| <!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/untrusted-0.7.1/src/untrusted.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>untrusted.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="../../untrusted/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="../../untrusted/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> |
| <span id="187">187</span> |
| <span id="188">188</span> |
| <span id="189">189</span> |
| <span id="190">190</span> |
| <span id="191">191</span> |
| <span id="192">192</span> |
| <span id="193">193</span> |
| <span id="194">194</span> |
| <span id="195">195</span> |
| <span id="196">196</span> |
| <span id="197">197</span> |
| <span id="198">198</span> |
| <span id="199">199</span> |
| <span id="200">200</span> |
| <span id="201">201</span> |
| <span id="202">202</span> |
| <span id="203">203</span> |
| <span id="204">204</span> |
| <span id="205">205</span> |
| <span id="206">206</span> |
| <span id="207">207</span> |
| <span id="208">208</span> |
| <span id="209">209</span> |
| <span id="210">210</span> |
| <span id="211">211</span> |
| <span id="212">212</span> |
| <span id="213">213</span> |
| <span id="214">214</span> |
| <span id="215">215</span> |
| <span id="216">216</span> |
| <span id="217">217</span> |
| <span id="218">218</span> |
| <span id="219">219</span> |
| <span id="220">220</span> |
| <span id="221">221</span> |
| <span id="222">222</span> |
| <span id="223">223</span> |
| <span id="224">224</span> |
| <span id="225">225</span> |
| <span id="226">226</span> |
| <span id="227">227</span> |
| <span id="228">228</span> |
| <span id="229">229</span> |
| <span id="230">230</span> |
| <span id="231">231</span> |
| <span id="232">232</span> |
| <span id="233">233</span> |
| <span id="234">234</span> |
| <span id="235">235</span> |
| <span id="236">236</span> |
| <span id="237">237</span> |
| <span id="238">238</span> |
| <span id="239">239</span> |
| <span id="240">240</span> |
| <span id="241">241</span> |
| <span id="242">242</span> |
| <span id="243">243</span> |
| <span id="244">244</span> |
| <span id="245">245</span> |
| <span id="246">246</span> |
| <span id="247">247</span> |
| <span id="248">248</span> |
| <span id="249">249</span> |
| <span id="250">250</span> |
| <span id="251">251</span> |
| <span id="252">252</span> |
| <span id="253">253</span> |
| <span id="254">254</span> |
| <span id="255">255</span> |
| <span id="256">256</span> |
| <span id="257">257</span> |
| <span id="258">258</span> |
| <span id="259">259</span> |
| <span id="260">260</span> |
| <span id="261">261</span> |
| <span id="262">262</span> |
| <span id="263">263</span> |
| <span id="264">264</span> |
| <span id="265">265</span> |
| <span id="266">266</span> |
| <span id="267">267</span> |
| <span id="268">268</span> |
| <span id="269">269</span> |
| <span id="270">270</span> |
| <span id="271">271</span> |
| <span id="272">272</span> |
| <span id="273">273</span> |
| <span id="274">274</span> |
| <span id="275">275</span> |
| <span id="276">276</span> |
| <span id="277">277</span> |
| <span id="278">278</span> |
| <span id="279">279</span> |
| <span id="280">280</span> |
| <span id="281">281</span> |
| <span id="282">282</span> |
| <span id="283">283</span> |
| <span id="284">284</span> |
| <span id="285">285</span> |
| <span id="286">286</span> |
| <span id="287">287</span> |
| <span id="288">288</span> |
| <span id="289">289</span> |
| <span id="290">290</span> |
| <span id="291">291</span> |
| <span id="292">292</span> |
| <span id="293">293</span> |
| <span id="294">294</span> |
| <span id="295">295</span> |
| <span id="296">296</span> |
| <span id="297">297</span> |
| <span id="298">298</span> |
| <span id="299">299</span> |
| <span id="300">300</span> |
| <span id="301">301</span> |
| <span id="302">302</span> |
| <span id="303">303</span> |
| <span id="304">304</span> |
| <span id="305">305</span> |
| <span id="306">306</span> |
| <span id="307">307</span> |
| <span id="308">308</span> |
