greptimedb/servers/http/memory_limit/index.html

<!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="Middleware for limiting total memory usage of concurrent HTTP request bodies."><title>servers::http::memory_limit - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-6b053e98.ttf.woff2,FiraSans-Italic-81dc35de.woff2,FiraSans-Regular-0fe48ade.woff2,FiraSans-MediumItalic-ccf7e434.woff2,FiraSans-Medium-e1aa3f0a.woff2,SourceCodePro-Regular-8badfe75.ttf.woff2,SourceCodePro-Semibold-aa29a496.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2"href="../../../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../../../static.files/normalize-9960930a.css"><link rel="stylesheet" href="../../../static.files/rustdoc-1ed95124.css"><meta name="rustdoc-vars" data-root-path="../../../" data-static-root-path="../../../static.files/" data-current-crate="servers" data-themes="" data-resource-suffix="" data-rustdoc-version="1.98.1 (48a229cea 2026-09-01)" data-channel="1.98.1" data-search-js="search-9944d736.js" data-stringdex-js="stringdex-2da4960a.js" data-settings-js="settings-170eb4bf.js" ><script src="../../../static.files/storage-41dd4d93.js"></script><script defer src="../sidebar-items.js"></script><script defer src="../../../static.files/main-417ebf0a.js"></script><noscript><link rel="stylesheet" href="../../../static.files/noscript-f7c3ffd8.css"></noscript><link rel="alternate icon" type="image/png" href="../../../static.files/favicon-32x32-eab170b8.png"><link rel="icon" type="image/svg+xml" href="../../../static.files/favicon-044be391.svg"></head><body class="rustdoc mod"><a class="skip-main-content" href="#main-content">Skip to main content</a><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><rustdoc-topbar><h2><a href="#">Module memory_limit</a></h2></rustdoc-topbar><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../../../servers/index.html">servers</a><span class="version">1.4.0-alpha.0</span></h2></div><div class="sidebar-elems"><section id="rustdoc-toc"><h2 class="location"><a href="#">Module memory_<wbr>limit</a></h2><h3><a href="#structs">Module Items</a></h3><ul class="block"><li><a href="#structs" title="Structs">Structs</a></li><li><a href="#enums" title="Enums">Enums</a></li><li><a href="#functions" title="Functions">Functions</a></li><li><a href="#types" title="Type Aliases">Type Aliases</a></li></ul></section><div id="rustdoc-modnav"><h2><a href="../index.html">In servers::<wbr>http</a></h2></div></div></nav><div class="sidebar-resizer" title="Drag to resize sidebar"></div><main><div class="width-limiter"><section id="main-content" class="content" tabindex="-1"><div class="main-heading"><div class="rustdoc-breadcrumbs"><a href="../../index.html">servers</a>::<wbr><a href="../index.html">http</a></div><h1>Module <span>memory_<wbr>limit</span>&nbsp;<button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><rustdoc-toolbar></rustdoc-toolbar><span class="sub-heading"><a class="src" href="../../../src/servers/http/memory_limit.rs.html#15-648">Source</a> </span></div><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Middleware for limiting total memory usage of concurrent HTTP request bodies.</p>
<p>Admission works in two stages:</p>
<ol>
<li>Upfront, the request’s <code>Content-Length</code> (if present) is charged to the
shared <a href="../../request_memory_limiter/struct.ServerMemoryLimiter.html" title="struct servers::request_memory_limiter::ServerMemoryLimiter"><code>ServerMemoryLimiter</code></a>, preserving the configured wait/fail
policy for regular requests.</li>
<li>While the body is streamed, <a href="struct.AccountedBody.html" title="struct servers::http::memory_limit::AccountedBody"><code>AccountedBody</code></a> charges every byte beyond
the upfront reservation. This closes two gaps of a header-only
reservation: HTTP/1.1 chunked requests carry no <code>Content-Length</code> (and
would otherwise be admitted for free), and a client can understate the
header while sending a much larger body.</li>
</ol>
<p>Permits acquired while streaming are held by <a href="struct.BodyMemoryAccounting.html" title="struct servers::http::memory_limit::BodyMemoryAccounting"><code>BodyMemoryAccounting</code></a>,
which is also inserted into the request extensions so they stay alive until
the whole request is finished (extractors collect the body into owned
