="lineno"> 498</span>  <span class="keywordflow">if</span> (bufbits > 0) { <span class="comment">// We are done encoding now, so we flush the bit buffer.</span></div> |
| <div class="line"><a name="l00499"></a><span class="lineno"> 499</span>  <span class="keywordflow">if</span> (bufbits >= 32) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"bufbits >= 32"</span>);</div> |
| <div class="line"><a name="l00500"></a><span class="lineno"> 500</span>  compressed_words[next_word_index++] = bitbuf & 0xffffffff;</div> |
| <div class="line"><a name="l00501"></a><span class="lineno"> 501</span>  bitbuf = 0; bufbits = 0; <span class="comment">// not really necessary</span></div> |
| <div class="line"><a name="l00502"></a><span class="lineno"> 502</span>  }</div> |
| <div class="line"><a name="l00503"></a><span class="lineno"> 503</span>  <span class="keywordflow">return</span> next_word_index;</div> |
| <div class="line"><a name="l00504"></a><span class="lineno"> 504</span> }</div> |
| <div class="line"><a name="l00505"></a><span class="lineno"> 505</span>  </div> |
| <div class="line"><a name="l00506"></a><span class="lineno"> 506</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00507"></a><span class="lineno"> 507</span> <span class="keywordtype">void</span> cpc_compressor<A>::low_level_uncompress_bytes(</div> |
| <div class="line"><a name="l00508"></a><span class="lineno"> 508</span>  uint8_t* byte_array, <span class="comment">// output</span></div> |
| <div class="line"><a name="l00509"></a><span class="lineno"> 509</span>  uint32_t num_bytes_to_decode,</div> |
| <div class="line"><a name="l00510"></a><span class="lineno"> 510</span>  <span class="keyword">const</span> uint16_t* decoding_table,</div> |
| <div class="line"><a name="l00511"></a><span class="lineno"> 511</span>  <span class="keyword">const</span> uint32_t* compressed_words, <span class="comment">// input</span></div> |
| <div class="line"><a name="l00512"></a><span class="lineno"> 512</span>  uint32_t num_compressed_words</div> |
| <div class="line"><a name="l00513"></a><span class="lineno"> 513</span> )<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00514"></a><span class="lineno"> 514</span>  uint32_t word_index = 0;</div> |
| <div class="line"><a name="l00515"></a><span class="lineno"> 515</span>  uint64_t bitbuf = 0;</div> |
| <div class="line"><a name="l00516"></a><span class="lineno"> 516</span>  uint8_t bufbits = 0;</div> |
| <div class="line"><a name="l00517"></a><span class="lineno"> 517</span>  </div> |
| <div class="line"><a name="l00518"></a><span class="lineno"> 518</span>  <span class="keywordflow">if</span> (byte_array == <span class="keyword">nullptr</span>) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"byte_array == NULL"</span>);</div> |
| <div class="line"><a name="l00519"></a><span class="lineno"> 519</span>  <span class="keywordflow">if</span> (decoding_table == <span class="keyword">nullptr</span>) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"decoding_table == NULL"</span>);</div> |
| <div class="line"><a name="l00520"></a><span class="lineno"> 520</span>  <span class="keywordflow">if</span> (compressed_words == <span class="keyword">nullptr</span>) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"compressed_words == NULL"</span>);</div> |
| <div class="line"><a name="l00521"></a><span class="lineno"> 521</span>  </div> |
| <div class="line"><a name="l00522"></a><span class="lineno"> 522</span>  <span class="keywordflow">for</span> (uint32_t byte_index = 0; byte_index < num_bytes_to_decode; byte_index++) {</div> |
| <div class="line"><a name="l00523"></a><span class="lineno"> 523</span>  maybe_fill_bitbuf(bitbuf, bufbits, compressed_words, word_index, 12); <span class="comment">// ensure 12 bits in bit buffer</span></div> |
| <div class="line"><a name="l00524"></a><span class="lineno"> 524</span>  </div> |
| <div class="line"><a name="l00525"></a><span class="lineno"> 525</span>  <span class="keyword">const</span> <span class="keywordtype">size_t</span> peek12 = bitbuf & 0xfff; <span class="comment">// These 12 bits will include an entire Huffman codeword.</span></div> |
| <div class="line"><a name="l00526"></a><span class="lineno"> 526</span>  <span class="keyword">const</span> uint16_t lookup = decoding_table[peek12];</div> |
| <div class="line"><a name="l00527"></a><span class="lineno"> 527</span>  <span class="keyword">const</span> uint8_t code_word_length = lookup >> 8;</div> |
