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205 lines
6.1 KiB
Python

# Copyright (c) Facebook, Inc. and its affiliates.
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.
# copied from fairseq/fairseq/data/indexed_dataset.py
# Removed IndexedRawTextDataset since it relied on Fairseq dictionary
# other slight modifications to remove fairseq dependencies
# Added document index to index file and made it accessible.
# An empty sentence no longer separates documents.
# copied from Megatron
# Used for building mmap datasets.
from functools import lru_cache
import struct
import numpy as np
import shutil
__all__ = ["make_mmap_builder"]
dtypes = {
1: np.uint8,
2: np.int8,
3: np.int16,
4: np.int32,
5: np.int64,
6: np.float,
7: np.double,
8: np.uint16,
}
def __best_fitting_dtype(vocab_size=None):
if vocab_size is not None and vocab_size < 65500:
return np.uint16
else:
return np.int32
def make_mmap_builder(out_file, vocab_size=None):
return MMapIndexedDatasetBuilder(
out_file, dtype=__best_fitting_dtype(vocab_size)
)
def code(dtype):
for k in dtypes.keys():
if dtypes[k] == dtype:
return k
raise ValueError(dtype)
def index_file_path(prefix_path):
return prefix_path + ".idx"
def data_file_path(prefix_path):
return prefix_path + ".bin"
class MMapIndexedDataset:
class Index(object):
_HDR_MAGIC = b"MMIDIDX\x00\x00"
@classmethod
def writer(cls, path, dtype):
class _Writer(object):
def __enter__(self):
self._file = open(path, "wb")
self._file.write(cls._HDR_MAGIC)
self._file.write(struct.pack("<Q", 1))
self._file.write(struct.pack("<B", code(dtype)))
return self
@staticmethod
def _get_pointers(sizes):
dtype_size = dtype().itemsize
address = 0
pointers = []
for size in sizes:
pointers.append(address)
address += size * dtype_size
return pointers
def write(self, sizes, doc_idx):
pointers = self._get_pointers(sizes)
self._file.write(struct.pack("<Q", len(sizes)))
self._file.write(struct.pack("<Q", len(doc_idx)))
sizes = np.array(sizes, dtype=np.int32)
self._file.write(sizes.tobytes(order="C"))
del sizes
pointers = np.array(pointers, dtype=np.int64)
self._file.write(pointers.tobytes(order="C"))
del pointers
doc_idx = np.array(doc_idx, dtype=np.int64)
self._file.write(doc_idx.tobytes(order="C"))
def __exit__(self, exc_type, exc_val, exc_tb):
self._file.close()
return _Writer()
def __init__(self, path, skip_warmup=False):
with open(path, "rb") as stream:
magic_test = stream.read(9)
assert self._HDR_MAGIC == magic_test, (
"Index file doesn't match expected format. "
"Make sure that --dataset-impl is configured properly."
)
version = struct.unpack("<Q", stream.read(8))
assert (1,) == version
(dtype_code,) = struct.unpack("<B", stream.read(1))
self._dtype = dtypes[dtype_code]
self._dtype_size = self._dtype().itemsize
self._len = struct.unpack("<Q", stream.read(8))[0]
self._doc_count = struct.unpack("<Q", stream.read(8))[0]
offset = stream.tell()
self._bin_buffer_mmap = np.memmap(path, mode="r", order="C")
self._bin_buffer = memoryview(self._bin_buffer_mmap)
self._sizes = np.frombuffer(
self._bin_buffer, dtype=np.int32, count=self._len, offset=offset
)
self._pointers = np.frombuffer(
self._bin_buffer,
dtype=np.int64,
count=self._len,
offset=offset + self._sizes.nbytes,
)
self._doc_idx = np.frombuffer(
self._bin_buffer,
dtype=np.int64,
count=self._doc_count,
offset=offset + self._sizes.nbytes + self._pointers.nbytes,
)
def __del__(self):
self._bin_buffer_mmap._mmap.close()
del self._bin_buffer_mmap
@property
def dtype(self):
return self._dtype
@property
def sizes(self):
return self._sizes
@property
def doc_idx(self):
return self._doc_idx
@lru_cache(maxsize=8)
def __getitem__(self, i):
return self._pointers[i], self._sizes[i]
def __len__(self):
return self._len
class MMapIndexedDatasetBuilder(object):
def __init__(self, out_file, dtype=np.int64):
self._data_file = open(out_file, "wb")
self._dtype = dtype
self._sizes = []
self._doc_idx = [0]
def add_item(self, tensor):
np_array = np.array(tensor.numpy(), dtype=self._dtype)
self._data_file.write(np_array.tobytes(order="C"))
self._sizes.append(np_array.size)
def end_document(self):
self._doc_idx.append(len(self._sizes))
def merge_file_(self, another_file):
# Concatenate index
index = MMapIndexedDataset.Index(index_file_path(another_file))
assert index.dtype == self._dtype
for size in index.sizes:
self._sizes.append(size)
# Concatenate data
with open(data_file_path(another_file), "rb") as f:
shutil.copyfileobj(f, self._data_file)
def finalize(self, index_file):
self._data_file.close()
with MMapIndexedDataset.Index.writer(index_file, self._dtype) as index:
index.write(self._sizes, self._doc_idx)