| <!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/bitpacked.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>bitpacked.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> |
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| </pre><pre class="rust"><code><span class="kw">use </span>std::io::{<span class="self">self</span>, Write}; |
| |
| <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>::serialize::NormalizedHeader; |
| <span class="kw">use crate</span>::{Column, FastFieldCodec, FastFieldCodecType}; |
| |
| <span class="doccomment">/// Depending on the field type, a different |
| /// fast field is required. |
| </span><span class="attribute">#[derive(Clone)] |
| </span><span class="kw">pub struct </span>BitpackedReader { |
| data: OwnedBytes, |
| bit_unpacker: BitUnpacker, |
| normalized_header: NormalizedHeader, |
| } |
| |
| <span class="kw">impl </span>Column <span class="kw">for </span>BitpackedReader { |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>get_val(<span class="kw-2">&</span><span class="self">self</span>, doc: u32) -> u64 { |
| <span class="self">self</span>.bit_unpacker.get(doc, <span class="kw-2">&</span><span class="self">self</span>.data) |
| } |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>min_value(<span class="kw-2">&</span><span class="self">self</span>) -> u64 { |
| <span class="comment">// The BitpackedReader assumes a normalized vector. |
| </span><span class="number">0 |
| </span>} |
| <span class="attribute">#[inline] |
| </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="attribute">#[inline] |
| </span><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 |
| } |
| } |
| |
| <span class="kw">pub struct </span>BitpackedCodec; |
| |
| <span class="kw">impl </span>FastFieldCodec <span class="kw">for </span>BitpackedCodec { |
| <span class="doccomment">/// The CODEC_TYPE is an enum value used for serialization. |
| </span><span class="kw">const </span>CODEC_TYPE: FastFieldCodecType = FastFieldCodecType::Bitpacked; |
| |
| <span class="kw">type </span>Reader = BitpackedReader; |
| |
| <span class="doccomment">/// Opens a fast field given a file. |
| </span><span class="kw">fn </span>open_from_bytes( |
| data: OwnedBytes, |
| normalized_header: NormalizedHeader, |
| ) -> io::Result<<span class="self">Self</span>::Reader> { |
| <span class="kw">let </span>num_bits = compute_num_bits(normalized_header.max_value); |
| <span class="kw">let </span>bit_unpacker = BitUnpacker::new(num_bits); |
| <span class="prelude-val">Ok</span>(BitpackedReader { |
| data, |
| bit_unpacker, |
| normalized_header, |
| }) |
| } |
| |
| <span class="doccomment">/// Serializes data with the BitpackedFastFieldSerializer. |
| /// |
| /// The bitpacker assumes that the column has been normalized. |
| /// i.e. It has already been shifted by its minimum value, so that its |
| /// current minimum value is 0. |
| /// |
| /// Ideally, we made a shift upstream on the column so that `col.min_value() == 0`. |
| </span><span class="kw">fn </span>serialize(column: <span class="kw-2">&</span><span class="kw">dyn </span>Column, write: <span class="kw-2">&mut </span><span class="kw">impl </span>Write) -> io::Result<()> { |
| <span class="macro">assert_eq!</span>(column.min_value(), <span class="number">0u64</span>); |
| <span class="kw">let </span>num_bits = compute_num_bits(column.max_value()); |
| <span class="kw">let </span><span class="kw-2">mut </span>bit_packer = BitPacker::new(); |
| <span class="kw">for </span>val <span class="kw">in </span>column.iter() { |
| bit_packer.write(val, num_bits, write)<span class="question-mark">?</span>; |
| } |
| bit_packer.close(write)<span class="question-mark">?</span>; |
| <span class="prelude-val">Ok</span>(()) |
| } |
| |
| <span class="kw">fn </span>estimate(column: <span class="kw-2">&</span><span class="kw">dyn </span>Column) -> <span class="prelude-ty">Option</span><f32> { |
| <span class="kw">let </span>num_bits = compute_num_bits(column.max_value()); |
| <span class="kw">let </span>num_bits_uncompressed = <span class="number">64</span>; |
| <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="attribute">#[cfg(test)] |
| </span><span class="kw">mod </span>tests { |
| <span class="kw">use super</span>::<span class="kw-2">*</span>; |
| <span class="kw">use </span><span class="kw">crate</span>::tests::get_codec_test_datasets; |
| |
| <span class="kw">fn </span>create_and_validate(data: <span class="kw-2">&</span>[u64], name: <span class="kw-2">&</span>str) { |
| <span class="kw">crate</span>::tests::create_and_validate::<BitpackedCodec>(data, name); |
| } |
| |
| <span class="attribute">#[test] |
| </span><span class="kw">fn </span>test_with_codec_data_sets() { |
| <span class="kw">let </span>data_sets = get_codec_test_datasets(); |
| <span class="kw">for </span>(<span class="kw-2">mut </span>data, name) <span class="kw">in </span>data_sets { |
| create_and_validate(<span class="kw-2">&</span>data, name); |
| data.reverse(); |
| create_and_validate(<span class="kw-2">&</span>data, name); |
| } |
| } |
| |
| <span class="attribute">#[test] |
| </span><span class="kw">fn </span>bitpacked_fast_field_rand() { |
| <span class="kw">for _ in </span><span class="number">0</span>..<span class="number">500 </span>{ |
| <span class="kw">let </span><span class="kw-2">mut </span>data = (<span class="number">0</span>..<span class="number">1 </span>+ rand::random::<u8>() <span class="kw">as </span>usize) |
| .map(|<span class="kw">_</span>| rand::random::<i64>() <span class="kw">as </span>u64 / <span class="number">2</span>) |
| .collect::<Vec<<span class="kw">_</span>>>(); |
| create_and_validate(<span class="kw-2">&</span>data, <span class="string">"rand"</span>); |
| |
| data.reverse(); |
| create_and_validate(<span class="kw-2">&</span>data, <span class="string">"rand"</span>); |
| } |
| } |
| } |
| </code></pre></div> |
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