| <div class="line"><a name="l00528"></a><span class="lineno"> 528</span>  <span class="keyword">const</span> uint8_t decoded_byte = lookup & 0xff;</div> |
| <div class="line"><a name="l00529"></a><span class="lineno"> 529</span>  byte_array[byte_index] = decoded_byte;</div> |
| <div class="line"><a name="l00530"></a><span class="lineno"> 530</span>  bitbuf >>= code_word_length;</div> |
| <div class="line"><a name="l00531"></a><span class="lineno"> 531</span>  bufbits -= code_word_length;</div> |
| <div class="line"><a name="l00532"></a><span class="lineno"> 532</span>  }</div> |
| <div class="line"><a name="l00533"></a><span class="lineno"> 533</span>  <span class="comment">// Buffer over-run should be impossible unless there is a bug.</span></div> |
| <div class="line"><a name="l00534"></a><span class="lineno"> 534</span>  <span class="comment">// However, we might as well check here.</span></div> |
| <div class="line"><a name="l00535"></a><span class="lineno"> 535</span>  <span class="keywordflow">if</span> (word_index > num_compressed_words) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"word_index > num_compressed_words"</span>);</div> |
| <div class="line"><a name="l00536"></a><span class="lineno"> 536</span> }</div> |
| <div class="line"><a name="l00537"></a><span class="lineno"> 537</span>  </div> |
| <div class="line"><a name="l00538"></a><span class="lineno"> 538</span> <span class="keyword">static</span> <span class="keyword">inline</span> uint64_t read_unary(</div> |
| <div class="line"><a name="l00539"></a><span class="lineno"> 539</span>  <span class="keyword">const</span> uint32_t* compressed_words,</div> |
| <div class="line"><a name="l00540"></a><span class="lineno"> 540</span>  uint32_t& next_word_index,</div> |
| <div class="line"><a name="l00541"></a><span class="lineno"> 541</span>  uint64_t& bitbuf,</div> |
| <div class="line"><a name="l00542"></a><span class="lineno"> 542</span>  uint8_t& bufbits</div> |
| <div class="line"><a name="l00543"></a><span class="lineno"> 543</span> );</div> |
| <div class="line"><a name="l00544"></a><span class="lineno"> 544</span>  </div> |
| <div class="line"><a name="l00545"></a><span class="lineno"> 545</span> <span class="keyword">static</span> <span class="keyword">inline</span> <span class="keywordtype">void</span> write_unary(</div> |
| <div class="line"><a name="l00546"></a><span class="lineno"> 546</span>  uint32_t* compressed_words,</div> |
| <div class="line"><a name="l00547"></a><span class="lineno"> 547</span>  uint32_t& next_word_index_ptr,</div> |
| <div class="line"><a name="l00548"></a><span class="lineno"> 548</span>  uint64_t& bit_buf_ptr,</div> |
| <div class="line"><a name="l00549"></a><span class="lineno"> 549</span>  uint8_t& buf_bits_ptr,</div> |
| <div class="line"><a name="l00550"></a><span class="lineno"> 550</span>  uint64_t value</div> |
| <div class="line"><a name="l00551"></a><span class="lineno"> 551</span> );</div> |
| <div class="line"><a name="l00552"></a><span class="lineno"> 552</span>  </div> |
| <div class="line"><a name="l00553"></a><span class="lineno"> 553</span> <span class="comment">// Here "pairs" refers to row/column pairs that specify</span></div> |
| <div class="line"><a name="l00554"></a><span class="lineno"> 554</span> <span class="comment">// the positions of surprising values in the bit matrix.</span></div> |
| <div class="line"><a name="l00555"></a><span class="lineno"> 555</span>  </div> |
| <div class="line"><a name="l00556"></a><span class="lineno"> 556</span> <span class="comment">// returns the number of compressed_words actually used</span></div> |
| <div class="line"><a name="l00557"></a><span class="lineno"> 557</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00558"></a><span class="lineno"> 558</span> uint32_t cpc_compressor<A>::low_level_compress_pairs(</div> |
| <div class="line"><a name="l00559"></a><span class="lineno"> 559</span>  <span class="keyword">const</span> uint32_t* pair_array, <span class="comment">// input</span></div> |
| <div class="line"><a name="l00560"></a><span class="lineno"> 560</span>  uint32_t num_pairs_to_encode,</div> |
| <div class="line"><a name="l00561"></a><span class="lineno"> 561</span>  uint8_t num_base_bits,</div> |
| <div class="line"><a name="l00562"></a><span class="lineno"> 562</span>  uint32_t* compressed_words <span class="comment">// output</span></div> |
| <div class="line"><a name="l00563"></a><span class="lineno"> 563</span> )<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00564"></a><span class="lineno"> 564</span>  uint64_t bitbuf = 0;</div> |
