| <!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="HTTP header types"><meta name="keywords" content="rust, rustlang, rust-lang, header"><title>hyper::header - 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="../../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 mod"><!--[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="../../hyper/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a><h2></h2></nav><nav class="sidebar"><a class="sidebar-logo" href="../../hyper/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a><h2 class="location"><a href="#">Module header</a></h2><div class="sidebar-elems"><section><ul class="block"><li><a href="#structs">Structs</a></li><li><a href="#enums">Enums</a></li><li><a href="#constants">Constants</a></li><li><a href="#traits">Traits</a></li></ul></section></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">Module <a href="../index.html">hyper</a>::<wbr><a class="mod" href="#">header</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/http/lib.rs.html#173">source</a> · <a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class="inner">−</span>]</a></span></div><details class="rustdoc-toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>HTTP header types</p> |
| <p>The module provides <a href="struct.HeaderName.html"><code>HeaderName</code></a>, <a href="struct.HeaderMap.html"><code>HeaderMap</code></a>, and a number of types |
| used for interacting with <code>HeaderMap</code>. These types allow representing both |
| HTTP/1 and HTTP/2 headers.</p> |
| <h2 id="headername"><a href="#headername"><code>HeaderName</code></a></h2> |
| <p>The <code>HeaderName</code> type represents both standard header names as well as |
| custom header names. The type handles the case insensitive nature of header |
| names and is used as the key portion of <code>HeaderMap</code>. Header names are |
| normalized to lower case. In other words, when creating a <code>HeaderName</code> with |
| a string, even if upper case characters are included, when getting a string |
| representation of the <code>HeaderName</code>, it will be all lower case. This allows |
| for faster <code>HeaderMap</code> comparison operations.</p> |
| <p>The internal representation is optimized to efficiently handle the cases |
| most commonly encountered when working with HTTP. Standard header names are |
| special cased and are represented internally as an enum. Short custom |
| headers will be stored directly in the <code>HeaderName</code> struct and will not |
| incur any allocation overhead, however longer strings will require an |
| allocation for storage.</p> |
| <h3 id="limitations"><a href="#limitations">Limitations</a></h3> |
| <p><code>HeaderName</code> has a max length of 32,768 for header names. Attempting to |
| parse longer names will result in a panic.</p> |
| <h2 id="headermap"><a href="#headermap"><code>HeaderMap</code></a></h2> |
| <p><code>HeaderMap</code> is a map structure of header names highly optimized for use |
| cases common with HTTP. It is a <a href="https://en.wikipedia.org/wiki/Multimap">multimap</a> structure, where each header name |
| may have multiple associated header values. Given this, some of the APIs |
| diverge from <a href="https://doc.rust-lang.org/std/collections/struct.HashMap.html"><code>HashMap</code></a>.</p> |
| <h3 id="overview"><a href="#overview">Overview</a></h3> |
| <p>Just like <code>HashMap</code> in Rust’s stdlib, <code>HeaderMap</code> is based on <a href="https://en.wikipedia.org/wiki/Hash_table#Robin_Hood_hashing">Robin Hood |
| hashing</a>. This algorithm tends to reduce the worst case search times in the |
| table and enables high load factors without seriously affecting performance. |
| Internally, keys and values are stored in vectors. As such, each insertion |
| will not incur allocation overhead. However, once the underlying vector |
| storage is full, a larger vector must be allocated and all values copied.</p> |
| <h3 id="deterministic-ordering"><a href="#deterministic-ordering">Deterministic ordering</a></h3> |
| <p>Unlike Rust’s <code>HashMap</code>, values in <code>HeaderMap</code> are deterministically |
| ordered. Roughly, values are ordered by insertion. This means that a |
| function that deterministically operates on a header map can rely on the |
| iteration order to remain consistent across processes and platforms.</p> |
| <h3 id="adaptive-hashing"><a href="#adaptive-hashing">Adaptive hashing</a></h3> |
| <p><code>HeaderMap</code> uses an adaptive hashing strategy in order to efficiently handle |
| most common cases. All standard headers have statically computed hash values |
| which removes the need to perform any hashing of these headers at runtime. |