| <span id="309">309</span> |
| <span id="310">310</span> |
| <span id="311">311</span> |
| <span id="312">312</span> |
| <span id="313">313</span> |
| <span id="314">314</span> |
| <span id="315">315</span> |
| <span id="316">316</span> |
| <span id="317">317</span> |
| <span id="318">318</span> |
| <span id="319">319</span> |
| <span id="320">320</span> |
| <span id="321">321</span> |
| <span id="322">322</span> |
| <span id="323">323</span> |
| <span id="324">324</span> |
| <span id="325">325</span> |
| <span id="326">326</span> |
| <span id="327">327</span> |
| <span id="328">328</span> |
| <span id="329">329</span> |
| <span id="330">330</span> |
| <span id="331">331</span> |
| <span id="332">332</span> |
| <span id="333">333</span> |
| <span id="334">334</span> |
| <span id="335">335</span> |
| <span id="336">336</span> |
| <span id="337">337</span> |
| <span id="338">338</span> |
| <span id="339">339</span> |
| <span id="340">340</span> |
| <span id="341">341</span> |
| <span id="342">342</span> |
| <span id="343">343</span> |
| <span id="344">344</span> |
| <span id="345">345</span> |
| <span id="346">346</span> |
| <span id="347">347</span> |
| <span id="348">348</span> |
| <span id="349">349</span> |
| <span id="350">350</span> |
| <span id="351">351</span> |
| <span id="352">352</span> |
| <span id="353">353</span> |
| <span id="354">354</span> |
| <span id="355">355</span> |
| <span id="356">356</span> |
| <span id="357">357</span> |
| <span id="358">358</span> |
| <span id="359">359</span> |
| <span id="360">360</span> |
| <span id="361">361</span> |
| <span id="362">362</span> |
| <span id="363">363</span> |
| <span id="364">364</span> |
| <span id="365">365</span> |
| <span id="366">366</span> |
| <span id="367">367</span> |
| <span id="368">368</span> |
| <span id="369">369</span> |
| <span id="370">370</span> |
| <span id="371">371</span> |
| <span id="372">372</span> |
| <span id="373">373</span> |
| <span id="374">374</span> |
| </pre><pre class="rust"><code><span class="comment">// Copyright 2015-2016 Brian Smith. |
| // |
| // Permission to use, copy, modify, and/or distribute this software for any |
| // purpose with or without fee is hereby granted, provided that the above |
| // copyright notice and this permission notice appear in all copies. |
| // |
| // THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES |
| // WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| // MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR |
| // ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| // WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
| // ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
| // OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| |
| </span><span class="doccomment">//! untrusted.rs: Safe, fast, zero-panic, zero-crashing, zero-allocation |
| //! parsing of untrusted inputs in Rust. |
| //! |
| //! <code>git clone https://github.com/briansmith/untrusted</code> |
| //! |
| //! untrusted.rs goes beyond Rust's normal safety guarantees by also |
| //! guaranteeing that parsing will be panic-free, as long as |
| //! `untrusted::Input::as_slice_less_safe()` is not used. It avoids copying |
| //! data and heap allocation and strives to prevent common pitfalls such as |
| //! accidentally parsing input bytes multiple times. In order to meet these |
| //! goals, untrusted.rs is limited in functionality such that it works best for |
| //! input languages with a small fixed amount of lookahead such as ASN.1, TLS, |
| //! TCP/IP, and many other networking, IPC, and related protocols. Languages |
| //! that require more lookahead and/or backtracking require some significant |
| //! contortions to parse using this framework. It would not be realistic to use |
| //! it for parsing programming language code, for example. |
| //! |
| //! The overall pattern for using untrusted.rs is: |
| //! |
| //! 1. Write a recursive-descent-style parser for the input language, where the |
