greptimedb/common_config/file_watcher/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="Common file watching utilities for configuration hot-reloading."><title>common_config::file_watcher - 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="common_config" 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 file_watcher</a></h2></rustdoc-topbar><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../../common_config/index.html">common_<wbr>config</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 file_<wbr>watcher</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="#constants" title="Constants">Constants</a></li><li><a href="#functions" title="Functions">Functions</a></li></ul></section><div id="rustdoc-modnav"><h2 class="in-crate"><a href="../index.html">In crate common_<wbr>config</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">common_config</a></div><h1>Module <span>file_<wbr>watcher</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/common_config/file_watcher.rs.html#15-639">Source</a> </span></div><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Common file watching utilities for configuration hot-reloading.</p>
<p>This module provides a generic file watcher that can be used to watch
files for changes and trigger callbacks when changes occur.</p>
<p>The watcher monitors the parent directory of each file rather than the
file itself. This ensures that file deletions and recreations are properly
tracked, which is common with editors that use atomic saves or when
configuration files are replaced.</p>
<p>If the path goes through symlinks (the file itself or any ancestor
directory), the directory holding each symlink is watched as well, so that
swapping a symlink anywhere in the chain (e.g. <code>ln -sfn secrets.2 secrets</code>,
as done by secret managers like sops-nix or Kubernetes volume mounts) is
detected. The chain is re-resolved after every relevant event and the set
of watched directories is updated accordingly.</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.FileWatcherBuilder.html" title="struct common_config::file_watcher::FileWatcherBuilder">File<wbr>Watcher<wbr>Builder</a></dt><dd>A builder for creating file watchers with flexible configuration.</dd><dt><a class="struct" href="struct.FileWatcherConfig.html" title="struct common_config::file_watcher::FileWatcherConfig">File<wbr>Watcher<wbr>Config</a></dt><dd>Configuration for the file watcher behavior.</dd><dt><a class="struct" href="struct.WatchTargets.html" title="struct common_config::file_watcher::WatchTargets">Watch<wbr>Targets</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dd>Directories to watch and the directory entries whose events are relevant.</dd></dl><h2 id="constants" class="section-header">Constants<a href="#constants" class="anchor">§</a></h2><dl class="item-table"><dt><a class="constant" href="constant.MAX_SYMLINK_HOPS.html" title="constant common_config::file_watcher::MAX_SYMLINK_HOPS">MAX_<wbr>SYMLINK_<wbr>HOPS</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dd>Maximum number of symlinks followed while resolving a single path. This
mirrors Linux’s <code>MAXSYMLINKS</code> and guards against symlink loops.</dd></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.entry_key.html" title="fn common_config::file_watcher::entry_key">entry_<wbr>key</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dd>Key used to compare an event path with <a href="struct.WatchTargets.html#structfield.entries" title="field common_config::file_watcher::WatchTargets::entries"><code>WatchTargets::entries</code></a>.</dd><dt><a class="fn" href="fn.is_relevant_event.html" title="fn common_config::file_watcher::is_relevant_event">is_<wbr>relevant_<wbr>event</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dd>Check if an event kind is relevant based on the configuration.</dd><dt><a class="fn" href="fn.rearm_watches.html" title="fn common_config::file_watcher::rearm_watches">rearm_<wbr>watches</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dd>Re-resolves <code>file_paths</code> and updates the watched directories, returning
the new targets. Failures are logged and retried on the next event that
matches a chain entry.</dd><dt><a class="fn" href="fn.resolve_one.html" title="fn common_config::file_watcher::resolve_one">resolve_<wbr>one</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dt><a class="fn" href="fn.resolve_watch_targets.html" title="fn common_config::file_watcher::resolve_watch_targets">resolve_<wbr>watch_<wbr>targets</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dd>Resolves every path component by component, following symlinks, and
collects what has to be watched to notice any change of what the path
points to.</dd><dt><a class="fn" href="fn.warn_if_root.html" title="fn common_config::file_watcher::warn_if_root">warn_<wbr>if_<wbr>root</a><span title="Restricted Visibility">&nbsp;🔒</span> </dt><dd>Warns when the root directory is watched, which happens when a path goes
through a symlink directly under it (e.g. <code>/tmp</code>, <code>/var</code> or <code>/etc</code> on
macOS). On macOS the FSEvents backend then receives every event on the
volume and filters them in user space.</dd></dl></section></div></main></body></html>