5.5 Value Operations

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5.5.1 RSI_QUERY_VALUES #

Returns every layer's entry for one value, or for all of a key's values when the request sets the query-all flag:

-- single value
SELECT name, layer, type, data, sequence
FROM main.[values] WHERE key_guid = ? AND name_folded = ?
UNION ALL
SELECT name, layer, type, data, sequence
FROM volatile.[values] WHERE key_guid = ? AND name_folded = ?

-- query all
SELECT name, layer, type, data, sequence
FROM main.[values] WHERE key_guid = ?
UNION ALL
SELECT name, layer, type, data, sequence
FROM volatile.[values] WHERE key_guid = ?

The response also carries the key's blanket-tombstone state:

SELECT layer, sequence
FROM main.blanket_tombstones WHERE key_guid = ?
UNION ALL
SELECT layer, sequence
FROM volatile.blanket_tombstones WHERE key_guid = ?

Value entries are sorted; blanket tombstones are not (§5.2).

An unresolvable GUID returns RSI_NOT_FOUND. An existing key with no values returns RSI_OK with empty arrays.

5.5.2 RSI_SET_VALUE #

The key's volatile flag selects the store; a key GUID in neither store returns RSI_NOT_FOUND.

INSERT OR REPLACE INTO [values]
    (key_guid, name, name_folded, layer, type, data, sequence)
VALUES (?, ?, fold(?), ?, ?, ?, ?)

5.5.2.1 Conditional writes #

When the request carries a non-zero expected_sequence, the write is a compare-and-swap. loregd reads the current entry's sequence and writes only if it matches:

SELECT sequence FROM [values]
WHERE key_guid = ? AND name_folded = ? AND layer = ?

If the row is absent, or its sequence differs, the operation returns RSI_CAS_FAILED and writes nothing.

Outside a transaction, the check and the write are wrapped in their own BEGIN IMMEDIATE transaction so no other writer can interleave; if that transaction cannot begin because the database is busy, the operation returns RSI_TXN_BUSY. Inside a transaction, the caller's transaction already provides the isolation.

5.5.3 RSI_DELETE_VALUE_ENTRY #

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

DELETE FROM [values]
WHERE key_guid = ? AND name_folded = ? AND layer = ?

No rows-affected check, so deleting an absent entry succeeds. A GUID that resolves to no hive returns RSI_NOT_FOUND.

5.5.4 RSI_SET_BLANKET_TOMBSTONE #

Sets or clears the tombstone that masks every value a key holds in lower layers. The key's volatile flag selects the store, and a GUID in neither returns RSI_NOT_FOUND.

-- set
INSERT OR REPLACE INTO blanket_tombstones (key_guid, layer, sequence)
VALUES (?, ?, ?)

-- clear
DELETE FROM blanket_tombstones WHERE key_guid = ? AND layer = ?

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