| //! input data is given as a `&mut untrusted::Reader` parameter to each |
| //! function. Each function should have a return type of `Result<V, E>` for |
| //! some value type `V` and some error type `E`, either or both of which may |
| //! be `()`. Functions for parsing the lowest-level language constructs |
| //! should be defined. Those lowest-level functions will parse their inputs |
| //! using `::read_byte()`, `Reader::peek()`, and similar functions. |
| //! Higher-level language constructs are then parsed by calling the |
| //! lower-level functions in sequence. |
| //! |
| //! 2. Wrap the top-most functions of your recursive-descent parser in |
| //! functions that take their input data as an `untrusted::Input`. The |
| //! wrapper functions should call the `Input`'s `read_all` (or a variant |
| //! thereof) method. The wrapper functions are the only ones that should be |
| //! exposed outside the parser's module. |
| //! |
| //! 3. After receiving the input data to parse, wrap it in an `untrusted::Input` |
| //! using `untrusted::Input::from()` as early as possible. Pass the |
| //! `untrusted::Input` to the wrapper functions when they need to be parsed. |
| //! |
| //! In general parsers built using `untrusted::Reader` do not need to explicitly |
| //! check for end-of-input unless they are parsing optional constructs, because |
| //! `Reader::read_byte()` will return `Err(EndOfInput)` on end-of-input. |
| //! Similarly, parsers using `untrusted::Reader` generally don't need to check |
| //! for extra junk at the end of the input as long as the parser's API uses the |
| //! pattern described above, as `read_all` and its variants automatically check |
| //! for trailing junk. `Reader::skip_to_end()` must be used when any remaining |
| //! unread input should be ignored without triggering an error. |
| //! |
| //! untrusted.rs works best when all processing of the input data is done |
| //! through the `untrusted::Input` and `untrusted::Reader` types. In |
| //! particular, avoid trying to parse input data using functions that take |
| //! byte slices. However, when you need to access a part of the input data as |
| //! a slice to use a function that isn't written using untrusted.rs, |
| //! `Input::as_slice_less_safe()` can be used. |
| //! |
| //! It is recommend to use `use untrusted;` and then `untrusted::Input`, |
| //! `untrusted::Reader`, etc., instead of using `use untrusted::*`. Qualifying |
| //! the names with `untrusted` helps remind the reader of the code that it is |
| //! dealing with *untrusted* input. |
| //! |
| //! # Examples |
| //! |
| //! [*ring*](https://github.com/briansmith/ring)'s parser for the subset of |
| //! ASN.1 DER it needs to understand, |
| //! [`ring::der`](https://github.com/briansmith/ring/blob/master/src/der.rs), |
| //! is built on top of untrusted.rs. *ring* also uses untrusted.rs to parse ECC |
| //! public keys, RSA PKCS#1 1.5 padding, and for all other parsing it does. |
| //! |
| //! All of [webpki](https://github.com/briansmith/webpki)'s parsing of X.509 |
| //! certificates (also ASN.1 DER) is done using untrusted.rs. |
| |
| </span><span class="attribute">#![doc(html_root_url = <span class="string">"https://briansmith.org/rustdoc/"</span>)] |
| </span><span class="comment">// `#[derive(...)]` uses `#[allow(unused_qualifications)]` internally. |
| </span><span class="attribute">#![deny(unused_qualifications)] |
| #![forbid( |
| anonymous_parameters, |
| box_pointers, |
| missing_docs, |
| trivial_casts, |
| trivial_numeric_casts, |
| unsafe_code, |
| unstable_features, |
| unused_extern_crates, |
| unused_import_braces, |
| unused_results, |
| variant_size_differences, |
| warnings |
| )] |
| #![no_std] |
| |
| </span><span class="doccomment">/// A wrapper around `&'a [u8]` that helps in writing panic-free code. |
| /// |
| /// No methods of `Input` will ever panic. |
| </span><span class="attribute">#[derive(Clone, Copy, Debug, Eq)] |
| </span><span class="kw">pub struct </span>Input<<span class="lifetime">'a</span>> { |
