| <!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/blockwise_linear.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>blockwise_linear.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> |
| <span id="171">171</span> |
| <span id="172">172</span> |
| <span id="173">173</span> |
| <span id="174">174</span> |
| <span id="175">175</span> |
| <span id="176">176</span> |
| <span id="177">177</span> |
| <span id="178">178</span> |
| <span id="179">179</span> |
| <span id="180">180</span> |
| <span id="181">181</span> |
| <span id="182">182</span> |
| <span id="183">183</span> |
| <span id="184">184</span> |
| <span id="185">185</span> |
| <span id="186">186</span> |
| </pre><pre class="rust"><code><span class="kw">use </span>std::sync::Arc; |
| <span class="kw">use </span>std::{io, iter}; |
| |
| <span class="kw">use </span>common::{BinarySerializable, CountingWriter, DeserializeFrom}; |
| <span class="kw">use </span>ownedbytes::OwnedBytes; |
| <span class="kw">use </span>tantivy_bitpacker::{compute_num_bits, BitPacker, BitUnpacker}; |
| |
| <span class="kw">use </span><span class="kw">crate</span>::line::Line; |
| <span class="kw">use </span><span class="kw">crate</span>::serialize::NormalizedHeader; |
| <span class="kw">use crate</span>::{Column, FastFieldCodec, FastFieldCodecType, VecColumn}; |
| |
| <span class="kw">const </span>CHUNK_SIZE: usize = <span class="number">512</span>; |
| |
| <span class="attribute">#[derive(Debug, Default)] |
| </span><span class="kw">struct </span>Block { |
| line: Line, |
| bit_unpacker: BitUnpacker, |
| data_start_offset: usize, |
| } |
| |
| <span class="kw">impl </span>BinarySerializable <span class="kw">for </span>Block { |
| <span class="kw">fn </span>serialize<W: io::Write>(<span class="kw-2">&</span><span class="self">self</span>, writer: <span class="kw-2">&mut </span>W) -> io::Result<()> { |
| <span class="self">self</span>.line.serialize(writer)<span class="question-mark">?</span>; |
| <span class="self">self</span>.bit_unpacker.bit_width().serialize(writer)<span class="question-mark">?</span>; |
| <span class="prelude-val">Ok</span>(()) |
| } |
| |
| <span class="kw">fn </span>deserialize<R: io::Read>(reader: <span class="kw-2">&mut </span>R) -> io::Result<<span class="self">Self</span>> { |
| <span class="kw">let </span>line = Line::deserialize(reader)<span class="question-mark">?</span>; |
| <span class="kw">let </span>bit_width = u8::deserialize(reader)<span class="question-mark">?</span>; |
| <span class="prelude-val">Ok</span>(Block { |
| line, |
| bit_unpacker: BitUnpacker::new(bit_width), |
| data_start_offset: <span class="number">0</span>, |
| }) |
| } |
| } |
| |
| <span class="kw">fn </span>compute_num_blocks(num_vals: u32) -> usize { |
| (num_vals <span class="kw">as </span>usize + CHUNK_SIZE - <span class="number">1</span>) / CHUNK_SIZE |
| } |
| |
| <span class="kw">pub struct </span>BlockwiseLinearCodec; |
| |
| <span class="kw">impl </span>FastFieldCodec <span class="kw">for </span>BlockwiseLinearCodec { |
| <span class="kw">const </span>CODEC_TYPE: <span class="kw">crate</span>::FastFieldCodecType = FastFieldCodecType::BlockwiseLinear; |
| <span class="kw">type </span>Reader = BlockwiseLinearReader; |
| |
| <span class="kw">fn </span>open_from_bytes( |
| bytes: ownedbytes::OwnedBytes, |
| normalized_header: NormalizedHeader, |
| ) -> io::Result<<span class="self">Self</span>::Reader> { |
| <span class="kw">let </span>footer_len: u32 = (<span class="kw-2">&</span>bytes[bytes.len() - <span class="number">4</span>..]).deserialize()<span class="question-mark">?</span>; |
| <span class="kw">let </span>footer_offset = bytes.len() - <span class="number">4 </span>- footer_len <span class="kw">as </span>usize; |
| <span class="kw">let </span>(data, <span class="kw-2">mut </span>footer) = bytes.split(footer_offset); |
