[GitHub] [flink] Vancior commented on a diff in pull request #19453: [FLINK-26477][python] Support side output in PyFlink DataStream API

[GitBox <gi...@apache.org>]

Vancior commented on code in PR #19453:
URL: https://github.com/apache/flink/pull/19453#discussion_r851847821


##########
flink-python/pyflink/datastream/output_tag.py:
##########
@@ -0,0 +1,50 @@
+################################################################################
+#  Licensed to the Apache Software Foundation (ASF) under one
+#  or more contributor license agreements.  See the NOTICE file
+#  distributed with this work for additional information
+#  regarding copyright ownership.  The ASF licenses this file
+#  to you under the Apache License, Version 2.0 (the
+#  "License"); you may not use this file except in compliance
+#  with the License.  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+# limitations under the License.
+################################################################################
+from pyflink.common.typeinfo import TypeInformation, Types, RowTypeInfo
+from pyflink.java_gateway import get_gateway
+
+
+class OutputTag(object):
+    """
+    An :class:`OutputTag` is a typed and named tag to use for tagging side outputs of an operator.
+
+    Example:
+    ::
+
+        >>> info = OutputTag("late-data", Types.TUPLE([Types.STRING(), Types.LONG()]))
+
+    """
+
+    def __init__(self, tag_id: str, type_info: TypeInformation = None):
+        if tag_id == "":
+            raise ValueError("tag_id cannot be empty string")
+        self.tag_id = tag_id
+        if type_info is None:
+            self.type_info = Types.PICKLED_BYTE_ARRAY()
+        elif isinstance(type_info, list):
+            self.type_info = RowTypeInfo(type_info)
+        else:
+            self.type_info = type_info
+
+    def get_java_output_tag(self):
+        gateway = get_gateway()
+        j_obj = gateway.jvm.org.apache.flink.util.OutputTag(self.tag_id,
+                                                            self.type_info.get_java_type_info())
+        # deal with serializability
+        self.type_info._j_typeinfo = None

Review Comment:
   A tag might be serialized into a UDF after getting its java type info, and the serialization would fail since it contains a py4j reference which has a thread lock.



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: issues-unsubscribe@flink.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org