| value: no_panic::Slice<<span class="lifetime">'a</span>>, |
| } |
| |
| <span class="kw">impl</span><<span class="lifetime">'a</span>> Input<<span class="lifetime">'a</span>> { |
| <span class="doccomment">/// Construct a new `Input` for the given input `bytes`. |
| </span><span class="kw">pub const fn </span>from(bytes: <span class="kw-2">&</span><span class="lifetime">'a </span>[u8]) -> <span class="self">Self </span>{ |
| <span class="comment">// This limit is important for avoiding integer overflow. In particular, |
| // `Reader` assumes that an `i + 1 > i` if `input.value.get(i)` does |
| // not return `None`. According to the Rust language reference, the |
| // maximum object size is `core::isize::MAX`, and in practice it is |
| // impossible to create an object of size `core::usize::MAX` or larger. |
| </span><span class="self">Self </span>{ |
| value: no_panic::Slice::new(bytes), |
| } |
| } |
| |
| <span class="doccomment">/// Returns `true` if the input is empty and false otherwise. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>is_empty(<span class="kw-2">&</span><span class="self">self</span>) -> bool { <span class="self">self</span>.value.is_empty() } |
| |
| <span class="doccomment">/// Returns the length of the `Input`. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>len(<span class="kw-2">&</span><span class="self">self</span>) -> usize { <span class="self">self</span>.value.len() } |
| |
| <span class="doccomment">/// Calls `read` with the given input as a `Reader`, ensuring that `read` |
| /// consumed the entire input. If `read` does not consume the entire input, |
| /// `incomplete_read` is returned. |
| </span><span class="kw">pub fn </span>read_all<F, R, E>(<span class="kw-2">&</span><span class="self">self</span>, incomplete_read: E, read: F) -> <span class="prelude-ty">Result</span><R, E> |
| <span class="kw">where |
| </span>F: FnOnce(<span class="kw-2">&mut </span>Reader<<span class="lifetime">'a</span>>) -> <span class="prelude-ty">Result</span><R, E>, |
| { |
| <span class="kw">let </span><span class="kw-2">mut </span>input = Reader::new(<span class="kw-2">*</span><span class="self">self</span>); |
| <span class="kw">let </span>result = read(<span class="kw-2">&mut </span>input)<span class="question-mark">?</span>; |
| <span class="kw">if </span>input.at_end() { |
| <span class="prelude-val">Ok</span>(result) |
| } <span class="kw">else </span>{ |
| <span class="prelude-val">Err</span>(incomplete_read) |
| } |
| } |
| |
| <span class="doccomment">/// Access the input as a slice so it can be processed by functions that |
| /// are not written using the Input/Reader framework. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>as_slice_less_safe(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="kw-2">&</span><span class="lifetime">'a </span>[u8] { <span class="self">self</span>.value.as_slice_less_safe() } |
| } |
| |
| <span class="kw">impl</span><<span class="lifetime">'a</span>> From<<span class="kw-2">&</span><span class="lifetime">'a </span>[u8]> <span class="kw">for </span>Input<<span class="lifetime">'a</span>> { |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from(value: <span class="kw-2">&</span><span class="lifetime">'a </span>[u8]) -> <span class="self">Self </span>{ <span class="self">Self </span>{ value: no_panic::Slice::new(value)} } |
| } |
| |
| <span class="comment">// #[derive(PartialEq)] would result in lifetime bounds that are |
| // unnecessarily restrictive; see |
| // https://github.com/rust-lang/rust/issues/26925. |
| </span><span class="kw">impl </span>PartialEq<Input<<span class="lifetime">'_</span>>> <span class="kw">for </span>Input<<span class="lifetime">'_</span>> { |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>eq(<span class="kw-2">&</span><span class="self">self</span>, other: <span class="kw-2">&</span>Input) -> bool { |
| <span class="self">self</span>.as_slice_less_safe() == other.as_slice_less_safe() |
| } |
| } |
| |
