Automatic removal of unreachable static chunks

[teh-cmc]

Unreachable static chunks are dead weight: there exists no query that can access their data (at least when using Rerun as a Visualizer).

By automatically removing dangling chunks, we make it possible for user to use the Rerun Viewer as a soft-realtime telemetry system (provided we properly invalidate our caches too, which is the subject of an upcoming PR).

This raises the question of what should happen when using Rerun as a database: should this data be kept and made accessible?
If so, this behavior should probably be made configurable (e.g. when instantiating a ChunkStore in the SDK).

• Part of static=True image logging still stores all the data #7404

---

Test:

from pathlib import Path

import rerun as rr

image_file_path = Path(__file__).parent / "ferris.png"

rr.init("rerun_example_encoded_image", spawn=True)

for _ in range(0, 10):
    rr.log("image", rr.EncodedImage(path=image_file_path), static=True)

Command:

RERUN_FLUSH_NUM_ROWS=0 python test.py

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After:

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[Wumpf]

so but what if I have a static image+mediatype and then were to override only the image? Then I'd always keep the first image+mediatype chunk around?

[teh-cmc]

so but what if I have a static image+mediatype and then were to override only the image? Then I'd always keep the first image+mediatype chunk around?

This is the subject of the next PR, but spoiler: no, if you overwrite the buffer, you'll drop every different media-type instantiations of that image..!