| <!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/root/.cargo/git/checkouts/tantivy-65d0bbbddbbd5d02/433372d/fastfield_codecs/src/gcd.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>gcd.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../normalize.css"><link rel="stylesheet" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../ayu.css" disabled><link rel="stylesheet" href="../../dark.css" disabled><link rel="stylesheet" href="../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../storage.js"></script><script defer src="../../source-script.js"></script><script defer src="../../source-files.js"></script><script defer src="../../main.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../favicon.svg"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../fastfield_codecs/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../fastfield_codecs/index.html"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></a><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
| <span id="2">2</span> |
| <span id="3">3</span> |
| <span id="4">4</span> |
| <span id="5">5</span> |
| <span id="6">6</span> |
| <span id="7">7</span> |
| <span id="8">8</span> |
| <span id="9">9</span> |
| <span id="10">10</span> |
| <span id="11">11</span> |
| <span id="12">12</span> |
| <span id="13">13</span> |
| <span id="14">14</span> |
| <span id="15">15</span> |
| <span id="16">16</span> |
| <span id="17">17</span> |
| <span id="18">18</span> |
| <span id="19">19</span> |
| <span id="20">20</span> |
| <span id="21">21</span> |
| <span id="22">22</span> |
| <span id="23">23</span> |
| <span id="24">24</span> |
| <span id="25">25</span> |
| <span id="26">26</span> |
| <span id="27">27</span> |
| <span id="28">28</span> |
| <span id="29">29</span> |
| <span id="30">30</span> |
| <span id="31">31</span> |
| <span id="32">32</span> |
| <span id="33">33</span> |
| <span id="34">34</span> |
| <span id="35">35</span> |
| <span id="36">36</span> |
| <span id="37">37</span> |
| <span id="38">38</span> |
| <span id="39">39</span> |
| <span id="40">40</span> |
| <span id="41">41</span> |
| <span id="42">42</span> |
| <span id="43">43</span> |
| <span id="44">44</span> |
| <span id="45">45</span> |
| <span id="46">46</span> |
| <span id="47">47</span> |
| <span id="48">48</span> |
| <span id="49">49</span> |
| <span id="50">50</span> |
| <span id="51">51</span> |
| <span id="52">52</span> |
| <span id="53">53</span> |
| <span id="54">54</span> |
| <span id="55">55</span> |
| <span id="56">56</span> |
| <span id="57">57</span> |
| <span id="58">58</span> |
| <span id="59">59</span> |
| <span id="60">60</span> |
| <span id="61">61</span> |
| <span id="62">62</span> |
| <span id="63">63</span> |
| <span id="64">64</span> |
| <span id="65">65</span> |
| <span id="66">66</span> |
| <span id="67">67</span> |
| <span id="68">68</span> |
| <span id="69">69</span> |
| <span id="70">70</span> |
| <span id="71">71</span> |
| <span id="72">72</span> |
| <span id="73">73</span> |
| <span id="74">74</span> |
| <span id="75">75</span> |
| <span id="76">76</span> |
| <span id="77">77</span> |
| <span id="78">78</span> |
| <span id="79">79</span> |
| <span id="80">80</span> |
| <span id="81">81</span> |
| <span id="82">82</span> |
| <span id="83">83</span> |
| <span id="84">84</span> |
| <span id="85">85</span> |
| <span id="86">86</span> |
| <span id="87">87</span> |
| <span id="88">88</span> |
| <span id="89">89</span> |
| <span id="90">90</span> |
| <span id="91">91</span> |
| <span id="92">92</span> |
| <span id="93">93</span> |
| <span id="94">94</span> |
| <span id="95">95</span> |
| <span id="96">96</span> |
| <span id="97">97</span> |
| <span id="98">98</span> |
| <span id="99">99</span> |
| <span id="100">100</span> |
| <span id="101">101</span> |
| <span id="102">102</span> |
| <span id="103">103</span> |
| <span id="104">104</span> |
| <span id="105">105</span> |
| <span id="106">106</span> |
| <span id="107">107</span> |
| <span id="108">108</span> |
| <span id="109">109</span> |
| <span id="110">110</span> |
| <span id="111">111</span> |
| <span id="112">112</span> |
| <span id="113">113</span> |
| <span id="114">114</span> |
| <span id="115">115</span> |
| <span id="116">116</span> |
| <span id="117">117</span> |
| <span id="118">118</span> |
| <span id="119">119</span> |
| <span id="120">120</span> |