| <div class="line"><a name="l00565"></a><span class="lineno"> 565</span>  uint8_t bufbits = 0;</div> |
| <div class="line"><a name="l00566"></a><span class="lineno"> 566</span>  uint32_t next_word_index = 0;</div> |
| <div class="line"><a name="l00567"></a><span class="lineno"> 567</span>  <span class="keyword">const</span> uint64_t golomb_lo_mask = (1 << num_base_bits) - 1;</div> |
| <div class="line"><a name="l00568"></a><span class="lineno"> 568</span>  uint32_t predicted_row_index = 0;</div> |
| <div class="line"><a name="l00569"></a><span class="lineno"> 569</span>  uint8_t predicted_col_index = 0;</div> |
| <div class="line"><a name="l00570"></a><span class="lineno"> 570</span>  </div> |
| <div class="line"><a name="l00571"></a><span class="lineno"> 571</span>  <span class="keywordflow">for</span> (uint32_t pair_index = 0; pair_index < num_pairs_to_encode; pair_index++) {</div> |
| <div class="line"><a name="l00572"></a><span class="lineno"> 572</span>  <span class="keyword">const</span> uint32_t row_col = pair_array[pair_index];</div> |
| <div class="line"><a name="l00573"></a><span class="lineno"> 573</span>  <span class="keyword">const</span> uint32_t row_index = row_col >> 6;</div> |
| <div class="line"><a name="l00574"></a><span class="lineno"> 574</span>  <span class="keyword">const</span> uint8_t col_index = row_col & 63;</div> |
| <div class="line"><a name="l00575"></a><span class="lineno"> 575</span>  </div> |
| <div class="line"><a name="l00576"></a><span class="lineno"> 576</span>  <span class="keywordflow">if</span> (row_index != predicted_row_index) predicted_col_index = 0;</div> |
| <div class="line"><a name="l00577"></a><span class="lineno"> 577</span>  </div> |
| <div class="line"><a name="l00578"></a><span class="lineno"> 578</span>  <span class="keywordflow">if</span> (row_index < predicted_row_index) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"row_index < predicted_row_index"</span>);</div> |
| <div class="line"><a name="l00579"></a><span class="lineno"> 579</span>  <span class="keywordflow">if</span> (col_index < predicted_col_index) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"col_index < predicted_col_index"</span>);</div> |
| <div class="line"><a name="l00580"></a><span class="lineno"> 580</span>  </div> |
| <div class="line"><a name="l00581"></a><span class="lineno"> 581</span>  <span class="keyword">const</span> uint32_t y_delta = row_index - predicted_row_index;</div> |
| <div class="line"><a name="l00582"></a><span class="lineno"> 582</span>  <span class="keyword">const</span> uint8_t x_delta = col_index - predicted_col_index;</div> |
| <div class="line"><a name="l00583"></a><span class="lineno"> 583</span>  </div> |
| <div class="line"><a name="l00584"></a><span class="lineno"> 584</span>  predicted_row_index = row_index;</div> |
| <div class="line"><a name="l00585"></a><span class="lineno"> 585</span>  predicted_col_index = col_index + 1;</div> |
| <div class="line"><a name="l00586"></a><span class="lineno"> 586</span>  </div> |
| <div class="line"><a name="l00587"></a><span class="lineno"> 587</span>  <span class="keyword">const</span> uint16_t code_info = length_limited_unary_encoding_table65[x_delta];</div> |
| <div class="line"><a name="l00588"></a><span class="lineno"> 588</span>  <span class="keyword">const</span> uint64_t code_val = code_info & 0xfff;</div> |
| <div class="line"><a name="l00589"></a><span class="lineno"> 589</span>  <span class="keyword">const</span> uint8_t code_len = <span class="keyword">static_cast<</span>uint8_t<span class="keyword">></span>(code_info >> 12);</div> |
| <div class="line"><a name="l00590"></a><span class="lineno"> 590</span>  bitbuf |= code_val << bufbits;</div> |
| <div class="line"><a name="l00591"></a><span class="lineno"> 591</span>  bufbits += code_len;</div> |
| <div class="line"><a name="l00592"></a><span class="lineno"> 592</span>  maybe_flush_bitbuf(bitbuf, bufbits, compressed_words, next_word_index);</div> |
| <div class="line"><a name="l00593"></a><span class="lineno"> 593</span>  </div> |
| <div class="line"><a name="l00594"></a><span class="lineno"> 594</span>  <span class="keyword">const</span> uint64_t golomb_lo = y_delta & golomb_lo_mask;</div> |
| <div class="line"><a name="l00595"></a><span class="lineno"> 595</span>  <span class="keyword">const</span> uint64_t golomb_hi = y_delta >> num_base_bits;</div> |
| <div class="line"><a name="l00596"></a><span class="lineno"> 596</span>  </div> |