buffers that outlive the body stream itself).</p>
</div></details><h2 id="structs" class="section-header">Structs<a href="#structs" class="anchor">§</a></h2><dl class="item-table"><dt><a class="struct" href="struct.AccountedBody.html" title="struct servers::http::memory_limit::AccountedBody">Accounted<wbr>Body</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dd>A request body wrapper that charges the shared limiter for every byte
streamed beyond <code>pre_charged</code> (the upfront <code>Content-Length</code> reservation).</dd><dt><a class="struct" href="struct.BodyMemoryAccounting.html" title="struct servers::http::memory_limit::BodyMemoryAccounting">Body<wbr>Memory<wbr>Accounting</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dd>Holds the memory guards acquired while a request body is streamed. Shared
between the <a href="struct.AccountedBody.html" title="struct servers::http::memory_limit::AccountedBody"><code>AccountedBody</code></a> wrapper, the request extensions and the
middleware itself, so the permits are only released when the request
(including any collected body buffers and the handler still using them)
is finished.</dd><dt><a class="struct" href="struct.ContentEncoded.html" title="struct servers::http::memory_limit::ContentEncoded">Content<wbr>Encoded</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dd>Marker inserted by <a href="fn.memory_limit_middleware.html" title="fn servers::http::memory_limit::memory_limit_middleware"><code>memory_limit_middleware</code></a> when the request arrives
with a non-identity <code>Content-Encoding</code> header. Route-local
<a href="../fn.decoded_body_accounting_middleware.html" title="fn servers::http::decoded_body_accounting_middleware"><code>decoded_body_accounting_middleware</code></a> uses it to account the decompressed
body: only such requests expand during request decompression.</dd></dl><h2 id="enums" class="section-header">Enums<a href="#enums" class="anchor">§</a></h2><dl class="item-table"><dt><a class="enum" href="enum.ChargeOutcome.html" title="enum servers::http::memory_limit::ChargeOutcome">Charge<wbr>Outcome</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt></dl><h2 id="functions" class="section-header">Functions<a href="#functions" class="anchor">§</a></h2><dl class="item-table"><dt><a class="fn" href="fn.decoded_body_accounting_middleware.html" title="fn servers::http::memory_limit::decoded_body_accounting_middleware">decoded_<wbr>body_<wbr>accounting_<wbr>middleware</a></dt><dd>Route-local accounting for routes that install <code>RequestDecompressionLayer</code>:
it must be layered <em>inside</em> the
decompression layer, so the body it wraps is the <strong>decompressed</strong> stream.
It requires the global accounting installed by <a href="../struct.HttpServer.html" title="struct servers::http::HttpServer"><code>crate::http::HttpServer</code></a>
and must use the same <a href="../../request_memory_limiter/struct.ServerMemoryLimiter.html" title="struct servers::request_memory_limiter::ServerMemoryLimiter"><code>ServerMemoryLimiter</code></a>.</dd><dt><a class="fn" href="fn.limit_exceeded_error.html" title="fn servers::http::memory_limit::limit_exceeded_error">limit_<wbr>exceeded_<wbr>error</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dt><a class="fn" href="fn.memory_limit_middleware.html" title="fn servers::http::memory_limit::memory_limit_middleware">memory_<wbr>limit_<wbr>middleware</a></dt><dt><a class="fn" href="fn.quota_exceeded_response.html" title="fn servers::http::memory_limit::quota_exceeded_response">quota_<wbr>exceeded_<wbr>response</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dd>Rewrites the response of a request whose body accounting hit the quota:
the failure aborts the body mid-stream, so the extractors reject the
request with a generic body error (mapped to 400). Quota exhaustion must
surface as 429, matching the upfront admission path, so clients can tell
backpressure apart from malformed input.</dd></dl><h2 id="types" class="section-header">Type Aliases<a href="#types" class="anchor">§</a></h2><dl class="item-table"><dt><a class="type" href="type.AcquireFuture.html" title="type servers::http::memory_limit::AcquireFuture">Acquire<wbr>Future</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt></dl></section></div></main></body></html>