def _shuffle_map(block: Block, idx: int, output_num_blocks: int,
random_shuffle: bool,
random_seed: Optional[int]) -> List[Block]:
block = BlockAccessor.for_block(block)
# Randomize the distribution of records to blocks.
if random_shuffle:
seed_i = random_seed + idx if random_seed is not None else None
block = block.random_shuffle(seed_i)
block = BlockAccessor.for_block(block)
slice_sz = max(1, math.ceil(block.num_rows() / output_num_blocks))
slices = []
for i in range(output_num_blocks):
slices.append(block.slice(i * slice_sz, (i + 1) * slice_sz, copy=True))
# Randomize the distribution order of the blocks (this matters when
# some blocks are larger than others).
if random_shuffle:
random = np.random.RandomState(seed_i)
random.shuffle(slices)
num_rows = sum(BlockAccessor.for_block(s).num_rows() for s in slices)
assert num_rows == block.num_rows(), (num_rows, block.num_rows())
# Needed to handle num_returns=1 edge case in Ray API.
if len(slices) == 1:
return slices[0]
else:
return slices
def _shuffle_map(
block: Block,
idx: int,
output_num_blocks: int,
random_shuffle: bool,
random_seed: Optional[int],
) -> List[Union[BlockMetadata, Block]]:
"""Returns list of [BlockMetadata, O1, O2, O3, ...output_num_blocks]."""
stats = BlockExecStats.builder()
block = BlockAccessor.for_block(block)
# Randomize the distribution of records to blocks.
if random_shuffle:
seed_i = random_seed + idx if random_seed is not None else None
block = block.random_shuffle(seed_i)
block = BlockAccessor.for_block(block)
slice_sz = max(1, math.ceil(block.num_rows() / output_num_blocks))
slices = []
for i in range(output_num_blocks):
slices.append(block.slice(i * slice_sz, (i + 1) * slice_sz, copy=True))
# Randomize the distribution order of the blocks (this matters when
# some blocks are larger than others).
if random_shuffle:
random = np.random.RandomState(seed_i)
random.shuffle(slices)
num_rows = sum(BlockAccessor.for_block(s).num_rows() for s in slices)
assert num_rows == block.num_rows(), (num_rows, block.num_rows())
metadata = block.get_metadata(input_files=None, exec_stats=stats.build())
return [metadata] + slices
def map(
idx: int,
block: Block,
output_num_blocks: int,
block_udf: Optional[Callable[[Block], Iterable[Block]]],
random_shuffle: bool,
random_seed: Optional[int],
) -> List[Union[BlockMetadata, Block]]:
stats = BlockExecStats.builder()
if block_udf:
# TODO(ekl) note that this effectively disables block splitting.
blocks = list(block_udf(block))
if len(blocks) > 1:
builder = BlockAccessor.for_block(blocks[0]).builder()
for b in blocks:
builder.add_block(b)
block = builder.build()
else:
block = blocks[0]
block = BlockAccessor.for_block(block)
# Randomize the distribution of records to blocks.
if random_shuffle:
seed_i = random_seed + idx if random_seed is not None else None
block = block.random_shuffle(seed_i)
block = BlockAccessor.for_block(block)
slice_sz = max(1, math.ceil(block.num_rows() / output_num_blocks))
slices = []
for i in range(output_num_blocks):
slices.append(
block.slice(i * slice_sz, (i + 1) * slice_sz, copy=True))
# Randomize the distribution order of the blocks (this prevents empty
# outputs when input blocks are very small).
if random_shuffle:
random = np.random.RandomState(seed_i)
random.shuffle(slices)
num_rows = sum(BlockAccessor.for_block(s).num_rows() for s in slices)
assert num_rows == block.num_rows(), (num_rows, block.num_rows())
metadata = block.get_metadata(input_files=None,
exec_stats=stats.build())
return [metadata] + slices