[dask] Moved dask_get_partition_size from bob.bio.base to bob.pipelines

bob/pipelines/distributed/__init__.py

@@ -16,3 +16,36 @@ __path__ = extend_path(__path__, __name__)
 # )
 
 VALID_DASK_CLIENT_STRINGS = ("single-threaded", "sync", "threaded", "processes")
+
+
+def dask_get_partition_size(cluster, n_objects, lower_bound=200):
+    """
+    Heuristics that gives you a number for dask.partition_size.
+    The heuristics is pretty simple, given the max number of possible workers to be run
+    in a queue (not the number of current workers running) and a total number objects to be processed do n_objects/n_max_workers:
+
+    Check https://docs.dask.org/en/latest/best-practices.html#avoid-very-large-partitions
+    for best practices
+
+    Parameters
+    ----------
+
+        cluster:  :any:`bob.pipelines.distributed.sge.SGEMultipleQueuesCluster`
+            Cluster of the type :any:`bob.pipelines.distributed.sge.SGEMultipleQueuesCluster`
+
+        n_objects: int
+            Number of objects to be processed
+
+        lower_bound: int
+            Minimum partition size.
+
+    """
+    if not isinstance(cluster, SGEMultipleQueuesCluster):
+        return None
+
+    max_jobs = cluster.sge_job_spec["default"]["max_jobs"]
+
+    # Trying to set a lower bound for the
+    return (
+        max(n_objects // max_jobs, lower_bound) if n_objects > max_jobs else n_objects
+    )