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| <div class="title">u32_table_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 U32_TABLE_IMPL_HPP_</span></div> |
| <div class="line"><a name="l00023"></a><span class="lineno"> 23</span> <span class="preprocessor">#define U32_TABLE_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 <stdexcept></span></div> |
| <div class="line"><a name="l00026"></a><span class="lineno"> 26</span> <span class="preprocessor">#include <algorithm></span></div> |
| <div class="line"><a name="l00027"></a><span class="lineno"> 27</span> <span class="preprocessor">#include <climits></span></div> |
| <div class="line"><a name="l00028"></a><span class="lineno"> 28</span>  </div> |
| <div class="line"><a name="l00029"></a><span class="lineno"> 29</span> <span class="keyword">namespace </span><a class="code" href="namespacedatasketches.html">datasketches</a> {</div> |
| <div class="line"><a name="l00030"></a><span class="lineno"> 30</span>  </div> |
| <div class="line"><a name="l00031"></a><span class="lineno"> 31</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00032"></a><span class="lineno"> 32</span> u32_table<A>::u32_table(<span class="keyword">const</span> A& allocator):</div> |
| <div class="line"><a name="l00033"></a><span class="lineno"> 33</span> lg_size(0),</div> |
| <div class="line"><a name="l00034"></a><span class="lineno"> 34</span> num_valid_bits(0),</div> |
| <div class="line"><a name="l00035"></a><span class="lineno"> 35</span> num_items(0),</div> |
| <div class="line"><a name="l00036"></a><span class="lineno"> 36</span> slots(allocator)</div> |
| <div class="line"><a name="l00037"></a><span class="lineno"> 37</span> {}</div> |
| <div class="line"><a name="l00038"></a><span class="lineno"> 38</span>  </div> |
| <div class="line"><a name="l00039"></a><span class="lineno"> 39</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00040"></a><span class="lineno"> 40</span> u32_table<A>::u32_table(uint8_t lg_size, uint8_t num_valid_bits, <span class="keyword">const</span> A& allocator):</div> |
| <div class="line"><a name="l00041"></a><span class="lineno"> 41</span> lg_size(lg_size),</div> |
| <div class="line"><a name="l00042"></a><span class="lineno"> 42</span> num_valid_bits(num_valid_bits),</div> |
| <div class="line"><a name="l00043"></a><span class="lineno"> 43</span> num_items(0),</div> |
| <div class="line"><a name="l00044"></a><span class="lineno"> 44</span> slots(1ULL << lg_size, UINT32_MAX, allocator)</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>  <span class="keywordflow">if</span> (lg_size < 2) <span class="keywordflow">throw</span> std::invalid_argument(<span class="stringliteral">"lg_size must be >= 2"</span>);</div> |
| <div class="line"><a name="l00047"></a><span class="lineno"> 47</span>  <span class="keywordflow">if</span> (num_valid_bits < 1 || num_valid_bits > 32) <span class="keywordflow">throw</span> std::invalid_argument(<span class="stringliteral">"num_valid_bits must be between 1 and 32"</span>);</div> |
| <div class="line"><a name="l00048"></a><span class="lineno"> 48</span> }</div> |
| <div class="line"><a name="l00049"></a><span class="lineno"> 49</span>  </div> |
| <div class="line"><a name="l00050"></a><span class="lineno"> 50</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00051"></a><span class="lineno"> 51</span> uint32_t u32_table<A>::get_num_items()<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00052"></a><span class="lineno"> 52</span>  <span class="keywordflow">return</span> num_items;</div> |
| <div class="line"><a name="l00053"></a><span class="lineno"> 53</span> }</div> |
| <div class="line"><a name="l00054"></a><span class="lineno"> 54</span>  </div> |
| <div class="line"><a name="l00055"></a><span class="lineno"> 55</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00056"></a><span class="lineno"> 56</span> <span class="keyword">const</span> uint32_t* u32_table<A>::get_slots()<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00057"></a><span class="lineno"> 57</span>  <span class="keywordflow">return</span> slots.data();</div> |