| The default hash function emphasizes performance over robustness. However, |
| <code>HeaderMap</code> detects high collision rates and switches to a secure hash |
| function in those events. The threshold is set such that only denial of |
| service attacks should trigger it.</p> |
| <h3 id="limitations-1"><a href="#limitations-1">Limitations</a></h3> |
| <p><code>HeaderMap</code> can store a maximum of 32,768 headers (header name / value |
| pairs). Attempting to insert more will result in a panic.</p> |
| </div></details><h2 id="structs" class="small-section-header"><a href="#structs">Structs</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Drain.html" title="hyper::header::Drain struct">Drain</a></div><div class="item-right docblock-short">A drain iterator for <code>HeaderMap</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.GetAll.html" title="hyper::header::GetAll struct">GetAll</a></div><div class="item-right docblock-short">A view to all values stored in a single entry.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.HeaderMap.html" title="hyper::header::HeaderMap struct">HeaderMap</a></div><div class="item-right docblock-short">A set of HTTP headers</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.HeaderName.html" title="hyper::header::HeaderName struct">HeaderName</a></div><div class="item-right docblock-short">Represents an HTTP header field name</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.HeaderValue.html" title="hyper::header::HeaderValue struct">HeaderValue</a></div><div class="item-right docblock-short">Represents an HTTP header field value.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.IntoIter.html" title="hyper::header::IntoIter struct">IntoIter</a></div><div class="item-right docblock-short">An owning iterator over the entries of a <code>HeaderMap</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.InvalidHeaderName.html" title="hyper::header::InvalidHeaderName struct">InvalidHeaderName</a></div><div class="item-right docblock-short">A possible error when converting a <code>HeaderName</code> from another type.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.InvalidHeaderValue.html" title="hyper::header::InvalidHeaderValue struct">InvalidHeaderValue</a></div><div class="item-right docblock-short">A possible error when converting a <code>HeaderValue</code> from a string or byte |
| slice.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Iter.html" title="hyper::header::Iter struct">Iter</a></div><div class="item-right docblock-short"><code>HeaderMap</code> entry iterator.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.IterMut.html" title="hyper::header::IterMut struct">IterMut</a></div><div class="item-right docblock-short"><code>HeaderMap</code> mutable entry iterator</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Keys.html" title="hyper::header::Keys struct">Keys</a></div><div class="item-right docblock-short">An iterator over <code>HeaderMap</code> keys.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.OccupiedEntry.html" title="hyper::header::OccupiedEntry struct">OccupiedEntry</a></div><div class="item-right docblock-short">A view into a single occupied location in a <code>HeaderMap</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ToStrError.html" title="hyper::header::ToStrError struct">ToStrError</a></div><div class="item-right docblock-short">A possible error when converting a <code>HeaderValue</code> to a string representation.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.VacantEntry.html" title="hyper::header::VacantEntry struct">VacantEntry</a></div><div class="item-right docblock-short">A view into a single empty location in a <code>HeaderMap</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ValueDrain.html" title="hyper::header::ValueDrain struct">ValueDrain</a></div><div class="item-right docblock-short">An drain iterator of all values associated with a single header name.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ValueIter.html" title="hyper::header::ValueIter struct">ValueIter</a></div><div class="item-right docblock-short">An iterator of all values associated with a single header name.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ValueIterMut.html" title="hyper::header::ValueIterMut struct">ValueIterMut</a></div><div class="item-right docblock-short">A mutable iterator of all values associated with a single header name.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Values.html" title="hyper::header::Values struct">Values</a></div><div class="item-right docblock-short"><code>HeaderMap</code> value iterator.