| <span class="kw">impl </span>PartialEq<[u8]> <span class="kw">for </span>Input<<span class="lifetime">'_</span>> { |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>eq(<span class="kw-2">&</span><span class="self">self</span>, other: <span class="kw-2">&</span>[u8]) -> bool { <span class="self">self</span>.as_slice_less_safe() == other } |
| } |
| |
| <span class="kw">impl </span>PartialEq<Input<<span class="lifetime">'_</span>>> <span class="kw">for </span>[u8] { |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>eq(<span class="kw-2">&</span><span class="self">self</span>, other: <span class="kw-2">&</span>Input) -> bool { other.as_slice_less_safe() == <span class="self">self </span>} |
| } |
| |
| <span class="doccomment">/// Calls `read` with the given input as a `Reader`, ensuring that `read` |
| /// consumed the entire input. When `input` is `None`, `read` will be |
| /// called with `None`. |
| </span><span class="kw">pub fn </span>read_all_optional<<span class="lifetime">'a</span>, F, R, E>( |
| input: <span class="prelude-ty">Option</span><Input<<span class="lifetime">'a</span>>>, incomplete_read: E, read: F, |
| ) -> <span class="prelude-ty">Result</span><R, E> |
| <span class="kw">where |
| </span>F: FnOnce(<span class="prelude-ty">Option</span><<span class="kw-2">&mut </span>Reader<<span class="lifetime">'a</span>>>) -> <span class="prelude-ty">Result</span><R, E>, |
| { |
| <span class="kw">match </span>input { |
| <span class="prelude-val">Some</span>(input) => { |
| <span class="kw">let </span><span class="kw-2">mut </span>input = Reader::new(input); |
| <span class="kw">let </span>result = read(<span class="prelude-val">Some</span>(<span class="kw-2">&mut </span>input))<span class="question-mark">?</span>; |
| <span class="kw">if </span>input.at_end() { |
| <span class="prelude-val">Ok</span>(result) |
| } <span class="kw">else </span>{ |
| <span class="prelude-val">Err</span>(incomplete_read) |
| } |
| }, |
| <span class="prelude-val">None </span>=> read(<span class="prelude-val">None</span>), |
| } |
| } |
| |
| <span class="doccomment">/// A read-only, forward-only* cursor into the data in an `Input`. |
| /// |
| /// Using `Reader` to parse input helps to ensure that no byte of the input |
| /// will be accidentally processed more than once. Using `Reader` in |
| /// conjunction with `read_all` and `read_all_optional` helps ensure that no |
| /// byte of the input is accidentally left unprocessed. The methods of `Reader` |
| /// never panic, so `Reader` also assists the writing of panic-free code. |
| /// |
| /// \* `Reader` is not strictly forward-only because of the method |
| /// `get_input_between_marks`, which is provided mainly to support calculating |
| /// digests over parsed data. |
| </span><span class="attribute">#[derive(Debug)] |
| </span><span class="kw">pub struct </span>Reader<<span class="lifetime">'a</span>> { |
| input: no_panic::Slice<<span class="lifetime">'a</span>>, |
| i: usize, |
| } |
| |
| <span class="doccomment">/// An index into the already-parsed input of a `Reader`. |
| </span><span class="kw">pub struct </span>Mark { |
| i: usize, |
| } |
| |
| <span class="kw">impl</span><<span class="lifetime">'a</span>> Reader<<span class="lifetime">'a</span>> { |
| <span class="doccomment">/// Construct a new Reader for the given input. Use `read_all` or |
| /// `read_all_optional` instead of `Reader::new` whenever possible. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>new(input: Input<<span class="lifetime">'a</span>>) -> <span class="self">Self </span>{ |
| <span class="self">Self </span>{ |
| input: input.value, |
| i: <span class="number">0</span>, |
| } |
| } |
| |
| <span class="doccomment">/// Returns `true` if the reader is at the end of the input, and `false` |
| /// otherwise. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>at_end(<span class="kw-2">&</span><span class="self">self</span>) -> bool { <span class="self">self</span>.i == <span class="self">self</span>.input.len() } |
| |
