--- title: Bun v0.1.9 description: Release notes for Bun v0.1.9 date: "2022-08-18T08:49:36Z" author: jarred thumbText: v0.1.9 --- To upgrade: ```bash bun upgrade ``` To install: ```bash curl https://bun.sh/install | bash ``` {% details summary="If you have any problems upgrading" %} Run the install script (you can run it multiple times): ```bash curl https://bun.sh/install | bash ``` {% /details %} ## What's new - Numerous crashes fixed by [@zhuzilin](https://github.com/zhuzilin)!! Incredible work. - [Linux] Improved event loop reliability and reduced CPU usage for concurrent/async IO (affects `bun install` and `fetch()` mostly) - `Bun.serve` gets about 20% faster outside of "hello world" benchmarks due to optimizing how `Headers` are copied/read and faster generated bindings - `require("buffer")` and `require("process")` now point to Bun's implementation instead of a browserify polyfill (thanks @zhuzilin) - Fixed a bug that would cause `setTimeout` or `setInterval` to not keep the process alive (thanks @zhuzilin) - Updated to latest WebKit - 6x - 10x faster `ptr()` in `bun:ffi` JIT-optimized `TextEncoder.encodeInto` can be a 1.5x perf boost up to around a 5x perf boost {% image width="536" alt="image" src="https://user-images.githubusercontent.com/709451/185333824-26c37ce4-dd29-4a2a-938e-182771eb8ce8.png" /%} The `hash()` function in this microbenchmark calls `ptr()`: {% image width="597" alt="image" src="https://user-images.githubusercontent.com/709451/185334865-e5451f5a-6214-4c83-b401-1247f3ef9ae1.png" /%} ## Internals #### Bun learns how to JIT `DOMJIT` is a JavaScriptCore API that gives 3rd-party embedders low-level access to the JIT compiler/assembler to optimize native functions and getters/setters. Safari leverages DOMJIT to make commonly-accessed properties like `element.parentNode` faster Bun is beginning to use DOMJIT now, starting in two places: - `ptr()` function in `bun:ffi` - [`TextEncoder.encodeInto`](https://developer.mozilla.org/en-US/docs/Web/API/TextEncoder/encodeInto) To better support Bun's usecase, I extended `DOMJIT` to support Typed Array arguments, as well as added support for specifying more kinds of side effects that enable/disable optimizations: - https://github.com/oven-sh/WebKit/commit/d2ef2fd828761778a3b04289563946354a457e29 - https://github.com/oven-sh/WebKit/commit/3262da8fd77667aaf95e75c7efa501dc135bc0ac - https://github.com/oven-sh/WebKit/commit/4ac5b04047a53ce2363495a79770a2ae6d67761b#diff-90a5d15b3faae39b6e5075902ae5fd2e0b7f7f40bb0590f3e298e7715db048e5 #### Faster and more reliable JSC <> Zig bindings At Bun's compile-time, Bun now code-generates C++ binding classes for JavaScript objects implemented in Zig. Previously, Bun mostly used the JavaScriptCore C API. Using JavaScriptCore's C++ API improves performance and is important for making the garbage collector better aware of Bun's usage. But, writing bindings manually can be very repetitive. Given a class definition in JavaScript [like this](https://github.com/oven-sh/bun/blob/eb5b298bc17a7ea2ede438b227c27c3fc0b5462e/src/bun.js/webcore/response.classes.ts#L60-L65): ```ts define({ name: "Response", construct: true, finalize: true, JSType: "0b11101110", klass: { json: { fn: "constructJSON", }, // rest of the code }, proto: { url: { getter: "getURL", cache: true, }, text: { fn: "getText" }, json: { fn: "getJSON" }, arrayBuffer: { fn: "getArrayBuffer" }, blob: { fn: "getBlob" }, clone: { fn: "doClone", length: 1 }, // rest of the code }, }); ``` Bun generates corresponding: - [C++ classes](https://github.com/oven-sh/bun/blob/eb5b298bc17a7ea2ede438b227c27c3fc0b5462e/src/bun.js/bindings/ZigGeneratedClasses.cpp#L2465-L2872) - [Zig bindings](https://github.com/oven-sh/bun/blob/eb5b298bc17a7ea2ede438b227c27c3fc0b5462e/src/bun.js/bindings/generated_classes.zig#L826-L937) with type checks that verify the expected ABI matches This approach is inspired by [WebIDL bindings](https://www.chromium.org/developers/web-idl-interfaces/) which both Safari and Chromium use. #### More reliable event loop on Linux This screenshot is with a simulated bandwidth limit and no throttling of max http connections Previously, bun had a tendency to hang in situations like this ![image](https://user-images.githubusercontent.com/709451/185347695-42182e74-6c09-4688-b2fd-c5ed0376422f.png) ## What's Changed - fix MD5 length and compile error by [@zhuzilin](https://github.com/zhuzilin) in https://github.com/oven-sh/bun/pull/1050 - fix appendFile permission by [@zhuzilin](https://github.com/zhuzilin) in https://github.com/oven-sh/bun/pull/1052 - Invalidate column name caches when the schema of table may change by [@zhuzilin](https://github.com/zhuzilin) in https://github.com/oven-sh/bun/pull/1056 - refactor(src/tagged_pointer): `IntPrimtiive` -> `IntPrimitive` by [@ryanrussell](https://github.com/ryanrussell) in https://github.com/oven-sh/bun/pull/1046 - Remove column name caches in js by [@zhuzilin](https://github.com/zhuzilin) in https://github.com/oven-sh/bun/pull/1057 - [bun error] fix typo in markdown.ts by [@eltociear](https://github.com/eltociear) in https://github.com/oven-sh/bun/pull/995 - [WIP] Native buffer module by [@zhuzilin](https://github.com/zhuzilin) in https://github.com/oven-sh/bun/pull/1067 - Improve event loop reliability on Linux by [@Jarred-Sumner](https://github.com/Jarred-Sumner) in https://github.com/oven-sh/bun/pull/1066 - Add synthetic buffer module by [@zhuzilin](https://github.com/zhuzilin) in https://github.com/oven-sh/bun/pull/1076 - Deps - Update libarchive by [@jonacollazo](https://github.com/jonacollazo) in https://github.com/oven-sh/bun/pull/1078 - Fix active_task count for timeout tasks by [@zhuzilin](https://github.com/zhuzilin) in https://github.com/oven-sh/bun/pull/1081 - Fix server segfault by making controller not early GC'ed by [@zhuzilin](https://github.com/zhuzilin) in https://github.com/oven-sh/bun/pull/1090 - Add native process module by [@zhuzilin](https://github.com/zhuzilin) in https://github.com/oven-sh/bun/pull/1095 ## New Contributors - @jonacollazo made their first contribution in https://github.com/oven-sh/bun/pull/1078 [**Full Changelog**](https://github.com/oven-sh/bun/compare/bun-v0.1.8...bun-v0.1.9)