Source code for pyflink.common.serialization

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from pyflink.common.utils import JavaObjectWrapper
from pyflink.java_gateway import get_gateway

__all__ = [
    'SerializationSchema',
    'DeserializationSchema',
    'SimpleStringSchema',
    'Encoder',
    'BulkWriterFactory'
]


[docs]class SerializationSchema(object): """ Base class for SerializationSchema. The serialization schema describes how to turn a data object into a different serialized representation. Most data sinks (for example Apache Kafka) require the data to be handed to them in a specific format (for example as byte strings). """ def __init__(self, j_serialization_schema=None): self._j_serialization_schema = j_serialization_schema
[docs]class DeserializationSchema(object): """ Base class for DeserializationSchema. The deserialization schema describes how to turn the byte messages delivered by certain data sources (for example Apache Kafka) into data types (Java/ Scala objects) that are processed by Flink. In addition, the DeserializationSchema describes the produced type which lets Flink create internal serializers and structures to handle the type. """ def __init__(self, j_deserialization_schema=None): self._j_deserialization_schema = j_deserialization_schema
[docs]class SimpleStringSchema(SerializationSchema, DeserializationSchema): """ Very simple serialization/deserialization schema for strings. By default, the serializer uses 'UTF-8' for string/byte conversion. """ def __init__(self, charset: str = 'UTF-8'): gate_way = get_gateway() j_char_set = gate_way.jvm.java.nio.charset.Charset.forName(charset) j_simple_string_serialization_schema = gate_way \ .jvm.org.apache.flink.api.common.serialization.SimpleStringSchema(j_char_set) SerializationSchema.__init__(self, j_serialization_schema=j_simple_string_serialization_schema) DeserializationSchema.__init__( self, j_deserialization_schema=j_simple_string_serialization_schema)
[docs]class Encoder(object): """ Encoder is used by the file sink to perform the actual writing of the incoming elements to the files in a bucket. """ def __init__(self, j_encoder): self._j_encoder = j_encoder @staticmethod def simple_string_encoder(charset_name: str = "UTF-8") -> 'Encoder': """ A simple Encoder that uses toString() on the input elements and writes them to the output bucket file separated by newline. """ j_encoder = get_gateway().jvm.org.apache.flink.api.common.serialization.\ SimpleStringEncoder(charset_name) return Encoder(j_encoder)
[docs]class BulkWriterFactory(JavaObjectWrapper): """ The Python wrapper of Java BulkWriter.Factory interface, which is the base interface for data sinks that write records into files in a bulk manner. """ def __init__(self, j_bulk_writer_factory): super().__init__(j_bulk_writer_factory)
[docs]class RowDataBulkWriterFactory(BulkWriterFactory): """ A :class:`´Ż×BulkWriterFactory` that receives records with RowData type. This is for indicating that Row record from Python must be first converted to RowData. """ def __init__(self, j_bulk_writer_factory, row_type): super().__init__(j_bulk_writer_factory) self._row_type = row_type def get_row_type(self): return self._row_type