| <span class="kw">let </span>num_blocks = compute_num_blocks(normalized_header.num_vals); |
| <span class="kw">let </span><span class="kw-2">mut </span>blocks: Vec<Block> = iter::repeat_with(|| Block::deserialize(<span class="kw-2">&mut </span>footer)) |
| .take(num_blocks) |
| .collect::<io::Result<<span class="kw">_</span>>>()<span class="question-mark">?</span>; |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>start_offset = <span class="number">0</span>; |
| <span class="kw">for </span>block <span class="kw">in </span><span class="kw-2">&mut </span>blocks { |
| block.data_start_offset = start_offset; |
| start_offset += (block.bit_unpacker.bit_width() <span class="kw">as </span>usize) * CHUNK_SIZE / <span class="number">8</span>; |
| } |
| <span class="prelude-val">Ok</span>(BlockwiseLinearReader { |
| blocks: Arc::new(blocks), |
| data, |
| normalized_header, |
| }) |
| } |
| |
| <span class="comment">// Estimate first_chunk and extrapolate |
| </span><span class="kw">fn </span>estimate(column: <span class="kw-2">&</span><span class="kw">dyn </span><span class="kw">crate</span>::Column) -> <span class="prelude-ty">Option</span><f32> { |
| <span class="kw">if </span>column.num_vals() < <span class="number">10 </span>* CHUNK_SIZE <span class="kw">as </span>u32 { |
| <span class="kw">return </span><span class="prelude-val">None</span>; |
| } |
| <span class="kw">let </span><span class="kw-2">mut </span>first_chunk: Vec<u64> = column.iter().take(CHUNK_SIZE <span class="kw">as </span>usize).collect(); |
| <span class="kw">let </span>line = Line::train(<span class="kw-2">&</span>VecColumn::from(<span class="kw-2">&</span>first_chunk)); |
| <span class="kw">for </span>(i, buffer_val) <span class="kw">in </span>first_chunk.iter_mut().enumerate() { |
| <span class="kw">let </span>interpolated_val = line.eval(i <span class="kw">as </span>u32); |
| <span class="kw-2">*</span>buffer_val = buffer_val.wrapping_sub(interpolated_val); |
| } |
| <span class="kw">let </span>estimated_bit_width = first_chunk |
| .iter() |
| .map(|el| ((el + <span class="number">1</span>) <span class="kw">as </span>f32 * <span class="number">3.0</span>) <span class="kw">as </span>u64) |
| .map(compute_num_bits) |
| .max() |
| .unwrap(); |
| |
| <span class="kw">let </span>metadata_per_block = { |
| <span class="kw">let </span><span class="kw-2">mut </span>out = <span class="macro">vec!</span>[]; |
| Block::default().serialize(<span class="kw-2">&mut </span>out).unwrap(); |
| out.len() |
| }; |
| <span class="kw">let </span>num_bits = estimated_bit_width <span class="kw">as </span>u64 * column.num_vals() <span class="kw">as </span>u64 |
| <span class="comment">// function metadata per block |
| </span>+ metadata_per_block <span class="kw">as </span>u64 * (column.num_vals() <span class="kw">as </span>u64 / CHUNK_SIZE <span class="kw">as </span>u64); |
| <span class="kw">let </span>num_bits_uncompressed = <span class="number">64 </span>* column.num_vals(); |
| <span class="prelude-val">Some</span>(num_bits <span class="kw">as </span>f32 / num_bits_uncompressed <span class="kw">as </span>f32) |
| } |
| |
| <span class="kw">fn </span>serialize(column: <span class="kw-2">&</span><span class="kw">dyn </span>Column, wrt: <span class="kw-2">&mut </span><span class="kw">impl </span>io::Write) -> io::Result<()> { |
| <span class="comment">// The BitpackedReader assumes a normalized vector. |
| </span><span class="macro">assert_eq!</span>(column.min_value(), <span class="number">0</span>); |
| <span class="kw">let </span><span class="kw-2">mut </span>buffer = Vec::with_capacity(CHUNK_SIZE); |
| <span class="kw">let </span>num_vals = column.num_vals(); |
| |
| <span class="kw">let </span>num_blocks = compute_num_blocks(num_vals); |
| <span class="kw">let </span><span class="kw-2">mut </span>blocks = Vec::with_capacity(num_blocks); |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>vals = column.iter(); |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>bit_packer = BitPacker::new(); |
