def bcast(input_list: PList, src_pid: int) -> PList:
"""
Broadcast the data at source processor to all processors.
Example::
>>> from pyske.core import PList, par
>>> bcast(PList.from_seq([42]), 0).to_seq() == \
list(map(lambda _: 42, par.procs()))
True
:param input_list: a parallel list.
:param src_pid: the source processor identifier.
Pre-condition: ``src_pid in par.procs()``
:return: a parallel list.
"""
assert src_pid in par.procs()
size = input_list.distribution[src_pid]
nprocs = len(par.procs())
return input_list \
.get_partition() \
.mapi(lambda pid, lst: list(map(lambda _: lst, par.procs())) if pid == src_pid else []) \
.flatten(Distribution([nprocs if pid == src_pid else 0 for pid in par.procs()])) \
.distribute(Distribution(map(lambda _: 1, par.procs()))) \
.flatten(Distribution(map(lambda _: size, par.procs())))
def _pyske_bcast(input_list: PList):
size = input_list.distribution[0]
nprocs = len(par.procs())
return input_list\
.get_partition()\
.mapi(lambda pid, a_list: list(map(lambda _: a_list, par.procs())) if pid == 0 else []) \
.flatten(Distribution([nprocs if pid == 0 else 0 for pid in par.procs()])) \
.distribute(Distribution(map(lambda _: 1, par.procs())))\
.flatten(Distribution(map(lambda _: size, par.procs())))
def test_balance_distr():
# pylint: disable=missing-docstring
data = generate_str_plist()
size = data.length()
dst = par.randpid()
distr = Distribution([0 for _ in par.procs()])
distr[dst] = size
res = get_distribution(data.distribute(distr).balance())
exp = Distribution.balanced(size)
assert res == exp
def test_scatter_range_distr():
# pylint: disable=missing-docstring
data = generate_str_plist()
min_, max_ = rand_min_max(data.length())
res = get_distribution(data.scatter_range(range(min_, max_)))
exp = Distribution.balanced(max_ - min_)
assert res == exp
def test_distribute_data():
# pylint: disable=missing-docstring
data = SList.init(int, 42)
size = data.length()
distr = Distribution([size])
res = data.distribute(distr)
exp = SList(range(0, size))
assert res == exp
def test_scatter_distr():
# pylint: disable=missing-docstring
data = generate_str_plist()
src = par.randpid()
distr = get_distribution(data)
res = get_distribution(data.scatter(src))
exp = Distribution.balanced(distr[src])
assert res == exp
def test_distribute_distr():
# pylint: disable=missing-docstring
data = generate_str_plist()
size = data.length()
dst = par.randpid()
exp = Distribution([0 for _ in par.procs()])
exp[dst] = size
res = get_distribution(data.distribute(exp))
assert res == exp
def test_distribute_data():
# pylint: disable=missing-docstring
dst = par.randpid()
data = generate_int_plist()
size = data.length()
distr = Distribution([0 for _ in par.procs()])
distr[dst] = size
res = data.distribute(distr).to_seq()
exp = SList(range(0, size))
assert res == exp