Avro serdes support

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "quixstreams"
-dynamic = ["version", "dependencies", "optional-dependencies"]
+dynamic = ["version", "dependencies"]
 description = "Python library for building stream processing applications with Apache Kafka"
 license = {file = "LICENSE"}
 readme = "README.md"
@@ -26,6 +26,13 @@ classifiers = [
 [project.urls]
 Homepage = "https://github.com/quixio/quix-streams"
 
+[project.optional-dependencies]
+all = [
+  "fastavro"
+]
+
+avro = ["fastavro"]
+
 [tool.setuptools.packages.find]
 include = ["quixstreams*"]
 exclude = ["tests*", "docs*", "examples*"]

quixstreams/models/serializers/avro.py

@@ -0,0 +1,58 @@
+from typing import Union, Mapping, Optional, Any, Iterable
+
+from io import BytesIO
+
+from fastavro import schemaless_reader, schemaless_writer, parse_schema
+from fastavro.types import Schema
+
+from .base import Serializer, Deserializer, SerializationContext
+from .exceptions import SerializationError
+
+__all__ = ("AvroSerializer", "AvroDeserializer")
+
+
+class AvroSerializer(Serializer):
+    def __init__(self, schema: Schema, **kwargs):
+        """
+        Serializer that returns data in Avro format.
+
+        Additional keyword arguments are passed directly to fastavro [schemaless_writer](https://fastavro.readthedocs.io/en/latest/writer.html#fastavro._write_py.schemaless_writer) method.
+
+        :param schema: The avro schema.
+        """
+        self._schema = parse_schema(schema)
+        self._kwargs = kwargs or {}
+
+    def __call__(self, value: Any, ctx: SerializationContext) -> bytes:
+        data = BytesIO()
+
+        try:
+            schemaless_writer(data, self._schema, value, self._kwargs)
+        except ValueError as exc:
+            raise SerializationError(str(exc)) from exc
+
+        result = data.getvalue()
+        data.close()
+        return result
+
+
+class AvroDeserializer(Deserializer):
+    def __init__(self, schema: Schema, **kwargs):
+        """
+        Deserializer that parses data from Avro.
+
+        Additional keyword arguments are passed directly to fastavro [schemaless_reader](https://fastavro.readthedocs.io/en/latest/reader.html#fastavro._read_py.schemaless_reader) method.
+
+        :param schema: The Avro schema.
+        """
+        super().__init__()
+        self._schema = parse_schema(schema)
+        self._kwargs = kwargs or {}
+
+    def __call__(
+        self, value: bytes, ctx: SerializationContext
+    ) -> Union[Iterable[Mapping], Mapping]:
+        try:
+            return schemaless_reader(BytesIO(value), self._schema, **self._kwargs)
+        except EOFError as exc:
+            raise SerializationError(str(exc)) from exc

tests/requirements.txt

@@ -3,3 +3,4 @@ testcontainers==4.5.1; python_version >= '3.9'
 pytest
 requests>=2.32
 docker>=7.1.0 # Required to use requests>=2.32
+fastavro

tests/test_quixstreams/test_models/test_serializers.py

@@ -18,6 +18,17 @@
 )
 from .utils import int_to_bytes, float_to_bytes
 
+from quixstreams.models.serializers.avro import AvroDeserializer, AvroSerializer
+
+AVRO_TEST_SCHEMA = {
+    "type": "record",
+    "name": "testschema",
+    "fields": [
+        {"name": "name", "type": "string"},
+        {"name": "id", "type": "int", "default": 0},
+    ],
+}
+
 dummy_context = SerializationContext(topic="topic")
 
 
@@ -34,6 +45,12 @@ class TestSerializers:
             (BytesSerializer(), b"abc", b"abc"),
             (JSONSerializer(), {"a": 123}, b'{"a":123}'),
             (JSONSerializer(), [1, 2, 3], b"[1,2,3]"),
+            (
+                AvroSerializer(AVRO_TEST_SCHEMA),
+                {"name": "foo", "id": 123},
+                b"\x06foo\xf6\x01",
+            ),
+            (AvroSerializer(AVRO_TEST_SCHEMA), {"name": "foo"}, b"\x06foo\x00"),
         ],
     )
     def test_serialize_success(self, serializer: Serializer, value, expected):
@@ -50,6 +67,9 @@ def test_serialize_success(self, serializer: Serializer, value, expected):
             (StringSerializer(), {"a": 123}),
             (JSONSerializer(), object()),
             (JSONSerializer(), complex(1, 2)),
+            (AvroSerializer(AVRO_TEST_SCHEMA), {"foo": "foo", "id": 123}),
+            (AvroSerializer(AVRO_TEST_SCHEMA), {"id": 123}),
+            (AvroSerializer(AVRO_TEST_SCHEMA, strict=True), {"name": "foo"}),
         ],
     )
     def test_serialize_error(self, serializer: Serializer, value):
@@ -70,6 +90,16 @@ class TestDeserializers:
             (BytesDeserializer(), b"123123", b"123123"),
             (JSONDeserializer(), b"123123", 123123),
             (JSONDeserializer(), b'{"a":"b"}', {"a": "b"}),
+            (
+                AvroDeserializer(AVRO_TEST_SCHEMA),
+                b"\x06foo\xf6\x01",
+                {"name": "foo", "id": 123},
+            ),
+            (
+                AvroDeserializer(AVRO_TEST_SCHEMA),
+                b"\x06foo\x00",
+                {"name": "foo", "id": 0},
+            ),
         ],
     )
     def test_deserialize_no_column_name_success(
@@ -84,6 +114,7 @@ def test_deserialize_no_column_name_success(
             (IntegerDeserializer(), b'{"abc": "abc"}'),
             (DoubleDeserializer(), b"abc"),
             (JSONDeserializer(), b"{"),
+            (AvroDeserializer(AVRO_TEST_SCHEMA), b"\x26foo\x00"),
         ],
     )
     def test_deserialize_error(self, deserializer: Deserializer, value):