| |
| <span class="kw">for _ in </span><span class="number">0</span>..num_blocks { |
| buffer.clear(); |
| buffer.extend((<span class="kw-2">&mut </span>vals).take(CHUNK_SIZE)); |
| <span class="kw">let </span>line = Line::train(<span class="kw-2">&</span>VecColumn::from(<span class="kw-2">&</span>buffer)); |
| |
| <span class="macro">assert!</span>(!buffer.is_empty()); |
| |
| <span class="kw">for </span>(i, buffer_val) <span class="kw">in </span>buffer.iter_mut().enumerate() { |
| <span class="kw">let </span>interpolated_val = line.eval(i <span class="kw">as </span>u32); |
| <span class="kw-2">*</span>buffer_val = buffer_val.wrapping_sub(interpolated_val); |
| } |
| <span class="kw">let </span>bit_width = buffer.iter().copied().map(compute_num_bits).max().unwrap(); |
| |
| <span class="kw">for </span><span class="kw-2">&</span>buffer_val <span class="kw">in </span><span class="kw-2">&</span>buffer { |
| bit_packer.write(buffer_val, bit_width, wrt)<span class="question-mark">?</span>; |
| } |
| |
| blocks.push(Block { |
| line, |
| bit_unpacker: BitUnpacker::new(bit_width), |
| data_start_offset: <span class="number">0</span>, |
| }); |
| } |
| |
| bit_packer.close(wrt)<span class="question-mark">?</span>; |
| |
| <span class="macro">assert_eq!</span>(blocks.len(), compute_num_blocks(num_vals)); |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>counting_wrt = CountingWriter::wrap(wrt); |
| <span class="kw">for </span>block <span class="kw">in </span><span class="kw-2">&</span>blocks { |
| block.serialize(<span class="kw-2">&mut </span>counting_wrt)<span class="question-mark">?</span>; |
| } |
| <span class="kw">let </span>footer_len = counting_wrt.written_bytes(); |
| (footer_len <span class="kw">as </span>u32).serialize(<span class="kw-2">&mut </span>counting_wrt)<span class="question-mark">?</span>; |
| |
| <span class="prelude-val">Ok</span>(()) |
| } |
| } |
| |
| <span class="attribute">#[derive(Clone)] |
| </span><span class="kw">pub struct </span>BlockwiseLinearReader { |
| blocks: Arc<Vec<Block>>, |
| normalized_header: NormalizedHeader, |
| data: OwnedBytes, |
| } |
| |
| <span class="kw">impl </span>Column <span class="kw">for </span>BlockwiseLinearReader { |
| <span class="attribute">#[inline(always)] |
| </span><span class="kw">fn </span>get_val(<span class="kw-2">&</span><span class="self">self</span>, idx: u32) -> u64 { |
| <span class="kw">let </span>block_id = (idx / CHUNK_SIZE <span class="kw">as </span>u32) <span class="kw">as </span>usize; |
| <span class="kw">let </span>idx_within_block = idx % (CHUNK_SIZE <span class="kw">as </span>u32); |
| <span class="kw">let </span>block = <span class="kw-2">&</span><span class="self">self</span>.blocks[block_id]; |
| <span class="kw">let </span>interpoled_val: u64 = block.line.eval(idx_within_block); |
| <span class="kw">let </span>block_bytes = <span class="kw-2">&</span><span class="self">self</span>.data[block.data_start_offset..]; |
| <span class="kw">let </span>bitpacked_diff = block.bit_unpacker.get(idx_within_block, block_bytes); |
| interpoled_val.wrapping_add(bitpacked_diff) |
| } |
| |
| <span class="kw">fn </span>min_value(<span class="kw-2">&</span><span class="self">self</span>) -> u64 { |
| <span class="comment">// The BlockwiseLinearReader assumes a normalized vector. |
| </span><span class="number">0u64 |
| </span>} |
| |
| <span class="kw">fn </span>max_value(<span class="kw-2">&</span><span class="self">self</span>) -> u64 { |
| <span class="self">self</span>.normalized_header.max_value |
| } |
| |
| <span class="kw">fn </span>num_vals(<span class="kw-2">&</span><span class="self">self</span>) -> u32 { |
| <span class="self">self</span>.normalized_header.num_vals |
| } |
| } |
| </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> |
