manishearth

<p><em>This is part 3 of a three-part series on interesting abstractions for zero-copy deserialization I’ve been working on over the last year. This part is about eliminating the deserialization step entirely. Part 1 is about making it more pleasant to work with and can be found <a href="http://manishearth.github.io/blog/2022/08/03/zero-copy-1-not-a-yoking-matter/">here</a>; while Part 2 is about making it work for more types and can be found <a href="http://manishearth.github.io/blog/2022/08/03/zero-copy-2-zero-copy-all-the-things/">here</a>. The posts can be read in any order, though only the first post contains an explanation of what zero-copy deserialization</em> is.</p> <blockquote> <p>And when Alexander saw the breadth of his work, he wept. For there were no more copies left to zero.</p> <p>—Hans Gruber, after designing three increasingly unhinged zero-copy crates</p> </blockquote> <p><a href="http://manishearth.github.io/blog/2022/08/03/zero-copy-1-not-a-yoking-matter/">…

<p><em>This is part 2 of a three-part series on interesting abstractions for zero-copy deserialization I’ve been working on over the last year. This part is about making zero-copy deserialization work for more types. Part 1 is about making it more pleasant to work with and can be found <a href="http://manishearth.github.io/blog/2022/08/03/zero-copy-1-not-a-yoking-matter/">here</a>; while Part 3 is about eliminating the deserialization step entirely and can be found <a href="http://manishearth.github.io/blog/2022/08/03/zero-copy-3-so-zero-its-dot-dot-dot-negative/">here</a>. The posts can be read in any order, though only the first post contains an explanation of what zero-copy deserialization</em> is.</p> <h2 id="background">Background</h2> <p><em>This section is the same as in the last article and can be skipped if you’ve read it</em></p> <p>For the past year and a half I’ve been working full time on <a href="https://github.com/unicode-org/icu4x">ICU4X</a>, a new internationalizati…

<p><em>This is part 1 of a three-part series on interesting abstractions for zero-copy deserialization I’ve been working on over the last year. This part is about making zero-copy deserialization more pleasant to work with. Part 2 is about making it work for more types and can be found <a href="http://manishearth.github.io/blog/2022/08/03/zero-copy-2-zero-copy-all-the-things/">here</a>; while Part 3 is about eliminating the deserialization step entirely and can be found <a href="http://manishearth.github.io/blog/2022/08/03/zero-copy-3-so-zero-its-dot-dot-dot-negative/">here</a>. The posts can be read in any order, though this post contains an explanation of what zero-copy deserialization</em> is.</p> <h2 id="background">Background</h2> <p>For the past year and a half I’ve been working full time on <a href="https://github.com/unicode-org/icu4x">ICU4X</a>, a new internationalization library in Rust being built under the Unicode Consortium as a collaboration between various companies.</…

<p>I’ve been thinking about garbage collection in Rust for a long time, ever since I started working on <a href="https://github.com/servo/servo">Servo</a>’s JS layer. I’ve <a href="https://manishearth.github.io/blog/2015/09/01/designing-a-gc-in-rust/">designed a GC library</a>, <a href="https://manishearth.github.io/blog/2016/08/18/gc-support-in-rust-api-design/">worked on GC integration ideas for Rust itself</a>, worked on Servo’s JS GC integration, and helped out with a <a href="https://github.com/asajeffrey/josephine">couple</a> <a href="https://github.com/kyren/gc-arena">other</a> GC projects in Rust.</p> <p>As a result, I tend to get pulled into GC discussions fairly often. I enjoy talking about GCs – don’t get me wrong – but I often end up going over the same stuff. Being <a href="https://manishearth.github.io/blog/2018/08/26/why-i-enjoy-blogging/#blogging-lets-me-be-lazy">lazy</a> I’d much prefer to be able to refer people to a single place where they can get up to speed on the…

<p>There’s been some discussion about arenas in Rust recently, and I thought I’d write about them.</p> <p>Arenas aren’t something you would typically reach for in Rust so fewer people know about them; you only really see them in applications for various niche use cases. Usually you can use an arena by pulling in a crate and not using additional <code class="language-plaintext highlighter-rouge">unsafe</code>, so there’s no need to be particularly skittish around them in Rust, and it seems like it would be useful knowledge, especially for people coming to Rust from fields where arenas are more common.</p> <p>Furthermore, there’s a set of <em>really cool</em> lifetime effects involved when implementing self-referential arenas, that I don’t think have been written about before.</p> <p>I’m mostly writing this to talk about the cool lifetime effects, but I figured it’s worth writing a general introduction that has something for all Rustaceans. If you know what arenas are and just want th…