Optimize header access #445
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There are a lot of attempts to directly set header values already, this unifies all Get/Set/Add/Del accesses to assume a canonical form already. In my personal testings, this actually stands out in our hot paths in flame graphs doing header Get/Sets. Within this codebase, we already have constants in place already in the correct formats. I've dug so deeply into this in the past that I created https://github.com/mattrobenolt/go-httpheaders which specifically highlights benchmarks of direct access vs using the Get/Set helpers. Since these are called multiple times in very hot paths, it's a worthwhile optimization since we can trust the inputs.
mattrobenolt
commented
Jan 26, 2023
| @@ -37,6 +37,7 @@ const ( | |||
| const ( | |||
| headerContentType = "Content-Type" | |||
| headerUserAgent = "User-Agent" | |||
| headerTrailer = "Trailer" | |||
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Figured since this was referenced multiple times, might as well elevate it to a constant.
akshayjshah
approved these changes
Jan 27, 2023
|
Perfect, those comments were more for yall while reviewing anyways, since I wasn't entirely sure if my assumption was true or not. |
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[](https://renovatebot.com) This PR contains the following updates: | Package | Type | Update | Change | |---|---|---|---| | [github.com/bufbuild/connect-go](https://togithub.com/bufbuild/connect-go) | require | patch | `v1.5.0` -> `v1.5.1` | --- ### Release Notes <details> <summary>bufbuild/connect-go</summary> ### [`v1.5.1`](https://togithub.com/bufbuild/connect-go/releases/tag/v1.5.1) [Compare Source](https://togithub.com/bufbuild/connect-go/compare/v1.5.0...v1.5.1) <!-- Release notes generated using configuration in .github/release.yml at main --> #### What's Changed Thanks to [@​mattrobenolt](https://togithub.com/mattrobenolt), v1.5.1 exclusively contains performance improvements. There should be no other user-visible behavior changes. ##### Bugfixes - Minimize allocations writing User-Agent header by [@​mattrobenolt](https://togithub.com/mattrobenolt) in [https://github.com/bufbuild/connect-go/pull/446](https://togithub.com/bufbuild/connect-go/pull/446) - Minimize allocations parsing Content-Type by [@​mattrobenolt](https://togithub.com/mattrobenolt) in [https://github.com/bufbuild/connect-go/pull/444](https://togithub.com/bufbuild/connect-go/pull/444) - Optimize header access by [@​mattrobenolt](https://togithub.com/mattrobenolt) in [https://github.com/bufbuild/connect-go/pull/445](https://togithub.com/bufbuild/connect-go/pull/445) - Optimize Peer lookups by [@​mattrobenolt](https://togithub.com/mattrobenolt) in [https://github.com/bufbuild/connect-go/pull/447](https://togithub.com/bufbuild/connect-go/pull/447) **Full Changelog**: bufbuild/connect-go@v1.5.0...v1.5.1 </details> --- ### Configuration 📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined). 🚦 **Automerge**: Enabled. ♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about this update again. --- - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box --- This PR has been generated by [Mend Renovate](https://www.mend.io/free-developer-tools/renovate/). View repository job log [here](https://app.renovatebot.com/dashboard#github/open-feature/flagd). <!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzNC4xMTkuMCIsInVwZGF0ZWRJblZlciI6IjM0LjExOS4wIn0=--> Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
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akshayjshah
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Jul 26, 2023
The standard library's `http.Header.{Get,Set,Add,Del}` automatically canonicalize header keys. This is nice, but expensive for us - we're using these APIs in many hot paths, and our constants are already in canonical form. This PR adds functions that bypass canonicalization and uses them wherever possible.
---------
Co-authored-by: Akshay Shah <[email protected]>
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There are a lot of attempts to directly set header values already, this unifies all Get/Set/Add/Del accesses to assume a canonical form already.
In my personal testings, this actually stands out in our hot paths in flame graphs doing header Get/Sets. Within this codebase, we already have constants in place already in the correct formats.
I've dug so deeply into this in the past that I created https://github.com/mattrobenolt/go-httpheaders which specifically highlights benchmarks of direct access vs using the Get/Set helpers.
Since these are called multiple times in very hot paths, it's a worthwhile optimization since we can trust the inputs.
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