| <div class="line"><a name="l00597"></a><span class="lineno"> 597</span>  write_unary(compressed_words, next_word_index, bitbuf, bufbits, golomb_hi);</div> |
| <div class="line"><a name="l00598"></a><span class="lineno"> 598</span>  </div> |
| <div class="line"><a name="l00599"></a><span class="lineno"> 599</span>  bitbuf |= golomb_lo << bufbits;</div> |
| <div class="line"><a name="l00600"></a><span class="lineno"> 600</span>  bufbits += num_base_bits;</div> |
| <div class="line"><a name="l00601"></a><span class="lineno"> 601</span>  maybe_flush_bitbuf(bitbuf, bufbits, compressed_words, next_word_index);</div> |
| <div class="line"><a name="l00602"></a><span class="lineno"> 602</span>  }</div> |
| <div class="line"><a name="l00603"></a><span class="lineno"> 603</span>  </div> |
| <div class="line"><a name="l00604"></a><span class="lineno"> 604</span>  <span class="comment">// Pad the bitstream so that the decompressor's 12-bit peek can't overrun its input.</span></div> |
| <div class="line"><a name="l00605"></a><span class="lineno"> 605</span>  <span class="keyword">const</span> uint8_t padding = (num_base_bits > 10) ? 0 : 10 - num_base_bits;</div> |
| <div class="line"><a name="l00606"></a><span class="lineno"> 606</span>  bufbits += padding;</div> |
| <div class="line"><a name="l00607"></a><span class="lineno"> 607</span>  maybe_flush_bitbuf(bitbuf, bufbits, compressed_words, next_word_index);</div> |
| <div class="line"><a name="l00608"></a><span class="lineno"> 608</span>  </div> |
| <div class="line"><a name="l00609"></a><span class="lineno"> 609</span>  <span class="keywordflow">if</span> (bufbits > 0) { <span class="comment">// We are done encoding now, so we flush the bit buffer</span></div> |
| <div class="line"><a name="l00610"></a><span class="lineno"> 610</span>  <span class="keywordflow">if</span> (bufbits >= 32) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"bufbits >= 32"</span>);</div> |
| <div class="line"><a name="l00611"></a><span class="lineno"> 611</span>  compressed_words[next_word_index++] = bitbuf & 0xffffffff;</div> |
| <div class="line"><a name="l00612"></a><span class="lineno"> 612</span>  bitbuf = 0; bufbits = 0; <span class="comment">// not really necessary</span></div> |
| <div class="line"><a name="l00613"></a><span class="lineno"> 613</span>  }</div> |
| <div class="line"><a name="l00614"></a><span class="lineno"> 614</span>  </div> |
| <div class="line"><a name="l00615"></a><span class="lineno"> 615</span>  <span class="keywordflow">return</span> next_word_index;</div> |
| <div class="line"><a name="l00616"></a><span class="lineno"> 616</span> }</div> |
| <div class="line"><a name="l00617"></a><span class="lineno"> 617</span>  </div> |
| <div class="line"><a name="l00618"></a><span class="lineno"> 618</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00619"></a><span class="lineno"> 619</span> <span class="keywordtype">void</span> cpc_compressor<A>::low_level_uncompress_pairs(</div> |
| <div class="line"><a name="l00620"></a><span class="lineno"> 620</span>  uint32_t* pair_array, <span class="comment">// output</span></div> |
| <div class="line"><a name="l00621"></a><span class="lineno"> 621</span>  uint32_t num_pairs_to_decode,</div> |
| <div class="line"><a name="l00622"></a><span class="lineno"> 622</span>  uint8_t num_base_bits,</div> |
| <div class="line"><a name="l00623"></a><span class="lineno"> 623</span>  <span class="keyword">const</span> uint32_t* compressed_words, <span class="comment">// input</span></div> |
| <div class="line"><a name="l00624"></a><span class="lineno"> 624</span>  uint32_t num_compressed_words</div> |
| <div class="line"><a name="l00625"></a><span class="lineno"> 625</span> )<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00626"></a><span class="lineno"> 626</span>  uint32_t word_index = 0;</div> |
| <div class="line"><a name="l00627"></a><span class="lineno"> 627</span>  uint64_t bitbuf = 0;</div> |
| <div class="line"><a name="l00628"></a><span class="lineno"> 628</span>  uint8_t bufbits = 0;</div> |
| <div class="line"><a name="l00629"></a><span class="lineno"> 629</span>  <span class="keyword">const</span> uint64_t golomb_lo_mask = (1 << num_base_bits) - 1;</div> |
| <div class="line"><a name="l00630"></a><span class="lineno"> 630</span>  uint32_t predicted_row_index = 0;</div> |
| <div class="line"><a name="l00631"></a><span class="lineno"> 631</span>  uint8_t predicted_col_index = 0;</div> |
| <div class="line"><a name="l00632"></a><span class="lineno"> 632</span>  </div> |
