5.4 Path Entry Operations

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5.4.1 RSI_LOOKUP #

Returns every layer's entry for one child name under one parent, together with metadata for the keys those entries point at.

SELECT layer, target_type, target_guid, sequence
FROM main.path_entries
WHERE parent_guid = ? AND child_name_folded = ?
UNION ALL
SELECT layer, target_type, target_guid, sequence
FROM volatile.path_entries
WHERE parent_guid = ? AND child_name_folded = ?

HIDDEN entries are returned as entries but contribute no metadata GUID. For each distinct non-HIDDEN target_guid, loregd fetches the key's metadata — one query per GUID — and emits the blocks in ascending GUID order (§5.2).

loregd does no layer filtering and no resolution: every entry it holds is returned, and choosing between them is the kernel's job.

An unresolvable parent GUID returns RSI_NOT_FOUND.

If a path entry names a target_guid for which no key record exists, the metadata fetch finds nothing and the whole request fails with RSI_STORAGE_ERROR. This is reachable in ordinary operation: the kernel issues RSI_CREATE_ENTRY before RSI_CREATE_KEY, so a lookup landing between the two sees an entry whose key has not yet been written.

5.4.2 RSI_CREATE_ENTRY #

INSERT INTO path_entries
    (parent_guid, child_name, child_name_folded, layer,
     target_type, target_guid, sequence)
VALUES (?, ?, fold(?), ?, 0, ?, ?)

The target table follows the child key's volatile flag (§5.1); a child GUID in neither store lands in the persistent table.

RSI_ALREADY_EXISTS comes from the target table's primary key on (parent_guid, child_name_folded, layer). Since that key is per-schema, an identical entry in the other store does not collide, and the same triple can come to exist in both — in which case both rows are returned by lookups and enumerations (§5.1).

An unresolvable parent GUID returns RSI_NOT_FOUND.

5.4.3 RSI_HIDE_ENTRY #

Writes a tombstone that masks the same name in lower layers:

INSERT OR REPLACE INTO path_entries
    (parent_guid, child_name, child_name_folded, layer,
     target_type, target_guid, sequence)
VALUES (?, ?, fold(?), ?, 1, NULL, ?)

target_type is 1 and target_guid is null. The target table follows the parent key's volatile flag, because a volatile parent's entire subtree is volatile. A parent GUID in neither store returns RSI_NOT_FOUND.

5.4.4 RSI_DELETE_ENTRY #

Removes one layer's entry for one name, from both stores:

DELETE FROM path_entries
WHERE parent_guid = ? AND child_name_folded = ? AND layer = ?

No rows-affected check is made, so deleting an entry that is not there succeeds. A parent GUID that resolves to no hive returns RSI_NOT_FOUND rather than succeeding.

5.4.5 RSI_ENUM_CHILDREN #

Returns every layer's entry for every child under a parent:

SELECT child_name, child_name_folded, layer, target_type,
       target_guid, sequence
FROM main.path_entries WHERE parent_guid = ?
UNION ALL
SELECT child_name, child_name_folded, layer, target_type,
       target_guid, sequence
FROM volatile.path_entries WHERE parent_guid = ?

Rows are grouped by folded child name into one block per child, each carrying that child's per-layer entries. Metadata for the distinct non-HIDDEN target GUIDs is fetched and emitted exactly as for RSI_LOOKUP, and the same RSI_STORAGE_ERROR arises for an entry whose key record does not yet exist.

Ordering, and the treatment of two rows whose folded names match but whose stored case differs, are covered in §5.2.

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