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ValuesMut.html" title="hyper::header::ValuesMut struct">ValuesMut</a></div><div class="item-right docblock-short"><code>HeaderMap</code> mutable value iterator</div></div></div><h2 id="enums" class="small-section-header"><a href="#enums">Enums</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.Entry.html" title="hyper::header::Entry enum">Entry</a></div><div class="item-right docblock-short">A view into a single location in a <code>HeaderMap</code>, which may be vacant or occupied.</div></div></div><h2 id="constants" class="small-section-header"><a href="#constants">Constants</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.ACCEPT.html" title="hyper::header::ACCEPT constant">ACCEPT</a></div><div class="item-right docblock-short">Advertises which content types the client is able to understand.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.ACCEPT_CHARSET.html" title="hyper::header::ACCEPT_CHARSET constant">ACCEPT_CHARSET</a></div><div class="item-right docblock-short">Advertises which character set the client is able to understand.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.ACCEPT_ENCODING.html" title="hyper::header::ACCEPT_ENCODING constant">ACCEPT_ENCODING</a></div><div class="item-right docblock-short">Advertises which content encoding the client is able to understand.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.ACCEPT_LANGUAGE.html" title="hyper::header::ACCEPT_LANGUAGE constant">ACCEPT_LANGUAGE</a></div><div class="item-right docblock-short">Advertises which languages the client is able to understand.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.ACCEPT_RANGES.html" title="hyper::header::ACCEPT_RANGES constant">ACCEPT_RANGES</a></div><div class="item-right docblock-short">Marker used by the server to advertise partial request support.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.ACCESS_CONTROL_ALLOW_CREDENTIALS.html" title="hyper::header::ACCESS_CONTROL_ALLOW_CREDENTIALS constant">ACCESS_CONTROL_ALLOW_CREDENTIALS</a></div><div class="item-right docblock-short">Preflight response indicating if the response to the request can be |
| exposed to the page.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.ACCESS_CONTROL_ALLOW_HEADERS.html" title="hyper::header::ACCESS_CONTROL_ALLOW_HEADERS constant">ACCESS_CONTROL_ALLOW_HEADERS</a></div><div class="item-right docblock-short">Preflight response indicating permitted HTTP headers.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.ACCESS_CONTROL_ALLOW_METHODS.html" title="hyper::header::ACCESS_CONTROL_ALLOW_METHODS constant">ACCESS_CONTROL_ALLOW_METHODS</a></div><div class="item-right docblock-short">Preflight header response indicating permitted access methods.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.ACCESS_CONTROL_ALLOW_ORIGIN.html" title="hyper::header::ACCESS_CONTROL_ALLOW_ORIGIN constant">ACCESS_CONTROL_ALLOW_ORIGIN</a></div><div class="item-right docblock-short">Indicates whether the response can be shared with resources with the |
| given origin.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.ACCESS_CONTROL_EXPOSE_HEADERS.html" title="hyper::header::ACCESS_CONTROL_EXPOSE_HEADERS constant">ACCESS_CONTROL_EXPOSE_HEADERS</a></div><div class="item-right docblock-short">Indicates which headers can be exposed as part of the response by |
| listing their names.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.ACCESS_CONTROL_MAX_AGE.html" title="hyper::header::ACCESS_CONTROL_MAX_AGE constant">ACCESS_CONTROL_MAX_AGE</a></div><div class="item-right docblock-short">Indicates how long the results of a preflight request can be cached.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.ACCESS_CONTROL_REQUEST_HEADERS.html" title="hyper::header::ACCESS_CONTROL_REQUEST_HEADERS constant">ACCESS_CONTROL_REQUEST_HEADERS</a></div><div class="item-right docblock-short">Informs the server which HTTP headers will be used when an actual |
| request is made.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.ACCESS_CONTROL_REQUEST_METHOD.html" title="hyper::header::ACCESS_CONTROL_REQUEST_METHOD constant">ACCESS_CONTROL_REQUEST_METHOD</a></div><div class="item-right docblock-short">Informs the server know which HTTP method will be used when the actual |
| request is made.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.AGE.html" title="hyper::header::AGE constant">AGE</a></div><div class="item-right docblock-short">Indicates the time in seconds the object has been in a proxy cache.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.ALLOW.html" title="hyper::header::ALLOW constant">ALLOW</a></div><div class="item-right docblock-short">Lists the set of methods support by a resource.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.ALT_SVC.html" title="hyper::header::ALT_SVC constant">ALT_SVC</a></div><div class="item-right docblock-short">Advertises the availability of alternate services to clients.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.AUTHORIZATION.html" title="hyper::header::AUTHORIZATION constant">AUTHORIZATION</a></div><div class="item-right docblock-short">Contains the credentials to authenticate a user agent with a server.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.CACHE_CONTROL.html" title="hyper::header::CACHE_CONTROL constant">CACHE_CONTROL</a></div><div class="item-right docblock-short">Specifies directives for caching mechanisms in both requests and |