| <div class="line"><a name="l00633"></a><span class="lineno"> 633</span>  <span class="comment">// for each pair we need to read:</span></div> |
| <div class="line"><a name="l00634"></a><span class="lineno"> 634</span>  <span class="comment">// x_delta (12-bit length-limited unary)</span></div> |
| <div class="line"><a name="l00635"></a><span class="lineno"> 635</span>  <span class="comment">// y_delta_hi (unary)</span></div> |
| <div class="line"><a name="l00636"></a><span class="lineno"> 636</span>  <span class="comment">// y_delta_lo (basebits)</span></div> |
| <div class="line"><a name="l00637"></a><span class="lineno"> 637</span>  </div> |
| <div class="line"><a name="l00638"></a><span class="lineno"> 638</span>  <span class="keywordflow">for</span> (uint32_t pair_index = 0; pair_index < num_pairs_to_decode; pair_index++) {</div> |
| <div class="line"><a name="l00639"></a><span class="lineno"> 639</span>  maybe_fill_bitbuf(bitbuf, bufbits, compressed_words, word_index, 12); <span class="comment">// ensure 12 bits in bit buffer</span></div> |
| <div class="line"><a name="l00640"></a><span class="lineno"> 640</span>  <span class="keyword">const</span> <span class="keywordtype">size_t</span> peek12 = bitbuf & 0xfff;</div> |
| <div class="line"><a name="l00641"></a><span class="lineno"> 641</span>  <span class="keyword">const</span> uint16_t lookup = length_limited_unary_decoding_table65[peek12];</div> |
| <div class="line"><a name="l00642"></a><span class="lineno"> 642</span>  <span class="keyword">const</span> uint8_t code_word_length = lookup >> 8;</div> |
| <div class="line"><a name="l00643"></a><span class="lineno"> 643</span>  <span class="keyword">const</span> int8_t x_delta = lookup & 0xff;</div> |
| <div class="line"><a name="l00644"></a><span class="lineno"> 644</span>  bitbuf >>= code_word_length;</div> |
| <div class="line"><a name="l00645"></a><span class="lineno"> 645</span>  bufbits -= code_word_length;</div> |
| <div class="line"><a name="l00646"></a><span class="lineno"> 646</span>  </div> |
| <div class="line"><a name="l00647"></a><span class="lineno"> 647</span>  <span class="keyword">const</span> uint64_t golomb_hi = read_unary(compressed_words, word_index, bitbuf, bufbits);</div> |
| <div class="line"><a name="l00648"></a><span class="lineno"> 648</span>  </div> |
| <div class="line"><a name="l00649"></a><span class="lineno"> 649</span>  maybe_fill_bitbuf(bitbuf, bufbits, compressed_words, word_index, num_base_bits); <span class="comment">// ensure num_base_bits in bit buffer</span></div> |
| <div class="line"><a name="l00650"></a><span class="lineno"> 650</span>  <span class="keyword">const</span> uint64_t golomb_lo = bitbuf & golomb_lo_mask;</div> |
| <div class="line"><a name="l00651"></a><span class="lineno"> 651</span>  bitbuf >>= num_base_bits;</div> |
| <div class="line"><a name="l00652"></a><span class="lineno"> 652</span>  bufbits -= num_base_bits;</div> |
| <div class="line"><a name="l00653"></a><span class="lineno"> 653</span>  <span class="keyword">const</span> int64_t y_delta = (golomb_hi << num_base_bits) | golomb_lo;</div> |
| <div class="line"><a name="l00654"></a><span class="lineno"> 654</span>  </div> |
| <div class="line"><a name="l00655"></a><span class="lineno"> 655</span>  <span class="comment">// Now that we have x_delta and y_delta, we can compute the pair's row and column</span></div> |
| <div class="line"><a name="l00656"></a><span class="lineno"> 656</span>  <span class="keywordflow">if</span> (y_delta > 0) predicted_col_index = 0;</div> |
| <div class="line"><a name="l00657"></a><span class="lineno"> 657</span>  <span class="keyword">const</span> uint32_t row_index = <span class="keyword">static_cast<</span>uint32_t<span class="keyword">></span>(predicted_row_index + y_delta);</div> |
| <div class="line"><a name="l00658"></a><span class="lineno"> 658</span>  <span class="keyword">const</span> uint8_t col_index = predicted_col_index + x_delta;</div> |
| <div class="line"><a name="l00659"></a><span class="lineno"> 659</span>  <span class="keyword">const</span> uint32_t row_col = (row_index << 6) | col_index;</div> |
| <div class="line"><a name="l00660"></a><span class="lineno"> 660</span>  pair_array[pair_index] = row_col;</div> |
| <div class="line"><a name="l00661"></a><span class="lineno"> 661</span>  predicted_row_index = row_index;</div> |
| <div class="line"><a name="l00662"></a><span class="lineno"> 662</span>  predicted_col_index = col_index + 1;</div> |
