Add access to pipeline options during pipeline construction and translation.

sdks/python/apache_beam/options/pipeline_options_context.py

@@ -0,0 +1,65 @@
+#
+# 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.
+#
+
+"""Context-scoped access to pipeline options during graph construction and
+translation.
+
+This module provides thread-safe and async-safe access to globally-available
+instances of PipelineOptions using contextvars, scoped by the current pipeline.
+It allows components like transforms and coders to access the pipeline's
+configuration without requiring explicit parameter passing through every
+level of the call stack.
+
+For internal use only; no backwards-compatibility guarantees.
+"""
+
+from contextlib import contextmanager
+from contextvars import ContextVar
+from typing import TYPE_CHECKING
+from typing import Optional
+
+if TYPE_CHECKING:
+  from apache_beam.options.pipeline_options import PipelineOptions
+
+# The contextvar holding the current pipeline's options.
+# Each thread and each asyncio task gets its own isolated copy.
+_pipeline_options: ContextVar[Optional['PipelineOptions']] = ContextVar(
+    'pipeline_options', default=None)
+
+
+def get_pipeline_options() -> Optional['PipelineOptions']:
+  """Get the current pipeline's options from the context.
+
+  Returns:
+    The PipelineOptions for the currently executing pipeline operation,
+    or None if called outside of a pipeline context.
+  """
+  return _pipeline_options.get()
+
+
+@contextmanager
+def scoped_pipeline_options(options: Optional['PipelineOptions']):
+  """Context manager that sets pipeline options for the duration of a block.
+
+  Args:
+    options: The PipelineOptions to make available during this scope.
+  """
+  token = _pipeline_options.set(options)
+  try:
+    yield
+  finally:
+    _pipeline_options.reset(token)