[performance] Reduce per-request overhead in hot path by tipsy · Pull Request #2559 · javalin/javalin

tipsy · 2026-03-13T21:01:43Z

Summary

Surgical optimizations to Javalin's request lifecycle hot path — 8 files changed, +55/-19 lines, all internal with no public API modifications.

Cache route match result — findHttpHandlerEntries is called once per request instead of 3-4 times, cached in a private field on JavalinServletContext (not request attributes)
Single-pass path param extraction — new matchAndExtract() combines match + extract in one regex execution instead of three
Zero-allocation content-type checks — ignoreCase = true instead of lowercase() string allocation
ArrayList over LinkedList — better cache locality for the small endpoint stack

Test plan

Full test suite passes (mvn test -pl javalin — 972 tests, 0 failures)

🤖 Generated with Claude Code

Cache route match result across lifecycle phases using private fields on JavalinServletContext, add single-pass matchAndExtract() to PathParser, replace lowercase() allocations with ignoreCase comparisons, and swap LinkedList for ArrayList in Endpoints. All changes are internal — no public API modifications. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

codecov · 2026-03-13T21:09:58Z

Codecov Report

❌ Patch coverage is 91.30435% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 86.24%. Comparing base (1e59eda) to head (fb05b96).
⚠️ Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
javalin/src/main/java/io/javalin/http/Context.kt	50.00%	0 Missing and 2 partials ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #2559      +/-   ##
============================================
- Coverage     86.29%   86.24%   -0.05%     
+ Complexity     1509     1507       -2     
============================================
  Files           155      155              
  Lines          4348     4356       +8     
  Branches        523      525       +2     
============================================
+ Hits           3752     3757       +5     
- Misses          363      366       +3     
  Partials        233      233

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- Add `inline` to cachedHttpHandler/cachedWillMatch to eliminate lambda allocations - Use primitive Int (0/1/-1) for boolean cache to avoid boxing overhead - Use @PublishedApi for UNSET sentinel to support inline access Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tipsy · 2026-03-13T21:38:01Z

augment review

augmentcode · 2026-03-13T21:42:38Z

🤖 Augment PR Summary

Summary: Reduces per-request overhead in Javalin’s request lifecycle hot path by avoiding repeated route lookups and string allocations.

Changes:

Caches the matched ParsedEndpoint and the willMatch decision on JavalinServletContext to reuse results across lifecycle phases
Derives route roles directly from the cached handler metadata (removing extra router queries)
Uses case-insensitive prefix checks for content-type and accept-encoding parsing to avoid lowercase() allocations
Switches the internal endpoint stack from LinkedList to a small pre-sized ArrayList

Tests: Adds a lifecycle test intended to cover cache hit and miss paths.

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Review completed. 1 suggestion posted.

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Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tipsy · 2026-03-13T21:54:43Z

augment review

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augmentcode · 2026-03-13T21:58:38Z

+    fun `router heavily exercises caching across lifecycle phases`() = TestUtil.test(Javalin.create { cfg ->
+        // Setup before/after filters to force the router to evaluate the endpoint multiple times
+        // during the same request lifecycle, triggering the cache hits.
+        cfg.routes.before("/*") { ctx -> ctx.attribute("req_start", true) }


This test sets up routes.before/routes.after (BEFORE/AFTER), which won’t necessarily evaluate the new cachedWillMatch logic that’s only used in BEFORE_MATCHED/AFTER_MATCHED. If the goal is to exercise caching “across lifecycle phases”, consider ensuring the test actually triggers BEFORE_MATCHED/AFTER_MATCHED behavior so the cache paths are covered.