| <div class="line"><a name="l00663"></a><span class="lineno"> 663</span>  }</div> |
| <div class="line"><a name="l00664"></a><span class="lineno"> 664</span>  <span class="keywordflow">if</span> (word_index > num_compressed_words) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"word_index > num_compressed_words"</span>); <span class="comment">// check for buffer over-run</span></div> |
| <div class="line"><a name="l00665"></a><span class="lineno"> 665</span> }</div> |
| <div class="line"><a name="l00666"></a><span class="lineno"> 666</span>  </div> |
| <div class="line"><a name="l00667"></a><span class="lineno"> 667</span> uint64_t read_unary(</div> |
| <div class="line"><a name="l00668"></a><span class="lineno"> 668</span>  <span class="keyword">const</span> uint32_t* compressed_words,</div> |
| <div class="line"><a name="l00669"></a><span class="lineno"> 669</span>  uint32_t& next_word_index,</div> |
| <div class="line"><a name="l00670"></a><span class="lineno"> 670</span>  uint64_t& bitbuf,</div> |
| <div class="line"><a name="l00671"></a><span class="lineno"> 671</span>  uint8_t& bufbits</div> |
| <div class="line"><a name="l00672"></a><span class="lineno"> 672</span> ) {</div> |
| <div class="line"><a name="l00673"></a><span class="lineno"> 673</span>  <span class="keywordflow">if</span> (compressed_words == <span class="keyword">nullptr</span>) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"compressed_words == NULL"</span>);</div> |
| <div class="line"><a name="l00674"></a><span class="lineno"> 674</span>  <span class="keywordtype">size_t</span> subtotal = 0;</div> |
| <div class="line"><a name="l00675"></a><span class="lineno"> 675</span>  <span class="keywordflow">while</span> (<span class="keyword">true</span>) {</div> |
| <div class="line"><a name="l00676"></a><span class="lineno"> 676</span>  maybe_fill_bitbuf(bitbuf, bufbits, compressed_words, next_word_index, 8); <span class="comment">// ensure 8 bits in bit buffer</span></div> |
| <div class="line"><a name="l00677"></a><span class="lineno"> 677</span>  </div> |
| <div class="line"><a name="l00678"></a><span class="lineno"> 678</span>  <span class="keyword">const</span> uint8_t peek8 = bitbuf & 0xff; <span class="comment">// These 8 bits include either all or part of the Unary codeword</span></div> |
| <div class="line"><a name="l00679"></a><span class="lineno"> 679</span>  <span class="keyword">const</span> uint8_t trailing_zeros = byte_trailing_zeros_table[peek8];</div> |
| <div class="line"><a name="l00680"></a><span class="lineno"> 680</span>  </div> |
| <div class="line"><a name="l00681"></a><span class="lineno"> 681</span>  <span class="keywordflow">if</span> (trailing_zeros > 8) <span class="keywordflow">throw</span> std::out_of_range(<span class="stringliteral">"trailing_zeros out of range"</span>);</div> |
| <div class="line"><a name="l00682"></a><span class="lineno"> 682</span>  <span class="keywordflow">if</span> (trailing_zeros < 8) {</div> |
| <div class="line"><a name="l00683"></a><span class="lineno"> 683</span>  bufbits -= 1 + trailing_zeros;</div> |
| <div class="line"><a name="l00684"></a><span class="lineno"> 684</span>  bitbuf >>= 1 + trailing_zeros;</div> |
| <div class="line"><a name="l00685"></a><span class="lineno"> 685</span>  <span class="keywordflow">return</span> subtotal + trailing_zeros;</div> |
| <div class="line"><a name="l00686"></a><span class="lineno"> 686</span>  }</div> |
| <div class="line"><a name="l00687"></a><span class="lineno"> 687</span>  <span class="comment">// The codeword was partial, so read some more</span></div> |
| <div class="line"><a name="l00688"></a><span class="lineno"> 688</span>  subtotal += 8;</div> |
| <div class="line"><a name="l00689"></a><span class="lineno"> 689</span>  bufbits -= 8;</div> |
| <div class="line"><a name="l00690"></a><span class="lineno"> 690</span>  bitbuf >>= 8;</div> |
| <div class="line"><a name="l00691"></a><span class="lineno"> 691</span>  }</div> |
| <div class="line"><a name="l00692"></a><span class="lineno"> 692</span> }</div> |
| <div class="line"><a name="l00693"></a><span class="lineno"> 693</span>  </div> |
| <div class="line"><a name="l00694"></a><span class="lineno"> 694</span> <span class="keywordtype">void</span> write_unary(</div> |
| <div class="line"><a name="l00695"></a><span class="lineno"> 695</span>  uint32_t* compressed_words,</div> |
| <div class="line"><a name="l00696"></a><span class="lineno"> 696</span>  uint32_t& next_word_index,</div> |
