Bind Payloads to sqlite3

[qstokkink]

Using our existing tools, we can already bind Payload instances to sqlite3 databases:

import sqlite3
from dataclasses import dataclass

from ipv8.messaging.payload_dataclass import DataClassPayload
from ipv8.messaging.serialization import default_serializer


# 1. Typical Payload
@dataclass
class DBPayload(DataClassPayload):
    a: int
    b: str
    c: bool


# 2. Register it as a database type
sqlite3.register_adapter(DBPayload, default_serializer.pack_serializable)
sqlite3.register_converter("DBPayload", lambda s: default_serializer.unpack_serializable(DBPayload, s))

# == Demo/how to use ==

con = sqlite3.connect(":memory:", detect_types=sqlite3.PARSE_DECLTYPES)
cur = con.execute("CREATE TABLE mytable(p DBPayload)")

cur.execute("INSERT INTO mytable(p) VALUES(?)", (DBPayload(1, "2", False),))
cur.execute("SELECT p FROM mytable")

result, length = cur.fetchone()[0]
print(result)

cur.close()
con.close()

Output:

DBPayload
| a: 1
| b: '2'
| c: False

We could add this to our documentation or offer a 1-liner to register payloads with sqlite3.

Additionally, we could show how to convert the format list of a Payload into a row in the database