| <!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/base64-0.21.2/src/lib.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>lib.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="../../base64/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="../../base64/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> |
| </pre><pre class="rust"><code><span class="doccomment">//! # Getting started |
| //! |
| //! 1. Perhaps one of the preconfigured engines in [engine::general_purpose] will suit, e.g. |
| //! [engine::general_purpose::STANDARD_NO_PAD]. |
| //! - These are re-exported in [prelude] with a `BASE64_` prefix for those who prefer to |
| //! `use base64::prelude::*` or equivalent, e.g. [prelude::BASE64_STANDARD_NO_PAD] |
| //! 1. If not, choose which alphabet you want. Most usage will want [alphabet::STANDARD] or [alphabet::URL_SAFE]. |
| //! 1. Choose which [Engine] implementation you want. For the moment there is only one: [engine::GeneralPurpose]. |
| //! 1. Configure the engine appropriately using the engine's `Config` type. |
| //! - This is where you'll select whether to add padding (when encoding) or expect it (when |
| //! decoding). If given the choice, prefer no padding. |
| //! 1. Build the engine using the selected alphabet and config. |
| //! |
| //! For more detail, see below. |
| //! |
| //! ## Alphabets |
| //! |
| //! An [alphabet::Alphabet] defines what ASCII symbols are used to encode to or decode from. |
| //! |
| //! Constants in [alphabet] like [alphabet::STANDARD] or [alphabet::URL_SAFE] provide commonly used |
| //! alphabets, but you can also build your own custom [alphabet::Alphabet] if needed. |
| //! |
| //! ## Engines |
| //! |
| //! Once you have an `Alphabet`, you can pick which `Engine` you want. A few parts of the public |
| //! API provide a default, but otherwise the user must provide an `Engine` to use. |
| //! |
| //! See [Engine] for more. |
| //! |
| //! ## Config |
| //! |
| //! In addition to an `Alphabet`, constructing an `Engine` also requires an [engine::Config]. Each |
| //! `Engine` has a corresponding `Config` implementation since different `Engine`s may offer different |
| //! levels of configurability. |
| //! |
| //! # Encoding |
| //! |
| //! Several different encoding methods on [Engine] are available to you depending on your desire for |
| //! convenience vs performance. |
| //! |
| //! | Method | Output | Allocates | |
| //! | ------------------------ | ---------------------------- | ------------------------------ | |
| //! | [Engine::encode] | Returns a new `String` | Always | |
| //! | [Engine::encode_string] | Appends to provided `String` | Only if `String` needs to grow | |
| //! | [Engine::encode_slice] | Writes to provided `&[u8]` | Never - fastest | |
| //! |
| //! All of the encoding methods will pad as per the engine's config. |
| //! |
| //! # Decoding |
| //! |
| //! Just as for encoding, there are different decoding methods available. |
| //! |
| //! | Method | Output | Allocates | |
| //! | ------------------------ | ----------------------------- | ------------------------------ | |
| //! | [Engine::decode] | Returns a new `Vec<u8>` | Always | |
| //! | [Engine::decode_vec] | Appends to provided `Vec<u8>` | Only if `Vec` needs to grow | |
| //! | [Engine::decode_slice] | Writes to provided `&[u8]` | Never - fastest | |
| //! |
| //! Unlike encoding, where all possible input is valid, decoding can fail (see [DecodeError]). |
| //! |
| //! Input can be invalid because it has invalid characters or invalid padding. The nature of how |
| //! padding is checked depends on the engine's config. |
| //! Whitespace in the input is invalid, just like any other non-base64 byte. |
| //! |
| //! # `Read` and `Write` |
| //! |
| //! To decode a [std::io::Read] of b64 bytes, wrap a reader (file, network socket, etc) with |
| //! [read::DecoderReader]. |
| //! |
| //! To write raw bytes and have them b64 encoded on the fly, wrap a [std::io::Write] with |
| //! [write::EncoderWriter]. |
| //! |
| //! There is some performance overhead (15% or so) because of the necessary buffer shuffling -- |
| //! still fast enough that almost nobody cares. Also, these implementations do not heap allocate. |
| //! |
| //! # `Display` |
| //! |
| //! See [display] for how to transparently base64 data via a `Display` implementation. |
| //! |
| //! # Examples |
| //! |
| //! ## Using predefined engines |
| //! |
| //! ``` |
| //! use base64::{Engine as _, engine::general_purpose}; |
| //! |
| //! let orig = b"data"; |
