Export StorageLevel and refactor

1 files changed, 43 insertions, 0 deletions

diff --git a/python/pyspark/storagelevel.py b/python/pyspark/storagelevel.py
new file mode 100644
index 0000000000..b31f4762e6
--- /dev/null
+++ b/python/pyspark/storagelevel.py
@@ -0,0 +1,43 @@
+#
+# 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.
+#
+
+__all__ = ["StorageLevel"]
+
+class StorageLevel:
+    """
+    Flags for controlling the storage of an RDD. Each StorageLevel records whether to use memory,
+    whether to drop the RDD to disk if it falls out of memory, whether to keep the data in memory
+    in a serialized format, and whether to replicate the RDD partitions on multiple nodes.
+    Also contains static constants for some commonly used storage levels, such as MEMORY_ONLY.
+    """
+
+    def __init__(self, useDisk, useMemory, deserialized, replication = 1):
+        self.useDisk = useDisk
+        self.useMemory = useMemory
+        self.deserialized = deserialized
+        self.replication = replication
+
+StorageLevel.DISK_ONLY = StorageLevel(True, False, False)
+StorageLevel.DISK_ONLY_2 = StorageLevel(True, False, False, 2)
+StorageLevel.MEMORY_ONLY = StorageLevel(False, True, True)
+StorageLevel.MEMORY_ONLY_2 = StorageLevel(False, True, True, 2)
+StorageLevel.MEMORY_ONLY_SER = StorageLevel(False, True, False)
+StorageLevel.MEMORY_ONLY_SER_2 = StorageLevel(False, True, False, 2)
+StorageLevel.MEMORY_AND_DISK = StorageLevel(True, True, True)
+StorageLevel.MEMORY_AND_DISK_2 = StorageLevel(True, True, True, 2)
+StorageLevel.MEMORY_AND_DISK_SER = StorageLevel(True, True, False)
+StorageLevel.MEMORY_AND_DISK_SER_2 = StorageLevel(True, True, False, 2)