| <span id="121">121</span> |
| <span id="122">122</span> |
| <span id="123">123</span> |
| <span id="124">124</span> |
| <span id="125">125</span> |
| <span id="126">126</span> |
| <span id="127">127</span> |
| <span id="128">128</span> |
| <span id="129">129</span> |
| <span id="130">130</span> |
| <span id="131">131</span> |
| <span id="132">132</span> |
| <span id="133">133</span> |
| <span id="134">134</span> |
| <span id="135">135</span> |
| <span id="136">136</span> |
| <span id="137">137</span> |
| <span id="138">138</span> |
| <span id="139">139</span> |
| <span id="140">140</span> |
| <span id="141">141</span> |
| <span id="142">142</span> |
| <span id="143">143</span> |
| <span id="144">144</span> |
| <span id="145">145</span> |
| <span id="146">146</span> |
| <span id="147">147</span> |
| <span id="148">148</span> |
| <span id="149">149</span> |
| <span id="150">150</span> |
| <span id="151">151</span> |
| <span id="152">152</span> |
| <span id="153">153</span> |
| <span id="154">154</span> |
| <span id="155">155</span> |
| <span id="156">156</span> |
| <span id="157">157</span> |
| <span id="158">158</span> |
| <span id="159">159</span> |
| <span id="160">160</span> |
| <span id="161">161</span> |
| <span id="162">162</span> |
| <span id="163">163</span> |
| <span id="164">164</span> |
| <span id="165">165</span> |
| <span id="166">166</span> |
| <span id="167">167</span> |
| <span id="168">168</span> |
| <span id="169">169</span> |
| <span id="170">170</span> |
| </pre><pre class="rust"><code><span class="kw">use </span>std::num::NonZeroU64; |
| |
| <span class="kw">use </span>fastdivide::DividerU64; |
| |
| <span class="doccomment">/// Compute the gcd of two non null numbers. |
| /// |
| /// It is recommended, but not required, to feed values such that `large >= small`. |
| </span><span class="kw">fn </span>compute_gcd(<span class="kw-2">mut </span>large: NonZeroU64, <span class="kw-2">mut </span>small: NonZeroU64) -> NonZeroU64 { |
| <span class="kw">loop </span>{ |
| <span class="kw">let </span>rem: u64 = large.get() % small; |
| <span class="kw">if let </span><span class="prelude-val">Some</span>(new_small) = NonZeroU64::new(rem) { |
| (large, small) = (small, new_small); |
| } <span class="kw">else </span>{ |
| <span class="kw">return </span>small; |
| } |
| } |
| } |
| |
| <span class="comment">// Find GCD for iterator of numbers |
| </span><span class="kw">pub fn </span>find_gcd(numbers: <span class="kw">impl </span>Iterator<Item = u64>) -> <span class="prelude-ty">Option</span><NonZeroU64> { |
| <span class="kw">let </span><span class="kw-2">mut </span>numbers = numbers.flat_map(NonZeroU64::new); |
| <span class="kw">let </span><span class="kw-2">mut </span>gcd: NonZeroU64 = numbers.next()<span class="question-mark">?</span>; |
| <span class="kw">if </span>gcd.get() == <span class="number">1 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Some</span>(gcd); |
| } |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>gcd_divider = DividerU64::divide_by(gcd.get()); |
| <span class="kw">for </span>val <span class="kw">in </span>numbers { |
| <span class="kw">let </span>remainder = val.get() - (gcd_divider.divide(val.get())) * gcd.get(); |
| <span class="kw">if </span>remainder == <span class="number">0 </span>{ |
| <span class="kw">continue</span>; |
| } |
| gcd = compute_gcd(val, gcd); |
| <span class="kw">if </span>gcd.get() == <span class="number">1 </span>{ |
| <span class="kw">return </span><span class="prelude-val">Some</span>(gcd); |
| } |
| |
| gcd_divider = DividerU64::divide_by(gcd.get()); |
| } |
| <span class="prelude-val">Some</span>(gcd) |
| } |
| |
| <span class="attribute">#[cfg(test)] |
| </span><span class="kw">mod </span>tests { |
| <span class="kw">use </span>std::io; |
| <span class="kw">use </span>std::num::NonZeroU64; |
| |
| <span class="kw">use </span>ownedbytes::OwnedBytes; |
| |
| <span class="kw">use </span><span class="kw">crate</span>::gcd::{compute_gcd, find_gcd}; |
| <span class="kw">use crate</span>::{FastFieldCodecType, VecColumn}; |
| |
| <span class="kw">fn </span>test_fastfield_gcd_i64_with_codec( |
| codec_type: FastFieldCodecType, |
| num_vals: usize, |
| ) -> io::Result<()> { |
| <span class="kw">let </span><span class="kw-2">mut </span>vals: Vec<i64> = (-<span class="number">4</span>..=(num_vals <span class="kw">as </span>i64) - <span class="number">5</span>).map(|val| val * <span class="number">1000</span>).collect(); |