| <div class="line"><a name="l00058"></a><span class="lineno"> 58</span> }</div> |
| <div class="line"><a name="l00059"></a><span class="lineno"> 59</span>  </div> |
| <div class="line"><a name="l00060"></a><span class="lineno"> 60</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00061"></a><span class="lineno"> 61</span> uint8_t u32_table<A>::get_lg_size()<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00062"></a><span class="lineno"> 62</span>  <span class="keywordflow">return</span> lg_size;</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>  </div> |
| <div class="line"><a name="l00065"></a><span class="lineno"> 65</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00066"></a><span class="lineno"> 66</span> <span class="keywordtype">void</span> u32_table<A>::clear() {</div> |
| <div class="line"><a name="l00067"></a><span class="lineno"> 67</span>  std::fill(slots.begin(), slots.end(), UINT32_MAX);</div> |
| <div class="line"><a name="l00068"></a><span class="lineno"> 68</span>  num_items = 0;</div> |
| <div class="line"><a name="l00069"></a><span class="lineno"> 69</span> }</div> |
| <div class="line"><a name="l00070"></a><span class="lineno"> 70</span>  </div> |
| <div class="line"><a name="l00071"></a><span class="lineno"> 71</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00072"></a><span class="lineno"> 72</span> <span class="keywordtype">bool</span> u32_table<A>::maybe_insert(uint32_t item) {</div> |
| <div class="line"><a name="l00073"></a><span class="lineno"> 73</span>  <span class="keyword">const</span> uint32_t index = lookup(item);</div> |
| <div class="line"><a name="l00074"></a><span class="lineno"> 74</span>  <span class="keywordflow">if</span> (slots[index] == item) <span class="keywordflow">return</span> <span class="keyword">false</span>;</div> |
| <div class="line"><a name="l00075"></a><span class="lineno"> 75</span>  <span class="keywordflow">if</span> (slots[index] != UINT32_MAX) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"could not insert"</span>);</div> |
| <div class="line"><a name="l00076"></a><span class="lineno"> 76</span>  slots[index] = item;</div> |
| <div class="line"><a name="l00077"></a><span class="lineno"> 77</span>  num_items++;</div> |
| <div class="line"><a name="l00078"></a><span class="lineno"> 78</span>  <span class="keywordflow">if</span> (U32_TABLE_UPSIZE_DENOM * num_items > U32_TABLE_UPSIZE_NUMER * (1 << lg_size)) {</div> |
| <div class="line"><a name="l00079"></a><span class="lineno"> 79</span>  rebuild(lg_size + 1);</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>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div> |
| <div class="line"><a name="l00082"></a><span class="lineno"> 82</span> }</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> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00085"></a><span class="lineno"> 85</span> <span class="keywordtype">bool</span> u32_table<A>::maybe_delete(uint32_t item) {</div> |
| <div class="line"><a name="l00086"></a><span class="lineno"> 86</span>  <span class="keyword">const</span> uint32_t index = lookup(item);</div> |
| <div class="line"><a name="l00087"></a><span class="lineno"> 87</span>  <span class="keywordflow">if</span> (slots[index] == UINT32_MAX) <span class="keywordflow">return</span> <span class="keyword">false</span>;</div> |
| <div class="line"><a name="l00088"></a><span class="lineno"> 88</span>  <span class="keywordflow">if</span> (slots[index] != item) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"item does not exist"</span>);</div> |
| <div class="line"><a name="l00089"></a><span class="lineno"> 89</span>  <span class="keywordflow">if</span> (num_items == 0) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"delete error"</span>);</div> |
| <div class="line"><a name="l00090"></a><span class="lineno"> 90</span>  <span class="comment">// delete the item</span></div> |
