opencode/specs/10-global-sync-message-part-cleanup.md

GlobalSync message/part cleanup

Prevent stale message parts and per-session maps from accumulating

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Summary

packages/app/src/context/global-sync.tsx keeps per-directory child stores that include:

• message: { [sessionID]: Message[] }
• part: { [messageID]: Part[] }

Currently:

• message.removed removes the message from message[sessionID] but does not delete part[messageID].
• session.deleted / archived sessions remove the session from the list but do not clear message[...], part[...], session_diff[...], todo[...], etc.

This can retain large arrays long after they are no longer reachable from UI.

This spec adds explicit cleanup on the relevant events without changing cache strategy or introducing new cross-module eviction utilities.

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Scoped files (parallel-safe)

• packages/app/src/context/global-sync.tsx

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Goals

• Delete part[messageID] when a message is removed
• Clear per-session maps when a session is deleted or archived
• Keep changes limited to event handling in global-sync.tsx

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Non-goals

• Implementing LRU/TTL eviction across sessions/directories (separate work)
• Changing how sync.tsx or layout prefetch populates message caches

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Current state

• Message list and part map can diverge over time.
• Deleting/archiving sessions does not reclaim memory for message history, parts, diffs, todos, permissions, questions.

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Proposed approach

Add small helper functions inside createGlobalSync() to keep event handler readable:

• purgeMessageParts(setStore, messageID)
• purgeSessionData(store, setStore, sessionID)
  • delete message[sessionID]
  • for each known message in that list, delete part[messageID]
  • delete session_diff[sessionID], todo[sessionID], permission[sessionID], question[sessionID], session_status[sessionID]

Then wire these into the existing event switch:

• message.removed: after removing from message[sessionID], also delete part[messageID]
• session.updated when time.archived is set: call purgeSessionData(...)
• session.deleted: call purgeSessionData(...)

Notes:

• Use setStore(produce(...)) to delete object keys safely.
• Purge should be idempotent (safe if called when keys are missing).

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Implementation steps

1. Add purge helpers near the event listener in global-sync.tsx

2. Update event handlers

• message.removed
• session.updated (archived path)
• session.deleted

3. (Optional) Tighten message.part.removed

• If a part list becomes empty after removal, optionally delete part[messageID] as well.

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Acceptance criteria

• After a message.removed event, store.part[messageID] is undefined
• After session.deleted or archive, all per-session maps for that sessionID are removed
• No runtime errors when purging sessions/messages that were never hydrated

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Validation plan

• Manual:
  • Load a session with many messages
  • Trigger message delete/remove events (or simulate by calling handlers in dev)
  • Confirm the associated part entries are removed
  • Delete/archive a session and confirm globalSync store no longer holds its message/part data