| <span class="kw">let </span><span class="kw-2">mut </span>buffer: Vec<u8> = Vec::new(); |
| <span class="kw">crate</span>::serialize(VecColumn::from(<span class="kw-2">&</span>vals), <span class="kw-2">&mut </span>buffer, <span class="kw-2">&</span>[codec_type])<span class="question-mark">?</span>; |
| <span class="kw">let </span>buffer = OwnedBytes::new(buffer); |
| <span class="kw">let </span>column = <span class="kw">crate</span>::open::<i64>(buffer.clone())<span class="question-mark">?</span>; |
| <span class="macro">assert_eq!</span>(column.get_val(<span class="number">0</span>), -<span class="number">4000i64</span>); |
| <span class="macro">assert_eq!</span>(column.get_val(<span class="number">1</span>), -<span class="number">3000i64</span>); |
| <span class="macro">assert_eq!</span>(column.get_val(<span class="number">2</span>), -<span class="number">2000i64</span>); |
| <span class="macro">assert_eq!</span>(column.max_value(), (num_vals <span class="kw">as </span>i64 - <span class="number">5</span>) * <span class="number">1000</span>); |
| <span class="macro">assert_eq!</span>(column.min_value(), -<span class="number">4000i64</span>); |
| |
| <span class="comment">// Can't apply gcd |
| </span><span class="kw">let </span><span class="kw-2">mut </span>buffer_without_gcd = Vec::new(); |
| vals.pop(); |
| vals.push(<span class="number">1001i64</span>); |
| <span class="kw">crate</span>::serialize( |
| VecColumn::from(<span class="kw-2">&</span>vals), |
| <span class="kw-2">&mut </span>buffer_without_gcd, |
| <span class="kw-2">&</span>[codec_type], |
| )<span class="question-mark">?</span>; |
| <span class="kw">let </span>buffer_without_gcd = OwnedBytes::new(buffer_without_gcd); |
| <span class="macro">assert!</span>(buffer_without_gcd.len() > buffer.len()); |
| |
| <span class="prelude-val">Ok</span>(()) |
| } |
| |
| <span class="attribute">#[test] |
| </span><span class="kw">fn </span>test_fastfield_gcd_i64() -> io::Result<()> { |
| <span class="kw">for </span><span class="kw-2">&</span>codec_type <span class="kw">in </span><span class="kw-2">&</span>[ |
| FastFieldCodecType::Bitpacked, |
| FastFieldCodecType::BlockwiseLinear, |
| FastFieldCodecType::Linear, |
| ] { |
| test_fastfield_gcd_i64_with_codec(codec_type, <span class="number">5500</span>)<span class="question-mark">?</span>; |
| } |
| <span class="prelude-val">Ok</span>(()) |
| } |
| |
| <span class="kw">fn </span>test_fastfield_gcd_u64_with_codec( |
| codec_type: FastFieldCodecType, |
| num_vals: usize, |
| ) -> io::Result<()> { |
| <span class="kw">let </span><span class="kw-2">mut </span>vals: Vec<u64> = (<span class="number">1</span>..=num_vals).map(|i| i <span class="kw">as </span>u64 * <span class="number">1000u64</span>).collect(); |
| <span class="kw">let </span><span class="kw-2">mut </span>buffer: Vec<u8> = Vec::new(); |
| <span class="kw">crate</span>::serialize(VecColumn::from(<span class="kw-2">&</span>vals), <span class="kw-2">&mut </span>buffer, <span class="kw-2">&</span>[codec_type])<span class="question-mark">?</span>; |
| <span class="kw">let </span>buffer = OwnedBytes::new(buffer); |
| <span class="kw">let </span>column = <span class="kw">crate</span>::open::<u64>(buffer.clone())<span class="question-mark">?</span>; |
| <span class="macro">assert_eq!</span>(column.get_val(<span class="number">0</span>), <span class="number">1000u64</span>); |
| <span class="macro">assert_eq!</span>(column.get_val(<span class="number">1</span>), <span class="number">2000u64</span>); |
| <span class="macro">assert_eq!</span>(column.get_val(<span class="number">2</span>), <span class="number">3000u64</span>); |
| <span class="macro">assert_eq!</span>(column.max_value(), num_vals <span class="kw">as </span>u64 * <span class="number">1000</span>); |
| <span class="macro">assert_eq!</span>(column.min_value(), <span class="number">1000u64</span>); |
| |
| <span class="comment">// Can't apply gcd |
| </span><span class="kw">let </span><span class="kw-2">mut </span>buffer_without_gcd = Vec::new(); |
| vals.pop(); |
| vals.push(<span class="number">1001u64</span>); |
| <span class="kw">crate</span>::serialize( |
| VecColumn::from(<span class="kw-2">&</span>vals), |
| <span class="kw-2">&mut </span>buffer_without_gcd, |