| <div class="line"><a name="l00091"></a><span class="lineno"> 91</span>  slots[index] = UINT32_MAX;</div> |
| <div class="line"><a name="l00092"></a><span class="lineno"> 92</span>  num_items--;</div> |
| <div class="line"><a name="l00093"></a><span class="lineno"> 93</span>  </div> |
| <div class="line"><a name="l00094"></a><span class="lineno"> 94</span>  <span class="comment">// re-insert all items between the freed slot and the next empty slot</span></div> |
| <div class="line"><a name="l00095"></a><span class="lineno"> 95</span>  <span class="keyword">const</span> <span class="keywordtype">size_t</span> mask = (1 << lg_size) - 1;</div> |
| <div class="line"><a name="l00096"></a><span class="lineno"> 96</span>  <span class="keywordtype">size_t</span> probe = (index + 1) & mask;</div> |
| <div class="line"><a name="l00097"></a><span class="lineno"> 97</span>  uint32_t fetched = slots[probe];</div> |
| <div class="line"><a name="l00098"></a><span class="lineno"> 98</span>  <span class="keywordflow">while</span> (fetched != UINT32_MAX) {</div> |
| <div class="line"><a name="l00099"></a><span class="lineno"> 99</span>  slots[probe] = UINT32_MAX;</div> |
| <div class="line"><a name="l00100"></a><span class="lineno"> 100</span>  must_insert(fetched);</div> |
| <div class="line"><a name="l00101"></a><span class="lineno"> 101</span>  probe = (probe + 1) & mask;</div> |
| <div class="line"><a name="l00102"></a><span class="lineno"> 102</span>  fetched = slots[probe];</div> |
| <div class="line"><a name="l00103"></a><span class="lineno"> 103</span>  }</div> |
| <div class="line"><a name="l00104"></a><span class="lineno"> 104</span>  <span class="comment">// shrink if necessary</span></div> |
| <div class="line"><a name="l00105"></a><span class="lineno"> 105</span>  <span class="keywordflow">if</span> (U32_TABLE_DOWNSIZE_DENOM * num_items < U32_TABLE_DOWNSIZE_NUMER * (1 << lg_size) && lg_size > 2) {</div> |
| <div class="line"><a name="l00106"></a><span class="lineno"> 106</span>  rebuild(lg_size - 1);</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>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div> |
| <div class="line"><a name="l00109"></a><span class="lineno"> 109</span> }</div> |
| <div class="line"><a name="l00110"></a><span class="lineno"> 110</span>  </div> |
| <div class="line"><a name="l00111"></a><span class="lineno"> 111</span> <span class="comment">// this one is specifically tailored to be a part of fm85 decompression scheme</span></div> |
| <div class="line"><a name="l00112"></a><span class="lineno"> 112</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00113"></a><span class="lineno"> 113</span> u32_table<A> u32_table<A>::make_from_pairs(<span class="keyword">const</span> uint32_t* pairs, uint32_t num_pairs, uint8_t lg_k, <span class="keyword">const</span> A& allocator) {</div> |
| <div class="line"><a name="l00114"></a><span class="lineno"> 114</span>  uint8_t lg_num_slots = 2;</div> |
| <div class="line"><a name="l00115"></a><span class="lineno"> 115</span>  <span class="keywordflow">while</span> (U32_TABLE_UPSIZE_DENOM * num_pairs > U32_TABLE_UPSIZE_NUMER * (1 << lg_num_slots)) lg_num_slots++;</div> |
| <div class="line"><a name="l00116"></a><span class="lineno"> 116</span>  u32_table<A> table(lg_num_slots, 6 + lg_k, allocator);</div> |
| <div class="line"><a name="l00117"></a><span class="lineno"> 117</span>  <span class="comment">// Note: there is a possible "snowplow effect" here because the caller is passing in a sorted pairs array</span></div> |
| <div class="line"><a name="l00118"></a><span class="lineno"> 118</span>  <span class="comment">// However, we are starting out with the correct final table size, so the problem might not occur</span></div> |
| <div class="line"><a name="l00119"></a><span class="lineno"> 119</span>  <span class="keywordflow">for</span> (<span class="keywordtype">size_t</span> i = 0; i < num_pairs; i++) {</div> |