| <span class="doccomment">/// Returns an `Input` for already-parsed input that has had its boundaries |
| /// marked using `mark`. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>get_input_between_marks( |
| <span class="kw-2">&</span><span class="self">self</span>, mark1: Mark, mark2: Mark, |
| ) -> <span class="prelude-ty">Result</span><Input<<span class="lifetime">'a</span>>, EndOfInput> { |
| <span class="self">self</span>.input |
| .subslice(mark1.i..mark2.i) |
| .map(|subslice| Input { value: subslice }) |
| .ok_or(EndOfInput) |
| } |
| |
| <span class="doccomment">/// Return the current position of the `Reader` for future use in a call |
| /// to `get_input_between_marks`. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>mark(<span class="kw-2">&</span><span class="self">self</span>) -> Mark { Mark { i: <span class="self">self</span>.i } } |
| |
| <span class="doccomment">/// Returns `true` if there is at least one more byte in the input and that |
| /// byte is equal to `b`, and false otherwise. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>peek(<span class="kw-2">&</span><span class="self">self</span>, b: u8) -> bool { |
| <span class="kw">match </span><span class="self">self</span>.input.get(<span class="self">self</span>.i) { |
| <span class="prelude-val">Some</span>(actual_b) => b == <span class="kw-2">*</span>actual_b, |
| <span class="prelude-val">None </span>=> <span class="bool-val">false</span>, |
| } |
| } |
| |
| <span class="doccomment">/// Reads the next input byte. |
| /// |
| /// Returns `Ok(b)` where `b` is the next input byte, or `Err(EndOfInput)` |
| /// if the `Reader` is at the end of the input. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>read_byte(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Result</span><u8, EndOfInput> { |
| <span class="kw">match </span><span class="self">self</span>.input.get(<span class="self">self</span>.i) { |
| <span class="prelude-val">Some</span>(b) => { |
| <span class="self">self</span>.i += <span class="number">1</span>; <span class="comment">// safe from overflow; see Input::from(). |
| </span><span class="prelude-val">Ok</span>(<span class="kw-2">*</span>b) |
| }, |
| <span class="prelude-val">None </span>=> <span class="prelude-val">Err</span>(EndOfInput), |
| } |
| } |
| |
| <span class="doccomment">/// Skips `num_bytes` of the input, returning the skipped input as an |
| /// `Input`. |
| /// |
| /// Returns `Ok(i)` if there are at least `num_bytes` of input remaining, |
| /// and `Err(EndOfInput)` otherwise. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>read_bytes(<span class="kw-2">&mut </span><span class="self">self</span>, num_bytes: usize) -> <span class="prelude-ty">Result</span><Input<<span class="lifetime">'a</span>>, EndOfInput> { |
| <span class="kw">let </span>new_i = <span class="self">self</span>.i.checked_add(num_bytes).ok_or(EndOfInput)<span class="question-mark">?</span>; |
| <span class="kw">let </span>ret = <span class="self">self |
| </span>.input |
| .subslice(<span class="self">self</span>.i..new_i) |
| .map(|subslice| Input { value: subslice }) |
| .ok_or(EndOfInput)<span class="question-mark">?</span>; |
| <span class="self">self</span>.i = new_i; |
| <span class="prelude-val">Ok</span>(ret) |
| } |
| |
| <span class="doccomment">/// Skips the reader to the end of the input, returning the skipped input |
| /// as an `Input`. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>read_bytes_to_end(<span class="kw-2">&mut </span><span class="self">self</span>) -> Input<<span class="lifetime">'a</span>> { |
| <span class="kw">let </span>to_skip = <span class="self">self</span>.input.len() - <span class="self">self</span>.i; |
| <span class="self">self</span>.read_bytes(to_skip).unwrap() |
| } |
| |
| <span class="doccomment">/// Calls `read()` with the given input as a `Reader`. On success, returns a |
| /// pair `(bytes_read, r)` where `bytes_read` is what `read()` consumed and |
| /// `r` is `read()`'s return value. |