| responses.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.CACHE_STATUS.html" title="hyper::header::CACHE_STATUS constant">CACHE_STATUS</a></div><div class="item-right docblock-short">Indicates how caches have handled a response and its corresponding request.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.CDN_CACHE_CONTROL.html" title="hyper::header::CDN_CACHE_CONTROL constant">CDN_CACHE_CONTROL</a></div><div class="item-right docblock-short">Specifies directives that allow origin servers to control the behavior of CDN caches |
| interposed between them and clients separately from other caches that might handle the |
| response.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.CONNECTION.html" title="hyper::header::CONNECTION constant">CONNECTION</a></div><div class="item-right docblock-short">Controls whether or not the network connection stays open after the |
| current transaction finishes.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.CONTENT_DISPOSITION.html" title="hyper::header::CONTENT_DISPOSITION constant">CONTENT_DISPOSITION</a></div><div class="item-right docblock-short">Indicates if the content is expected to be displayed inline.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.CONTENT_ENCODING.html" title="hyper::header::CONTENT_ENCODING constant">CONTENT_ENCODING</a></div><div class="item-right docblock-short">Used to compress the media-type.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.CONTENT_LANGUAGE.html" title="hyper::header::CONTENT_LANGUAGE constant">CONTENT_LANGUAGE</a></div><div class="item-right docblock-short">Used to describe the languages intended for the audience.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.CONTENT_LENGTH.html" title="hyper::header::CONTENT_LENGTH constant">CONTENT_LENGTH</a></div><div class="item-right docblock-short">Indicates the size of the entity-body.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.CONTENT_LOCATION.html" title="hyper::header::CONTENT_LOCATION constant">CONTENT_LOCATION</a></div><div class="item-right docblock-short">Indicates an alternate location for the returned data.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.CONTENT_RANGE.html" title="hyper::header::CONTENT_RANGE constant">CONTENT_RANGE</a></div><div class="item-right docblock-short">Indicates where in a full body message a partial message belongs.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.CONTENT_SECURITY_POLICY.html" title="hyper::header::CONTENT_SECURITY_POLICY constant">CONTENT_SECURITY_POLICY</a></div><div class="item-right docblock-short">Allows controlling resources the user agent is allowed to load for a |
| given page.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.CONTENT_SECURITY_POLICY_REPORT_ONLY.html" title="hyper::header::CONTENT_SECURITY_POLICY_REPORT_ONLY constant">CONTENT_SECURITY_POLICY_REPORT_ONLY</a></div><div class="item-right docblock-short">Allows experimenting with policies by monitoring their effects.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.CONTENT_TYPE.html" title="hyper::header::CONTENT_TYPE constant">CONTENT_TYPE</a></div><div class="item-right docblock-short">Used to indicate the media type of the resource.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.COOKIE.html" title="hyper::header::COOKIE constant">COOKIE</a></div><div class="item-right docblock-short">Contains stored HTTP cookies previously sent by the server with the |
| Set-Cookie header.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.DATE.html" title="hyper::header::DATE constant">DATE</a></div><div class="item-right docblock-short">Contains the date and time at which the message was originated.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.DNT.html" title="hyper::header::DNT constant">DNT</a></div><div class="item-right docblock-short">Indicates the client’s tracking preference.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.ETAG.html" title="hyper::header::ETAG constant">ETAG</a></div><div class="item-right docblock-short">Identifier for a specific version of a resource.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.EXPECT.html" title="hyper::header::EXPECT constant">EXPECT</a></div><div class="item-right docblock-short">Indicates expectations that need to be fulfilled by the server in order |