| <div class="line"><a name="l00120"></a><span class="lineno"> 120</span>  table.must_insert(pairs[i]);</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>  table.num_items = num_pairs;</div> |
| <div class="line"><a name="l00123"></a><span class="lineno"> 123</span>  <span class="keywordflow">return</span> table;</div> |
| <div class="line"><a name="l00124"></a><span class="lineno"> 124</span> }</div> |
| <div class="line"><a name="l00125"></a><span class="lineno"> 125</span>  </div> |
| <div class="line"><a name="l00126"></a><span class="lineno"> 126</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00127"></a><span class="lineno"> 127</span> uint32_t u32_table<A>::lookup(uint32_t item)<span class="keyword"> const </span>{</div> |
| <div class="line"><a name="l00128"></a><span class="lineno"> 128</span>  <span class="keyword">const</span> uint32_t size = 1 << lg_size;</div> |
| <div class="line"><a name="l00129"></a><span class="lineno"> 129</span>  <span class="keyword">const</span> uint32_t mask = size - 1;</div> |
| <div class="line"><a name="l00130"></a><span class="lineno"> 130</span>  <span class="keyword">const</span> uint8_t shift = num_valid_bits - lg_size;</div> |
| <div class="line"><a name="l00131"></a><span class="lineno"> 131</span>  uint32_t probe = item >> shift;</div> |
| <div class="line"><a name="l00132"></a><span class="lineno"> 132</span>  <span class="keywordflow">if</span> (probe > mask) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"probe out of range"</span>);</div> |
| <div class="line"><a name="l00133"></a><span class="lineno"> 133</span>  <span class="keywordflow">while</span> (slots[probe] != item && slots[probe] != UINT32_MAX) {</div> |
| <div class="line"><a name="l00134"></a><span class="lineno"> 134</span>  probe = (probe + 1) & mask;</div> |
| <div class="line"><a name="l00135"></a><span class="lineno"> 135</span>  }</div> |
| <div class="line"><a name="l00136"></a><span class="lineno"> 136</span>  <span class="keywordflow">return</span> probe;</div> |
| <div class="line"><a name="l00137"></a><span class="lineno"> 137</span> }</div> |
| <div class="line"><a name="l00138"></a><span class="lineno"> 138</span>  </div> |
| <div class="line"><a name="l00139"></a><span class="lineno"> 139</span> <span class="comment">// counts and resizing must be handled by the caller</span></div> |
| <div class="line"><a name="l00140"></a><span class="lineno"> 140</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00141"></a><span class="lineno"> 141</span> <span class="keywordtype">void</span> u32_table<A>::must_insert(uint32_t item) {</div> |
| <div class="line"><a name="l00142"></a><span class="lineno"> 142</span>  <span class="keyword">const</span> uint32_t index = lookup(item);</div> |
| <div class="line"><a name="l00143"></a><span class="lineno"> 143</span>  <span class="keywordflow">if</span> (slots[index] == item) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"item exists"</span>);</div> |
| <div class="line"><a name="l00144"></a><span class="lineno"> 144</span>  <span class="keywordflow">if</span> (slots[index] != UINT32_MAX) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"could not insert"</span>);</div> |
| <div class="line"><a name="l00145"></a><span class="lineno"> 145</span>  slots[index] = item;</div> |
| <div class="line"><a name="l00146"></a><span class="lineno"> 146</span> }</div> |
| <div class="line"><a name="l00147"></a><span class="lineno"> 147</span>  </div> |
| <div class="line"><a name="l00148"></a><span class="lineno"> 148</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00149"></a><span class="lineno"> 149</span> <span class="keywordtype">void</span> u32_table<A>::rebuild(uint8_t new_lg_size) {</div> |
| <div class="line"><a name="l00150"></a><span class="lineno"> 150</span>  <span class="keywordflow">if</span> (new_lg_size < 2) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"lg_size must be >= 2"</span>);</div> |
| <div class="line"><a name="l00151"></a><span class="lineno"> 151</span>  <span class="keyword">const</span> uint32_t old_size = 1 << lg_size;</div> |
