[Streaming] Streaming data transfer and python integration (#6185)

streaming/python/config.py

@@ -0,0 +1,23 @@
+class Config:
+    STREAMING_JOB_NAME = "streaming.job.name"
+    STREAMING_OP_NAME = "streaming.op_name"
+    TASK_JOB_ID = "streaming.task_job_id"
+    STREAMING_WORKER_NAME = "streaming.worker_name"
+    # channel
+    CHANNEL_TYPE = "channel_type"
+    MEMORY_CHANNEL = "memory_channel"
+    NATIVE_CHANNEL = "native_channel"
+    CHANNEL_SIZE = "channel_size"
+    CHANNEL_SIZE_DEFAULT = 10**8
+    IS_RECREATE = "streaming.is_recreate"
+    # return from StreamingReader.getBundle if only empty message read in this
+    # interval.
+    TIMER_INTERVAL_MS = "timer_interval_ms"
+
+    STREAMING_RING_BUFFER_CAPACITY = "streaming.ring_buffer_capacity"
+    # write an empty message if there is no data to be written in this
+    # interval.
+    STREAMING_EMPTY_MESSAGE_INTERVAL = "streaming.empty_message_interval"
+
+    # operator type
+    OPERATOR_TYPE = "operator_type"