OSCL-LXR spark-3.0.0/​python/​pyspark/​taskcontext.py	Source navigation Diff markup Identifier search General search
	Version: spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 Revert   Change

 #
 # 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 __future__ import print_function
 import json
 
 from pyspark.java_gateway import local_connect_and_auth
 from pyspark.serializers import read_int, write_int, write_with_length, UTF8Deserializer
 
 
 class TaskContext(object):
 
     """
     Contextual information about a task which can be read or mutated during
     execution. To access the TaskContext for a running task, use:
     :meth:`TaskContext.get`.
     """
 
     _taskContext = None
 
     _attemptNumber = None
     _partitionId = None
     _stageId = None
     _taskAttemptId = None
     _localProperties = None
     _resources = None
 
     def __new__(cls):
         """Even if users construct TaskContext instead of using get, give them the singleton."""
         taskContext = cls._taskContext
         if taskContext is not None:
             return taskContext
         cls._taskContext = taskContext = object.__new__(cls)
         return taskContext
 
     @classmethod
     def _getOrCreate(cls):
         """Internal function to get or create global TaskContext."""
         if cls._taskContext is None:
             cls._taskContext = TaskContext()
         return cls._taskContext
 
     @classmethod
     def _setTaskContext(cls, taskContext):
         cls._taskContext = taskContext
 
     @classmethod
     def get(cls):
         """
         Return the currently active TaskContext. This can be called inside of
         user functions to access contextual information about running tasks.
 
         .. note:: Must be called on the worker, not the driver. Returns None if not initialized.
         """
         return cls._taskContext
 
     def stageId(self):
         """The ID of the stage that this task belong to."""
         return self._stageId
 
     def partitionId(self):
         """
         The ID of the RDD partition that is computed by this task.
         """
         return self._partitionId
 
     def attemptNumber(self):
         """"
         How many times this task has been attempted.  The first task attempt will be assigned
         attemptNumber = 0, and subsequent attempts will have increasing attempt numbers.
         """
         return self._attemptNumber
 
     def taskAttemptId(self):
         """
         An ID that is unique to this task attempt (within the same SparkContext, no two task
         attempts will share the same attempt ID).  This is roughly equivalent to Hadoop's
         TaskAttemptID.
         """
         return self._taskAttemptId
 
     def getLocalProperty(self, key):
         """
         Get a local property set upstream in the driver, or None if it is missing.
         """
         return self._localProperties.get(key, None)
 
     def resources(self):
         """
         Resources allocated to the task. The key is the resource name and the value is information
         about the resource.
         """
         return self._resources
 
 
 BARRIER_FUNCTION = 1
 ALL_GATHER_FUNCTION = 2
 
 
 def _load_from_socket(port, auth_secret, function, all_gather_message=None):
     """
     Load data from a given socket, this is a blocking method thus only return when the socket
     connection has been closed.
     """
     (sockfile, sock) = local_connect_and_auth(port, auth_secret)
 
     # The call may block forever, so no timeout
     sock.settimeout(None)
 
     if function == BARRIER_FUNCTION:
         # Make a barrier() function call.
         write_int(function, sockfile)
     elif function == ALL_GATHER_FUNCTION:
         # Make a all_gather() function call.
         write_int(function, sockfile)
         write_with_length(all_gather_message.encode("utf-8"), sockfile)
     else:
         raise ValueError("Unrecognized function type")
     sockfile.flush()
 
     # Collect result.
     len = read_int(sockfile)
     res = []
     for i in range(len):
         res.append(UTF8Deserializer().loads(sockfile))
 
     # Release resources.
     sockfile.close()
     sock.close()
 
     return res
 
 
 class BarrierTaskContext(TaskContext):
 
     """
     .. note:: Experimental
 
     A :class:`TaskContext` with extra contextual info and tooling for tasks in a barrier stage.
     Use :func:`BarrierTaskContext.get` to obtain the barrier context for a running barrier task.
 
     .. versionadded:: 2.4.0
     """
 
     _port = None
     _secret = None
 
     @classmethod
     def _getOrCreate(cls):
         """
         Internal function to get or create global BarrierTaskContext. We need to make sure
         BarrierTaskContext is returned from here because it is needed in python worker reuse
         scenario, see SPARK-25921 for more details.
         """
         if not isinstance(cls._taskContext, BarrierTaskContext):
             cls._taskContext = object.__new__(cls)
         return cls._taskContext
 
     @classmethod
     def get(cls):
         """
         .. note:: Experimental
 
         Return the currently active :class:`BarrierTaskContext`.
         This can be called inside of user functions to access contextual information about
         running tasks.
 
         .. note:: Must be called on the worker, not the driver. Returns None if not initialized.
             An Exception will raise if it is not in a barrier stage.
         """
         if not isinstance(cls._taskContext, BarrierTaskContext):
             raise Exception('It is not in a barrier stage')
         return cls._taskContext
 
     @classmethod
     def _initialize(cls, port, secret):
         """
         Initialize BarrierTaskContext, other methods within BarrierTaskContext can only be called
         after BarrierTaskContext is initialized.
         """
         cls._port = port
         cls._secret = secret
 
     def barrier(self):
         """
         .. note:: Experimental
 
         Sets a global barrier and waits until all tasks in this stage hit this barrier.
         Similar to `MPI_Barrier` function in MPI, this function blocks until all tasks
         in the same stage have reached this routine.
 
         .. warning:: In a barrier stage, each task much have the same number of `barrier()`
             calls, in all possible code branches.
             Otherwise, you may get the job hanging or a SparkException after timeout.
 
         .. versionadded:: 2.4.0
         """
         if self._port is None or self._secret is None:
             raise Exception("Not supported to call barrier() before initialize " +
                             "BarrierTaskContext.")
         else:
             _load_from_socket(self._port, self._secret, BARRIER_FUNCTION)
 
     def allGather(self, message=""):
         """
         .. note:: Experimental
 
         This function blocks until all tasks in the same stage have reached this routine.
         Each task passes in a message and returns with a list of all the messages passed in
         by each of those tasks.
 
         .. warning:: In a barrier stage, each task much have the same number of `allGather()`
             calls, in all possible code branches.
             Otherwise, you may get the job hanging or a SparkException after timeout.
 
         .. versionadded:: 3.0.0
         """
         if not isinstance(message, str):
             raise ValueError("Argument `message` must be of type `str`")
         elif self._port is None or self._secret is None:
             raise Exception("Not supported to call barrier() before initialize " +
                             "BarrierTaskContext.")
         else:
             return _load_from_socket(self._port, self._secret, ALL_GATHER_FUNCTION, message)
 
     def getTaskInfos(self):
         """
         .. note:: Experimental
 
         Returns :class:`BarrierTaskInfo` for all tasks in this barrier stage,
         ordered by partition ID.
 
         .. versionadded:: 2.4.0
         """
         if self._port is None or self._secret is None:
             raise Exception("Not supported to call getTaskInfos() before initialize " +
                             "BarrierTaskContext.")
         else:
             addresses = self._localProperties.get("addresses", "")
             return [BarrierTaskInfo(h.strip()) for h in addresses.split(",")]
 
 
 class BarrierTaskInfo(object):
     """
     .. note:: Experimental
 
     Carries all task infos of a barrier task.
 
     :var address: The IPv4 address (host:port) of the executor that the barrier task is running on
 
     .. versionadded:: 2.4.0
     """
 
     def __init__(self, address):
         self.address = address

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