| <div class="line"><a name="l00152"></a><span class="lineno"> 152</span>  <span class="keyword">const</span> uint32_t new_size = 1 << new_lg_size;</div> |
| <div class="line"><a name="l00153"></a><span class="lineno"> 153</span>  <span class="keywordflow">if</span> (new_size <= num_items) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"new_size <= num_items"</span>);</div> |
| <div class="line"><a name="l00154"></a><span class="lineno"> 154</span>  vector_u32 old_slots = std::move(slots);</div> |
| <div class="line"><a name="l00155"></a><span class="lineno"> 155</span>  slots = vector_u32(new_size, UINT32_MAX, old_slots.get_allocator());</div> |
| <div class="line"><a name="l00156"></a><span class="lineno"> 156</span>  lg_size = new_lg_size;</div> |
| <div class="line"><a name="l00157"></a><span class="lineno"> 157</span>  <span class="keywordflow">for</span> (uint32_t i = 0; i < old_size; i++) {</div> |
| <div class="line"><a name="l00158"></a><span class="lineno"> 158</span>  <span class="keywordflow">if</span> (old_slots[i] != UINT32_MAX) {</div> |
| <div class="line"><a name="l00159"></a><span class="lineno"> 159</span>  must_insert(old_slots[i]);</div> |
| <div class="line"><a name="l00160"></a><span class="lineno"> 160</span>  }</div> |
| <div class="line"><a name="l00161"></a><span class="lineno"> 161</span>  }</div> |
| <div class="line"><a name="l00162"></a><span class="lineno"> 162</span> }</div> |
| <div class="line"><a name="l00163"></a><span class="lineno"> 163</span>  </div> |
| <div class="line"><a name="l00164"></a><span class="lineno"> 164</span> <span class="comment">// While extracting the items from a linear probing hashtable,</span></div> |
| <div class="line"><a name="l00165"></a><span class="lineno"> 165</span> <span class="comment">// this will usually undo the wrap-around provided that the table</span></div> |
| <div class="line"><a name="l00166"></a><span class="lineno"> 166</span> <span class="comment">// isn't too full. Experiments suggest that for sufficiently large tables</span></div> |
| <div class="line"><a name="l00167"></a><span class="lineno"> 167</span> <span class="comment">// the load factor would have to be over 90 percent before this would fail frequently,</span></div> |
| <div class="line"><a name="l00168"></a><span class="lineno"> 168</span> <span class="comment">// and even then the subsequent sort would fix things up.</span></div> |
| <div class="line"><a name="l00169"></a><span class="lineno"> 169</span> <span class="comment">// The result is nearly sorted, so make sure to use an efficient sort for that case</span></div> |
| <div class="line"><a name="l00170"></a><span class="lineno"> 170</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00171"></a><span class="lineno"> 171</span> <span class="keyword">auto</span> u32_table<A>::unwrapping_get_items() const -> vector_u32 {</div> |
| <div class="line"><a name="l00172"></a><span class="lineno"> 172</span>  <span class="keywordflow">if</span> (num_items == 0) <span class="keywordflow">return</span> vector_u32(slots.get_allocator());</div> |
| <div class="line"><a name="l00173"></a><span class="lineno"> 173</span>  <span class="keyword">const</span> uint32_t table_size = 1 << lg_size;</div> |
| <div class="line"><a name="l00174"></a><span class="lineno"> 174</span>  vector_u32 result(num_items, 0, slots.get_allocator());</div> |
| <div class="line"><a name="l00175"></a><span class="lineno"> 175</span>  <span class="keywordtype">size_t</span> i = 0;</div> |
| <div class="line"><a name="l00176"></a><span class="lineno"> 176</span>  <span class="keywordtype">size_t</span> l = 0;</div> |
| <div class="line"><a name="l00177"></a><span class="lineno"> 177</span>  <span class="keywordtype">size_t</span> r = num_items - 1;</div> |
| <div class="line"><a name="l00178"></a><span class="lineno"> 178</span>  </div> |
| <div class="line"><a name="l00179"></a><span class="lineno"> 179</span>  <span class="comment">// special rules for the region before the first empty slot</span></div> |