| <div class="line"><a name="l00697"></a><span class="lineno"> 697</span>  uint64_t& bitbuf,</div> |
| <div class="line"><a name="l00698"></a><span class="lineno"> 698</span>  uint8_t& bufbits,</div> |
| <div class="line"><a name="l00699"></a><span class="lineno"> 699</span>  uint64_t value</div> |
| <div class="line"><a name="l00700"></a><span class="lineno"> 700</span> ) {</div> |
| <div class="line"><a name="l00701"></a><span class="lineno"> 701</span>  <span class="keywordflow">if</span> (compressed_words == <span class="keyword">nullptr</span>) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"compressed_words == NULL"</span>);</div> |
| <div class="line"><a name="l00702"></a><span class="lineno"> 702</span>  <span class="keywordflow">if</span> (bufbits > 31) <span class="keywordflow">throw</span> std::out_of_range(<span class="stringliteral">"bufbits out of range"</span>);</div> |
| <div class="line"><a name="l00703"></a><span class="lineno"> 703</span>  </div> |
| <div class="line"><a name="l00704"></a><span class="lineno"> 704</span>  uint64_t remaining = value;</div> |
| <div class="line"><a name="l00705"></a><span class="lineno"> 705</span>  </div> |
| <div class="line"><a name="l00706"></a><span class="lineno"> 706</span>  <span class="keywordflow">while</span> (remaining >= 16) {</div> |
| <div class="line"><a name="l00707"></a><span class="lineno"> 707</span>  remaining -= 16;</div> |
| <div class="line"><a name="l00708"></a><span class="lineno"> 708</span>  <span class="comment">// Here we output 16 zeros, but we don't need to physically write them into bitbuf</span></div> |
| <div class="line"><a name="l00709"></a><span class="lineno"> 709</span>  <span class="comment">// because it already contains zeros in that region.</span></div> |
| <div class="line"><a name="l00710"></a><span class="lineno"> 710</span>  bufbits += 16; <span class="comment">// Record the fact that 16 bits of output have occurred.</span></div> |
| <div class="line"><a name="l00711"></a><span class="lineno"> 711</span>  maybe_flush_bitbuf(bitbuf, bufbits, compressed_words, next_word_index);</div> |
| <div class="line"><a name="l00712"></a><span class="lineno"> 712</span>  }</div> |
| <div class="line"><a name="l00713"></a><span class="lineno"> 713</span>  </div> |
| <div class="line"><a name="l00714"></a><span class="lineno"> 714</span>  <span class="keywordflow">if</span> (remaining > 15) <span class="keywordflow">throw</span> std::out_of_range(<span class="stringliteral">"remaining out of range"</span>);</div> |
| <div class="line"><a name="l00715"></a><span class="lineno"> 715</span>  </div> |
| <div class="line"><a name="l00716"></a><span class="lineno"> 716</span>  <span class="keyword">const</span> uint64_t the_unary_code = 1ULL << remaining;</div> |
| <div class="line"><a name="l00717"></a><span class="lineno"> 717</span>  bitbuf |= the_unary_code << bufbits;</div> |
| <div class="line"><a name="l00718"></a><span class="lineno"> 718</span>  bufbits += <span class="keyword">static_cast<</span>uint8_t<span class="keyword">></span>(remaining + 1);</div> |
| <div class="line"><a name="l00719"></a><span class="lineno"> 719</span>  maybe_flush_bitbuf(bitbuf, bufbits, compressed_words, next_word_index);</div> |
| <div class="line"><a name="l00720"></a><span class="lineno"> 720</span> }</div> |
| <div class="line"><a name="l00721"></a><span class="lineno"> 721</span>  </div> |
| <div class="line"><a name="l00722"></a><span class="lineno"> 722</span> <span class="comment">// The empty space that this leaves at the beginning of the output array</span></div> |
| <div class="line"><a name="l00723"></a><span class="lineno"> 723</span> <span class="comment">// will be filled in later by the caller.</span></div> |
| <div class="line"><a name="l00724"></a><span class="lineno"> 724</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00725"></a><span class="lineno"> 725</span> <span class="keyword">auto</span> cpc_compressor<A>::tricky_get_pairs_from_window(<span class="keyword">const</span> uint8_t* window, uint32_t k, uint32_t num_pairs_to_get,</div> |
| <div class="line"><a name="l00726"></a><span class="lineno"> 726</span>  uint32_t empty_space, <span class="keyword">const</span> A& allocator) -> vector_u32 {</div> |
| <div class="line"><a name="l00727"></a><span class="lineno"> 727</span>  <span class="keyword">const</span> <span class="keywordtype">size_t</span> output_length = empty_space + num_pairs_to_get;</div> |
