docs(session-persistence): tighten SQLite permission prose

This commit is contained in:
Tianyi Cui
2026-07-19 11:37:41 +08:00
parent 7ba5b95d8e
commit 85fc58943e
4 changed files with 20 additions and 15 deletions
@@ -10,7 +10,9 @@ A SQLite durable session-persistence backend — a second `SessionPersistence` i
Each `SessionEvent` maps 1:1 onto a row in an `events` table `(session_id, seq, type, time, data, source_event_seqs, surface_op)``data` is the event payload as JSON text, so the row shape is the event verbatim (including `assistant/chunk`, keeping `seq` contiguous). The two `TEXT` columns `source_event_seqs` and `surface_op` are nullable; they store the event's optional surface-metadata fields (see [session surface](../../../docs/rfc/implemented/architecture/2026-06-18-session-surface.md)). Out-of-log metadata (`SessionHeader`) lives in a `sessions` row. A `sessions` row is written only by the first `append` — its existence is the lazy-materialization signal (`list` reports exactly the sessions that have a row), so no separate column is needed.
The repository's Node range supports unflagged `node:sqlite`. The database enables foreign keys and uses the configured journal mode (`wal` by default; use a rollback mode where WAL shared-memory files are unsuitable). On filesystems with POSIX modes, missing directories are created as `0700` and a missing database is exclusively created as `0600` before SQLite opens it, causing new WAL sidecars to inherit owner-only access. Existing directories, database files, and sidecars keep their modes; ordinary filesystem access errors still fail initialization. This default prevents incidental exposure through the process umask; it does not protect database integrity when another principal can modify entries in an existing parent directory. `PRAGMA user_version` stores the table-layout version; databases with any other version are rejected because this unreleased format has no migrations.
The repository's Node range supports unflagged `node:sqlite`. The database enables foreign keys and uses the configured journal mode (`wal` by default; use a rollback mode where WAL shared-memory files are unsuitable). `PRAGMA user_version` stores the table-layout version; databases with any other version are rejected because this unreleased format has no migrations.
On filesystems with POSIX modes, the backend creates missing directories as `0700` and exclusively creates a missing database as `0600` before SQLite opens it. New WAL sidecars receive the database's owner-only mode. Existing directories, database files, and sidecars keep their modes; filesystem setup errors other than an existing database fail initialization. These defaults prevent incidental exposure through the process umask, but do not protect database integrity when another principal can replace the database entry in its parent directory.
## Contract semantics over rows