| <div class="line"><a name="l00180"></a><span class="lineno"> 180</span>  uint32_t hi_bit = 1 << (num_valid_bits - 1);</div> |
| <div class="line"><a name="l00181"></a><span class="lineno"> 181</span>  <span class="keywordflow">while</span> (i < table_size && slots[i] != UINT32_MAX) {</div> |
| <div class="line"><a name="l00182"></a><span class="lineno"> 182</span>  <span class="keyword">const</span> uint32_t item = slots[i++];</div> |
| <div class="line"><a name="l00183"></a><span class="lineno"> 183</span>  <span class="keywordflow">if</span> (item & hi_bit) { result[r--] = item; } <span class="comment">// this item was probably wrapped, so move to end</span></div> |
| <div class="line"><a name="l00184"></a><span class="lineno"> 184</span>  <span class="keywordflow">else</span> { result[l++] = item; }</div> |
| <div class="line"><a name="l00185"></a><span class="lineno"> 185</span>  }</div> |
| <div class="line"><a name="l00186"></a><span class="lineno"> 186</span>  </div> |
| <div class="line"><a name="l00187"></a><span class="lineno"> 187</span>  <span class="comment">// the rest of the table is processed normally</span></div> |
| <div class="line"><a name="l00188"></a><span class="lineno"> 188</span>  <span class="keywordflow">while</span> (i < table_size) {</div> |
| <div class="line"><a name="l00189"></a><span class="lineno"> 189</span>  <span class="keyword">const</span> uint32_t item = slots[i++];</div> |
| <div class="line"><a name="l00190"></a><span class="lineno"> 190</span>  <span class="keywordflow">if</span> (item != UINT32_MAX) result[l++] = item;</div> |
| <div class="line"><a name="l00191"></a><span class="lineno"> 191</span>  }</div> |
| <div class="line"><a name="l00192"></a><span class="lineno"> 192</span>  <span class="keywordflow">if</span> (l != r + 1) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"unwrapping error"</span>);</div> |
| <div class="line"><a name="l00193"></a><span class="lineno"> 193</span>  <span class="keywordflow">return</span> result;</div> |
| <div class="line"><a name="l00194"></a><span class="lineno"> 194</span> }</div> |
| <div class="line"><a name="l00195"></a><span class="lineno"> 195</span>  </div> |
| <div class="line"><a name="l00196"></a><span class="lineno"> 196</span> <span class="comment">// This merge is safe to use in carefully designed overlapping scenarios.</span></div> |
| <div class="line"><a name="l00197"></a><span class="lineno"> 197</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00198"></a><span class="lineno"> 198</span> <span class="keywordtype">void</span> u32_table<A>::merge(</div> |
| <div class="line"><a name="l00199"></a><span class="lineno"> 199</span>  <span class="keyword">const</span> uint32_t* arr_a, <span class="keywordtype">size_t</span> start_a, <span class="keywordtype">size_t</span> length_a, <span class="comment">// input</span></div> |
| <div class="line"><a name="l00200"></a><span class="lineno"> 200</span>  <span class="keyword">const</span> uint32_t* arr_b, <span class="keywordtype">size_t</span> start_b, <span class="keywordtype">size_t</span> length_b, <span class="comment">// input</span></div> |
| <div class="line"><a name="l00201"></a><span class="lineno"> 201</span>  uint32_t* arr_c, <span class="keywordtype">size_t</span> start_c <span class="comment">// output</span></div> |
| <div class="line"><a name="l00202"></a><span class="lineno"> 202</span> ) {</div> |
| <div class="line"><a name="l00203"></a><span class="lineno"> 203</span>  <span class="keyword">const</span> <span class="keywordtype">size_t</span> length_c = length_a + length_b;</div> |
| <div class="line"><a name="l00204"></a><span class="lineno"> 204</span>  <span class="keyword">const</span> <span class="keywordtype">size_t</span> lim_a = start_a + length_a;</div> |
| <div class="line"><a name="l00205"></a><span class="lineno"> 205</span>  <span class="keyword">const</span> <span class="keywordtype">size_t</span> lim_b = start_b + length_b;</div> |