| </span><span class="kw">pub fn </span>read_partial<F, R, E>(<span class="kw-2">&mut </span><span class="self">self</span>, read: F) -> <span class="prelude-ty">Result</span><(Input<<span class="lifetime">'a</span>>, R), E> |
| <span class="kw">where |
| </span>F: FnOnce(<span class="kw-2">&mut </span>Reader<<span class="lifetime">'a</span>>) -> <span class="prelude-ty">Result</span><R, E>, |
| { |
| <span class="kw">let </span>start = <span class="self">self</span>.i; |
| <span class="kw">let </span>r = read(<span class="self">self</span>)<span class="question-mark">?</span>; |
| <span class="kw">let </span>bytes_read = Input { |
| value: <span class="self">self</span>.input.subslice(start..<span class="self">self</span>.i).unwrap() |
| }; |
| <span class="prelude-val">Ok</span>((bytes_read, r)) |
| } |
| |
| <span class="doccomment">/// Skips `num_bytes` of the input. |
| /// |
| /// Returns `Ok(i)` if there are at least `num_bytes` of input remaining, |
| /// and `Err(EndOfInput)` otherwise. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>skip(<span class="kw-2">&mut </span><span class="self">self</span>, num_bytes: usize) -> <span class="prelude-ty">Result</span><(), EndOfInput> { |
| <span class="self">self</span>.read_bytes(num_bytes).map(|<span class="kw">_</span>| ()) |
| } |
| |
| <span class="doccomment">/// Skips the reader to the end of the input. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>skip_to_end(<span class="kw-2">&mut </span><span class="self">self</span>) -> () { <span class="kw">let _ </span>= <span class="self">self</span>.read_bytes_to_end(); } |
| } |
| |
| <span class="doccomment">/// The error type used to indicate the end of the input was reached before the |
| /// operation could be completed. |
| </span><span class="attribute">#[derive(Clone, Copy, Debug, Eq, PartialEq)] |
| </span><span class="kw">pub struct </span>EndOfInput; |
| |
| <span class="kw">mod </span>no_panic { |
| <span class="kw">use </span>core; |
| |
| <span class="doccomment">/// A wrapper around a slice that exposes no functions that can panic. |
| </span><span class="attribute">#[derive(Clone, Copy, Debug, Eq, PartialEq)] |
| </span><span class="kw">pub struct </span>Slice<<span class="lifetime">'a</span>> { |
| bytes: <span class="kw-2">&</span><span class="lifetime">'a </span>[u8], |
| } |
| |
| <span class="kw">impl</span><<span class="lifetime">'a</span>> Slice<<span class="lifetime">'a</span>> { |
| <span class="attribute">#[inline] |
| </span><span class="kw">pub const fn </span>new(bytes: <span class="kw-2">&</span><span class="lifetime">'a </span>[u8]) -> <span class="self">Self </span>{ <span class="self">Self </span>{ bytes } } |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>get(<span class="kw-2">&</span><span class="self">self</span>, i: usize) -> <span class="prelude-ty">Option</span><<span class="kw-2">&</span>u8> { <span class="self">self</span>.bytes.get(i) } |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>subslice(<span class="kw-2">&</span><span class="self">self</span>, r: core::ops::Range<usize>) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>> { |
| <span class="self">self</span>.bytes.get(r).map(|bytes| <span class="self">Self </span>{ bytes }) |
| } |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>is_empty(<span class="kw-2">&</span><span class="self">self</span>) -> bool { <span class="self">self</span>.bytes.is_empty() } |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>len(<span class="kw-2">&</span><span class="self">self</span>) -> usize { <span class="self">self</span>.bytes.len() } |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>as_slice_less_safe(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="kw-2">&</span><span class="lifetime">'a </span>[u8] { <span class="self">self</span>.bytes } |
| } |
| |
| } <span class="comment">// mod no_panic |
| </span></code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="untrusted" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
