def gen_dataset_from_path(
self,
path: str,
rank: int = 0,
world_size: int = 1,
include_label_fields: bool = True,
use_cache: bool = True,
) -> textdata.Dataset:
"""
Generate a dataset from file
Returns:
dataset (TorchText.Dataset)
"""
if use_cache and path in self._data_cache and rank == 0 and world_size == 1:
return self._data_cache[path]
shard_range = (dist_utils.get_shard_range(
self.metadata.dataset_sizes[path], rank, world_size)
if world_size > 1 else None)
res = self.gen_dataset(
self.read_from_file(path, self.raw_columns),
include_label_fields,
shard_range,
)
if rank == 0 and world_size == 1:
self._data_cache[path] = res
return res
def read_from_file(
self,
file_name: str,
columns_to_use: Union[Dict[str, int], List[str]],
rank: int = 0,
world_size: int = 1,
) -> List[Dict[str, Any]]:
"""
Read data from csv file. Input file format is required to be
tab-separated columns
Args:
file_name (str): csv file name
columns_to_use (Union[Dict[str, int], List[str]]): either a list of
column names or a dict of column name -> column index in the file
"""
print("reading data from {}".format(file_name))
if isinstance(columns_to_use, list):
columns_to_use = {
name: idx
for name, idx in zip(columns_to_use, range(len(
columns_to_use)))
}
shard_range = (dist_utils.get_shard_range(
self.metadata.dataset_sizes[file_name], rank, world_size)
if world_size > 1 else None)
with open(file_name, "r", encoding="utf-8",
errors="replace") as f_handle:
csv_reader = csv.reader(f_handle,
delimiter="\t",
quoting=csv.QUOTE_NONE)
data = []
i, row_idx = 0, 0
while True:
i += 1
try:
row = next(csv_reader)
except csv.Error:
print("ignoring line {}".format(i))
continue
except StopIteration:
break
if not shard_range or shard_range[0] <= row_idx < shard_range[
1]:
data.append({
name: row[index] if index < len(row) else ""
for name, index in columns_to_use.items()
})
row_idx += 1
# some shard might have 1 less example due to data_size % world_size
# pad the shard to make sure all shard dataset have same size
dist_utils.pad_shard_data(data, row_idx, world_size)
return data
def get_train_iter_from_raw_data(
self,
train_data: List[Dict[str, Any]],
batch_size: int,
rank: int = 0,
world_size: int = 1,
) -> BatchIterator:
shard_range = dist_utils.get_shard_range(len(train_data), rank,
world_size)
shard_data = train_data[shard_range[0]:shard_range[1]]
dist_utils.pad_shard_data(shard_data, len(train_data), world_size)
return self._get_train_iter(self.gen_dataset(shard_data), batch_size,
world_size)
def test_get_shard_range(self):
# first 5 ranks should take 3 examples
# last 3 ranks should take 2 examples, but to make sure all shard have
# same size, we pad with the previous example.
dataset_size, world_size = 21, 8
expected = [
(0, (0, 2)),
(1, (3, 5)),
(2, (6, 8)),
(3, (9, 11)),
(4, (12, 14)),
(5, (14, 16)),
(6, (16, 18)),
(7, (18, 20)),
]
for rank, expected_range in expected:
shard_range = get_shard_range(dataset_size, rank, world_size)
self.assertEqual(shard_range, expected_range)
dataset_size, world_size = 16, 4
expected = [(0, (0, 3)), (1, (4, 7)), (2, (8, 11)), (3, (12, 15))]
for rank, expected_range in expected:
shard_range = get_shard_range(dataset_size, rank, world_size)
self.assertEqual(shard_range, expected_range)
