Serializers

Serializer (ABC, Generic)

Base interface to inherit for all the serializers

Source code in melange/serializers/interfaces.py

class Serializer(ABC, Generic[T]):
    """
    Base interface to inherit for all the serializers
    """

    @staticmethod
    @abstractmethod
    def identifier() -> int:
        raise NotImplementedError

    def manifest(self, data: T) -> Optional[str]:
        """
        Given an object which represents some data, return the
        manifest of that object (if any)
        Args:
            data:

        Returns:
            The manifest of the object
        """
        return None

    def deserialize(self, data: str, manifest: Optional[str] = None) -> T:
        """
        Deserializes a data string. The manifest helps the serializer by
        providing information on how this object must be deserialized.
        Args:
            data: the data string to deserialize
            manifest: the manifest that corresponds to the serialized string

        Returns:
            The data object
        """
        pass

    def serialize(self, data: T) -> str:
        """
        Serializes and object to a string representation
        Args:
            data: the data object to serialize

        Returns:
            A string representation of the `data` object made with this serializer
        """
        pass

deserialize(self, data, manifest=None)

Deserializes a data string. The manifest helps the serializer by providing information on how this object must be deserialized.

Parameters:

Name	Type	Description	Default
data	str	the data string to deserialize	required
manifest	Optional[str]	the manifest that corresponds to the serialized string	None

Returns:

Type	Description
~T	The data object

Source code in melange/serializers/interfaces.py

def deserialize(self, data: str, manifest: Optional[str] = None) -> T:
    """
    Deserializes a data string. The manifest helps the serializer by
    providing information on how this object must be deserialized.
    Args:
        data: the data string to deserialize
        manifest: the manifest that corresponds to the serialized string

    Returns:
        The data object
    """
    pass

manifest(self, data)

Given an object which represents some data, return the manifest of that object (if any)

Parameters:

Name	Type	Description	Default
data	~T		required

Returns:

Type	Description
Optional[str]	The manifest of the object

Source code in melange/serializers/interfaces.py

def manifest(self, data: T) -> Optional[str]:
    """
    Given an object which represents some data, return the
    manifest of that object (if any)
    Args:
        data:

    Returns:
        The manifest of the object
    """
    return None

serialize(self, data)

Serializes and object to a string representation

Parameters:

Name	Type	Description	Default
data	~T	the data object to serialize	required

Returns:

Type	Description
str	A string representation of the data object made with this serializer

Source code in melange/serializers/interfaces.py

def serialize(self, data: T) -> str:
    """
    Serializes and object to a string representation
    Args:
        data: the data object to serialize

    Returns:
        A string representation of the `data` object made with this serializer
    """
    pass

JsonSerializer (Serializer)

Serializes and deserializes python dictionaries in json format

Source code in melange/serializers/json.py

class JsonSerializer(Serializer[Dict]):
    """
    Serializes and deserializes python dictionaries in json format
    """

    @staticmethod
    def identifier() -> int:
        return 1

    def manifest(self, data: Dict) -> str:
        return "json"

    def deserialize(self, serialized_data: str, manifest: Optional[str] = None) -> Dict:
        data = json.loads(serialized_data)
        return data

    def serialize(self, data: Dict) -> str:
        return json.dumps(data)

deserialize(self, serialized_data, manifest=None)

Deserializes a data string. The manifest helps the serializer by providing information on how this object must be deserialized.

Parameters:

Name	Type	Description	Default
data		the data string to deserialize	required
manifest	Optional[str]	the manifest that corresponds to the serialized string	None

Returns:

Type	Description
Dict	The data object

Source code in melange/serializers/json.py

def deserialize(self, serialized_data: str, manifest: Optional[str] = None) -> Dict:
    data = json.loads(serialized_data)
    return data

manifest(self, data)

Given an object which represents some data, return the manifest of that object (if any)

Parameters:

Name	Type	Description	Default
data	Dict		required

Returns:

Type	Description
str	The manifest of the object

Source code in melange/serializers/json.py

def manifest(self, data: Dict) -> str:
    return "json"

serialize(self, data)

Serializes and object to a string representation

Parameters:

Name	Type	Description	Default
data	Dict	the data object to serialize	required

Returns:

Type	Description
str	A string representation of the data object made with this serializer

Source code in melange/serializers/json.py

def serialize(self, data: Dict) -> str:
    return json.dumps(data)

PickleSerializer (Serializer)

Serializes DomainEvents with pickle.

Source code in melange/serializers/pickle.py

class PickleSerializer(Serializer[DomainEvent]):
    """
    Serializes DomainEvents with pickle.
    """

    @staticmethod
    def identifier() -> int:
        return 2

    def manifest(self, data: DomainEvent) -> str:
        return data.__class__.__qualname__

    def deserialize(self, data: str, manifest: Optional[str] = None) -> DomainEvent:
        return pickle.loads(codecs.decode(data.encode(), "base64"))

    def serialize(self, data: DomainEvent) -> str:
        return codecs.encode(pickle.dumps(data), "base64").decode()

deserialize(self, data, manifest=None)

Deserializes a data string. The manifest helps the serializer by providing information on how this object must be deserialized.

Parameters:

Name	Type	Description	Default
data	str	the data string to deserialize	required
manifest	Optional[str]	the manifest that corresponds to the serialized string	None

Returns:

Type	Description
DomainEvent	The data object

Source code in melange/serializers/pickle.py

def deserialize(self, data: str, manifest: Optional[str] = None) -> DomainEvent:
    return pickle.loads(codecs.decode(data.encode(), "base64"))

manifest(self, data)

Given an object which represents some data, return the manifest of that object (if any)

Parameters:

Name	Type	Description	Default
data	DomainEvent		required

Returns:

Type	Description
str	The manifest of the object

Source code in melange/serializers/pickle.py

def manifest(self, data: DomainEvent) -> str:
    return data.__class__.__qualname__

serialize(self, data)

Serializes and object to a string representation

Parameters:

Name	Type	Description	Default
data	DomainEvent	the data object to serialize	required

Returns:

Type	Description
str	A string representation of the data object made with this serializer

Source code in melange/serializers/pickle.py

def serialize(self, data: DomainEvent) -> str:
    return codecs.encode(pickle.dumps(data), "base64").decode()