Handle event ring-buffer resizing safely in set_max_events

[priscaenoch]

Problem

The explorer contract stores decoded events in a ring buffer indexed by seq % max (see the slot computation in get_events/submit_event). set_max_events (explorer/src/lib.rs) validates only that the new value is at least MIN_MAX_EVENTS, then overwrites DataKey::MaxEvents. It does not remap existing entries. After a resize, seq % new_max points at different physical slots than the data was written to, so get_event/get_events return wrong, misordered, or missing events for everything already stored. This silently corrupts the readable history.

What needs to be done

• Define and implement safe resize semantics. Options, to be chosen and documented:
  • Rebuild/migrate the buffer contents into the new layout during set_max_events.
  • Or reset/clear the buffer on resize with an explicit event and documented consequence.
  • Or forbid resizing while the buffer is non-empty and require an explicit clear first.
• Ensure get_event/get_events remain correct across a resize.
• Extend the instance TTL on the write and emit an event describing the resize.

Files

• explorer/src/lib.rs

Acceptance deliverables

• Reads return correct, correctly ordered events before and after a resize (per the chosen, documented semantics).
• The resize behavior is documented in the README.
• All CI checks pass; the change cannot be merged until CI is green.

Tests to pass

• Test: write events, call set_max_events, then read back and assert the documented behavior (no silent corruption).
• Test: get_events ordering is correct after a resize.

[Ayinkx01]

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[Ayinkx01]

Hi i would like to work on this issue please assign to me
I can do it perfectly

[Ayinkx01]

Hi i would like to work on this issue please assign to me
I can do it perfectly