Severity: low

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Bumps `javalin.version` from 7.0.1 to 7.1.0. Updates `io.javalin:javalin-bundle` from 7.0.1 to 7.1.0 Release notes *Sourced from [io.javalin:javalin-bundle's releases](https://github.com/javalin/javalin/releases).* > 7.1.0 > ----- > > What's Changed > -------------- > > * Bump com.fasterxml.jackson.core:jackson-core from 2.21.0 to 2.21.1 by [`@dependabot`](https://github.com/dependabot)[bot] in [javalin/javalin#2543](https://redirect.github.com/javalin/javalin/pull/2543) > * [deps]: Bump the dependencies group across 1 directory with 17 updates by [`@dependabot`](https://github.com/dependabot)[bot] in [javalin/javalin#2545](https://redirect.github.com/javalin/javalin/pull/2545) > * [websocket] Fix WebSocket over HTTP/2 Extended Connect (RFC 8441) by [`@tipsy`](https://github.com/tipsy) in [javalin/javalin#2547](https://redirect.github.com/javalin/javalin/pull/2547) > * fix(README): update artifactId for SSL plugin in `README.md` by [`@yvasyliev`](https://github.com/yvasyliev) in [javalin/javalin#2556](https://redirect.github.com/javalin/javalin/pull/2556) > * Add `wsExceptionHandler` to `MicrometerPlugin` for WebSocket exception tagging by [`@Copilot`](https://github.com/Copilot) in [javalin/javalin#2557](https://redirect.github.com/javalin/javalin/pull/2557) > * [rendering] jte - introduce directoryTemplateEngine for (6.x-like), rename default to classPathTemplateEngine by [`@elwin013`](https://github.com/elwin013) in [javalin/javalin#2551](https://redirect.github.com/javalin/javalin/pull/2551) > * Add javalin-bom module by [`@Copilot`](https://github.com/Copilot) in [javalin/javalin#2558](https://redirect.github.com/javalin/javalin/pull/2558) > * [performance] Reduce per-request overhead in hot path by [`@tipsy`](https://github.com/tipsy) in [javalin/javalin#2559](https://redirect.github.com/javalin/javalin/pull/2559) > * [performance] Eliminate per-request regex and allocation overhead by [`@tipsy`](https://github.com/tipsy) in [javalin/javalin#2560](https://redirect.github.com/javalin/javalin/pull/2560) > > New Contributors > ---------------- > > * [`@yvasyliev`](https://github.com/yvasyliev) made their first contribution in [javalin/javalin#2556](https://redirect.github.com/javalin/javalin/pull/2556) > * [`@elwin013`](https://github.com/elwin013) made their first contribution in [javalin/javalin#2551](https://redirect.github.com/javalin/javalin/pull/2551) > > **Full Changelog**: <javalin/javalin@javalin-parent-7.0.1...javalin-parent-7.1.0> Commits * [`e458dba`](javalin/javalin@e458dba) [maven-release-plugin] prepare for next development iteration * [`9766d2f`](javalin/javalin@9766d2f) [maven-release-plugin] prepare release javalin-parent-7.1.0 * [`12acf0b`](javalin/javalin@12acf0b) [performance] Eliminate per-request regex and allocation overhead ([#2560](https://redirect.github.com/javalin/javalin/issues/2560)) * [`f6a1e40`](javalin/javalin@f6a1e40) [performance] Reduce per-request overhead in hot path * [`1e59eda`](javalin/javalin@1e59eda) [pom] Add javalin-bom module ([#2558](https://redirect.github.com/javalin/javalin/issues/2558)) * [`b43f37a`](javalin/javalin@b43f37a) [rendering] jte - introduce directoryTemplateEngine for (6.x-like behavior) * [`72b2320`](javalin/javalin@72b2320) [micrometer] Add `wsExceptionHandler` to `MicrometerPlugin` * [`37c91c4`](javalin/javalin@37c91c4) [readme] Update artifactId for SSL plugin * [`9acf45e`](javalin/javalin@9acf45e) [cleanup] Use Header constants * [`0289084`](javalin/javalin@0289084) [headers] Add missing headers to Header.kt * Additional commits viewable in [compare view](javalin/javalin@javalin-parent-7.0.1...7.1.0) Updates `io.javalin.community.openapi:javalin-openapi-plugin` from 7.0.1 to 7.1.0 Release notes *Sourced from [io.javalin.community.openapi:javalin-openapi-plugin's releases](https://github.com/javalin/javalin-openapi/releases).