| to properly handle the request.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.EXPIRES.html" title="hyper::header::EXPIRES constant">EXPIRES</a></div><div class="item-right docblock-short">Contains the date/time after which the response is considered stale.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.FORWARDED.html" title="hyper::header::FORWARDED constant">FORWARDED</a></div><div class="item-right docblock-short">Contains information from the client-facing side of proxy servers that |
| is altered or lost when a proxy is involved in the path of the request.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.FROM.html" title="hyper::header::FROM constant">FROM</a></div><div class="item-right docblock-short">Contains an Internet email address for a human user who controls the |
| requesting user agent.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.HOST.html" title="hyper::header::HOST constant">HOST</a></div><div class="item-right docblock-short">Specifies the domain name of the server and (optionally) the TCP port |
| number on which the server is listening.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.IF_MATCH.html" title="hyper::header::IF_MATCH constant">IF_MATCH</a></div><div class="item-right docblock-short">Makes a request conditional based on the E-Tag.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.IF_MODIFIED_SINCE.html" title="hyper::header::IF_MODIFIED_SINCE constant">IF_MODIFIED_SINCE</a></div><div class="item-right docblock-short">Makes a request conditional based on the modification date.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.IF_NONE_MATCH.html" title="hyper::header::IF_NONE_MATCH constant">IF_NONE_MATCH</a></div><div class="item-right docblock-short">Makes a request conditional based on the E-Tag.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.IF_RANGE.html" title="hyper::header::IF_RANGE constant">IF_RANGE</a></div><div class="item-right docblock-short">Makes a request conditional based on range.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.IF_UNMODIFIED_SINCE.html" title="hyper::header::IF_UNMODIFIED_SINCE constant">IF_UNMODIFIED_SINCE</a></div><div class="item-right docblock-short">Makes the request conditional based on the last modification date.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.LAST_MODIFIED.html" title="hyper::header::LAST_MODIFIED constant">LAST_MODIFIED</a></div><div class="item-right docblock-short">Content-Types that are acceptable for the response.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.LINK.html" title="hyper::header::LINK constant">LINK</a></div><div class="item-right docblock-short">Allows the server to point an interested client to another resource |
| containing metadata about the requested resource.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.LOCATION.html" title="hyper::header::LOCATION constant">LOCATION</a></div><div class="item-right docblock-short">Indicates the URL to redirect a page to.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.MAX_FORWARDS.html" title="hyper::header::MAX_FORWARDS constant">MAX_FORWARDS</a></div><div class="item-right docblock-short">Indicates the max number of intermediaries the request should be sent |
| through.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.ORIGIN.html" title="hyper::header::ORIGIN constant">ORIGIN</a></div><div class="item-right docblock-short">Indicates where a fetch originates from.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.PRAGMA.html" title="hyper::header::PRAGMA constant">PRAGMA</a></div><div class="item-right docblock-short">HTTP/1.0 header usually used for backwards compatibility.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.PROXY_AUTHENTICATE.html" title="hyper::header::PROXY_AUTHENTICATE constant">PROXY_AUTHENTICATE</a></div><div class="item-right docblock-short">Defines the authentication method that should be used to gain access to |
| a proxy.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.PROXY_AUTHORIZATION.html" title="hyper::header::PROXY_AUTHORIZATION constant">PROXY_AUTHORIZATION</a></div><div class="item-right docblock-short">Contains the credentials to authenticate a user agent to a proxy server.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.PUBLIC_KEY_PINS.html" title="hyper::header::PUBLIC_KEY_PINS constant">PUBLIC_KEY_PINS</a></div><div class="item-right docblock-short">Associates a specific cryptographic public key with a certain server.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.PUBLIC_KEY_PINS_REPORT_ONLY.html" title="hyper::header::PUBLIC_KEY_PINS_REPORT_ONLY constant">PUBLIC_KEY_PINS_REPORT_ONLY</a></div><div class="item-right docblock-short">Sends reports of pinning violation to the report-uri specified in the |
