| <!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/registry/src/github.com-1ecc6299db9ec823/slab-0.4.8/src/builder.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>builder.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="../../slab/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="../../slab/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 crate</span>::{Entry, Slab}; |
| |
| <span class="comment">// Building `Slab` from pairs (usize, T). |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">struct </span>Builder<T> { |
| slab: Slab<T>, |
| vacant_list_broken: bool, |
| first_vacant_index: <span class="prelude-ty">Option</span><usize>, |
| } |
| |
| <span class="kw">impl</span><T> Builder<T> { |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>with_capacity(capacity: usize) -> <span class="self">Self </span>{ |
| <span class="self">Self </span>{ |
| slab: Slab::with_capacity(capacity), |
| vacant_list_broken: <span class="bool-val">false</span>, |
| first_vacant_index: <span class="prelude-val">None</span>, |
| } |
| } |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>pair(<span class="kw-2">&mut </span><span class="self">self</span>, key: usize, value: T) { |
| <span class="kw">let </span>slab = <span class="kw-2">&mut </span><span class="self">self</span>.slab; |
| <span class="kw">if </span>key < slab.entries.len() { |
| <span class="comment">// iterator is not sorted, might need to recreate vacant list |
| </span><span class="kw">if let </span>Entry::Vacant(<span class="kw">_</span>) = slab.entries[key] { |
| <span class="self">self</span>.vacant_list_broken = <span class="bool-val">true</span>; |
| slab.len += <span class="number">1</span>; |
| } |
| <span class="comment">// if an element with this key already exists, replace it. |
| // This is consistent with HashMap and BtreeMap |
| </span>slab.entries[key] = Entry::Occupied(value); |
| } <span class="kw">else </span>{ |
| <span class="kw">if </span><span class="self">self</span>.first_vacant_index.is_none() && slab.entries.len() < key { |
| <span class="self">self</span>.first_vacant_index = <span class="prelude-val">Some</span>(slab.entries.len()); |
| } |
| <span class="comment">// insert holes as necessary |
| </span><span class="kw">while </span>slab.entries.len() < key { |
| <span class="comment">// add the entry to the start of the vacant list |
| </span><span class="kw">let </span>next = slab.next; |
| slab.next = slab.entries.len(); |
| slab.entries.push(Entry::Vacant(next)); |
| } |
| slab.entries.push(Entry::Occupied(value)); |
| slab.len += <span class="number">1</span>; |
| } |
| } |
| |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>build(<span class="self">self</span>) -> Slab<T> { |
| <span class="kw">let </span><span class="kw-2">mut </span>slab = <span class="self">self</span>.slab; |
| <span class="kw">if </span>slab.len == slab.entries.len() { |
| <span class="comment">// no vacant entries, so next might not have been updated |
| </span>slab.next = slab.entries.len(); |
| } <span class="kw">else if </span><span class="self">self</span>.vacant_list_broken { |
| slab.recreate_vacant_list(); |
| } <span class="kw">else if let </span><span class="prelude-val">Some</span>(first_vacant_index) = <span class="self">self</span>.first_vacant_index { |
| <span class="kw">let </span>next = slab.entries.len(); |
| <span class="kw">match </span><span class="kw-2">&mut </span>slab.entries[first_vacant_index] { |
| Entry::Vacant(n) => <span class="kw-2">*</span>n = next, |
| <span class="kw">_ </span>=> <span class="macro">unreachable!</span>(), |
| } |
| } <span class="kw">else </span>{ |
| <span class="macro">unreachable!</span>() |
| } |
| slab |
| } |
| } |
| </code></pre></div> |
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