* > 7.1.0 > ----- > > **Changes** > > * [javalin/javalin-openapi#275](https://redirect.github.com/javalin/javalin-openapi/issues/275) [Make ClassLoader used for loading resources configurable](javalin/javalin-openapi@de1b6b7) > * Support Javalin 7.1.0 > > **Sponsors** > Thanks to everyone who supported me this month 💜 > > **Minimal requirements** > > * Java 17+ / Kotlin 2.3+ > * Javalin 7.1.0 Commits * [`5388862`](javalin/javalin-openapi@5388862) [GH-275](https://redirect.github.com/javalin/javalin-openapi/issues/275) Cover missing resource loaders and release 7.1.1-rc.1 * [`cbbc8d0`](javalin/javalin-openapi@cbbc8d0) [GH-276](https://redirect.github.com/javalin/javalin-openapi/issues/276) Release 7.1.0 (Resolves [#276](https://redirect.github.com/javalin/javalin-openapi/issues/276)) * [`de1b6b7`](javalin/javalin-openapi@de1b6b7) [GH-275](https://redirect.github.com/javalin/javalin-openapi/issues/275) Make ClassLoader used for loading resources configurable (Resolves [#275](https://redirect.github.com/javalin/javalin-openapi/issues/275)) * See full diff in [compare view](javalin/javalin-openapi@7.0.1...7.1.0) Updates `io.javalin.community.openapi:javalin-swagger-plugin` from 7.0.1 to 7.1.0 Release notes *Sourced from [io.javalin.community.openapi:javalin-swagger-plugin's releases](https://github.com/javalin/javalin-openapi/releases).* > 7.1.0 > ----- > > **Changes** > > * [javalin/javalin-openapi#275](https://redirect.github.com/javalin/javalin-openapi/issues/275) [Make ClassLoader used for loading resources configurable](javalin/javalin-openapi@de1b6b7) > * Support Javalin 7.1.0 > > **Sponsors** > Thanks to everyone who supported me this month 💜 > > **Minimal requirements** > > * Java 17+ / Kotlin 2.3+ > * Javalin 7.1.0 Commits * [`5388862`](javalin/javalin-openapi@5388862) [GH-275](https://redirect.github.com/javalin/javalin-openapi/issues/275) Cover missing resource loaders and release 7.1.1-rc.1 * [`cbbc8d0`](javalin/javalin-openapi@cbbc8d0) [GH-276](https://redirect.github.com/javalin/javalin-openapi/issues/276) Release 7.1.0 (Resolves [#276](https://redirect.github.com/javalin/javalin-openapi/issues/276)) * [`de1b6b7`](javalin/javalin-openapi@de1b6b7) [GH-275](https://redirect.github.com/javalin/javalin-openapi/issues/275) Make ClassLoader used for loading resources configurable (Resolves [#275](https://redirect.github.com/javalin/javalin-openapi/issues/275)) * See full diff in [compare view](javalin/javalin-openapi@7.0.1...7.1.0) Updates `io.javalin:javalin-micrometer` from 7.0.1 to 7.1.0 Release notes *Sourced from [io.javalin:javalin-micrometer's releases](https://github.com/javalin/javalin/releases).* > 7.1.0 > ----- > > What's Changed > -------------- > > * Bump com.fasterxml.jackson.core:jackson-core from 2.21.0 to 2.21.1 by [`@dependabot`](https://github.com/dependabot)[bot] in [javalin/javalin#2543](https://redirect.github.com/javalin/javalin/pull/2543) > * [deps]: Bump the dependencies group across 1 directory with 17 updates by [`@dependabot`](https://github.com/dependabot)[bot] in [javalin/javalin#2545](https://redirect.github.com/javalin/javalin/pull/2545) > * [websocket] Fix WebSocket over HTTP/2 Extended Connect (RFC 8441) by [`@tipsy`](https://github.com/tipsy) in [javalin/javalin#2547](https://redirect.github.com/javalin/javalin/pull/2547) > * fix(README): update artifactId for SSL plugin in `README.md` by [`@yvasyliev`](https://github.com/yvasyliev) in [javalin/javalin#2556](https://redirect.github.com/javalin/javalin/pull/2556) > * Add `wsExceptionHandler` to `MicrometerPlugin` for WebSocket exception tagging by [`@Copilot`](https://github.com/Copilot) in [javalin/javalin#2557](https://redirect.github.com/javalin/javalin/pull/2557) > * [rendering] jte - introduce directoryTemplateEngine for (6.x-like), rename default to classPathTemplateEngine by [`@elwin013`](https://github.com/elwin013) in [javalin/javalin#2551](https://redirect.github.com/javalin/javalin/pull/2551) > * Add javalin-bom module by [`@Copilot`](https://github.com/Copilot) in [javalin/javalin#2558](https://redirect.github.com/javalin/javalin/pull/2558) > * [performance] Reduce per-request overhead in hot path by [`@tipsy`](https://github.com/tipsy) in [javalin/javalin#2559](https://redirect.github.com/javalin/javalin/pull/2559) > * [performance] Eliminate per-request regex and allocation overhead by [`@tipsy`](https://github.com/tipsy) in [javalin/javalin#2560](https://redirect.github.com/javalin/javalin/pull/2560) > > New Contributors > ---------------- > > * [`@yvasyliev`](https://github.com/yvasyliev) made their first contribution in [javalin/javalin#2556](https://redirect.github.com/javalin/javalin/pull/2556) > * [`@elwin013`](https://github.com/elwin013) made their first contribution in [javalin/javalin#2551](https://redirect.github.com/javalin/javalin/pull/2551) > > **Full Changelog**: <javalin/javalin@javalin-parent-7.0.1...javalin-parent-7.1.0> Commits * [`e458dba`](javalin/javalin@e458dba) [maven-release-plugin] prepare for next development iteration * [`9766d2f`](javalin/javalin@9766d2f) [maven-release-plugin] prepare release javalin-parent-7.1.0 * [`12acf0b`](javalin/javalin@12acf0b) [performance] Eliminate per-request regex and allocation overhead ([#2560](https://redirect.github.com/javalin/javalin/issues/2560)) * [`f6a1e40`](javalin/javalin@f6a1e40) [performance] Reduce per-request overhead in hot path * [`1e59eda`](javalin/javalin@1e59eda) [pom] Add javalin-bom module ([#2558](https://redirect.github.com/javalin/javalin/issues/2558)) * [`b43f37a`](javalin/javalin@b43f37a) [rendering] jte - introduce directoryTemplateEngine for (6.x-like behavior) * [`72b2320`](javalin/javalin@72b2320) [micrometer] Add `wsExceptionHandler` to `MicrometerPlugin` * [`37c91c4`](javalin/javalin@37c91c4) [readme] Update artifactId for SSL plugin * [`9acf45e`](javalin/javalin@9acf45e) [cleanup] Use Header constants * [`0289084`](javalin/javalin@0289084) [headers] Add missing headers to Header.kt * Additional commits viewable in [compare view](javalin/javalin@javalin-parent-7.0.1...7.1.0) Updates `io.javalin:javalin-testtools` from 7.0.1 to 7.1.0 Release notes *Sourced from [io.javalin:javalin-testtools's releases](https://github.com/javalin/javalin/releases).* > 7.1.0 > ----- > > What's Changed > -------------- > > * Bump com.fasterxml.jackson.core:jackson-core from 2.21.0 to 2.21.1 by [`@dependabot`](https://github.com/dependabot)[bot] in [javalin/javalin#2543](https://redirect.github.com/javalin/javalin/pull/2543) > * [deps]: Bump the dependencies group across 1 directory with 17 updates by [`@dependabot`](https://github.com/dependabot)[bot] in [javalin/javalin#2545](https://redirect.github.com/javalin/javalin/pull/2545) > * [websocket] Fix WebSocket over HTTP/2 Extended Connect (RFC 8441) by [`@tipsy`](https://github.com/tipsy) in [javalin/javalin#2547](https://redirect.github.com/javalin/javalin/pull/2547) > * fix(README): update artifactId for SSL plugin in `README.md` by [`@yvasyliev`](https://github.com/yvasyliev) in [javalin/javalin#2556](https://redirect.github.com/javalin/javalin/pull/2556) > * Add `wsExceptionHandler` to `MicrometerPlugin` for WebSocket exception tagging by [`@Copilot`](https://github.com/Copilot) in [javalin/javalin#2557](https://redirect.github.com/javalin/javalin/pull/2557) > * [rendering] jte - introduce directoryTemplateEngine for (6.x-like), rename default to classPathTemplateEngine by [`@elwin013`](https://github.com/elwin013) in [javalin/javalin#2551](https://redirect.github.com/javalin/javalin/pull/2551) > * Add