fix: Use correct parsing for stackframes

[noahsmartin]

Fixes https://github.com/getsentry/sentry-cocoa/issues/4040

The problem was that for some events such as app hangs and CPUDiagnostics the metric kit payload contains an entire flamegraph. This change parses the flame graph into samples, and then picks the longest duration sample as the one we use for a stack trace. It also fixes over-counting the CPUDiagnostics which was emitting more than one event per exception. This is also fixed by identifying the longest duration sample.

Eventually we should support showing the full flame graph on the frontend, but with this PR the bug is fixed and we can consider that a future improvement.

I tested this on test flight by triggering crashes and verifying they are still correct, as well as manually replaying hang reports received in production

[codecov[bot]]

Codecov Report

:white_check_mark: All modified and coverable lines are covered by tests. :white_check_mark: Project coverage is 84.895%. Comparing base (6c20265) to head (ac40ad2). :warning: Report is 7 commits behind head on main. :white_check_mark: All tests successful. No failed tests found.

Additional details and impacted files

@@              Coverage Diff              @@
##              main     #6908       +/-   ##
=============================================
- Coverage   84.968%   84.895%   -0.073%     
=============================================
  Files          457       459        +2     
  Lines        27608     27575       -33     
  Branches     12142     12145        +3     
=============================================
- Hits         23458     23410       -48     
- Misses        4109      4126       +17     
+ Partials        41        39        -2     

Files with missing lines	Coverage Δ
Sources/Sentry/SentryFormatterSwift.m	100.000% <100.000%> (ø)
Sources/Sentry/SentryMetricKitIntegration.m	100.000% <100.000%> (ø)
...Core/MetricKit/SentryMXCallStackTree+Parsing.swift	100.000% <100.000%> (ø)
...s/Swift/Core/MetricKit/SentryMXCallStackTree.swift	100.000% <ø> (+25.000%)	:arrow_up:
Sources/Swift/Core/MetricKit/SentryMXManager.swift	100.000% <100.000%> (ø)

... and 18 files with indirect coverage changes

---

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[github-actions[bot]]

Performance metrics :rocket:

	Plain	With Sentry	Diff
Startup time	1192.81 ms	1220.30 ms	27.49 ms
Size	24.14 KiB	1.03 MiB	1.01 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
af848c439ac97ab7850767f9f49d7a935b511cd9	1224.02 ms	1251.00 ms	26.98 ms
2ec27000f0f0c2e2b99104488c080e9b6ea6fea2	1238.28 ms	1258.82 ms	20.53 ms
b358363efd7e81b5a9e0ecb3ee7daf003dba6754	1228.33 ms	1262.34 ms	34.01 ms
dcaec4e4f4f31a02aa5c5c409308dcc9eb9c7a0c	1209.06 ms	1246.02 ms	36.96 ms
5ff1b04b314290120c468597d0d1add73e15bf04	1226.00 ms	1259.98 ms	33.98 ms
1b9991e062e58b3eca64ce9b3a4ced2a8ca0aae2	1233.45 ms	1256.61 ms	23.17 ms
f8cad3cab6dfd77a717640313a4208d27fc41b54	1217.94 ms	1257.96 ms	40.02 ms
5cfc76877e04e23aca2f156286738a33882cd485	1220.74 ms	1245.06 ms	24.32 ms
650d8026fd8bf70270211b709910dfe2454660a4	1231.86 ms	1255.64 ms	23.78 ms
5ec90e0df18400cbc7615eb74351d1c74216ed59	1235.57 ms	1258.45 ms	22.88 ms

App size

Revision	Plain	With Sentry	Diff
af848c439ac97ab7850767f9f49d7a935b511cd9	24.14 KiB	1.01 MiB	1012.94 KiB
2ec27000f0f0c2e2b99104488c080e9b6ea6fea2	23.75 KiB	980.80 KiB	957.05 KiB
b358363efd7e81b5a9e0ecb3ee7daf003dba6754	23.75 KiB	987.92 KiB	964.18 KiB
dcaec4e4f4f31a02aa5c5c409308dcc9eb9c7a0c	24.15 KiB	1.01 MiB	1014.80 KiB
5ff1b04b314290120c468597d0d1add73e15bf04	23.75 KiB	1.01 MiB	1016.24 KiB
1b9991e062e58b3eca64ce9b3a4ced2a8ca0aae2	23.75 KiB	908.01 KiB	884.26 KiB
f8cad3cab6dfd77a717640313a4208d27fc41b54	23.75 KiB	1.01 MiB	1016.13 KiB
5cfc76877e04e23aca2f156286738a33882cd485	23.75 KiB	850.73 KiB	826.98 KiB
650d8026fd8bf70270211b709910dfe2454660a4	23.74 KiB	913.13 KiB	889.39 KiB
5ec90e0df18400cbc7615eb74351d1c74216ed59	23.74 KiB	872.67 KiB	848.92 KiB

Previous results on branch: mxRewriting

Startup times

Revision	Plain	With Sentry	Diff
c20c3c1f7ebc95d803b37d1eff568f5cd84a68a8	1209.08 ms	1237.69 ms	28.61 ms
d0cf095ad820ba9dbe4396a4edff95dd803fbd8b	1225.92 ms	1255.11 ms	29.20 ms
44da6c5a9de2260920863120d24ab1b21dab708c	1234.22 ms	1266.02 ms	31.80 ms
bf3e24564ad2afafb07f1064d327a0fbe64e8d9b	1222.17 ms	1257.09 ms	34.92 ms
793ffeaa475333263edbabfadf1bff06fbf0252f	1229.79 ms	1264.65 ms	34.86 ms
c5b3f7a87064b019b3bd371c44a595ef4661f184	1220.18 ms	1259.44 ms	39.25 ms
f3b889c5cc28f02df8c3fee53c2e06a4bd5efeea	1221.57 ms	1252.77 ms	31.20 ms
8824c94ec3da9a676607b441f388cab6a1913f56	1226.98 ms	1262.65 ms	35.67 ms

App size

Revision	Plain	With Sentry	Diff
c20c3c1f7ebc95d803b37d1eff568f5cd84a68a8	24.14 KiB	1.03 MiB	1.01 MiB
d0cf095ad820ba9dbe4396a4edff95dd803fbd8b	24.14 KiB	1.03 MiB	1.01 MiB
44da6c5a9de2260920863120d24ab1b21dab708c	24.14 KiB	1.03 MiB	1.00 MiB
bf3e24564ad2afafb07f1064d327a0fbe64e8d9b	24.14 KiB	1.03 MiB	1.00 MiB
793ffeaa475333263edbabfadf1bff06fbf0252f	24.14 KiB	1.03 MiB	1.00 MiB
c5b3f7a87064b019b3bd371c44a595ef4661f184	24.14 KiB	1.01 MiB	1013.45 KiB
f3b889c5cc28f02df8c3fee53c2e06a4bd5efeea	24.14 KiB	1.03 MiB	1.01 MiB
8824c94ec3da9a676607b441f388cab6a1913f56	24.14 KiB	1.01 MiB	1014.88 KiB

[noahsmartin]

Thanks @philipphofmann this is ready for another look!