seirdy.one/content/notes/short-cache-busting-fingerprints-in-hugo.md

title	date	replyURI	replyTitle	replyType	replyAuthor	replyAuthorURI	syndicatedCopies
Short cache busting fingerprints in Hugo	2024-03-28T00:16:48-04:00	https://github.com/gohugoio/hugo/issues/6241	Shorter fingerprinting (Hugo issue 6241)	DiscussionForumPosting	XhmikosR	https://github.com/XhmikosR	title url GitHub https://github.com/gohugoio/hugo/issues/6241#issuecomment-2024366155 title url The Fediverse https://pleroma.envs.net/notice/AgIhXz3q628odren2G title url IndieNews https://news.indieweb.org/en

I use a quick crypto.FNV32a-based fix for short cache-busting fingerprints that doesn't directly rely on the unstable .Key method.

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I use Hugo's crypto.FNV32a to generate a short hash, then copy the resource to a new path with that fingerprint.

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{{ $resource := resources.Get . -}}
{{- $target_path_formatStr := (replaceRE `(\.[^\.]*)$` ".%d$1" .) -}}
{{- $cacheBuster := $resource.Content | crypto.FNV32a -}}
{{- $target_path := printf $target_path_formatStr $cacheBuster -}}
{{- return resources.Copy $target_path $resource -}}

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You can see it used in my site's head element. I invoke it using partialCached so the fingerprinting only happens once per resource:

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{{ $icon_svg := partialCached "cache-bust.html" "/favicon.svg" "/favicon.svg" }}
{{- printf `<link rel="icon" sizes="any" href="%s" type="image/svg+xml" />` $icon_svg.RelPermalink | safeHTML }}

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Here's a snippet of the final rendered result:

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<link rel="icon" sizes="any" href="/favicon.2229316949.svg" type="image/svg+xml"/>

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Encoding it to a higher base and using alphanumerics could shave off 1-2 ch.