| <div class="line"><a name="l00206"></a><span class="lineno"> 206</span>  <span class="keyword">const</span> <span class="keywordtype">size_t</span> lim_c = start_c + length_c;</div> |
| <div class="line"><a name="l00207"></a><span class="lineno"> 207</span>  <span class="keywordtype">size_t</span> a = start_a;</div> |
| <div class="line"><a name="l00208"></a><span class="lineno"> 208</span>  <span class="keywordtype">size_t</span> b = start_b;</div> |
| <div class="line"><a name="l00209"></a><span class="lineno"> 209</span>  <span class="keywordtype">size_t</span> c = start_c;</div> |
| <div class="line"><a name="l00210"></a><span class="lineno"> 210</span>  <span class="keywordflow">for</span> ( ; c < lim_c ; c++) {</div> |
| <div class="line"><a name="l00211"></a><span class="lineno"> 211</span>  <span class="keywordflow">if</span> (b >= lim_b) { arr_c[c] = arr_a[a++]; }</div> |
| <div class="line"><a name="l00212"></a><span class="lineno"> 212</span>  <span class="keywordflow">else</span> <span class="keywordflow">if</span> (a >= lim_a) { arr_c[c] = arr_b[b++]; }</div> |
| <div class="line"><a name="l00213"></a><span class="lineno"> 213</span>  <span class="keywordflow">else</span> <span class="keywordflow">if</span> (arr_a[a] < arr_b[b]) { arr_c[c] = arr_a[a++]; }</div> |
| <div class="line"><a name="l00214"></a><span class="lineno"> 214</span>  <span class="keywordflow">else</span> { arr_c[c] = arr_b[b++]; }</div> |
| <div class="line"><a name="l00215"></a><span class="lineno"> 215</span>  }</div> |
| <div class="line"><a name="l00216"></a><span class="lineno"> 216</span>  <span class="keywordflow">if</span> (a != lim_a || b != lim_b) <span class="keywordflow">throw</span> std::logic_error(<span class="stringliteral">"merging error"</span>);</div> |
| <div class="line"><a name="l00217"></a><span class="lineno"> 217</span> }</div> |
| <div class="line"><a name="l00218"></a><span class="lineno"> 218</span>  </div> |
| <div class="line"><a name="l00219"></a><span class="lineno"> 219</span> <span class="comment">// In applications where the input array is already nearly sorted,</span></div> |
| <div class="line"><a name="l00220"></a><span class="lineno"> 220</span> <span class="comment">// insertion sort runs in linear time with a very small constant.</span></div> |
| <div class="line"><a name="l00221"></a><span class="lineno"> 221</span> <span class="comment">// This introspective version of insertion sort protects against</span></div> |
| <div class="line"><a name="l00222"></a><span class="lineno"> 222</span> <span class="comment">// the quadratic cost of sorting bad input arrays.</span></div> |
| <div class="line"><a name="l00223"></a><span class="lineno"> 223</span> <span class="comment">// It keeps track of how much work has been done, and if that exceeds a</span></div> |
| <div class="line"><a name="l00224"></a><span class="lineno"> 224</span> <span class="comment">// constant times the array length, it switches to a different sorting algorithm.</span></div> |
| <div class="line"><a name="l00225"></a><span class="lineno"> 225</span>  </div> |
| <div class="line"><a name="l00226"></a><span class="lineno"> 226</span> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00227"></a><span class="lineno"> 227</span> <span class="keywordtype">void</span> u32_table<A>::introspective_insertion_sort(uint32_t* a, <span class="keywordtype">size_t</span> l, <span class="keywordtype">size_t</span> r) { <span class="comment">// r points past the rightmost element</span></div> |
| <div class="line"><a name="l00228"></a><span class="lineno"> 228</span>  <span class="keyword">const</span> <span class="keywordtype">size_t</span> length = r - l;</div> |
| <div class="line"><a name="l00229"></a><span class="lineno"> 229</span>  <span class="keyword">const</span> <span class="keywordtype">size_t</span> cost_limit = 8 * length;</div> |