| header.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.RANGE.html" title="hyper::header::RANGE constant">RANGE</a></div><div class="item-right docblock-short">Indicates the part of a document that the server should return.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.REFERER.html" title="hyper::header::REFERER constant">REFERER</a></div><div class="item-right docblock-short">Contains the address of the previous web page from which a link to the |
| currently requested page was followed.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.REFERRER_POLICY.html" title="hyper::header::REFERRER_POLICY constant">REFERRER_POLICY</a></div><div class="item-right docblock-short">Governs which referrer information should be included with requests |
| made.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.REFRESH.html" title="hyper::header::REFRESH constant">REFRESH</a></div><div class="item-right docblock-short">Informs the web browser that the current page or frame should be |
| refreshed.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.RETRY_AFTER.html" title="hyper::header::RETRY_AFTER constant">RETRY_AFTER</a></div><div class="item-right docblock-short">The Retry-After response HTTP header indicates how long the user agent |
| should wait before making a follow-up request. There are two main cases |
| this header is used:</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.SEC_WEBSOCKET_ACCEPT.html" title="hyper::header::SEC_WEBSOCKET_ACCEPT constant">SEC_WEBSOCKET_ACCEPT</a></div><div class="item-right docblock-short">The |Sec-WebSocket-Accept| header field is used in the WebSocket |
| opening handshake. It is sent from the server to the client to |
| confirm that the server is willing to initiate the WebSocket |
| connection.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.SEC_WEBSOCKET_EXTENSIONS.html" title="hyper::header::SEC_WEBSOCKET_EXTENSIONS constant">SEC_WEBSOCKET_EXTENSIONS</a></div><div class="item-right docblock-short">The |Sec-WebSocket-Extensions| header field is used in the WebSocket |
| opening handshake. It is initially sent from the client to the |
| server, and then subsequently sent from the server to the client, to |
| agree on a set of protocol-level extensions to use for the duration |
| of the connection.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.SEC_WEBSOCKET_KEY.html" title="hyper::header::SEC_WEBSOCKET_KEY constant">SEC_WEBSOCKET_KEY</a></div><div class="item-right docblock-short">The |Sec-WebSocket-Key| header field is used in the WebSocket opening |
| handshake. It is sent from the client to the server to provide part |
| of the information used by the server to prove that it received a |
| valid WebSocket opening handshake. This helps ensure that the server |
| does not accept connections from non-WebSocket clients (e.g., HTTP |
| clients) that are being abused to send data to unsuspecting WebSocket |
| servers.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.SEC_WEBSOCKET_PROTOCOL.html" title="hyper::header::SEC_WEBSOCKET_PROTOCOL constant">SEC_WEBSOCKET_PROTOCOL</a></div><div class="item-right docblock-short">The |Sec-WebSocket-Protocol| header field is used in the WebSocket |
| opening handshake. It is sent from the client to the server and back |
| from the server to the client to confirm the subprotocol of the |
| connection. This enables scripts to both select a subprotocol and be |
| sure that the server agreed to serve that subprotocol.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.SEC_WEBSOCKET_VERSION.html" title="hyper::header::SEC_WEBSOCKET_VERSION constant">SEC_WEBSOCKET_VERSION</a></div><div class="item-right docblock-short">The |Sec-WebSocket-Version| header field is used in the WebSocket |
| opening handshake. It is sent from the client to the server to |
| indicate the protocol version of the connection. This enables |
| servers to correctly interpret the opening handshake and subsequent |
| data being sent from the data, and close the connection if the server |
| cannot interpret that data in a safe manner.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.SERVER.html" title="hyper::header::SERVER constant">SERVER</a></div><div class="item-right docblock-short">Contains information about the software used by the origin server to |
