DNS: ui: Heap Dump Explorer diffing#5826
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Wow exciting stuff! I'd love to test this but CI build seems to be failing. Will take a look immediately after the bot gives me a build! |
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Adds a baseline-vs-current diff mode to the Heap Dump Explorer with
per-tab diff views (Overview, Classes, Objects, Dominators, Bitmaps,
Strings, Arrays) and a same-trace flamegraph diff that paints each
node by Δ direction *while preserving the standard per-name palette
hue* — grew nodes saturate and darken, shrunk nodes lighten and
desaturate towards the background, unchanged nodes stay neutral, and
new nodes pop with a small saturation boost. The natural pprof-style
palette is intact so users see colour continuity between diff and
non-diff modes.
Both same-trace (two heap_graph snapshots in one .pftrace) and
cross-trace (separate primary + baseline .hprof or .pftrace files)
workflows are supported.
Changes vs. the upstream heap_diff branch (zezeozue/heap_diff):
- Fix engine-identity comparison in heap_dump_page.ts and
baseline/state.ts. Trace.engine returns a fresh per-access proxy via
createTraceProxy, so `getActiveBaseline()?.trace.engine === engine`
is always false and the same-trace flamegraph diff path never fired.
Use the stable `disposable === false` flag instead.
- Update header.ts to the new SegmentedButtons children-based API
(selectedValue + SegmentedButton vnodes) — the upstream branch was
written against the old `options:` prop and produced a runtime
error.
- Replace the absolute hsl(0, ...) / hsl(220, ...) red/blue diff
colouring with palette-modulated colours so each class keeps its
natural pprof-style hue and we only modulate saturation/lightness
to encode direction. Implemented in
ui/src/widgets/flamegraph.ts (new modulatePaletteScheme helper +
extended getColorSchemeFromHint signature) with the SQL emitting
'palette:DIR[:INTENSITY]' hints.
- Add tools/heap_dump_diff_test_app/HeapDumpDiffTest.java: a real
Java app that builds a deep, branchy Android-app-shaped object
graph (Application → ActivityManager → Activity → … → byte[]) and
captures two .hprof snapshots via HotSpotDiagnosticMXBean.dumpHeap
for the cross-trace diff workflow.
- Add tools/heap_dump_diff_test_app/build_rich_fixture.py: textproto
generator for the synthetic two-snapshot fixture used by the
same-trace flamegraph diff test.
- Add docs/heap_diff/{README.md,screenshots/}: end-to-end screenshots
of every diff tab and the primary-dump popup, captured against the
rich fixture and against real JVM hprofs (cross-trace screenshots
under cross_trace/).
Rebased onto current upstream/main so both the new
'Default to Heapdump Explorer' callout and the diff feature work
together.
Change-Id: I61f8e5e7f9988a89a7fd861b2e68ff9922568510
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matteozanettii
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Adds a baseline-vs-current diff mode to the Heap Dump Explorer, introducing per-tab diff views (Overview, Classes, Objects, Dominators, Bitmaps, Strings, Arrays). This supports both same-trace workflows (multiple snapshots in one file) and cross-trace workflows (separate primary and baseline files).
A key feature is the same-trace flamegraph diff, which paints each node by its Δ direction while preserving the standard per-name palette hue. Grown nodes saturate and darken, shrunk nodes lighten and desaturate, unchanged nodes stay neutral, and new nodes receive a saturation boost. This ensures natural pprof-style color continuity between diff and non-diff modes rather than relying on absolute red/blue diff coloring.