perf(core): [SDK Overhead reduction for JVM 1] Remove redundant event map copies

[adinauer]

PR Stack (SDK Overhead reduction for JVM)

• perf(core): SDK Overhead reduction for JVM #5535
• perf(core): [SDK Overhead reduction for JVM 1] Remove redundant event map copies #5536
• perf(core): [SDK Overhead reduction for JVM 2] Short-circuit combined scope breadcrumbs #5541
• perf(core): [SDK Overhead reduction for JVM 3] Reduce writer buffer size #5544

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📜 Description

Remove redundant intermediate HashMap copies when applying scope and options tags, and scope extras, to events.

The event setters still copy the provided maps, so this keeps event map containers isolated from the source scope/options maps while avoiding one temporary allocation per application path.

💡 Motivation and Context

This implements AR-04b from the SDK overhead reduction research. The previous code copied tags/extras before calling setters that already copy their input. Removing the extra copy reduces allocation overhead without exposing live scope or options maps to events.

💚 How did you test it?

• ./gradlew :sentry:test --tests io.sentry.SentryClientTest --tests io.sentry.MainEventProcessorTest --tests io.sentry.protocol.SentryBaseEventSerializationTest
• ./gradlew spotlessApply apiDump

📝 Checklist

• I added GH Issue ID & Linear ID
• I added tests to verify the changes.
• No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled.
• I updated the docs if needed.
• I updated the wizard if needed.
• Review from the native team if needed.
• No breaking change or entry added to the changelog.
• No breaking change for hybrid SDKs or communicated to hybrid SDKs.

🔮 Next steps

#skip-changelog

⚠️ Merge this PR using a merge commit (not squash). Only the collection branch is squash-merged into main.

[sentry]

📲 Install Builds

Android

🔗 App Name	App ID	Version	Configuration
SDK Size	io.sentry.tests.size	8.44.0 (1)	release

⚙️ sentry-android Build Distribution Settings

[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	313.57 ms	366.38 ms	52.81 ms
Size	0 B	0 B	0 B

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
a416a65	333.78 ms	410.37 ms	76.59 ms
d15471f	304.55 ms	408.43 ms	103.87 ms
ca6b6d8	380.45 ms	460.38 ms	79.93 ms
c8125f3	397.65 ms	485.14 ms	87.49 ms
b936425	302.69 ms	372.86 ms	70.17 ms
ed33deb	334.19 ms	362.30 ms	28.11 ms
cf708bd	408.35 ms	458.98 ms	50.63 ms
eb95ded	317.51 ms	369.08 ms	51.57 ms
a5ab36f	320.47 ms	389.77 ms	69.30 ms
80fd6ad	321.06 ms	375.79 ms	54.73 ms

App size

Revision	Plain	With Sentry	Diff
a416a65	1.58 MiB	2.12 MiB	555.26 KiB
d15471f	1.58 MiB	2.13 MiB	559.54 KiB
ca6b6d8	0 B	0 B	0 B
c8125f3	1.58 MiB	2.10 MiB	532.32 KiB
b936425	0 B	0 B	0 B
ed33deb	1.58 MiB	2.13 MiB	559.52 KiB
cf708bd	1.58 MiB	2.11 MiB	539.71 KiB
eb95ded	0 B	0 B	0 B
a5ab36f	1.58 MiB	2.12 MiB	555.26 KiB
80fd6ad	0 B	0 B	0 B

Previous results on branch: perf/sdk-overhead-jvm-map-copies-v2

Startup times

Revision	Plain	With Sentry	Diff
51ca2fb	312.13 ms	365.27 ms	53.14 ms

App size

Revision	Plain	With Sentry	Diff
51ca2fb	0 B	0 B	0 B