| handle the request.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.SET_COOKIE.html" title="hyper::header::SET_COOKIE constant">SET_COOKIE</a></div><div class="item-right docblock-short">Used to send cookies from the server to the user agent.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.STRICT_TRANSPORT_SECURITY.html" title="hyper::header::STRICT_TRANSPORT_SECURITY constant">STRICT_TRANSPORT_SECURITY</a></div><div class="item-right docblock-short">Tells the client to communicate with HTTPS instead of using HTTP.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.TE.html" title="hyper::header::TE constant">TE</a></div><div class="item-right docblock-short">Informs the server of transfer encodings willing to be accepted as part |
| of the response.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.TRAILER.html" title="hyper::header::TRAILER constant">TRAILER</a></div><div class="item-right docblock-short">Allows the sender to include additional fields at the end of chunked |
| messages.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.TRANSFER_ENCODING.html" title="hyper::header::TRANSFER_ENCODING constant">TRANSFER_ENCODING</a></div><div class="item-right docblock-short">Specifies the form of encoding used to safely transfer the entity to the |
| client.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.UPGRADE.html" title="hyper::header::UPGRADE constant">UPGRADE</a></div><div class="item-right docblock-short">Used as part of the exchange to upgrade the protocol.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.UPGRADE_INSECURE_REQUESTS.html" title="hyper::header::UPGRADE_INSECURE_REQUESTS constant">UPGRADE_INSECURE_REQUESTS</a></div><div class="item-right docblock-short">Sends a signal to the server expressing the client’s preference for an |
| encrypted and authenticated response.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.USER_AGENT.html" title="hyper::header::USER_AGENT constant">USER_AGENT</a></div><div class="item-right docblock-short">Contains a string that allows identifying the requesting client’s |
| software.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.VARY.html" title="hyper::header::VARY constant">VARY</a></div><div class="item-right docblock-short">Determines how to match future requests with cached responses.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.VIA.html" title="hyper::header::VIA constant">VIA</a></div><div class="item-right docblock-short">Added by proxies to track routing.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.WARNING.html" title="hyper::header::WARNING constant">WARNING</a></div><div class="item-right docblock-short">General HTTP header contains information about possible problems with |
| the status of the message.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.WWW_AUTHENTICATE.html" title="hyper::header::WWW_AUTHENTICATE constant">WWW_AUTHENTICATE</a></div><div class="item-right docblock-short">Defines the authentication method that should be used to gain access to |
| a resource.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.X_CONTENT_TYPE_OPTIONS.html" title="hyper::header::X_CONTENT_TYPE_OPTIONS constant">X_CONTENT_TYPE_OPTIONS</a></div><div class="item-right docblock-short">Marker used by the server to indicate that the MIME types advertised in |
| the <code>content-type</code> headers should not be changed and be followed.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.X_DNS_PREFETCH_CONTROL.html" title="hyper::header::X_DNS_PREFETCH_CONTROL constant">X_DNS_PREFETCH_CONTROL</a></div><div class="item-right docblock-short">Controls DNS prefetching.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.X_FRAME_OPTIONS.html" title="hyper::header::X_FRAME_OPTIONS constant">X_FRAME_OPTIONS</a></div><div class="item-right docblock-short">Indicates whether or not a browser should be allowed to render a page in |
| a frame.</div></div><div class="item-row"><div class="item-left module-item"><a class="constant" href="constant.X_XSS_PROTECTION.html" title="hyper::header::X_XSS_PROTECTION constant">X_XSS_PROTECTION</a></div><div class="item-right docblock-short">Stop pages from loading when an XSS attack is detected.</div></div></div><h2 id="traits" class="small-section-header"><a href="#traits">Traits</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="trait" href="trait.AsHeaderName.html" title="hyper::header::AsHeaderName trait">AsHeaderName</a></div><div class="item-right docblock-short">A marker trait used to identify values that can be used as search keys |
| to a <code>HeaderMap</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="trait" href="trait.IntoHeaderName.html" title="hyper::header::IntoHeaderName trait">IntoHeaderName</a></div><div class="item-right docblock-short">A marker trait used to identify values that can be used as insert keys |
| to a <code>HeaderMap</code>.</div></div></div></section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="hyper" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