| <div class="line"><a name="l00728"></a><span class="lineno"> 728</span>  vector_u32 pairs(output_length, 0, allocator);</div> |
| <div class="line"><a name="l00729"></a><span class="lineno"> 729</span>  <span class="keywordtype">size_t</span> pair_index = empty_space;</div> |
| <div class="line"><a name="l00730"></a><span class="lineno"> 730</span>  <span class="keywordflow">for</span> (<span class="keywordtype">unsigned</span> row_index = 0; row_index < k; row_index++) {</div> |
| <div class="line"><a name="l00731"></a><span class="lineno"> 731</span>  uint8_t <span class="keywordtype">byte</span> = window[row_index];</div> |
| <div class="line"><a name="l00732"></a><span class="lineno"> 732</span>  <span class="keywordflow">while</span> (<span class="keywordtype">byte</span> != 0) {</div> |
| <div class="line"><a name="l00733"></a><span class="lineno"> 733</span>  <span class="keyword">const</span> uint8_t col_index = byte_trailing_zeros_table[byte];</div> |
| <div class="line"><a name="l00734"></a><span class="lineno"> 734</span>  <span class="keywordtype">byte</span> = <span class="keywordtype">byte</span> ^ (1 << col_index); <span class="comment">// erase the 1</span></div> |
| <div class="line"><a name="l00735"></a><span class="lineno"> 735</span>  pairs[pair_index++] = (row_index << 6) | col_index;</div> |
| <div class="line"><a name="l00736"></a><span class="lineno"> 736</span>  }</div> |
| <div class="line"><a name="l00737"></a><span class="lineno"> 737</span>  }</div> |
| <div class="line"><a name="l00738"></a><span class="lineno"> 738</span>  <span class="keywordflow">if</span> (pair_index != output_length) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"pair_index != output_length"</span>);</div> |
| <div class="line"><a name="l00739"></a><span class="lineno"> 739</span>  <span class="keywordflow">return</span> pairs;</div> |
| <div class="line"><a name="l00740"></a><span class="lineno"> 740</span> }</div> |
| <div class="line"><a name="l00741"></a><span class="lineno"> 741</span>  </div> |
| <div class="line"><a name="l00742"></a><span class="lineno"> 742</span> <span class="comment">// returns an integer that is between</span></div> |
| <div class="line"><a name="l00743"></a><span class="lineno"> 743</span> <span class="comment">// zero and ceiling(log_2(k)) - 1, inclusive</span></div> |
| <div class="line"><a name="l00744"></a><span class="lineno"> 744</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00745"></a><span class="lineno"> 745</span> uint8_t cpc_compressor<A>::golomb_choose_number_of_base_bits(uint32_t k, uint64_t count) {</div> |
| <div class="line"><a name="l00746"></a><span class="lineno"> 746</span>  <span class="keywordflow">if</span> (k < 1) <span class="keywordflow">throw</span> std::invalid_argument(<span class="stringliteral">"golomb_choose_number_of_base_bits: k < 1"</span>);</div> |
| <div class="line"><a name="l00747"></a><span class="lineno"> 747</span>  <span class="keywordflow">if</span> (count < 1) <span class="keywordflow">throw</span> std::invalid_argument(<span class="stringliteral">"golomb_choose_number_of_base_bits: count < 1"</span>);</div> |
| <div class="line"><a name="l00748"></a><span class="lineno"> 748</span>  <span class="keyword">const</span> uint64_t quotient = (k - count) / count; <span class="comment">// integer division</span></div> |
| <div class="line"><a name="l00749"></a><span class="lineno"> 749</span>  <span class="keywordflow">if</span> (quotient == 0) <span class="keywordflow">return</span> 0;</div> |
| <div class="line"><a name="l00750"></a><span class="lineno"> 750</span>  <span class="keywordflow">else</span> <span class="keywordflow">return</span> floor_log2_of_long(quotient);</div> |
| <div class="line"><a name="l00751"></a><span class="lineno"> 751</span> }</div> |
| <div class="line"><a name="l00752"></a><span class="lineno"> 752</span>  </div> |
| <div class="line"><a name="l00753"></a><span class="lineno"> 753</span> } <span class="comment">/* namespace datasketches */</span></div> |
| <div class="line"><a name="l00754"></a><span class="lineno"> 754</span>  </div> |
| <div class="line"><a name="l00755"></a><span class="lineno"> 755</span> <span class="preprocessor">#endif</span></div> |
| <div class="ttc" id="anamespacedatasketches_html"><div class="ttname"><a href="namespacedatasketches.html">datasketches</a></div><div class="ttdoc">DataSketches namespace.</div><div class="ttdef"><b>Definition:</b> binomial_bounds.hpp:38</div></div> |
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