Source Code for Module pyspark.storagelevel

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17   
18  __all__ = ["StorageLevel"] 
19   
20   
21 -class StorageLevel: 
22   
23      """ 
24      Flags for controlling the storage of an RDD. Each StorageLevel records whether to use memory, 
25      whether to drop the RDD to disk if it falls out of memory, whether to keep the data in memory 
26      in a serialized format, and whether to replicate the RDD partitions on multiple nodes. 
27      Also contains static constants for some commonly used storage levels, such as MEMORY_ONLY. 
28      """ 
29   
30 -    def __init__(self, useDisk, useMemory, useOffHeap, deserialized, replication=1): 
31          self.useDisk = useDisk 
32          self.useMemory = useMemory 
33          self.useOffHeap = useOffHeap 
34          self.deserialized = deserialized 
35          self.replication = replication 
36   
37 -    def __repr__(self): 
38          return "StorageLevel(%s, %s, %s, %s, %s)" % ( 
39              self.useDisk, self.useMemory, self.useOffHeap, self.deserialized, self.replication) 
40   
41 -    def __str__(self): 
42          result = "" 
43          result += "Disk " if self.useDisk else "" 
44          result += "Memory " if self.useMemory else "" 
45          result += "Tachyon " if self.useOffHeap else "" 
46          result += "Deserialized " if self.deserialized else "Serialized " 
47          result += "%sx Replicated" % self.replication 
48          return result 
49   
50  StorageLevel.DISK_ONLY = StorageLevel(True, False, False, False) 
51  StorageLevel.DISK_ONLY_2 = StorageLevel(True, False, False, False, 2) 
52  StorageLevel.MEMORY_ONLY = StorageLevel(False, True, False, True) 
53  StorageLevel.MEMORY_ONLY_2 = StorageLevel(False, True, False, True, 2) 
54  StorageLevel.MEMORY_ONLY_SER = StorageLevel(False, True, False, False) 
55  StorageLevel.MEMORY_ONLY_SER_2 = StorageLevel(False, True, False, False, 2) 
56  StorageLevel.MEMORY_AND_DISK = StorageLevel(True, True, False, True) 
57  StorageLevel.MEMORY_AND_DISK_2 = StorageLevel(True, True, False, True, 2) 
58  StorageLevel.MEMORY_AND_DISK_SER = StorageLevel(True, True, False, False) 
59  StorageLevel.MEMORY_AND_DISK_SER_2 = StorageLevel(True, True, False, False, 2) 
60  StorageLevel.OFF_HEAP = StorageLevel(False, False, True, False, 1) 
61