| <!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="A gRPC interceptor."><meta name="keywords" content="rust, rustlang, rust-lang, Interceptor"><title>Interceptor in tonic::service - Rust</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="sidebar-items.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 trait"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle">☰</button><a class="sidebar-logo" href="../../tonic/index.html"><div class="logo-container"><img src="https://raw.githubusercontent.com/tokio-rs/website/master/public/img/icons/tonic.svg" alt="logo"></div></a><h2></h2></nav><nav class="sidebar"><a class="sidebar-logo" href="../../tonic/index.html"><div class="logo-container"> |
| <img src="https://raw.githubusercontent.com/tokio-rs/website/master/public/img/icons/tonic.svg" alt="logo"></div></a><h2 class="location"><a href="#">Interceptor</a></h2><div class="sidebar-elems"><section><h3><a href="#required-methods">Required Methods</a></h3><ul class="block"><li><a href="#tymethod.call">call</a></li></ul><h3><a href="#implementors">Implementors</a></h3></section><h2><a href="index.html">In tonic::service</a></h2></div></nav><main><div class="width-limiter"><nav class="sub"><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="main-heading"><h1 class="fqn">Trait <a href="../index.html">tonic</a>::<wbr><a href="index.html">service</a>::<wbr><a class="trait" href="#">Interceptor</a><button id="copy-path" onclick="copy_path(this)" title="Copy item path to clipboard"><img src="../../clipboard.svg" width="19" height="18" alt="Copy item path"></button></h1><span class="out-of-band"><a class="srclink" href="../../src/tonic/service/interceptor.rs.html#41-44">source</a> · <a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class="inner">−</span>]</a></span></div><div class="item-decl"><pre class="rust trait"><code>pub trait Interceptor { |
| fn <a href="#tymethod.call" class="fnname">call</a>(&mut self, request: <a class="struct" href="../struct.Request.html" title="struct tonic::Request">Request</a><()>) -> Result<<a class="struct" href="../struct.Request.html" title="struct tonic::Request">Request</a><()>, <a class="struct" href="../struct.Status.html" title="struct tonic::Status">Status</a>>; |
| }</code></pre></div><details class="rustdoc-toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>A gRPC interceptor.</p> |
| <p>gRPC interceptors are similar to middleware but have less flexibility. An interceptor allows |
| you to do two main things, one is to add/remove/check items in the <code>MetadataMap</code> of each |
| request. Two, cancel a request with a <code>Status</code>.</p> |
| <p>Any function that satisfies the bound <code>FnMut(Request<()>) -> Result<Request<()>, Status></code> can be |
| used as an <code>Interceptor</code>.</p> |
| <p>An interceptor can be used on both the server and client side through the <code>tonic-build</code> crate’s |
| generated structs.</p> |
| <p>See the <a href="https://github.com/hyperium/tonic/tree/master/examples/src/interceptor">interceptor example</a> for more details.</p> |
| <p>If you need more powerful middleware, <a href="https://crates.io/crates/tower">tower</a> is the recommended approach. You can find |
| examples of how to use tower with tonic <a href="https://github.com/hyperium/tonic/tree/master/examples/src/tower">here</a>.</p> |
| <p>Additionally, interceptors is not the recommended way to add logging to your service. For that |
| a <a href="https://crates.io/crates/tower">tower</a> middleware is more appropriate since it can also act on the response. For example |
| tower-http’s <a href="https://docs.rs/tower-http/latest/tower_http/trace/index.html"><code>Trace</code></a> |
| middleware supports gRPC out of the box.</p> |
| </div></details><h2 id="required-methods" class="small-section-header">Required Methods<a href="#required-methods" class="anchor"></a></h2><div class="methods"><details class="rustdoc-toggle method-toggle" open><summary><section id="tymethod.call" class="method has-srclink"><a class="srclink rightside" href="../../src/tonic/service/interceptor.rs.html#43">source</a><h4 class="code-header">fn <a href="#tymethod.call" class="fnname">call</a>(&mut self, request: <a class="struct" href="../struct.Request.html" title="struct tonic::Request">Request</a><()>) -> Result<<a class="struct" href="../struct.Request.html" title="struct tonic::Request">Request</a><()>, <a class="struct" href="../struct.Status.html" title="struct tonic::Status">Status</a>></h4></section></summary><div class="docblock"><p>Intercept a request before it is sent, optionally cancelling it.</p> |
| </div></details></div><h2 id="implementors" class="small-section-header">Implementors<a href="#implementors" class="anchor"></a></h2><div id="implementors-list"><section id="impl-Interceptor-for-F" class="impl has-srclink"><a class="srclink rightside" href="../../src/tonic/service/interceptor.rs.html#46-53">source</a><a href="#impl-Interceptor-for-F" class="anchor"></a><h3 class="code-header">impl<F> <a class="trait" href="trait.Interceptor.html" title="trait tonic::service::Interceptor">Interceptor</a> for F<span class="where fmt-newline">where<br> F: FnMut(<a class="struct" href="../struct.Request.html" title="struct tonic::Request">Request</a><()>) -> Result<<a class="struct" href="../struct.Request.html" title="struct tonic::Request">Request</a><()>, <a class="struct" href="../struct.Status.html" title="struct tonic::Status">Status</a>>,</span></h3></section></div><script src="../../implementors/tonic/service/interceptor/trait.Interceptor.js" async></script></section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="tonic" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