| //! let encoded: String = general_purpose::STANDARD_NO_PAD.encode(orig); |
| //! assert_eq!("ZGF0YQ", encoded); |
| //! assert_eq!(orig.as_slice(), &general_purpose::STANDARD_NO_PAD.decode(encoded).unwrap()); |
| //! |
| //! // or, URL-safe |
| //! let encoded_url = general_purpose::URL_SAFE_NO_PAD.encode(orig); |
| //! ``` |
| //! |
| //! ## Custom alphabet, config, and engine |
| //! |
| //! ``` |
| //! use base64::{engine, alphabet, Engine as _}; |
| //! |
| //! // bizarro-world base64: +/ as the first symbols instead of the last |
| //! let alphabet = |
| //! alphabet::Alphabet::new("+/ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789") |
| //! .unwrap(); |
| //! |
| //! // a very weird config that encodes with padding but requires no padding when decoding...? |
| //! let crazy_config = engine::GeneralPurposeConfig::new() |
| //! .with_decode_allow_trailing_bits(true) |
| //! .with_encode_padding(true) |
| //! .with_decode_padding_mode(engine::DecodePaddingMode::RequireNone); |
| //! |
| //! let crazy_engine = engine::GeneralPurpose::new(&alphabet, crazy_config); |
| //! |
| //! let encoded = crazy_engine.encode(b"abc 123"); |
| //! |
| //! ``` |
| //! |
| //! # Panics |
| //! |
| //! If length calculations result in overflowing `usize`, a panic will result. |
| |
| </span><span class="attribute">#![cfg_attr(feature = <span class="string">"cargo-clippy"</span>, allow(clippy::cast_lossless))] |
| #![deny( |
| missing_docs, |
| trivial_casts, |
| trivial_numeric_casts, |
| unused_extern_crates, |
| unused_import_braces, |
| unused_results, |
| variant_size_differences, |
| warnings |
| )] |
| #![forbid(unsafe_code)] |
| </span><span class="comment">// Allow globally until https://github.com/rust-lang/rust-clippy/issues/8768 is resolved. |
| // The desired state is to allow it only for the rstest_reuse import. |
| </span><span class="attribute">#![allow(clippy::single_component_path_imports)] |
| #![cfg_attr(not(any(feature = <span class="string">"std"</span>, test)), no_std)] |
| |
| #[cfg(all(feature = <span class="string">"alloc"</span>, not(any(feature = <span class="string">"std"</span>, test))))] |
| </span><span class="kw">extern crate </span>alloc; |
| <span class="attribute">#[cfg(any(feature = <span class="string">"std"</span>, test))] |
| </span><span class="kw">extern crate </span>std <span class="kw">as </span>alloc; |
| |
| <span class="comment">// has to be included at top level because of the way rstest_reuse defines its macros |
| </span><span class="attribute">#[cfg(test)] |
| </span><span class="kw">use </span>rstest_reuse; |
| |
| <span class="kw">mod </span>chunked_encoder; |
| <span class="kw">pub mod </span>display; |
| <span class="attribute">#[cfg(any(feature = <span class="string">"std"</span>, test))] |
| </span><span class="kw">pub mod </span>read; |
| <span class="attribute">#[cfg(any(feature = <span class="string">"std"</span>, test))] |
| </span><span class="kw">pub mod </span>write; |
| |
| <span class="kw">pub mod </span>engine; |
| <span class="kw">pub use </span>engine::Engine; |
| |
| <span class="kw">pub mod </span>alphabet; |
| |
| <span class="kw">mod </span>encode; |
| <span class="attribute">#[allow(deprecated)] |
| #[cfg(any(feature = <span class="string">"alloc"</span>, feature = <span class="string">"std"</span>, test))] |
| </span><span class="kw">pub use </span><span class="kw">crate</span>::encode::{encode, encode_engine, encode_engine_string}; |
| <span class="attribute">#[allow(deprecated)] |
| </span><span class="kw">pub use </span><span class="kw">crate</span>::encode::{encode_engine_slice, encoded_len, EncodeSliceError}; |
| |
| <span class="kw">mod </span>decode; |
| <span class="attribute">#[allow(deprecated)] |
| #[cfg(any(feature = <span class="string">"alloc"</span>, feature = <span class="string">"std"</span>, test))] |
| </span><span class="kw">pub use </span><span class="kw">crate</span>::decode::{decode, decode_engine, decode_engine_vec}; |
| <span class="attribute">#[allow(deprecated)] |
| </span><span class="kw">pub use </span><span class="kw">crate</span>::decode::{decode_engine_slice, decoded_len_estimate, DecodeError, DecodeSliceError}; |
| |
| <span class="kw">pub mod </span>prelude; |
| |
| <span class="attribute">#[cfg(test)] |
| </span><span class="kw">mod </span>tests; |
| |
| <span class="kw">const </span>PAD_BYTE: u8 = <span class="string">b'='</span>; |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="base64" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
