Put a key/value pair in the database. It is added if needed; if the key already exists, it is updated.
Request
----------------------------------------- | request | key length | key ----------------------------------------- 1 byte 2 bytes n bytes ----------------------------------------- | data length | data ----------------------------------------- 4 bytes n bytes
Response
---------- | answer | ---------- 1 byte
Sync/async
The response is meaningful only for synchronous requests.
- PUT: Can be synchronous or asynchronous.
- ADD: Can be synchronous or asynchronous.
- UPDATE: Synchronous only (not managed natively by LMDB, FineDB has to handle it using a transaction).