| <div class="line"><a name="l00230"></a><span class="lineno"> 230</span>  <span class="keywordtype">size_t</span> cost = 0;</div> |
| <div class="line"><a name="l00231"></a><span class="lineno"> 231</span>  <span class="keywordflow">for</span> (<span class="keywordtype">size_t</span> i = l + 1; i < r; i++) {</div> |
| <div class="line"><a name="l00232"></a><span class="lineno"> 232</span>  <span class="keywordtype">size_t</span> j = i;</div> |
| <div class="line"><a name="l00233"></a><span class="lineno"> 233</span>  uint32_t v = a[i];</div> |
| <div class="line"><a name="l00234"></a><span class="lineno"> 234</span>  <span class="keywordflow">while</span> (j >= l + 1 && v < a[j - 1]) {</div> |
| <div class="line"><a name="l00235"></a><span class="lineno"> 235</span>  a[j] = a[j - 1];</div> |
| <div class="line"><a name="l00236"></a><span class="lineno"> 236</span>  j--;</div> |
| <div class="line"><a name="l00237"></a><span class="lineno"> 237</span>  }</div> |
| <div class="line"><a name="l00238"></a><span class="lineno"> 238</span>  a[j] = v;</div> |
| <div class="line"><a name="l00239"></a><span class="lineno"> 239</span>  cost += i - j; <span class="comment">// distance moved is a measure of work</span></div> |
| <div class="line"><a name="l00240"></a><span class="lineno"> 240</span>  <span class="keywordflow">if</span> (cost > cost_limit) {</div> |
| <div class="line"><a name="l00241"></a><span class="lineno"> 241</span>  knuth_shell_sort3(a, l, r);</div> |
| <div class="line"><a name="l00242"></a><span class="lineno"> 242</span>  <span class="keywordflow">return</span>;</div> |
| <div class="line"><a name="l00243"></a><span class="lineno"> 243</span>  }</div> |
| <div class="line"><a name="l00244"></a><span class="lineno"> 244</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> <span class="keyword">template</span><<span class="keyword">typename</span> A></div> |
| <div class="line"><a name="l00248"></a><span class="lineno"> 248</span> <span class="keywordtype">void</span> u32_table<A>::knuth_shell_sort3(uint32_t* a, <span class="keywordtype">size_t</span> l, <span class="keywordtype">size_t</span> r) {</div> |
| <div class="line"><a name="l00249"></a><span class="lineno"> 249</span>  <span class="keywordtype">size_t</span> h;</div> |
| <div class="line"><a name="l00250"></a><span class="lineno"> 250</span>  <span class="keywordflow">for</span> (h = 1; h < (r - l) / 9; h = 3 * h + 1);</div> |
| <div class="line"><a name="l00251"></a><span class="lineno"> 251</span>  <span class="keywordflow">for</span> ( ; h > 0; h /= 3) {</div> |
| <div class="line"><a name="l00252"></a><span class="lineno"> 252</span>  <span class="keywordflow">for</span> (<span class="keywordtype">size_t</span> i = l + h; i < r; i++) {</div> |
| <div class="line"><a name="l00253"></a><span class="lineno"> 253</span>  <span class="keywordtype">size_t</span> j = i;</div> |
| <div class="line"><a name="l00254"></a><span class="lineno"> 254</span>  <span class="keyword">const</span> uint32_t v = a[i];</div> |
| <div class="line"><a name="l00255"></a><span class="lineno"> 255</span>  <span class="keywordflow">while</span> (j >= l + h && v < a[j - h]) {</div> |
| <div class="line"><a name="l00256"></a><span class="lineno"> 256</span>  a[j] = a[j - h];</div> |
| <div class="line"><a name="l00257"></a><span class="lineno"> 257</span>  j -= h;</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>  a[j] = v;</div> |
| <div class="line"><a name="l00260"></a><span class="lineno"> 260</span>  }</div> |
| <div class="line"><a name="l00261"></a><span class="lineno"> 261</span>  }</div> |
| <div class="line"><a name="l00262"></a><span class="lineno"> 262</span> }</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> } <span class="comment">/* namespace datasketches */</span></div> |
| <div class="line"><a name="l00265"></a><span class="lineno"> 265</span>  </div> |
| <div class="line"><a name="l00266"></a><span class="lineno"> 266</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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