Module: migrations

Migrations between pydantic model versions, refer to Serialization and Migration

exception doubleratchet.migrations.InconsistentSerializationException

Bases: Exception

Raised by parse_double_ratchet_model() in case data migration from pre-stable serialization format is performed, and the data is structurally correct, but incomplete.

doubleratchet.migrations.parse_diffie_hellman_ratchet_model(serialized)

Parse a serialized DiffieHellmanRatchet instance, as returned by json, into the most recent pydantic model available for the class. Perform migrations in case the pydantic models were updated.

Parameters:

serialized (JSONObject) – The serialized instance.

Return type:

DiffieHellmanRatchetModel

Returns:

The model, which can be used to restore the instance using from_model().

Note

Pre-stable data can only be migrated as a whole using parse_double_ratchet_model().

doubleratchet.migrations.parse_double_ratchet_model(serialized)

Parse a serialized DoubleRatchet instance, as returned by json, into the most recent pydantic model available for the class. Perform migrations in case the pydantic models were updated. Supports migration of pre-stable data.

Parameters:

serialized (JSONObject) – The serialized instance.

Return type:

DoubleRatchetModel

Returns:

The model, which can be used to restore the instance using from_model().

Raises:

InconsistentSerializationException – if migration from pre-stable serialization format is performed, and the data is structurally correct, but incomplete. In pre-stable, it was possible to serialize instances which were not fully initialized yet. Those instances can be treated as non-existent and be replaced without losing information/messages.

Note

The pre-stable serialization format left it up to the user to implement serialization of key pairs. The migration code assumes the format used by pre-stable python-omemo and will raise an exception if a different format was used. In that case, the custom format has to be migrated first by the user.

doubleratchet.migrations.parse_kdf_chain_model(serialized)

Parse a serialized KDFChain instance, as returned by json, into the most recent pydantic model available for the class. Perform migrations in case the pydantic models were updated.

Parameters:

serialized (JSONObject) – The serialized instance.

Return type:

KDFChainModel

Returns:

The model, which can be used to restore the instance using from_model().

Note

Pre-stable data can only be migrated as a whole using parse_double_ratchet_model().

doubleratchet.migrations.parse_symmetric_key_ratchet_model(serialized)

Parse a serialized SymmetricKeyRatchet instance, as returned by json, into the most recent pydantic model available for the class. Perform migrations in case the pydantic models were updated.

Parameters:

serialized (JSONObject) – The serialized instance.

Return type:

SymmetricKeyRatchetModel

Returns:

The model, which can be used to restore the instance using from_model().

Note

Pre-stable data can only be migrated as a whole using parse_double_ratchet_model().