hget and hset commands using hashes internally, thus
they are not using the existing write_strings() function.
Limitations:
- hset only supports 3 params, instead of multiple field/value
list that is available in official redis-server.
- hset should return 0 when the key and field already exists,
but I am not sure it's possible to retrieve this information
without doing read-before-write, which would not be atomic.
I factorized a bit the query_* functions to reduce duplication, but
I am not 100% sure of the naming, it may still be a bit confusing
between the schema used (strings, hashes) and the returned format
(currently only string but array should come later with hgetall).
Signed-off-by: Etienne Adam <etienne.adam@gmail.com>
Message-Id: <20200830190128.18534-1-etienne.adam@gmail.com>