Use speculation rules prefetch/prerender when available#126
Use speculation rules prefetch/prerender when available#126dieulot merged 1 commit intoinstantpage:masterfrom domenic:speculationrules
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Speculation rules prefetch, currently only available in Chromium-based browsers, has some advantages over <link rel=prefetch>: * It stores the resources in a per-document in-memory cache, instead of in the HTTP cache, which can be slightly faster. * Because it has its own cache, it is not disabled by HTTP caching headers like Vary or Cache-Control. * It is automatically integrated into various user-respectful browser settings like Data Saver, Battery Saver, and memory pressure monitoring. * It has better cross-site support than <link rel=prefetch>, including the nonstandard as=document variant, because it disables itself if the destination site has cookies, whereas <link rel=prefetch> can cache the wrong version of the document (the version without cookies). * It shows up nicely in the DevTools speculative loads panel. The implementation strategy is to just insert a <script type=speculationrules> element, with a single list rule pointing to the target URL, instead of inserting the corresponding <link rel=prefetch> element. Additionally, we add the ability to configure prerendering, instead of prerendering, via the data-instant-specrules=prerender attribute. (Use of speculation rules can also be turned off, via data-instant-specrules=no.) Prerendering is more complex and risky, but can give a significant speed boost. More information on speculation rules prefetch and prerender is available at https://developer.mozilla.org/en-US/docs/Web/API/Speculation_Rules_API. When speculation rules are not available, we fall back to <link rel=prefetch> as usual.
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lgtm although it looks like the implementation doesn't allow cancelling (by removing the script tag, which might mean we run into max prefetches sooner compared to link rel=prefetch)? |
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Right, I didn't see that ability with |
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Thanks for your great PR! Release-wise, my hope is that I can deliver a major version incorporating it soon enough. If that isn’t done by mid-April, I’ll release a minor version just for it. Regarding the ability to cancel a request, it was removed way back in 2019 with 3.0.0, mostly because it made the code easier. (It should eventually come back.) |
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Hi @dieulot, any progress on releasing a new version? :) |
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Speculation rules prefetch, currently only available in Chromium-based browsers, has some advantages over
<link rel=prefetch>:It stores the resources in a per-document in-memory cache, instead of in the HTTP cache, which can be slightly faster.
Because it has its own cache, it is not disabled by HTTP caching headers like Vary or Cache-Control.
It is automatically integrated into various user-respectful browser settings like Data Saver, Battery Saver, and memory pressure monitoring.
It has better cross-site support than
<link rel=prefetch>, including the nonstandard as=document variant, because it disables itself if the destination site has cookies, whereas<link rel=prefetch>can cache the wrong version of the document (the version without cookies).It shows up nicely in the DevTools speculative loads panel.
The implementation strategy is to just insert a
<script type=speculationrules>element, with a single list rule pointing to the target URL, instead of inserting the corresponding<link rel=prefetch>element.Additionally, we add the ability to configure prerendering, instead of prerendering, via the
data-instant-specrules=prerenderattribute. (Use of speculation rules can also be turned off, viadata-instant-specrules=no.) Prerendering is more complex and risky, but can give a significant speed boost.More information on speculation rules prefetch and prerender is available at https://developer.mozilla.org/en-US/docs/Web/API/Speculation_Rules_API.
When speculation rules are not available, we fall back to
<link rel=prefetch>as usual.