Source code for rising.loading.dataset

import logging
import os
import pathlib
from functools import partial
from multiprocessing import cpu_count
from typing import Any, Sequence, Callable, Union, List, Iterator, Generator, Optional

    import dill

except ImportError:

from torch.multiprocessing import Pool
from import Dataset as TorchDset, Subset
from tqdm import tqdm

logger = logging.getLogger(__file__)

__all__ = ["Dataset", "AsyncDataset"]

[docs]def dill_helper(payload: Any) -> Any: """ Load single sample from data serialized by dill Args: payload: data which is loaded with dill Returns: Any: loaded data """ if not DILL_AVAILABLE: raise RuntimeError('dill is not installed. For async loading ' 'please install it') fn, args, kwargs = dill.loads(payload) return fn(*args, **kwargs)
[docs]def load_async(pool: Pool, fn: Callable, *args, callback: Callable = None, **kwargs) -> Any: """ Load data asynchronously and serialize data via dill Args: pool: multiprocessing pool to use for :func:`apply_async` fn: function to load a single sample *args: positional arguments to dump with dill callback: optional callback. defaults to None. **kwargs: keyword arguments to dump with dill Returns: Any: reference to obtain data with :func:`get` """ if not DILL_AVAILABLE: raise RuntimeError('dill is not installed. For async loading ' 'please install it') payload = dill.dumps((fn, args, kwargs)) return pool.apply_async(dill_helper, (payload,), callback=callback)
[docs]class Dataset(TorchDset): """ Extension of :class:`` by a ``get_subset`` method which returns a sub-dataset. """ def __iter__(self) -> Generator: """ Yields: sample: dataset sample """ for i in range(len(self)): yield self[i]
[docs] def get_subset(self, indices: Sequence[int]) -> Subset: """ Returns a :class:`` of the current dataset based on given indices Args: indices: valid indices to extract subset from current dataset Returns: Subset: the subset of the current dataset """ subset = Subset(self, indices) subset.__iter__ = self.__iter__ return subset
[docs]class AsyncDataset(Dataset): """ A dataset to preload all the data and cache it for the entire lifetime of this class. """ def __init__(self, data_path: Union[pathlib.Path, str, list], load_fn: Callable, mode: str = "append", num_workers: Optional[int] = 0, verbose: bool = False, **load_kwargs): """ Args: data_path: the path(s) containing the actual data samples load_fn: function to load the actual data mode: whether to append the sample to a list or to extend the list by it. Supported modes are: ``append`` and ``extend``. Default: ``append`` num_workers: the number of workers to use for preloading. ``0`` means, all the data will be loaded in the main process, while ``None`` means, the number of processes will default to the number of logical cores. verbose: whether to show the loading progress. **load_kwargs: additional keyword arguments. Passed directly to :attr:`load_fn` Warnings: if using multiprocessing to load data, there are some restrictions to which :func:`load_fn` are supported, please refer to the :mod:`dill` or :mod:`pickle` documentation """ super().__init__() self._num_workers = num_workers self._verbosity = verbose self._load_fn = load_fn self._load_kwargs = load_kwargs = self._make_dataset(data_path, mode)
[docs] def _make_dataset(self, path: Union[pathlib.Path, str, list], mode: str) -> List[Any]: """ Function to build the entire dataset Args: path: the path(s) containing the data samples mode: whether to append or extend the dataset by the loaded sample Returns: list: the loaded data """ data = [] if not isinstance(path, list): assert os.path.isdir(path), '%s is not a valid directory' % path path = [os.path.join(path, p) for p in os.listdir(path)] # sort for reproducibility (this is done explicitly since the listdir # function does not return the paths in an ordered way on all OS) path = sorted(path) # add loading kwargs load_fn = partial(self._load_fn, **self._load_kwargs) if self._num_workers is None or self._num_workers > 0: _data = self.load_multi_process(load_fn, path) else: _data = self.load_single_process(load_fn, path) for sample in _data: self._add_item(data, sample, mode) return data
[docs] def load_single_process(self, load_fn: Callable, path: Sequence) -> Iterator: """ Helper function to load dataset with single process Args: load_fn: function to load a single sample path: a sequence of paths which should be loaded Returns: Iterator: iterator of loaded data """ if self._verbosity: path = tqdm(path, unit='samples', desc="Loading Samples") return map(load_fn, path)
[docs] def load_multi_process(self, load_fn: Callable, path: Sequence) -> List: """ Helper function to load dataset with multiple processes Args: load_fn: function to load a single sample path: a sequence of paths which should be loaded Returns: list: loaded data """ _processes = cpu_count() if self._num_workers is None else self._num_workers if self._verbosity: pbar = tqdm(total=len(path), unit='samples', desc="Loading Samples") def update(*a): pbar.update(1) callback = update else: callback = None with Pool(processes=_processes) as pool: jobs = [load_async(pool, load_fn, p, callback=callback) for p in path] _data = [j.get() for j in jobs] return _data
[docs] @staticmethod def _add_item(data: list, item: Any, mode: str) -> None: """ Adds items to the given data list. The actual way of adding these items depends on :attr:`mode` Args: data: the list containing the already loaded data item: the current item which will be added to the list mode: the string specifying the mode of how the item should be added.F Raises: TypeError: No known mode detected """ _mode = mode.lower() if _mode == 'append': data.append(item) elif _mode == 'extend': data.extend(item) else: raise TypeError(f"Unknown mode detected: {mode} not supported.")
def __getitem__(self, index: int) -> Union[Any, dict]: """ Making the whole Dataset indexeable. Args: index: the integer specifying which sample to return Returns: Union[Any, dict]: can be any object containing a single sample, but in practice is often a dict """ return[index] def __len__(self) -> int: """ Length of dataset Returns: int: number of elements """ return len(

© Copyright Copyright (c) 2019-2020, Justus Schock, Michael Baumgartner.. Revision 871c839e.

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