javalin-bom module by [`@Copilot`](https://github.com/Copilot) in [javalin/javalin#2558](https://redirect.github.com/javalin/javalin/pull/2558) > * [performance] Reduce per-request overhead in hot path by [`@tipsy`](https://github.com/tipsy) in [javalin/javalin#2559](https://redirect.github.com/javalin/javalin/pull/2559) > * [performance] Eliminate per-request regex and allocation overhead by [`@tipsy`](https://github.com/tipsy) in [javalin/javalin#2560](https://redirect.github.com/javalin/javalin/pull/2560) > > New Contributors > ---------------- > > * [`@yvasyliev`](https://github.com/yvasyliev) made their first contribution in [javalin/javalin#2556](https://redirect.github.com/javalin/javalin/pull/2556) > * [`@elwin013`](https://github.com/elwin013) made their first contribution in [javalin/javalin#2551](https://redirect.github.com/javalin/javalin/pull/2551) > > **Full Changelog**: <javalin/javalin@javalin-parent-7.0.1...javalin-parent-7.1.0> Commits * [`e458dba`](javalin/javalin@e458dba) [maven-release-plugin] prepare for next development iteration * [`9766d2f`](javalin/javalin@9766d2f) [maven-release-plugin] prepare release javalin-parent-7.1.0 * [`12acf0b`](javalin/javalin@12acf0b) [performance] Eliminate per-request regex and allocation overhead ([#2560](https://redirect.github.com/javalin/javalin/issues/2560)) * [`f6a1e40`](javalin/javalin@f6a1e40) [performance] Reduce per-request overhead in hot path * [`1e59eda`](javalin/javalin@1e59eda) [pom] Add javalin-bom module ([#2558](https://redirect.github.com/javalin/javalin/issues/2558)) * [`b43f37a`](javalin/javalin@b43f37a) [rendering] jte - introduce directoryTemplateEngine for (6.x-like behavior) * [`72b2320`](javalin/javalin@72b2320) [micrometer] Add `wsExceptionHandler` to `MicrometerPlugin` * [`37c91c4`](javalin/javalin@37c91c4) [readme] Update artifactId for SSL plugin * [`9acf45e`](javalin/javalin@9acf45e) [cleanup] Use Header constants * [`0289084`](javalin/javalin@0289084) [headers] Add missing headers to Header.kt * Additional commits viewable in [compare view](javalin/javalin@javalin-parent-7.0.1...7.1.0) Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting `@dependabot rebase`. [//]: # (dependabot-automerge-start) [//]: # (dependabot-automerge-end) --- Dependabot commands and options You can trigger Dependabot actions by commenting on this PR: - `@dependabot rebase` will rebase this PR - `@dependabot recreate` will recreate this PR, overwriting any edits that have been made to it - `@dependabot show ignore conditions` will show all of the ignore conditions of the specified dependency - `@dependabot ignore this major version` will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this minor version` will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this dependency` will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)

tipsy force-pushed the javalin-performance-v2 branch from 08bb8a4 to d8cf339 Compare March 13, 2026 21:21

[performance] Remove unused matchAndExtract methods

fa8fa5f

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

augmentcode Bot reviewed Mar 13, 2026

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Comment thread javalin/src/main/java/io/javalin/http/servlet/JavalinServletContext.kt

[test] Add cache lifecycle test for route match caching

fb05b96

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

augmentcode Bot reviewed Mar 13, 2026

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tipsy merged commit f6a1e40 into master Mar 13, 2026
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tipsy deleted the javalin-performance-v2 branch March 13, 2026 22:05

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[performance] Reduce per-request overhead in hot path#2559

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