| <span class="kw-2">&</span>[codec_type], |
| )<span class="question-mark">?</span>; |
| <span class="kw">let </span>buffer_without_gcd = OwnedBytes::new(buffer_without_gcd); |
| <span class="macro">assert!</span>(buffer_without_gcd.len() > buffer.len()); |
| <span class="prelude-val">Ok</span>(()) |
| } |
| |
| <span class="attribute">#[test] |
| </span><span class="kw">fn </span>test_fastfield_gcd_u64() -> io::Result<()> { |
| <span class="kw">for </span><span class="kw-2">&</span>codec_type <span class="kw">in </span><span class="kw-2">&</span>[ |
| FastFieldCodecType::Bitpacked, |
| FastFieldCodecType::BlockwiseLinear, |
| FastFieldCodecType::Linear, |
| ] { |
| test_fastfield_gcd_u64_with_codec(codec_type, <span class="number">5500</span>)<span class="question-mark">?</span>; |
| } |
| <span class="prelude-val">Ok</span>(()) |
| } |
| |
| <span class="attribute">#[test] |
| </span><span class="kw">pub fn </span>test_fastfield2() { |
| <span class="kw">let </span>test_fastfield = <span class="kw">crate</span>::serialize_and_load(<span class="kw-2">&</span>[<span class="number">100u64</span>, <span class="number">200u64</span>, <span class="number">300u64</span>]); |
| <span class="macro">assert_eq!</span>(test_fastfield.get_val(<span class="number">0</span>), <span class="number">100</span>); |
| <span class="macro">assert_eq!</span>(test_fastfield.get_val(<span class="number">1</span>), <span class="number">200</span>); |
| <span class="macro">assert_eq!</span>(test_fastfield.get_val(<span class="number">2</span>), <span class="number">300</span>); |
| } |
| |
| <span class="attribute">#[test] |
| </span><span class="kw">fn </span>test_compute_gcd() { |
| <span class="kw">let </span>test_compute_gcd_aux = |large, small, expected| { |
| <span class="kw">let </span>large = NonZeroU64::new(large).unwrap(); |
| <span class="kw">let </span>small = NonZeroU64::new(small).unwrap(); |
| <span class="kw">let </span>expected = NonZeroU64::new(expected).unwrap(); |
| <span class="macro">assert_eq!</span>(compute_gcd(small, large), expected); |
| <span class="macro">assert_eq!</span>(compute_gcd(large, small), expected); |
| }; |
| test_compute_gcd_aux(<span class="number">1</span>, <span class="number">4</span>, <span class="number">1</span>); |
| test_compute_gcd_aux(<span class="number">2</span>, <span class="number">4</span>, <span class="number">2</span>); |
| test_compute_gcd_aux(<span class="number">10</span>, <span class="number">25</span>, <span class="number">5</span>); |
| test_compute_gcd_aux(<span class="number">25</span>, <span class="number">25</span>, <span class="number">25</span>); |
| } |
| |
| <span class="attribute">#[test] |
| </span><span class="kw">fn </span>find_gcd_test() { |
| <span class="macro">assert_eq!</span>(find_gcd([<span class="number">0</span>].into_iter()), <span class="prelude-val">None</span>); |
| <span class="macro">assert_eq!</span>(find_gcd([<span class="number">0</span>, <span class="number">10</span>].into_iter()), NonZeroU64::new(<span class="number">10</span>)); |
| <span class="macro">assert_eq!</span>(find_gcd([<span class="number">10</span>, <span class="number">0</span>].into_iter()), NonZeroU64::new(<span class="number">10</span>)); |
| <span class="macro">assert_eq!</span>(find_gcd([].into_iter()), <span class="prelude-val">None</span>); |
| <span class="macro">assert_eq!</span>(find_gcd([<span class="number">15</span>, <span class="number">30</span>, <span class="number">5</span>, <span class="number">10</span>].into_iter()), NonZeroU64::new(<span class="number">5</span>)); |
| <span class="macro">assert_eq!</span>(find_gcd([<span class="number">15</span>, <span class="number">16</span>, <span class="number">10</span>].into_iter()), NonZeroU64::new(<span class="number">1</span>)); |
| <span class="macro">assert_eq!</span>(find_gcd([<span class="number">0</span>, <span class="number">5</span>, <span class="number">5</span>, <span class="number">5</span>].into_iter()), NonZeroU64::new(<span class="number">5</span>)); |
| <span class="macro">assert_eq!</span>(find_gcd([<span class="number">0</span>, <span class="number">0</span>].into_iter()), <span class="prelude-val">None</span>); |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="fastfield_codecs" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |