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ckpts/universal/global_step120/zero/10.attention.dense.weight/fp32.pt

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ckpts/universal/global_step120/zero/20.attention.dense.weight/exp_avg_sq.pt

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venv/lib/python3.10/site-packages/torch/utils/bottleneck/__main__.py

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+import argparse
+import cProfile
+import pstats
+import sys
+import os
+from typing import Dict
+
+import torch
+from torch.autograd import profiler
+from torch.utils.collect_env import get_env_info
+
+
+def redirect_argv(new_argv):
+    sys.argv[:] = new_argv[:]
+
+
+def compiled_with_cuda(sysinfo):
+    if sysinfo.cuda_compiled_version:
+        return f'compiled w/ CUDA {sysinfo.cuda_compiled_version}'
+    return 'not compiled w/ CUDA'
+
+
+env_summary = """
+--------------------------------------------------------------------------------
+  Environment Summary
+--------------------------------------------------------------------------------
+PyTorch {pytorch_version}{debug_str} {cuda_compiled}
+Running with Python {py_version} and {cuda_runtime}
+
+`{pip_version} list` truncated output:
+{pip_list_output}
+""".strip()
+
+
+def run_env_analysis():
+    print('Running environment analysis...')
+    info = get_env_info()
+
+    result: Dict[str, str] = {}
+
+    debug_str = ''
+    if info.is_debug_build:
+        debug_str = ' DEBUG'
+
+    cuda_avail = ''
+    if info.is_cuda_available:
+        cuda = info.cuda_runtime_version
+        if cuda is not None:
+            cuda_avail = 'CUDA ' + cuda
+    else:
+        cuda = 'CUDA unavailable'
+
+    pip_version = info.pip_version
+    pip_list_output = info.pip_packages
+    if pip_list_output is None:
+        pip_list_output = 'Unable to fetch'
+
+    result = {
+        'debug_str': debug_str,
+        'pytorch_version': info.torch_version,
+        'cuda_compiled': compiled_with_cuda(info),
+        'py_version': f'{sys.version_info[0]}.{sys.version_info[1]}',
+        'cuda_runtime': cuda_avail,
+        'pip_version': pip_version,
+        'pip_list_output': pip_list_output,
+    }
+
+    return env_summary.format(**result)
+
+
+def run_cprofile(code, globs, launch_blocking=False):
+    print('Running your script with cProfile')
+    prof = cProfile.Profile()
+    prof.enable()
+    exec(code, globs, None)
+    prof.disable()
+    return prof
+
+
+cprof_summary = """
+--------------------------------------------------------------------------------
+  cProfile output
+--------------------------------------------------------------------------------
+""".strip()
+
+
+def print_cprofile_summary(prof, sortby='tottime', topk=15):
+    print(cprof_summary)
+    cprofile_stats = pstats.Stats(prof).sort_stats(sortby)
+    cprofile_stats.print_stats(topk)
+
+
+def run_autograd_prof(code, globs):
+    def run_prof(use_cuda=False):
+        with profiler.profile(use_cuda=use_cuda) as prof:
+            exec(code, globs, None)
+        return prof
+
+    print('Running your script with the autograd profiler...')
+    result = [run_prof(use_cuda=False)]
+    if torch.cuda.is_available():
+        result.append(run_prof(use_cuda=True))
+    else:
+        result.append(None)
+
+    return result
+
+
+autograd_prof_summary = """
+--------------------------------------------------------------------------------
+  autograd profiler output ({mode} mode)
+--------------------------------------------------------------------------------
+        {description}
+{cuda_warning}
+{output}
+""".strip()
+
+
+def print_autograd_prof_summary(prof, mode, sortby='cpu_time', topk=15):
+    valid_sortby = ['cpu_time', 'cuda_time', 'cpu_time_total', 'cuda_time_total', 'count']
+    if sortby not in valid_sortby:
+        warn = ('WARNING: invalid sorting option for autograd profiler results: {}\n'
+                'Expected `cpu_time`, `cpu_time_total`, or `count`. '
+                'Defaulting to `cpu_time`.')
+        print(warn.format(sortby))
+        sortby = 'cpu_time'
+
+    if mode == 'CUDA':
+        cuda_warning = ('\n\tBecause the autograd profiler uses the CUDA event API,\n'
+                        '\tthe CUDA time column reports approximately max(cuda_time, cpu_time).\n'
+                        '\tPlease ignore this output if your code does not use CUDA.\n')
+    else:
+        cuda_warning = ''
+
+    sorted_events = sorted(prof.function_events,
+                           key=lambda x: getattr(x, sortby), reverse=True)
+    topk_events = sorted_events[:topk]
+
+    result = {
+        'mode': mode,
+        'description': f'top {topk} events sorted by {sortby}',
+        'output': torch.autograd.profiler_util._build_table(topk_events),
+        'cuda_warning': cuda_warning
+    }
+
+    print(autograd_prof_summary.format(**result))
+
+
+descript = """
+`bottleneck` is a tool that can be used as an initial step for debugging
+bottlenecks in your program.
+
+It summarizes runs of your script with the Python profiler and PyTorch\'s
+autograd profiler. Because your script will be profiled, please ensure that it
+exits in a finite amount of time.
+
+For more complicated uses of the profilers, please see
+https://docs.python.org/3/library/profile.html and
+https://pytorch.org/docs/master/autograd.html#profiler for more information.
+""".strip()
+
+
+def parse_args():
+    parser = argparse.ArgumentParser(description=descript)
+    parser.add_argument('scriptfile', type=str,
+                        help='Path to the script to be run. '
+                        'Usually run with `python path/to/script`.')
+    parser.add_argument('args', type=str, nargs=argparse.REMAINDER,
+                        help='Command-line arguments to be passed to the script.')
+    return parser.parse_args()
+
+
+def cpu_time_total(autograd_prof):
+    return sum([event.cpu_time_total for event in autograd_prof.function_events])
+
+
+def main():
+    args = parse_args()
+
+    # Customizable constants.
+    scriptfile = args.scriptfile
+    scriptargs = [] if args.args is None else args.args
+    scriptargs.insert(0, scriptfile)
+    cprofile_sortby = 'tottime'
+    cprofile_topk = 15
+    autograd_prof_sortby = 'cpu_time_total'
+    autograd_prof_topk = 15
+
+    redirect_argv(scriptargs)
+
+    sys.path.insert(0, os.path.dirname(scriptfile))
+    with open(scriptfile, 'rb') as stream:
+        code = compile(stream.read(), scriptfile, 'exec')
+    globs = {
+        '__file__': scriptfile,
+        '__name__': '__main__',
+        '__package__': None,
+        '__cached__': None,
+    }
+
+    print(descript)
+
+    env_summary = run_env_analysis()
+
+    if torch.cuda.is_available():
+        torch.cuda.init()
+    cprofile_prof = run_cprofile(code, globs)
+    autograd_prof_cpu, autograd_prof_cuda = run_autograd_prof(code, globs)
+
+    print(env_summary)
+    print_cprofile_summary(cprofile_prof, cprofile_sortby, cprofile_topk)
+
+    if not torch.cuda.is_available():
+        print_autograd_prof_summary(autograd_prof_cpu, 'CPU', autograd_prof_sortby, autograd_prof_topk)
+        return
+
+    # Print both the result of the CPU-mode and CUDA-mode autograd profilers
+    # if their execution times are very different.
+    cuda_prof_exec_time = cpu_time_total(autograd_prof_cuda)
+    if len(autograd_prof_cpu.function_events) > 0:
+        cpu_prof_exec_time = cpu_time_total(autograd_prof_cpu)
+        pct_diff = (cuda_prof_exec_time - cpu_prof_exec_time) / cuda_prof_exec_time
+        if abs(pct_diff) > 0.05:
+            print_autograd_prof_summary(autograd_prof_cpu, 'CPU', autograd_prof_sortby, autograd_prof_topk)
+
+    print_autograd_prof_summary(autograd_prof_cuda, 'CUDA', autograd_prof_sortby, autograd_prof_topk)
+
+if __name__ == '__main__':
+    main()

venv/lib/python3.10/site-packages/torch/utils/data/_utils/__init__.py

@@ -0,0 +1,51 @@
+r"""Utility classes & functions for data loading. Code in this folder is mostly used by ../dataloder.py.
+
+A lot of multiprocessing is used in data loading, which only supports running
+functions defined in global environment (py2 can't serialize static methods).
+Therefore, for code tidiness we put these functions into different files in this
+folder.
+"""
+
+import sys
+import atexit
+
+# old private location of the ExceptionWrapper that some users rely on:
+from torch._utils import ExceptionWrapper
+
+
+IS_WINDOWS = sys.platform == "win32"
+
+
+MP_STATUS_CHECK_INTERVAL = 5.0
+r"""Interval (in seconds) to check status of processes to avoid hanging in
+    multiprocessing data loading. This is mainly used in getting data from
+    another process, in which case we need to periodically check whether the
+    sender is alive to prevent hanging."""
+
+
+python_exit_status = False
+r"""Whether Python is shutting down. This flag is guaranteed to be set before
+the Python core library resources are freed, but Python may already be exiting
+for some time when this is set.
+
+Hook to set this flag is `_set_python_exit_flag`, and is inspired by a similar
+hook in Python 3.7 multiprocessing library:
+https://github.com/python/cpython/blob/d4d60134b29290049e28df54f23493de4f1824b6/Lib/multiprocessing/util.py#L277-L327
+"""
+
+
+try:
+    import numpy
+    HAS_NUMPY = True
+except ModuleNotFoundError:
+    HAS_NUMPY = False
+
+
+def _set_python_exit_flag():
+    global python_exit_status
+    python_exit_status = True
+
+atexit.register(_set_python_exit_flag)
+
+
+from . import worker, signal_handling, pin_memory, collate, fetch

venv/lib/python3.10/site-packages/torch/utils/data/_utils/collate.py

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+r"""Contains definitions of the methods used by the _BaseDataLoaderIter workers.
+
+These methods are used to collate samples fetched from dataset into Tensor(s).
+These **needs** to be in global scope since Py2 doesn't support serializing
+static methods.
+
+`default_collate` and `default_convert` are exposed to users via 'dataloader.py'.
+"""
+
+import collections
+import contextlib
+import copy
+import re
+import torch
+
+from typing import Callable, Dict, Optional, Tuple, Type, Union
+
+np_str_obj_array_pattern = re.compile(r'[SaUO]')
+
+
+def default_convert(data):
+    r"""
+    Convert each NumPy array element into a :class:`torch.Tensor`.
+
+    If the input is a `Sequence`, `Collection`, or `Mapping`, it tries to convert each element inside to a :class:`torch.Tensor`.
+    If the input is not an NumPy array, it is left unchanged.
+    This is used as the default function for collation when both `batch_sampler` and `batch_size`
+    are NOT defined in :class:`~torch.utils.data.DataLoader`.
+
+    The general input type to output type mapping is similar to that
+    of :func:`~torch.utils.data.default_collate`. See the description there for more details.
+
+    Args:
+        data: a single data point to be converted
+
+    Examples:
+        >>> # xdoctest: +SKIP
+        >>> # Example with `int`
+        >>> default_convert(0)
+        0
+        >>> # Example with NumPy array
+        >>> default_convert(np.array([0, 1]))
+        tensor([0, 1])
+        >>> # Example with NamedTuple
+        >>> Point = namedtuple('Point', ['x', 'y'])
+        >>> default_convert(Point(0, 0))
+        Point(x=0, y=0)
+        >>> default_convert(Point(np.array(0), np.array(0)))
+        Point(x=tensor(0), y=tensor(0))
+        >>> # Example with List
+        >>> default_convert([np.array([0, 1]), np.array([2, 3])])
+        [tensor([0, 1]), tensor([2, 3])]
+    """
+    elem_type = type(data)
+    if isinstance(data, torch.Tensor):
+        return data
+    elif elem_type.__module__ == 'numpy' and elem_type.__name__ != 'str_' \
+            and elem_type.__name__ != 'string_':
+        # array of string classes and object
+        if elem_type.__name__ == 'ndarray' \
+                and np_str_obj_array_pattern.search(data.dtype.str) is not None:
+            return data
+        return torch.as_tensor(data)
+    elif isinstance(data, collections.abc.Mapping):
+        try:
+            if isinstance(data, collections.abc.MutableMapping):
+                # The mapping type may have extra properties, so we can't just
+                # use `type(data)(...)` to create the new mapping.
+                # Create a clone and update it if the mapping type is mutable.
+                clone = copy.copy(data)
+                clone.update({key: default_convert(data[key]) for key in data})
+                return clone
+            else:
+                return elem_type({key: default_convert(data[key]) for key in data})
+        except TypeError:
+            # The mapping type may not support `copy()` / `update(mapping)`
+            # or `__init__(iterable)`.
+            return {key: default_convert(data[key]) for key in data}
+    elif isinstance(data, tuple) and hasattr(data, '_fields'):  # namedtuple
+        return elem_type(*(default_convert(d) for d in data))
+    elif isinstance(data, tuple):
+        return [default_convert(d) for d in data]  # Backwards compatibility.
+    elif isinstance(data, collections.abc.Sequence) and not isinstance(data, (str, bytes)):
+        try:
+            if isinstance(data, collections.abc.MutableSequence):
+                # The sequence type may have extra properties, so we can't just
+                # use `type(data)(...)` to create the new sequence.
+                # Create a clone and update it if the sequence type is mutable.
+                clone = copy.copy(data)  # type: ignore[arg-type]
+                for i, d in enumerate(data):
+                    clone[i] = default_convert(d)
+                return clone
+            else:
+                return elem_type([default_convert(d) for d in data])
+        except TypeError:
+            # The sequence type may not support `copy()` / `__setitem__(index, item)`
+            # or `__init__(iterable)` (e.g., `range`).
+            return [default_convert(d) for d in data]
+    else:
+        return data
+
+
+default_collate_err_msg_format = (
+    "default_collate: batch must contain tensors, numpy arrays, numbers, "
+    "dicts or lists; found {}")
+
+
+def collate(batch, *, collate_fn_map: Optional[Dict[Union[Type, Tuple[Type, ...]], Callable]] = None):
+    r"""
+    General collate function that handles collection type of element within each batch.
+
+    The function also opens function registry to deal with specific element types. `default_collate_fn_map`
+    provides default collate functions for tensors, numpy arrays, numbers and strings.
+
+    Args:
+        batch: a single batch to be collated
+        collate_fn_map: Optional dictionary mapping from element type to the corresponding collate function.
+            If the element type isn't present in this dictionary,
+            this function will go through each key of the dictionary in the insertion order to
+            invoke the corresponding collate function if the element type is a subclass of the key.
+
+    Examples:
+        >>> def collate_tensor_fn(batch, *, collate_fn_map):
+        >>> # Extend this function to handle batch of tensors
+        ...     return torch.stack(batch, 0)
+        >>> def custom_collate(batch):
+        ...     collate_map = {torch.Tensor: collate_tensor_fn}
+        ...     return collate(batch, collate_fn_map=collate_map)
+        >>> # Extend `default_collate` by in-place modifying `default_collate_fn_map`
+        >>> default_collate_fn_map.update({torch.Tensor: collate_tensor_fn})
+
+    Note:
+        Each collate function requires a positional argument for batch and a keyword argument
+        for the dictionary of collate functions as `collate_fn_map`.
+    """
+    elem = batch[0]
+    elem_type = type(elem)
+
+    if collate_fn_map is not None:
+        if elem_type in collate_fn_map:
+            return collate_fn_map[elem_type](batch, collate_fn_map=collate_fn_map)
+
+        for collate_type in collate_fn_map:
+            if isinstance(elem, collate_type):
+                return collate_fn_map[collate_type](batch, collate_fn_map=collate_fn_map)
+
+    if isinstance(elem, collections.abc.Mapping):
+        try:
+            if isinstance(elem, collections.abc.MutableMapping):
+                # The mapping type may have extra properties, so we can't just
+                # use `type(data)(...)` to create the new mapping.
+                # Create a clone and update it if the mapping type is mutable.
+                clone = copy.copy(elem)
+                clone.update({key: collate([d[key] for d in batch], collate_fn_map=collate_fn_map) for key in elem})
+                return clone
+            else:
+                return elem_type({key: collate([d[key] for d in batch], collate_fn_map=collate_fn_map) for key in elem})
+        except TypeError:
+            # The mapping type may not support `copy()` / `update(mapping)`
+            # or `__init__(iterable)`.
+            return {key: collate([d[key] for d in batch], collate_fn_map=collate_fn_map) for key in elem}
+    elif isinstance(elem, tuple) and hasattr(elem, '_fields'):  # namedtuple
+        return elem_type(*(collate(samples, collate_fn_map=collate_fn_map) for samples in zip(*batch)))
+    elif isinstance(elem, collections.abc.Sequence):
+        # check to make sure that the elements in batch have consistent size
+        it = iter(batch)
+        elem_size = len(next(it))
+        if not all(len(elem) == elem_size for elem in it):
+            raise RuntimeError('each element in list of batch should be of equal size')
+        transposed = list(zip(*batch))  # It may be accessed twice, so we use a list.
+
+        if isinstance(elem, tuple):
+            return [collate(samples, collate_fn_map=collate_fn_map) for samples in transposed]  # Backwards compatibility.
+        else:
+            try:
+                if isinstance(elem, collections.abc.MutableSequence):
+                    # The sequence type may have extra properties, so we can't just
+                    # use `type(data)(...)` to create the new sequence.
+                    # Create a clone and update it if the sequence type is mutable.
+                    clone = copy.copy(elem)  # type: ignore[arg-type]
+                    for i, samples in enumerate(transposed):
+                        clone[i] = collate(samples, collate_fn_map=collate_fn_map)
+                    return clone
+                else:
+                    return elem_type([collate(samples, collate_fn_map=collate_fn_map) for samples in transposed])
+            except TypeError:
+                # The sequence type may not support `copy()` / `__setitem__(index, item)`
+                # or `__init__(iterable)` (e.g., `range`).
+                return [collate(samples, collate_fn_map=collate_fn_map) for samples in transposed]
+
+    raise TypeError(default_collate_err_msg_format.format(elem_type))
+
+
+def collate_tensor_fn(batch, *, collate_fn_map: Optional[Dict[Union[Type, Tuple[Type, ...]], Callable]] = None):
+    elem = batch[0]
+    out = None
+    if elem.is_nested:
+        raise RuntimeError(
+            "Batches of nested tensors are not currently supported by the default collate_fn; "
+            "please provide a custom collate_fn to handle them appropriately."
+        )
+    if elem.layout in {torch.sparse_coo, torch.sparse_csr, torch.sparse_bsr, torch.sparse_csc, torch.sparse_bsc}:
+        raise RuntimeError(
+            "Batches of sparse tensors are not currently supported by the default collate_fn; "
+            "please provide a custom collate_fn to handle them appropriately."
+        )
+    if torch.utils.data.get_worker_info() is not None:
+        # If we're in a background process, concatenate directly into a
+        # shared memory tensor to avoid an extra copy
+        numel = sum(x.numel() for x in batch)
+        storage = elem._typed_storage()._new_shared(numel, device=elem.device)
+        out = elem.new(storage).resize_(len(batch), *list(elem.size()))
+    return torch.stack(batch, 0, out=out)
+
+
+def collate_numpy_array_fn(batch, *, collate_fn_map: Optional[Dict[Union[Type, Tuple[Type, ...]], Callable]] = None):
+    elem = batch[0]
+    # array of string classes and object
+    if np_str_obj_array_pattern.search(elem.dtype.str) is not None:
+        raise TypeError(default_collate_err_msg_format.format(elem.dtype))
+
+    return collate([torch.as_tensor(b) for b in batch], collate_fn_map=collate_fn_map)
+
+
+def collate_numpy_scalar_fn(batch, *, collate_fn_map: Optional[Dict[Union[Type, Tuple[Type, ...]], Callable]] = None):
+    return torch.as_tensor(batch)
+
+
+def collate_float_fn(batch, *, collate_fn_map: Optional[Dict[Union[Type, Tuple[Type, ...]], Callable]] = None):
+    return torch.tensor(batch, dtype=torch.float64)
+
+
+def collate_int_fn(batch, *, collate_fn_map: Optional[Dict[Union[Type, Tuple[Type, ...]], Callable]] = None):
+    return torch.tensor(batch)
+
+
+def collate_str_fn(batch, *, collate_fn_map: Optional[Dict[Union[Type, Tuple[Type, ...]], Callable]] = None):
+    return batch
+
+
+default_collate_fn_map: Dict[Union[Type, Tuple[Type, ...]], Callable] = {torch.Tensor: collate_tensor_fn}
+with contextlib.suppress(ImportError):
+    import numpy as np
+    # For both ndarray and memmap (subclass of ndarray)
+    default_collate_fn_map[np.ndarray] = collate_numpy_array_fn
+    # See scalars hierarchy: https://numpy.org/doc/stable/reference/arrays.scalars.html
+    # Skip string scalars
+    default_collate_fn_map[(np.bool_, np.number, np.object_)] = collate_numpy_scalar_fn
+default_collate_fn_map[float] = collate_float_fn
+default_collate_fn_map[int] = collate_int_fn
+default_collate_fn_map[str] = collate_str_fn
+default_collate_fn_map[bytes] = collate_str_fn
+
+
+def default_collate(batch):
+    r"""
+    Take in a batch of data and put the elements within the batch into a tensor with an additional outer dimension - batch size.
+
+    The exact output type can be a :class:`torch.Tensor`, a `Sequence` of :class:`torch.Tensor`, a
+    Collection of :class:`torch.Tensor`, or left unchanged, depending on the input type.
+    This is used as the default function for collation when
+    `batch_size` or `batch_sampler` is defined in :class:`~torch.utils.data.DataLoader`.
+
+    Here is the general input type (based on the type of the element within the batch) to output type mapping:
+
+        * :class:`torch.Tensor` -> :class:`torch.Tensor` (with an added outer dimension batch size)
+        * NumPy Arrays -> :class:`torch.Tensor`
+        * `float` -> :class:`torch.Tensor`
+        * `int` -> :class:`torch.Tensor`
+        * `str` -> `str` (unchanged)
+        * `bytes` -> `bytes` (unchanged)
+        * `Mapping[K, V_i]` -> `Mapping[K, default_collate([V_1, V_2, ...])]`
+        * `NamedTuple[V1_i, V2_i, ...]` -> `NamedTuple[default_collate([V1_1, V1_2, ...]),
+          default_collate([V2_1, V2_2, ...]), ...]`
+        * `Sequence[V1_i, V2_i, ...]` -> `Sequence[default_collate([V1_1, V1_2, ...]),
+          default_collate([V2_1, V2_2, ...]), ...]`
+
+    Args:
+        batch: a single batch to be collated
+
+    Examples:
+        >>> # xdoctest: +SKIP
+        >>> # Example with a batch of `int`s:
+        >>> default_collate([0, 1, 2, 3])
+        tensor([0, 1, 2, 3])
+        >>> # Example with a batch of `str`s:
+        >>> default_collate(['a', 'b', 'c'])
+        ['a', 'b', 'c']
+        >>> # Example with `Map` inside the batch:
+        >>> default_collate([{'A': 0, 'B': 1}, {'A': 100, 'B': 100}])
+        {'A': tensor([  0, 100]), 'B': tensor([  1, 100])}
+        >>> # Example with `NamedTuple` inside the batch:
+        >>> Point = namedtuple('Point', ['x', 'y'])
+        >>> default_collate([Point(0, 0), Point(1, 1)])
+        Point(x=tensor([0, 1]), y=tensor([0, 1]))
+        >>> # Example with `Tuple` inside the batch:
+        >>> default_collate([(0, 1), (2, 3)])
+        [tensor([0, 2]), tensor([1, 3])]
+        >>> # Example with `List` inside the batch:
+        >>> default_collate([[0, 1], [2, 3]])
+        [tensor([0, 2]), tensor([1, 3])]
+        >>> # Two options to extend `default_collate` to handle specific type
+        >>> # Option 1: Write custom collate function and invoke `default_collate`
+        >>> def custom_collate(batch):
+        ...     elem = batch[0]
+        ...     if isinstance(elem, CustomType):  # Some custom condition
+        ...         return ...
+        ...     else:  # Fall back to `default_collate`
+        ...         return default_collate(batch)
+        >>> # Option 2: In-place modify `default_collate_fn_map`
+        >>> def collate_customtype_fn(batch, *, collate_fn_map=None):
+        ...     return ...
+        >>> default_collate_fn_map.update(CustoType, collate_customtype_fn)
+        >>> default_collate(batch)  # Handle `CustomType` automatically
+    """
+    return collate(batch, collate_fn_map=default_collate_fn_map)

venv/lib/python3.10/site-packages/torch/utils/data/_utils/fetch.py

@@ -0,0 +1,54 @@
+r"""Contains definitions of the methods used by the _BaseDataLoaderIter to fetch data from an iterable-style or map-style dataset.
+
+This logic is shared in both single- and multi-processing data loading.
+"""
+
+
+class _BaseDatasetFetcher:
+    def __init__(self, dataset, auto_collation, collate_fn, drop_last):
+        self.dataset = dataset
+        self.auto_collation = auto_collation
+        self.collate_fn = collate_fn
+        self.drop_last = drop_last
+
+    def fetch(self, possibly_batched_index):
+        raise NotImplementedError()
+
+
+class _IterableDatasetFetcher(_BaseDatasetFetcher):
+    def __init__(self, dataset, auto_collation, collate_fn, drop_last):
+        super().__init__(dataset, auto_collation, collate_fn, drop_last)
+        self.dataset_iter = iter(dataset)
+        self.ended = False
+
+    def fetch(self, possibly_batched_index):
+        if self.ended:
+            raise StopIteration
+
+        if self.auto_collation:
+            data = []
+            for _ in possibly_batched_index:
+                try:
+                    data.append(next(self.dataset_iter))
+                except StopIteration:
+                    self.ended = True
+                    break
+            if len(data) == 0 or (
+                self.drop_last and len(data) < len(possibly_batched_index)
+            ):
+                raise StopIteration
+        else:
+            data = next(self.dataset_iter)
+        return self.collate_fn(data)
+
+
+class _MapDatasetFetcher(_BaseDatasetFetcher):
+    def fetch(self, possibly_batched_index):
+        if self.auto_collation:
+            if hasattr(self.dataset, "__getitems__") and self.dataset.__getitems__:
+                data = self.dataset.__getitems__(possibly_batched_index)
+            else:
+                data = [self.dataset[idx] for idx in possibly_batched_index]
+        else:
+            data = self.dataset[possibly_batched_index]
+        return self.collate_fn(data)

venv/lib/python3.10/site-packages/torch/utils/data/_utils/pin_memory.py

@@ -0,0 +1,98 @@
+r"""Contains definitions of the methods used by the _BaseDataLoaderIter to put fetched tensors into pinned memory.
+
+These **needs** to be in global scope since Py2 doesn't support serializing
+static methods.
+"""
+
+import collections
+import copy
+import queue
+
+import torch
+from . import MP_STATUS_CHECK_INTERVAL
+from torch._utils import ExceptionWrapper
+
+
+def _pin_memory_loop(in_queue, out_queue, device_id, done_event, device):
+    # This setting is thread local, and prevents the copy in pin_memory from
+    # consuming all CPU cores.
+    torch.set_num_threads(1)
+
+    if device == "cuda":
+        torch.cuda.set_device(device_id)
+    elif device == "xpu":
+        torch.xpu.set_device(device_id)  # type: ignore[attr-defined]
+    elif device == torch._C._get_privateuse1_backend_name():
+        custom_device_mod = getattr(torch, torch._C._get_privateuse1_backend_name())
+        custom_device_mod.set_device(device_id)
+
+    def do_one_step():
+        try:
+            r = in_queue.get(timeout=MP_STATUS_CHECK_INTERVAL)
+        except queue.Empty:
+            return
+        idx, data = r
+        if not done_event.is_set() and not isinstance(data, ExceptionWrapper):
+            try:
+                data = pin_memory(data, device)
+            except Exception:
+                data = ExceptionWrapper(
+                    where=f"in pin memory thread for device {device_id}")
+            r = (idx, data)
+        while not done_event.is_set():
+            try:
+                out_queue.put(r, timeout=MP_STATUS_CHECK_INTERVAL)
+                break
+            except queue.Full:
+                continue
+
+    # See NOTE [ Data Loader Multiprocessing Shutdown Logic ] for details on the
+    # logic of this function.
+    while not done_event.is_set():
+        # Make sure that we don't preserve any object from one iteration
+        # to the next
+        do_one_step()
+
+def pin_memory(data, device=None):
+    if isinstance(data, torch.Tensor):
+        return data.pin_memory(device)
+    elif isinstance(data, (str, bytes)):
+        return data
+    elif isinstance(data, collections.abc.Mapping):
+        try:
+            if isinstance(data, collections.abc.MutableMapping):
+                # The sequence type may have extra properties, so we can't just
+                # use `type(data)(...)` to create the new sequence.
+                # Create a clone and update it if the sequence type is mutable.
+                clone = copy.copy(data)
+                clone.update({k: pin_memory(sample, device) for k, sample in data.items()})
+                return clone
+            else:
+                return type(data)({k: pin_memory(sample, device) for k, sample in data.items()})  # type: ignore[call-arg]
+        except TypeError:
+            # The mapping type may not support `copy()` / `update(mapping)`
+            # or `__init__(iterable)`.
+            return {k: pin_memory(sample, device) for k, sample in data.items()}
+    elif isinstance(data, tuple) and hasattr(data, '_fields'):  # namedtuple
+        return type(data)(*(pin_memory(sample, device) for sample in data))
+    elif isinstance(data, tuple):
+        return [pin_memory(sample, device) for sample in data]  # Backwards compatibility.
+    elif isinstance(data, collections.abc.Sequence):
+        try:
+            if isinstance(data, collections.abc.MutableSequence):
+                # The sequence type may have extra properties, so we can't just
+                # use `type(data)(...)` to create the new sequence.
+                # Create a clone and update it if the sequence type is mutable.
+                clone = copy.copy(data)  # type: ignore[arg-type]
+                for i, item in enumerate(data):
+                    clone[i] = pin_memory(item, device)
+                return clone
+            return type(data)([pin_memory(sample, device) for sample in data])  # type: ignore[call-arg]
+        except TypeError:
+            # The sequence type may not support `copy()` / `__setitem__(index, item)`
+            # or `__init__(iterable)` (e.g., `range`).
+            return [pin_memory(sample, device) for sample in data]
+    elif hasattr(data, "pin_memory"):
+        return data.pin_memory()
+    else:
+        return data

venv/lib/python3.10/site-packages/torch/utils/data/_utils/signal_handling.py

@@ -0,0 +1,72 @@
+r"""Signal handling for multiprocessing data loading.
+
+NOTE [ Signal handling in multiprocessing data loading ]
+
+In cases like DataLoader, if a worker process dies due to bus error/segfault
+or just hang, the main process will hang waiting for data. This is difficult
+to avoid on PyTorch side as it can be caused by limited shm, or other
+libraries users call in the workers. In this file and `DataLoader.cpp`, we make
+our best effort to provide some error message to users when such unfortunate
+events happen.
+
+When a _BaseDataLoaderIter starts worker processes, their pids are registered in a
+defined in `DataLoader.cpp`: id(_BaseDataLoaderIter) => Collection[ Worker pids ]
+via `_set_worker_pids`.
+
+When an error happens in a worker process, the main process received a SIGCHLD,
+and Python will eventually call the handler registered below
+(in `_set_SIGCHLD_handler`). In the handler, the `_error_if_any_worker_fails`
+call checks all registered worker pids and raise proper error message to
+prevent main process from hanging waiting for data from worker.
+
+Additionally, at the beginning of each worker's `_utils.worker._worker_loop`,
+`_set_worker_signal_handlers` is called to register critical signal handlers
+(e.g., for SIGSEGV, SIGBUS, SIGFPE, SIGTERM) in C, which just prints an error
+message to stderr before triggering the default handler. So a message will also
+be printed from the worker process when it is killed by such signals.
+
+See NOTE [ Data Loader Multiprocessing Shutdown Logic ] for the reasoning of
+this signal handling design and other mechanism we implement to make our
+multiprocessing data loading robust to errors.
+"""
+
+import signal
+import threading
+from . import IS_WINDOWS
+
+# Some of the following imported functions are not used in this file, but are to
+# be used `_utils.signal_handling.XXXXX`.
+from torch._C import _set_worker_pids, _remove_worker_pids  # noqa: F401
+from torch._C import _error_if_any_worker_fails, _set_worker_signal_handlers  # noqa: F401
+
+_SIGCHLD_handler_set = False
+r"""Whether SIGCHLD handler is set for DataLoader worker failures. Only one
+handler needs to be set for all DataLoaders in a process."""
+
+
+def _set_SIGCHLD_handler():
+    # Windows doesn't support SIGCHLD handler
+    if IS_WINDOWS:
+        return
+    # can't set signal in child threads
+    if not isinstance(threading.current_thread(), threading._MainThread):  # type: ignore[attr-defined]
+        return
+    global _SIGCHLD_handler_set
+    if _SIGCHLD_handler_set:
+        return
+    previous_handler = signal.getsignal(signal.SIGCHLD)
+    if not callable(previous_handler):
+        # This doesn't catch default handler, but SIGCHLD default handler is a
+        # no-op.
+        previous_handler = None
+
+    def handler(signum, frame):
+        # This following call uses `waitid` with WNOHANG from C side. Therefore,
+        # Python can still get and update the process status successfully.
+        _error_if_any_worker_fails()
+        if previous_handler is not None:
+            assert callable(previous_handler)
+            previous_handler(signum, frame)
+
+    signal.signal(signal.SIGCHLD, handler)
+    _SIGCHLD_handler_set = True

venv/lib/python3.10/site-packages/torch/utils/data/_utils/worker.py

@@ -0,0 +1,329 @@
+r""""Contains definitions of the methods used by the _BaseDataLoaderIter workers.
+
+These **needs** to be in global scope since Py2 doesn't support serializing
+static methods.
+"""
+
+import torch
+import random
+import os
+import queue
+from dataclasses import dataclass
+from torch._utils import ExceptionWrapper
+from typing import Optional, Union, TYPE_CHECKING
+from . import signal_handling, MP_STATUS_CHECK_INTERVAL, IS_WINDOWS, HAS_NUMPY
+if TYPE_CHECKING:
+    from torch.utils.data import Dataset
+
+if IS_WINDOWS:
+    import ctypes
+    from ctypes.wintypes import DWORD, BOOL, HANDLE
+
+    # On Windows, the parent ID of the worker process remains unchanged when the manager process
+    # is gone, and the only way to check it through OS is to let the worker have a process handle
+    # of the manager and ask if the process status has changed.
+    class ManagerWatchdog:
+        def __init__(self):
+            self.manager_pid = os.getppid()
+
+            # mypy cannot detect this code is windows only
+            self.kernel32 = ctypes.WinDLL('kernel32', use_last_error=True)  # type: ignore[attr-defined]
+            self.kernel32.OpenProcess.argtypes = (DWORD, BOOL, DWORD)
+            self.kernel32.OpenProcess.restype = HANDLE
+            self.kernel32.WaitForSingleObject.argtypes = (HANDLE, DWORD)
+            self.kernel32.WaitForSingleObject.restype = DWORD
+
+            # Value obtained from https://msdn.microsoft.com/en-us/library/ms684880.aspx
+            SYNCHRONIZE = 0x00100000
+            self.manager_handle = self.kernel32.OpenProcess(SYNCHRONIZE, 0, self.manager_pid)
+
+            if not self.manager_handle:
+                raise ctypes.WinError(ctypes.get_last_error())  # type: ignore[attr-defined]
+
+            self.manager_dead = False
+
+        def is_alive(self):
+            if not self.manager_dead:
+                # Value obtained from https://msdn.microsoft.com/en-us/library/windows/desktop/ms687032.aspx
+                self.manager_dead = self.kernel32.WaitForSingleObject(self.manager_handle, 0) == 0
+            return not self.manager_dead
+else:
+    class ManagerWatchdog:  # type: ignore[no-redef]
+        def __init__(self):
+            self.manager_pid = os.getppid()
+            self.manager_dead = False
+
+        def is_alive(self):
+            if not self.manager_dead:
+                self.manager_dead = os.getppid() != self.manager_pid
+            return not self.manager_dead
+
+_worker_info: Optional["WorkerInfo"] = None
+
+
+class WorkerInfo:
+    id: int
+    num_workers: int
+    seed: int
+    dataset: 'Dataset'
+    __initialized = False
+
+    def __init__(self, **kwargs):
+        for k, v in kwargs.items():
+            setattr(self, k, v)
+        self.__keys = tuple(kwargs.keys())
+        self.__initialized = True
+
+    def __setattr__(self, key, val):
+        if self.__initialized:
+            raise RuntimeError(f"Cannot assign attributes to {self.__class__.__name__} objects")
+        return super().__setattr__(key, val)
+
+    def __repr__(self):
+        items = []
+        for k in self.__keys:
+            items.append(f'{k}={getattr(self, k)}')
+        return f"{self.__class__.__name__}({', '.join(items)})"
+
+
+def get_worker_info() -> Optional[WorkerInfo]:
+    r"""Returns the information about the current
+    :class:`~torch.utils.data.DataLoader` iterator worker process.
+
+    When called in a worker, this returns an object guaranteed to have the
+    following attributes:
+
+    * :attr:`id`: the current worker id.
+    * :attr:`num_workers`: the total number of workers.
+    * :attr:`seed`: the random seed set for the current worker. This value is
+      determined by main process RNG and the worker id. See
+      :class:`~torch.utils.data.DataLoader`'s documentation for more details.
+    * :attr:`dataset`: the copy of the dataset object in **this** process. Note
+      that this will be a different object in a different process than the one
+      in the main process.
+
+    When called in the main process, this returns ``None``.
+
+    .. note::
+       When used in a :attr:`worker_init_fn` passed over to
+       :class:`~torch.utils.data.DataLoader`, this method can be useful to
+       set up each worker process differently, for instance, using ``worker_id``
+       to configure the ``dataset`` object to only read a specific fraction of a
+       sharded dataset, or use ``seed`` to seed other libraries used in dataset
+       code.
+    """
+    return _worker_info
+
+
+r"""Dummy class used to signal the end of an IterableDataset"""
+@dataclass(frozen=True)
+class _IterableDatasetStopIteration:
+    worker_id: int
+
+r"""Dummy class used to resume the fetching when worker reuse is enabled"""
+@dataclass(frozen=True)
+class _ResumeIteration:
+    seed: Optional[int] = None
+
+# The function `_generate_state` is adapted from `numpy.random.SeedSequence`
+# from https://github.com/numpy/numpy/blob/main/numpy/random/bit_generator.pyx
+# It's MIT licensed, here is the copyright:
+
+# Copyright (c) 2015 Melissa E. O'Neill
+# Copyright (c) 2019 NumPy Developers
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+# This function generates an array of int32 as the seed for
+# `numpy.random`, in order to prevent state collision due to same
+# seed and algorithm for `numpy.random` and `random` modules.
+# TODO: Implement `SeedSequence` like object for `torch.random`
+def _generate_state(base_seed, worker_id):
+    INIT_A = 0x43b0d7e5
+    MULT_A = 0x931e8875
+    INIT_B = 0x8b51f9dd
+    MULT_B = 0x58f38ded
+    MIX_MULT_L = 0xca01f9dd
+    MIX_MULT_R = 0x4973f715
+    XSHIFT = 4 * 8 // 2
+    MASK32 = 0xFFFFFFFF
+
+    entropy = [worker_id, base_seed & MASK32, base_seed >> 32, 0]
+    pool = [0] * 4
+
+    hash_const_A = INIT_A
+
+    def hash(value):
+        nonlocal hash_const_A
+        value = (value ^ hash_const_A) & MASK32
+        hash_const_A = (hash_const_A * MULT_A) & MASK32
+        value = (value * hash_const_A) & MASK32
+        value = (value ^ (value >> XSHIFT)) & MASK32
+        return value
+
+    def mix(x, y):
+        result_x = (MIX_MULT_L * x) & MASK32
+        result_y = (MIX_MULT_R * y) & MASK32
+        result = (result_x - result_y) & MASK32
+        result = (result ^ (result >> XSHIFT)) & MASK32
+        return result
+
+    # Add in the entropy to the pool.
+    for i in range(len(pool)):
+        pool[i] = hash(entropy[i])
+
+    # Mix all bits together so late bits can affect earlier bits.
+    for i_src in range(len(pool)):
+        for i_dst in range(len(pool)):
+            if i_src != i_dst:
+                pool[i_dst] = mix(pool[i_dst], hash(pool[i_src]))
+
+    hash_const_B = INIT_B
+    state = []
+    for i_dst in range(4):
+        data_val = pool[i_dst]
+        data_val = (data_val ^ hash_const_B) & MASK32
+        hash_const_B = (hash_const_B * MULT_B) & MASK32
+        data_val = (data_val * hash_const_B) & MASK32
+        data_val = (data_val ^ (data_val >> XSHIFT)) & MASK32
+        state.append(data_val)
+    return state
+
+def _worker_loop(dataset_kind, dataset, index_queue, data_queue, done_event,
+                 auto_collation, collate_fn, drop_last, base_seed, init_fn, worker_id,
+                 num_workers, persistent_workers, shared_seed):
+    # See NOTE [ Data Loader Multiprocessing Shutdown Logic ] for details on the
+    # logic of this function.
+
+    try:
+        # Initialize C side signal handlers for SIGBUS and SIGSEGV. Python signal
+        # module's handlers are executed after Python returns from C low-level
+        # handlers, likely when the same fatal signal had already happened
+        # again.
+        # https://docs.python.org/3/library/signal.html#execution-of-python-signal-handlers
+        signal_handling._set_worker_signal_handlers()
+
+        torch.set_num_threads(1)
+        seed = base_seed + worker_id
+        random.seed(seed)
+        torch.manual_seed(seed)
+        if HAS_NUMPY:
+            np_seed = _generate_state(base_seed, worker_id)
+            import numpy as np
+            np.random.seed(np_seed)
+
+        from torch.utils.data import IterDataPipe
+        from torch.utils.data.graph_settings import apply_random_seed
+
+        shared_rng = torch.Generator()
+        if isinstance(dataset, IterDataPipe):
+            assert shared_seed is not None
+            shared_rng.manual_seed(shared_seed)
+            dataset = apply_random_seed(dataset, shared_rng)
+
+        global _worker_info
+        _worker_info = WorkerInfo(id=worker_id, num_workers=num_workers,
+                                  seed=seed, dataset=dataset)
+
+        from torch.utils.data import _DatasetKind
+
+        init_exception = None
+
+        try:
+            if init_fn is not None:
+                init_fn(worker_id)
+
+            fetcher = _DatasetKind.create_fetcher(dataset_kind, dataset, auto_collation, collate_fn, drop_last)
+        except Exception:
+            init_exception = ExceptionWrapper(
+                where=f"in DataLoader worker process {worker_id}")
+
+        # When using Iterable mode, some worker can exit earlier than others due
+        # to the IterableDataset behaving differently for different workers.
+        # When such things happen, an `_IterableDatasetStopIteration` object is
+        # sent over to the main process with the ID of this worker, so that the
+        # main process won't send more tasks to this worker, and will send
+        # `None` to this worker to properly exit it.
+        #
+        # Note that we cannot set `done_event` from a worker as it is shared
+        # among all processes. Instead, we set the `iteration_end` flag to
+        # signify that the iterator is exhausted. When either `done_event` or
+        # `iteration_end` is set, we skip all processing step and just wait for
+        # `None`.
+        iteration_end = False
+
+        watchdog = ManagerWatchdog()
+
+        while watchdog.is_alive():
+            try:
+                r = index_queue.get(timeout=MP_STATUS_CHECK_INTERVAL)
+            except queue.Empty:
+                continue
+            if isinstance(r, _ResumeIteration):
+                # Acknowledge the main process
+                data_queue.put((r, None))
+                iteration_end = False
+
+                if isinstance(dataset, IterDataPipe):
+                    assert r.seed is not None
+                    shared_rng.manual_seed(r.seed)
+                    dataset = apply_random_seed(dataset, shared_rng)
+
+                # Recreate the fetcher for worker-reuse policy
+                fetcher = _DatasetKind.create_fetcher(
+                    dataset_kind, dataset, auto_collation, collate_fn, drop_last)
+                continue
+            elif r is None:
+                # Received the final signal
+                assert done_event.is_set() or iteration_end
+                break
+            elif done_event.is_set() or iteration_end:
+                # `done_event` is set. But I haven't received the final signal
+                # (None) yet. I will keep continuing until get it, and skip the
+                # processing steps.
+                continue
+            idx, index = r
+            data: Union[_IterableDatasetStopIteration, ExceptionWrapper]
+            if init_exception is not None:
+                data = init_exception
+                init_exception = None
+            else:
+                try:
+                    data = fetcher.fetch(index)  # type: ignore[possibly-undefined]
+                except Exception as e:
+                    if isinstance(e, StopIteration) and dataset_kind == _DatasetKind.Iterable:
+                        data = _IterableDatasetStopIteration(worker_id)
+                        # Set `iteration_end`
+                        #   (1) to save future `next(...)` calls, and
+                        #   (2) to avoid sending multiple `_IterableDatasetStopIteration`s.
+                        iteration_end = True
+                    else:
+                        # It is important that we don't store exc_info in a variable.
+                        # `ExceptionWrapper` does the correct thing.
+                        # See NOTE [ Python Traceback Reference Cycle Problem ]
+                        data = ExceptionWrapper(
+                            where=f"in DataLoader worker process {worker_id}")
+            data_queue.put((idx, data))
+            del data, idx, index, r  # save memory
+    except KeyboardInterrupt:
+        # Main process will raise KeyboardInterrupt anyways.
+        pass
+    if done_event.is_set():
+        data_queue.cancel_join_thread()
+        data_queue.close()

venv/lib/python3.10/site-packages/torch/utils/data/datapipes/iter/__init__.py

@@ -0,0 +1,64 @@
+from torch.utils.data.datapipes.iter.utils import (
+    IterableWrapperIterDataPipe as IterableWrapper,
+)
+from torch.utils.data.datapipes.iter.callable import (
+    CollatorIterDataPipe as Collator,
+    MapperIterDataPipe as Mapper,
+)
+from torch.utils.data.datapipes.iter.combinatorics import (
+    SamplerIterDataPipe as Sampler,
+    ShufflerIterDataPipe as Shuffler,
+)
+from torch.utils.data.datapipes.iter.combining import (
+    ConcaterIterDataPipe as Concater,
+    DemultiplexerIterDataPipe as Demultiplexer,
+    ForkerIterDataPipe as Forker,
+    MultiplexerIterDataPipe as Multiplexer,
+    ZipperIterDataPipe as Zipper,
+)
+from torch.utils.data.datapipes.iter.filelister import (
+    FileListerIterDataPipe as FileLister,
+)
+from torch.utils.data.datapipes.iter.fileopener import (
+    FileOpenerIterDataPipe as FileOpener,
+)
+from torch.utils.data.datapipes.iter.grouping import (
+    BatcherIterDataPipe as Batcher,
+    GrouperIterDataPipe as Grouper,
+    UnBatcherIterDataPipe as UnBatcher,
+)
+from torch.utils.data.datapipes.iter.sharding import (
+    ShardingFilterIterDataPipe as ShardingFilter,
+)
+from torch.utils.data.datapipes.iter.routeddecoder import (
+    RoutedDecoderIterDataPipe as RoutedDecoder,
+)
+from torch.utils.data.datapipes.iter.selecting import (
+    FilterIterDataPipe as Filter,
+)
+from torch.utils.data.datapipes.iter.streamreader import (
+    StreamReaderIterDataPipe as StreamReader,
+)
+
+__all__ = ['Batcher',
+           'Collator',
+           'Concater',
+           'Demultiplexer',
+           'FileLister',
+           'FileOpener',
+           'Filter',
+           'Forker',
+           'Grouper',
+           'IterableWrapper',
+           'Mapper',
+           'Multiplexer',
+           'RoutedDecoder',
+           'Sampler',
+           'ShardingFilter',
+           'Shuffler',
+           'StreamReader',
+           'UnBatcher',
+           'Zipper']
+
+# Please keep this list sorted
+assert __all__ == sorted(__all__)

venv/lib/python3.10/site-packages/torch/utils/data/datapipes/iter/combinatorics.py

@@ -0,0 +1,183 @@
+import random
+import torch
+
+from torch.utils.data import Sampler, SequentialSampler
+from torch.utils.data.datapipes._decorator import functional_datapipe
+from torch.utils.data.datapipes.datapipe import IterDataPipe
+from typing import Dict, Iterator, List, Optional, Sized, Tuple, Type, TypeVar
+
+__all__ = [
+    "SamplerIterDataPipe",
+    "ShufflerIterDataPipe",
+]
+
+T_co = TypeVar('T_co', covariant=True)
+
+
+class SamplerIterDataPipe(IterDataPipe[T_co]):
+    r"""
+    Generate sample elements using the provided ``Sampler`` (defaults to :class:`SequentialSampler`).
+
+    Args:
+        datapipe: IterDataPipe to sample from
+        sampler: Sampler class to generate sample elements from input DataPipe.
+            Default is :class:`SequentialSampler` for IterDataPipe
+    """
+
+    datapipe: IterDataPipe
+    sampler: Sampler
+
+    def __init__(self,
+                 datapipe: IterDataPipe,
+                 sampler: Type[Sampler] = SequentialSampler,
+                 sampler_args: Optional[Tuple] = None,
+                 sampler_kwargs: Optional[Dict] = None
+                 ) -> None:
+        assert isinstance(datapipe, Sized), \
+            "Sampler class requires input datapipe implemented `__len__`"
+        super().__init__()
+        self.datapipe = datapipe
+        self.sampler_args = () if sampler_args is None else sampler_args
+        self.sampler_kwargs = {} if sampler_kwargs is None else sampler_kwargs
+        # https://github.com/python/mypy/pull/9629 will solve
+        self.sampler = sampler(*self.sampler_args, data_source=self.datapipe, **self.sampler_kwargs)  # type: ignore[misc]
+
+    def __iter__(self) -> Iterator[T_co]:
+        return iter(self.sampler)
+
+    def __len__(self) -> int:
+        # Dataset has been tested as `Sized`
+        if isinstance(self.sampler, Sized):
+            return len(self.sampler)
+        raise TypeError(f"{type(self).__name__} instance doesn't have valid length")
+
+
+@functional_datapipe('shuffle')
+class ShufflerIterDataPipe(IterDataPipe[T_co]):
+    r"""
+    Shuffle the input DataPipe with a buffer (functional name: ``shuffle``).
+
+    The buffer with ``buffer_size`` is filled with elements from the datapipe first. Then,
+    each item will be yielded from the buffer by reservoir sampling via iterator.
+
+    ``buffer_size`` is required to be larger than ``0``. For ``buffer_size == 1``, the
+    datapipe is not shuffled. In order to fully shuffle all elements from datapipe,
+    ``buffer_size`` is required to be greater than or equal to the size of datapipe.
+
+    When it is used with :class:`torch.utils.data.DataLoader`, the methods to
+    set up random seed are different based on :attr:`num_workers`.
+
+    For single-process mode (:attr:`num_workers == 0`), the random seed is set before
+    the :class:`~torch.utils.data.DataLoader` in the main process. For multi-process
+    mode (:attr:`num_worker > 0`), `worker_init_fn` is used to set up a random seed
+    for each worker process.
+
+    Args:
+        datapipe: The IterDataPipe being shuffled
+        buffer_size: The buffer size for shuffling (default to ``10000``)
+        unbatch_level: Specifies if it is necessary to unbatch source data before
+            applying the shuffle
+
+    Example:
+        >>> # xdoctest: +SKIP
+        >>> from torchdata.datapipes.iter import IterableWrapper
+        >>> dp = IterableWrapper(range(10))
+        >>> shuffle_dp = dp.shuffle()
+        >>> list(shuffle_dp)
+        [0, 4, 1, 6, 3, 2, 9, 5, 7, 8]
+    """
+
+    datapipe: IterDataPipe[T_co]
+    buffer_size: int
+    _buffer: List[T_co]
+    _enabled: bool
+    _seed: Optional[int]
+    _rng: random.Random
+
+    def __init__(self,
+                 datapipe: IterDataPipe[T_co],
+                 *,
+                 buffer_size: int = 10000,
+                 unbatch_level: int = 0
+                 ) -> None:
+        super().__init__()
+        # TODO: Performance optimization
+        #       buffer can be a fixed size and remove expensive `append()` and `len()` operations
+        self._buffer: List[T_co] = []
+        assert buffer_size > 0, "buffer_size should be larger than 0"
+        if unbatch_level == 0:
+            self.datapipe = datapipe
+        else:
+            self.datapipe = datapipe.unbatch(unbatch_level=unbatch_level)
+        self.buffer_size = buffer_size
+        self._enabled = True
+        self._seed = None
+        self._rng = random.Random()
+
+    def set_shuffle(self, shuffle=True):
+        self._enabled = shuffle
+        return self
+
+    def set_seed(self, seed: int):
+        self._seed = seed
+        return self
+
+    def __iter__(self) -> Iterator[T_co]:
+        if not self._enabled:
+            yield from self.datapipe
+        else:
+            for x in self.datapipe:
+                if len(self._buffer) == self.buffer_size:
+                    idx = self._rng.randint(0, len(self._buffer) - 1)
+                    val, self._buffer[idx] = self._buffer[idx], x
+                    yield val
+                else:
+                    self._buffer.append(x)
+            while self._buffer:
+                idx = self._rng.randint(0, len(self._buffer) - 1)
+                yield self._buffer.pop(idx)
+
+    def __len__(self) -> int:
+        if isinstance(self.datapipe, Sized):
+            return len(self.datapipe)
+        raise TypeError(f"{type(self).__name__} instance doesn't have valid length")
+
+    def reset(self) -> None:
+        self._buffer = []
+        if self._enabled:
+            if self._seed is None:
+                self._seed = int(torch.empty((), dtype=torch.int64).random_().item())
+            self._rng.seed(self._seed)
+            self._seed = None
+
+    def __getstate__(self):
+        state = (
+            self.datapipe,
+            self.buffer_size,
+            self._enabled,
+            self._seed,
+            self._buffer,
+            self._rng.getstate(),
+            self._valid_iterator_id,
+            self._number_of_samples_yielded,
+        )
+        if IterDataPipe.getstate_hook is not None:
+            return IterDataPipe.getstate_hook(state)
+        return state
+
+    def __setstate__(self, state):
+        (
+            self.datapipe,
+            self.buffer_size,
+            self._enabled,
+            self._seed,
+            self._buffer,
+            rng_state,
+            self._valid_iterator_id,
+            self._number_of_samples_yielded,
+        ) = state
+        self._rng = random.Random()
+        self._rng.setstate(rng_state)
+
+    def __del__(self):
+        self._buffer.clear()

venv/lib/python3.10/site-packages/torch/utils/data/datapipes/iter/combining.py

@@ -0,0 +1,639 @@
+import warnings
+
+from abc import ABC, abstractmethod
+from collections import deque
+import copy as copymodule
+from typing import Any, Callable, Iterator, List, Literal, Optional, Sized, Tuple, TypeVar, Deque
+
+from torch.utils.data.datapipes._decorator import functional_datapipe
+from torch.utils.data.datapipes._hook_iterator import _SnapshotState
+from torch.utils.data.datapipes.datapipe import IterDataPipe
+from torch.utils.data.datapipes.utils.common import StreamWrapper, _check_unpickable_fn
+
+__all__ = [
+    "ConcaterIterDataPipe",
+    "DemultiplexerIterDataPipe",
+    "ForkerIterDataPipe",
+    "MultiplexerIterDataPipe",
+    "ZipperIterDataPipe",
+]
+
+T_co = TypeVar('T_co', covariant=True)
+
+
+@functional_datapipe('concat')
+class ConcaterIterDataPipe(IterDataPipe):
+    r"""
+    Concatenates multiple Iterable DataPipes (functional name: ``concat``).
+
+    The resulting DataPipe will yield all the elements from the first input DataPipe, before yielding from the subsequent ones.
+
+    Args:
+        datapipes: Iterable DataPipes being concatenated
+
+    Example:
+        >>> # xdoctest: +REQUIRES(module:torchdata)
+        >>> import random
+        >>> from torchdata.datapipes.iter import IterableWrapper
+        >>> dp1 = IterableWrapper(range(3))
+        >>> dp2 = IterableWrapper(range(5))
+        >>> list(dp1.concat(dp2))
+        [0, 1, 2, 0, 1, 2, 3, 4]
+    """
+
+    datapipes: Tuple[IterDataPipe]
+
+    def __init__(self, *datapipes: IterDataPipe):
+        if len(datapipes) == 0:
+            raise ValueError("Expected at least one DataPipe, but got nothing")
+        if not all(isinstance(dp, IterDataPipe) for dp in datapipes):
+            raise TypeError("Expected all inputs to be `IterDataPipe`")
+        self.datapipes = datapipes  # type: ignore[assignment]
+
+    def __iter__(self) -> Iterator:
+        for dp in self.datapipes:
+            yield from dp
+
+    def __len__(self) -> int:
+        if all(isinstance(dp, Sized) for dp in self.datapipes):
+            return sum(len(dp) for dp in self.datapipes)
+        else:
+            raise TypeError(f"{type(self).__name__} instance doesn't have valid length")
+
+
+@functional_datapipe('fork')
+class ForkerIterDataPipe(IterDataPipe):
+    r"""
+    Creates multiple instances of the same Iterable DataPipe (functional name: ``fork``).
+
+    Args:
+        datapipe: Iterable DataPipe being copied
+        num_instances: number of instances of the datapipe to create
+        buffer_size: this restricts how far ahead the leading child DataPipe
+           can read relative to the slowest child DataPipe.
+           Defaults to ``1000``. Use ``-1`` for the unlimited buffer.
+        copy: copy strategy to use for items yielded by each branch. Supported
+            options are ``None`` for no copying, ``"shallow"`` for shallow object
+            copies, and ``"deep"`` for deep object copies. Defaults to ``None``.
+
+    Note:
+        All branches of the forked pipeline return the identical object unless
+        the copy parameter is supplied. If the object is mutable or contains
+        mutable objects, changing them in one branch will affect all others.
+
+    Example:
+        >>> # xdoctest: +REQUIRES(module:torchdata)
+        >>> from torchdata.datapipes.iter import IterableWrapper
+        >>> source_dp = IterableWrapper(range(5))
+        >>> dp1, dp2 = source_dp.fork(num_instances=2)
+        >>> list(dp1)
+        [0, 1, 2, 3, 4]
+        >>> list(dp2)
+        [0, 1, 2, 3, 4]
+    """
+
+    def __new__(
+        cls,
+        datapipe: IterDataPipe,
+        num_instances: int,
+        buffer_size: int = 1000,
+        copy: Optional[Literal["shallow", "deep"]] = None
+    ):
+        if num_instances < 1:
+            raise ValueError(f"Expected `num_instances` larger than 0, but {num_instances} is found")
+        if num_instances == 1:
+            return datapipe
+        container = _ForkerIterDataPipe(datapipe, num_instances, buffer_size, copy)  # type: ignore[abstract]
+        return [_ChildDataPipe(container, i) for i in range(num_instances)]
+
+
+class _ContainerTemplate(ABC):
+    r"""Abstract class for container ``DataPipes``. The followings are three required methods."""
+
+    @abstractmethod
+    def get_next_element_by_instance(self, instance_id: int):
+        ...
+
+    @abstractmethod
+    def is_every_instance_exhausted(self) -> bool:
+        ...
+
+    @abstractmethod
+    def reset(self) -> None:
+        ...
+
+    @abstractmethod
+    def get_length_by_instance(self, instance_id: int):
+        r"""Raise TypeError if it's not supposed to be implemented to support `list(datapipe)`."""
+
+
+def _no_op(x):
+    return x
+
+
+class _ForkerIterDataPipe(IterDataPipe, _ContainerTemplate):
+    r"""
+    Container to hold instance-specific information on behalf of ForkerIterDataPipe.
+
+    It tracks the state of its child DataPipes, maintains the buffer, and yields the next value
+    as requested by the child DataPipes.
+    """
+
+    def __init__(
+        self,
+        datapipe: IterDataPipe,
+        num_instances: int,
+        buffer_size: int = 1000,
+        copy: Optional[Literal["shallow", "deep"]] = None
+    ):
+        self.main_datapipe = datapipe
+        self._datapipe_iterator: Optional[Iterator[Any]] = None
+        self.num_instances = num_instances
+        self.buffer: Deque = deque()
+        self.buffer_size = buffer_size
+        if self.buffer_size < 0:
+            warnings.warn(
+                "Unlimited buffer size is set for `fork`, "
+                "please be aware of OOM at random places",
+                UserWarning
+            )
+        if copy is None:
+            self.copy_fn = _no_op
+        elif copy == "shallow":
+            self.copy_fn = copymodule.copy
+        elif copy == "deep":
+            self.copy_fn = copymodule.deepcopy
+        else:
+            raise ValueError(f"Unknown copy method `{copy}` requested, choose one of None, `shallow` or `deep`.")
+
+        self.child_pointers: List[int] = [0] * num_instances  # Indicate the indices of the next element to get
+        self.slowest_ptr = 0  # The index to read by the slowest child
+        self.leading_ptr = 0  # The index to read by the fastest child
+        self.end_ptr: Optional[int] = None  # The index to stop child
+        self._child_stop: List[bool] = [True for _ in range(num_instances)]
+
+    def __len__(self):
+        return len(self.main_datapipe)
+
+    def get_next_element_by_instance(self, instance_id: int):
+        if self._datapipe_iterator is None and self._child_stop[instance_id]:
+            self._datapipe_iterator = iter(self.main_datapipe)
+            self._snapshot_state = _SnapshotState.Iterating
+            for i in range(self.num_instances):
+                self._child_stop[i] = False
+        try:
+            while not self._child_stop[instance_id]:
+                self.child_pointers[instance_id] += 1
+                if self.end_ptr is not None and self.child_pointers[instance_id] == self.end_ptr:
+                    self._child_stop[instance_id] = True
+                    break
+                # Use buffer
+                if self.buffer and self.child_pointers[instance_id] <= self.leading_ptr:
+                    idx = self.child_pointers[instance_id] - self.slowest_ptr - 1
+                    return_val = self.buffer[idx]
+                else:  # Retrieve one element from main datapipe
+                    self.leading_ptr = self.child_pointers[instance_id]
+                    try:
+                        return_val = next(self._datapipe_iterator)  # type: ignore[arg-type]
+                        self.buffer.append(return_val)
+                    except StopIteration:
+                        self._child_stop[instance_id] = True
+                        self._datapipe_iterator = None
+                        self.end_ptr = self.leading_ptr
+                        continue
+                if self.child_pointers[instance_id] == self.slowest_ptr + 1:
+                    new_min = min(self.child_pointers)  # Can optimize by avoiding the call to min()
+                    if self.slowest_ptr < new_min:
+                        self.slowest_ptr = new_min
+                        self.buffer.popleft()
+                if self.buffer_size >= 0 and self.leading_ptr > self.buffer_size + self.slowest_ptr:
+                    raise BufferError("ForkerIterDataPipe buffer overflow," +
+                                      f"buffer size {self.buffer_size} is insufficient.")
+
+                yield self.copy_fn(return_val)  # type: ignore[possibly-undefined]
+        finally:
+            self._child_stop[instance_id] = True
+            # Cleanup _datapipe_iterator for the case that fork exits earlier
+            if all(self._child_stop):
+                self._datapipe_iterator = None
+                self._cleanup()
+
+    def is_every_instance_exhausted(self) -> bool:
+        return self.end_ptr is not None and all(self._child_stop)
+
+    def get_length_by_instance(self, instance_id: int) -> int:
+        return len(self.main_datapipe)
+
+    def reset(self) -> None:
+        self._datapipe_iterator = None
+        self.buffer = deque()
+        self.child_pointers = [0] * self.num_instances
+        self.slowest_ptr = 0
+        self.leading_ptr = 0
+        self.end_ptr = None
+        self._child_stop = [True for _ in range(self.num_instances)]
+
+    def __getstate__(self):
+        state = (
+            self.main_datapipe,
+            self.num_instances,
+            self.buffer_size,
+            self.copy_fn,
+            self._valid_iterator_id,
+            self._number_of_samples_yielded,
+        )
+        if IterDataPipe.getstate_hook is not None:
+            return IterDataPipe.getstate_hook(state)
+        return state
+
+    def __setstate__(self, state):
+        (
+            self.main_datapipe,
+            self.num_instances,
+            self.buffer_size,
+            self.copy_fn,
+            self._valid_iterator_id,
+            self._number_of_samples_yielded,
+        ) = state
+        self._datapipe_iterator = None
+        self.buffer = deque()
+        self.child_pointers = [0] * self.num_instances
+        self.slowest_ptr = 0
+        self.leading_ptr = 0
+        self.end_ptr = None
+        self._child_stop = [True for _ in range(self.num_instances)]
+
+    def _cleanup(self):
+        while self.buffer:
+            d = self.buffer.popleft()
+            StreamWrapper.close_streams(d)
+
+    def __del__(self):
+        self._cleanup()
+
+
+class _ChildDataPipe(IterDataPipe):
+    r"""
+    Iterable Datapipe that is a child of a main DataPipe.
+
+    The instance of this class will pass its instance_id to get the next value from its main DataPipe.
+
+    Note:
+        ChildDataPipe, like all other IterDataPipe, follows the single iterator per IterDataPipe constraint.
+        Since ChildDataPipes share a common buffer, when an iterator is created for one of the ChildDataPipes,
+        the previous iterators  for all ChildDataPipes must be invalidated, with the exception when a ChildDataPipe
+        hasn't had an iterator created from it since the last invalidation. See the example below.
+
+    Example:
+        >>> # xdoctest: +REQUIRES(module:torchdata)
+        >>> # Singler Iterator per IteraDataPipe Invalidation
+        >>> from torchdata.datapipes.iter import IterableWrapper
+        >>> source_dp = IterableWrapper(range(10))
+        >>> cdp1, cdp2 = source_dp.fork(num_instances=2)
+        >>> it1, it2 = iter(cdp1), iter(cdp2)
+        >>> it3 = iter(cdp1)
+        >>> # The line above invalidates `it1` and `it2`, and resets `ForkerIterDataPipe`.
+        >>> it4 = iter(cdp2)
+        >>> # The line above doesn't invalidate `it3`, because an iterator for `cdp2` hasn't been created since
+        >>> # the last invalidation.
+
+    Args:
+        main_datapipe: Main DataPipe with a method 'get_next_element_by_instance(instance_id)'
+        instance_id: integer identifier of this instance
+    """
+
+    _is_child_datapipe: bool = True
+
+    def __init__(self, main_datapipe: IterDataPipe, instance_id: int):
+        assert isinstance(main_datapipe, _ContainerTemplate)
+
+        self.main_datapipe: IterDataPipe = main_datapipe
+        self.instance_id = instance_id
+
+    def __iter__(self):
+        # Note that the logic behind setting iterator ID and `reset` are handled within `hook_iterator`
+        # We want to separate the code for reset and yield, so that 'reset' executes before __next__ is called
+        return self.main_datapipe.get_next_element_by_instance(self.instance_id)
+
+    def __len__(self):
+        return self.main_datapipe.get_length_by_instance(self.instance_id)
+
+    # This method is called by `hook_iterator` in `_typing.py`.
+    def _set_main_datapipe_valid_iterator_id(self) -> int:
+        r"""
+        Update the valid iterator ID for both this DataPipe object and `main_datapipe`.
+
+        `main_datapipe.reset()` is called when the ID is incremented to a new generation.
+        """
+        # 1. First time any child iterator is created
+        if self.main_datapipe._valid_iterator_id is None:
+            self.main_datapipe._valid_iterator_id = 0  # type: ignore[attr-defined]
+        # 2. This instance was already in the same generation as `main_datapipe`,
+        #    we need to increment the ID further by 1
+        elif self.main_datapipe._valid_iterator_id == self._valid_iterator_id:  # type: ignore[has-type]
+            self.main_datapipe._valid_iterator_id += 1  # type: ignore[attr-defined]
+            # Whenever a new generation of iterator is created, the `main_datapipe` must reset
+            if not self.main_datapipe.is_every_instance_exhausted():
+                warnings.warn("Some child DataPipes are not exhausted when __iter__ is called. We are resetting "
+                              "the buffer and each child DataPipe will read from the start again.", UserWarning)
+            self.main_datapipe.reset()
+        # 3. Otherwise, the iterator is behind the others, so it will just need to catch up by setting
+        #    the instance's iterator to match that of `main_datapipe`
+        self._valid_iterator_id = self.main_datapipe._valid_iterator_id
+        return self._valid_iterator_id
+
+    # This method is called by `hook_iterator` in `_typing.py`.
+    def _check_valid_iterator_id(self, iterator_id) -> bool:
+        r"""Check the valid iterator ID against that of DataPipe object and that of `main_datapipe`."""
+        return iterator_id == self._valid_iterator_id and iterator_id == self.main_datapipe._valid_iterator_id
+
+
+@functional_datapipe('demux')
+class DemultiplexerIterDataPipe(IterDataPipe):
+    r"""
+    Splits the input DataPipe into multiple child DataPipes, using the given classification function (functional name: ``demux``).
+
+    A list of the child DataPipes is returned from this operation.
+
+    Args:
+        datapipe: Iterable DataPipe being filtered
+        num_instances: number of instances of the DataPipe to create
+        classifier_fn: a function that maps values to an integer within the range ``[0, num_instances - 1]`` or ``None``
+        drop_none: defaults to ``False``, if ``True``, the function will skip over elements classified as ``None``
+        buffer_size: this defines the maximum number of inputs that the buffer can hold across all child
+            DataPipes while waiting for their values to be yielded.
+            Defaults to ``1000``. Use ``-1`` for the unlimited buffer.
+
+    Examples:
+        >>> # xdoctest: +REQUIRES(module:torchdata)
+        >>> from torchdata.datapipes.iter import IterableWrapper
+        >>> def odd_or_even(n):
+        ...     return n % 2
+        >>> source_dp = IterableWrapper(range(5))
+        >>> dp1, dp2 = source_dp.demux(num_instances=2, classifier_fn=odd_or_even)
+        >>> list(dp1)
+        [0, 2, 4]
+        >>> list(dp2)
+        [1, 3]
+        >>> # It can also filter out any element that gets `None` from the `classifier_fn`
+        >>> def odd_or_even_no_zero(n):
+        ...     return n % 2 if n != 0 else None
+        >>> dp1, dp2 = source_dp.demux(num_instances=2, classifier_fn=odd_or_even_no_zero, drop_none=True)
+        >>> list(dp1)
+        [2, 4]
+        >>> list(dp2)
+        [1, 3]
+    """
+
+    def __new__(cls, datapipe: IterDataPipe, num_instances: int,
+                classifier_fn: Callable[[T_co], Optional[int]], drop_none: bool = False, buffer_size: int = 1000):
+        if num_instances < 1:
+            raise ValueError(f"Expected `num_instances` larger than 0, but {num_instances} is found")
+
+        _check_unpickable_fn(classifier_fn)
+
+        # When num_instances == 1, demux can be replaced by filter,
+        # but keep it as Demultiplexer for the sake of consistency
+        # like throwing Error when classification result is out of o range
+        container = _DemultiplexerIterDataPipe(datapipe, num_instances, classifier_fn, drop_none, buffer_size)  # type: ignore[abstract]
+        return [_ChildDataPipe(container, i) for i in range(num_instances)]
+
+
+class _DemultiplexerIterDataPipe(IterDataPipe, _ContainerTemplate):
+    r"""
+    Container to hold instance-specific information on behalf of DemultiplexerIterDataPipe.
+
+    It tracks the state of its child DataPipes, maintains the buffer, classifies and yields the next correct value
+    as requested by the child DataPipes.
+    """
+
+    def __init__(self, datapipe: IterDataPipe[T_co], num_instances: int,
+                 classifier_fn: Callable[[T_co], Optional[int]], drop_none: bool, buffer_size: int):
+        self.main_datapipe = datapipe
+        self._datapipe_iterator: Optional[Iterator[Any]] = None
+        self.num_instances = num_instances
+        self.buffer_size = buffer_size
+        if self.buffer_size < 0:
+            warnings.warn(
+                "Unlimited buffer size is set for `demux`, "
+                "please be aware of OOM at random places",
+                UserWarning
+            )
+        self.current_buffer_usage = 0
+        self.child_buffers: List[Deque[T_co]] = [deque() for _ in range(num_instances)]
+        self.classifier_fn = classifier_fn
+        self.drop_none = drop_none
+        self.main_datapipe_exhausted = False
+        self._child_stop: List[bool] = [True for _ in range(num_instances)]
+
+    def _find_next(self, instance_id: int) -> T_co:  # type: ignore[type-var]
+        while True:
+            if self.main_datapipe_exhausted or self._child_stop[instance_id]:
+                raise StopIteration
+            if self._datapipe_iterator is None:
+                raise ValueError(
+                    "_datapipe_iterator has not been set, likely because this private method is called directly "
+                    "without invoking get_next_element_by_instance() first.")
+            value = next(self._datapipe_iterator)
+            classification = self.classifier_fn(value)
+            if classification is None and self.drop_none:
+                StreamWrapper.close_streams(value)
+                continue
+            if classification is None or classification >= self.num_instances or classification < 0:
+                raise ValueError(f"Output of the classification fn should be between 0 and {self.num_instances - 1}. " +
+                                 f"{classification} is returned.")
+            if classification == instance_id:
+                return value
+            self.child_buffers[classification].append(value)
+            self.current_buffer_usage += 1
+            if self.buffer_size >= 0 and self.current_buffer_usage > self.buffer_size:
+                raise BufferError(
+                    f"DemultiplexerIterDataPipe buffer overflow, buffer size {self.buffer_size} is insufficient.")
+
+    def get_next_element_by_instance(self, instance_id: int):
+        if self._datapipe_iterator is None and self._child_stop[instance_id]:
+            self._datapipe_iterator = iter(self.main_datapipe)
+            self._snapshot_state = _SnapshotState.Iterating  # This is necessary for the DataPipe to reset properly.
+            self.main_datapipe_exhausted = False
+            for i in range(self.num_instances):
+                self._child_stop[i] = False
+
+        try:
+            while not self._child_stop[instance_id]:
+                if self.child_buffers[instance_id]:
+                    self.current_buffer_usage -= 1
+                    yield self.child_buffers[instance_id].popleft()
+                else:
+                    try:
+                        yield self._find_next(instance_id)
+                    except StopIteration:
+                        self._child_stop[instance_id] = True
+                        self.main_datapipe_exhausted = True
+                        self._datapipe_iterator = None
+        finally:
+            self._child_stop[instance_id] = True
+            # Cleanup _datapipe_iterator for the case that demux exits earlier
+            if all(self._child_stop):
+                self._datapipe_iterator = None
+            if self.child_buffers[instance_id]:
+                self._cleanup(instance_id)
+
+    def is_every_instance_exhausted(self) -> bool:
+        return self.main_datapipe_exhausted and all(self._child_stop)
+
+    def get_length_by_instance(self, instance_id: int) -> int:
+        raise TypeError
+
+    def reset(self) -> None:
+        self._datapipe_iterator = None
+        self.current_buffer_usage = 0
+        self.child_buffers = [deque() for _ in range(self.num_instances)]
+        self._child_stop = [True for _ in range(self.num_instances)]
+        self.main_datapipe_exhausted = False
+
+    def __getstate__(self):
+        state = (
+            self.main_datapipe,
+            self.num_instances,
+            self.buffer_size,
+            self.classifier_fn,
+            self.drop_none,
+            self._valid_iterator_id,
+            self._number_of_samples_yielded,
+        )
+        if IterDataPipe.getstate_hook is not None:
+            return IterDataPipe.getstate_hook(state)
+        return state
+
+    def __setstate__(self, state):
+        (
+            self.main_datapipe,
+            self.num_instances,
+            self.buffer_size,
+            self.classifier_fn,
+            self.drop_none,
+            self._valid_iterator_id,
+            self._number_of_samples_yielded,
+        ) = state
+        self._datapipe_iterator = None
+        self.current_buffer_usage = 0
+        self.child_buffers = [deque() for _ in range(self.num_instances)]
+        self._child_stop = [True for _ in range(self.num_instances)]
+        self.main_datapipe_exhausted = False
+
+    def _cleanup(self, instance_id: Optional[int] = None):
+        ids = range(self.num_instances) if instance_id is None else [instance_id, ]
+        for i in ids:
+            q = self.child_buffers[i]
+            while q:
+                d = q.popleft()
+                StreamWrapper.close_streams(d)
+
+
+    def __del__(self):
+        self._cleanup()
+
+
+@functional_datapipe('mux')
+class MultiplexerIterDataPipe(IterDataPipe):
+    r"""
+    Yields one element at a time from each of the input Iterable DataPipes (functional name: ``mux``).
+
+    As in, one element from the 1st input DataPipe, then one element from the 2nd DataPipe in the next iteration,
+    and so on. It ends when the shortest input DataPipe is exhausted.
+
+    Args:
+        datapipes: Iterable DataPipes that will take turn to yield their elements, until the shortest DataPipe is exhausted
+
+    Example:
+        >>> # xdoctest: +REQUIRES(module:torchdata)
+        >>> from torchdata.datapipes.iter import IterableWrapper
+        >>> dp1, dp2, dp3 = IterableWrapper(range(3)), IterableWrapper(range(10, 15)), IterableWrapper(range(20, 25))
+        >>> list(dp1.mux(dp2, dp3))
+        [0, 10, 20, 1, 11, 21, 2, 12, 22]
+    """
+
+    def __init__(self, *datapipes):
+        self.datapipes = datapipes
+        self.buffer: List = []  # Store values to be yielded only when every iterator provides one
+
+    def __iter__(self):
+        iterators = [iter(x) for x in self.datapipes]
+        while len(iterators):
+            for it in iterators:
+                try:
+                    value = next(it)
+                    self.buffer.append(value)
+                except StopIteration:
+                    self.buffer.clear()
+                    return
+            yield from self.buffer
+            self.buffer.clear()
+
+    def __len__(self):
+        if all(isinstance(dp, Sized) for dp in self.datapipes):
+            return min(len(dp) for dp in self.datapipes) * len(self.datapipes)
+        else:
+            raise TypeError(f"{type(self).__name__} instance doesn't have valid length")
+
+    def reset(self) -> None:
+        self.buffer = []
+
+    def __getstate__(self):
+        state = (
+            self.datapipes,
+            self._valid_iterator_id,
+            self._number_of_samples_yielded,
+        )
+        if IterDataPipe.getstate_hook is not None:
+            return IterDataPipe.getstate_hook(state)
+        return state
+
+    def __setstate__(self, state):
+        (
+            self.datapipes,
+            self._valid_iterator_id,
+            self._number_of_samples_yielded,
+        ) = state
+        self.buffer = []
+
+    def __del__(self):
+        self.buffer.clear()
+
+
+@functional_datapipe('zip')
+class ZipperIterDataPipe(IterDataPipe[Tuple[T_co]]):
+    r"""
+    Aggregates elements into a tuple from each of the input DataPipes (functional name: ``zip``).
+
+    The output is stopped as soon as the shortest input DataPipe is exhausted.
+
+    Args:
+        *datapipes: Iterable DataPipes being aggregated
+
+    Example:
+        >>> # xdoctest: +REQUIRES(module:torchdata)
+        >>> from torchdata.datapipes.iter import IterableWrapper
+        >>> dp1, dp2, dp3 = IterableWrapper(range(5)), IterableWrapper(range(10, 15)), IterableWrapper(range(20, 25))
+        >>> list(dp1.zip(dp2, dp3))
+        [(0, 10, 20), (1, 11, 21), (2, 12, 22), (3, 13, 23), (4, 14, 24)]
+    """
+
+    datapipes: Tuple[IterDataPipe]
+
+    def __init__(self, *datapipes: IterDataPipe):
+        if not all(isinstance(dp, IterDataPipe) for dp in datapipes):
+            raise TypeError("All inputs are required to be `IterDataPipe` "
+                            "for `ZipIterDataPipe`.")
+        super().__init__()
+        self.datapipes = datapipes  # type: ignore[assignment]
+
+    def __iter__(self) -> Iterator[Tuple[T_co]]:
+        iterators = [iter(datapipe) for datapipe in self.datapipes]
+        yield from zip(*iterators)
+
+    def __len__(self) -> int:
+        if all(isinstance(dp, Sized) for dp in self.datapipes):
+            return min(len(dp) for dp in self.datapipes)
+        else:
+            raise TypeError(f"{type(self).__name__} instance doesn't have valid length")

venv/lib/python3.10/site-packages/torch/utils/data/datapipes/iter/filelister.py

@@ -0,0 +1,66 @@
+from typing import Iterator, List, Sequence, Union
+
+
+from torch.utils.data.datapipes._decorator import functional_datapipe
+
+from torch.utils.data.datapipes.datapipe import IterDataPipe
+from torch.utils.data.datapipes.iter import IterableWrapper
+from torch.utils.data.datapipes.utils.common import get_file_pathnames_from_root
+
+__all__ = ["FileListerIterDataPipe", ]
+
+
+@functional_datapipe("list_files")
+class FileListerIterDataPipe(IterDataPipe[str]):
+    r"""
+    Given path(s) to the root directory, yields file pathname(s) (path + filename) of files within the root directory.
+
+    Multiple root directories can be provided (functional name: ``list_files``).
+
+    Args:
+        root: Root directory or a sequence of root directories
+        masks: Unix style filter string or string list for filtering file name(s)
+        recursive: Whether to return pathname from nested directories or not
+        abspath: Whether to return relative pathname or absolute pathname
+        non_deterministic: Whether to return pathname in sorted order or not.
+            If ``False``, the results yielded from each root directory will be sorted
+        length: Nominal length of the datapipe
+
+    Example:
+        >>> # xdoctest: +SKIP
+        >>> from torchdata.datapipes.iter import FileLister
+        >>> dp = FileLister(root=".", recursive=True)
+        >>> list(dp)
+        ['example.py', './data/data.tar']
+    """
+
+    def __init__(
+        self,
+        root: Union[str, Sequence[str], IterDataPipe] = '.',
+        masks: Union[str, List[str]] = '',
+        *,
+        recursive: bool = False,
+        abspath: bool = False,
+        non_deterministic: bool = False,
+        length: int = -1
+    ) -> None:
+        super().__init__()
+        if isinstance(root, str):
+            root = [root, ]
+        if not isinstance(root, IterDataPipe):
+            root = IterableWrapper(root)
+        self.datapipe: IterDataPipe = root
+        self.masks: Union[str, List[str]] = masks
+        self.recursive: bool = recursive
+        self.abspath: bool = abspath
+        self.non_deterministic: bool = non_deterministic
+        self.length: int = length
+
+    def __iter__(self) -> Iterator[str] :
+        for path in self.datapipe:
+            yield from get_file_pathnames_from_root(path, self.masks, self.recursive, self.abspath, self.non_deterministic)
+
+    def __len__(self):
+        if self.length == -1:
+            raise TypeError(f"{type(self).__name__} instance doesn't have valid length")
+        return self.length

venv/lib/python3.10/site-packages/torch/utils/data/datapipes/iter/grouping.py

@@ -0,0 +1,300 @@
+import warnings
+from collections import defaultdict
+from typing import Any, Callable, DefaultDict, Iterator, List, Optional, Sized, TypeVar
+
+import torch.utils.data.datapipes.iter.sharding
+
+from torch.utils.data.datapipes._decorator import functional_datapipe
+from torch.utils.data.datapipes.datapipe import DataChunk, IterDataPipe
+from torch.utils.data.datapipes.utils.common import _check_unpickable_fn
+
+__all__ = [
+    "BatcherIterDataPipe",
+    "GrouperIterDataPipe",
+    "UnBatcherIterDataPipe",
+]
+
+T_co = TypeVar("T_co", covariant=True)
+
+def __getattr__(name: str):
+    if name in ["SHARDING_PRIORITIES", "ShardingFilterIterDataPipe"]:
+        warnings.warn(f"`{name}` from `torch.utils.data.datapipes.iter.grouping` is going to be removed in PyTorch 2.1"
+                      f"Please use `{name}` from the `torch.utils.data.datapipes.iter.sharding`",
+                      category=FutureWarning, stacklevel=2)
+
+        return getattr(torch.utils.data.datapipes.iter.sharding, name)
+
+    raise AttributeError(f"module {__name__} has no attribute {name}")
+
+@functional_datapipe('batch')
+class BatcherIterDataPipe(IterDataPipe[DataChunk]):
+    r"""
+    Creates mini-batches of data (functional name: ``batch``).
+
+    An outer dimension will be added as ``batch_size`` if ``drop_last`` is set to ``True``, or ``length % batch_size`` for the
+    last batch if ``drop_last`` is set to ``False``.
+
+    Args:
+        datapipe: Iterable DataPipe being batched
+        batch_size: The size of each batch
+        drop_last: Option to drop the last batch if it's not full
+        wrapper_class: wrapper to apply onto each batch (type ``List``) before yielding,
+            defaults to ``DataChunk``
+
+    Example:
+        >>> # xdoctest: +SKIP
+        >>> from torchdata.datapipes.iter import IterableWrapper
+        >>> dp = IterableWrapper(range(10))
+        >>> dp = dp.batch(batch_size=3, drop_last=True)
+        >>> list(dp)
+        [[0, 1, 2], [3, 4, 5], [6, 7, 8]]
+    """
+
+    datapipe: IterDataPipe
+    batch_size: int
+    drop_last: bool
+
+    def __init__(self,
+                 datapipe: IterDataPipe,
+                 batch_size: int,
+                 drop_last: bool = False,
+                 wrapper_class=DataChunk,
+                 ) -> None:
+        assert batch_size > 0, "Batch size is required to be larger than 0!"
+        super().__init__()
+        self.datapipe = datapipe
+        self.batch_size = batch_size
+        self.drop_last = drop_last
+        self.wrapper_class = wrapper_class
+
+    def __iter__(self) -> Iterator[DataChunk]:
+        batch: List = []
+        for x in self.datapipe:
+            batch.append(x)
+            if len(batch) == self.batch_size:
+                yield self.wrapper_class(batch)
+                batch = []
+        if len(batch) > 0:
+            if not self.drop_last:
+                yield self.wrapper_class(batch)
+
+    def __len__(self) -> int:
+        if isinstance(self.datapipe, Sized):
+            if self.drop_last:
+                return len(self.datapipe) // self.batch_size
+            else:
+                return (len(self.datapipe) + self.batch_size - 1) // self.batch_size
+        else:
+            raise TypeError(f"{type(self).__name__} instance doesn't have valid length")
+
+
+@functional_datapipe('unbatch')
+class UnBatcherIterDataPipe(IterDataPipe):
+    r"""
+    Undos batching of data (functional name: ``unbatch``).
+
+    In other words, it flattens the data up to the specified level within a batched DataPipe.
+
+    Args:
+        datapipe: Iterable DataPipe being un-batched
+        unbatch_level: Defaults to ``1`` (only flattening the top level). If set to ``2``,
+            it will flatten the top two levels, and ``-1`` will flatten the entire DataPipe.
+
+    Example:
+        >>> # xdoctest: +SKIP
+        >>> from torchdata.datapipes.iter import IterableWrapper
+        >>> source_dp = IterableWrapper([[[0, 1], [2]], [[3, 4], [5]], [[6]]])
+        >>> dp1 = source_dp.unbatch()
+        >>> list(dp1)
+        [[0, 1], [2], [3, 4], [5], [6]]
+        >>> dp2 = source_dp.unbatch(unbatch_level=2)
+        >>> list(dp2)
+        [0, 1, 2, 3, 4, 5, 6]
+    """
+
+    def __init__(self,
+                 datapipe: IterDataPipe,
+                 unbatch_level: int = 1):
+        self.datapipe = datapipe
+        self.unbatch_level = unbatch_level
+
+    def __iter__(self):
+        for element in self.datapipe:
+            yield from self._dive(element, unbatch_level=self.unbatch_level)
+
+    def _dive(self, element, unbatch_level):
+        if unbatch_level < -1:
+            raise ValueError("unbatch_level must be -1 or >= 0")
+        if unbatch_level == -1:
+            if isinstance(element, (list, DataChunk)):
+                for item in element:
+                    yield from self._dive(item, unbatch_level=-1)
+            else:
+                yield element
+        elif unbatch_level == 0:
+            yield element
+        else:
+            if isinstance(element, (list, DataChunk)):
+                for item in element:
+                    yield from self._dive(item, unbatch_level=unbatch_level - 1)
+            else:
+                raise IndexError(f"unbatch_level {self.unbatch_level} exceeds the depth of the DataPipe")
+
+
+@functional_datapipe('groupby')
+class GrouperIterDataPipe(IterDataPipe[DataChunk]):
+    r"""
+    Groups data from IterDataPipe by keys from ``group_key_fn``, yielding a ``DataChunk`` with batch size up to ``group_size``.
+
+    (functional name: ``groupby``).
+
+    The samples are read sequentially from the source ``datapipe``, and a batch of samples belonging to the same group
+    will be yielded as soon as the size of the batch reaches ``group_size``. When the buffer is full,
+    the DataPipe will yield the largest batch with the same key, provided that its size is larger
+    than ``guaranteed_group_size``. If its size is smaller, it will be dropped if ``drop_remaining=True``.
+
+    After iterating through the entirety of source ``datapipe``, everything not dropped due to the buffer capacity
+    will be yielded from the buffer, even if the group sizes are smaller than ``guaranteed_group_size``.
+
+    Args:
+        datapipe: Iterable datapipe to be grouped
+        group_key_fn: Function used to generate group key from the data of the source datapipe
+        keep_key: Option to yield the matching key along with the items in a tuple,
+            resulting in `(key, [items])` otherwise returning [items]
+        buffer_size: The size of buffer for ungrouped data
+        group_size: The max size of each group, a batch is yielded as soon as it reaches this size
+        guaranteed_group_size: The guaranteed minimum group size to be yielded in case the buffer is full
+        drop_remaining: Specifies if the group smaller than ``guaranteed_group_size`` will be dropped from buffer
+            when the buffer is full
+
+    Example:
+        >>> import os
+        >>> # xdoctest: +SKIP
+        >>> from torchdata.datapipes.iter import IterableWrapper
+        >>> def group_fn(file):
+        ...     return os.path.basename(file).split(".")[0]
+        >>> source_dp = IterableWrapper(["a.png", "b.png", "a.json", "b.json", "a.jpg", "c.json"])
+        >>> dp0 = source_dp.groupby(group_key_fn=group_fn)
+        >>> list(dp0)
+        [['a.png', 'a.json', 'a.jpg'], ['b.png', 'b.json'], ['c.json']]
+        >>> # A group is yielded as soon as its size equals to `group_size`
+        >>> dp1 = source_dp.groupby(group_key_fn=group_fn, group_size=2)
+        >>> list(dp1)
+        [['a.png', 'a.json'], ['b.png', 'b.json'], ['a.jpg'], ['c.json']]
+        >>> # Scenario where `buffer` is full, and group 'a' needs to be yielded since its size > `guaranteed_group_size`
+        >>> dp2 = source_dp.groupby(group_key_fn=group_fn, buffer_size=3, group_size=3, guaranteed_group_size=2)
+        >>> list(dp2)
+        [['a.png', 'a.json'], ['b.png', 'b.json'], ['a.jpg'], ['c.json']]
+    """
+
+    def __init__(self,
+                 datapipe: IterDataPipe[T_co],
+                 group_key_fn: Callable[[T_co], Any],
+                 *,
+                 keep_key: bool = False,
+                 buffer_size: int = 10000,
+                 group_size: Optional[int] = None,
+                 guaranteed_group_size: Optional[int] = None,
+                 drop_remaining: bool = False):
+        _check_unpickable_fn(group_key_fn)
+        self.datapipe = datapipe
+        self.group_key_fn = group_key_fn
+
+        self.keep_key = keep_key
+        self.max_buffer_size = buffer_size
+        self.buffer_elements: DefaultDict[Any, List] = defaultdict(list)
+        self.curr_buffer_size = 0
+        self.group_size = group_size
+        self.guaranteed_group_size = None
+        if group_size is not None and buffer_size is not None:
+            assert 0 < group_size <= buffer_size
+            self.guaranteed_group_size = group_size
+        if guaranteed_group_size is not None:
+            assert group_size is not None and 0 < guaranteed_group_size <= group_size
+            self.guaranteed_group_size = guaranteed_group_size
+        self.drop_remaining = drop_remaining
+        self.wrapper_class = DataChunk
+
+    def _remove_biggest_key(self):
+        biggest_key = None
+        biggest_size = 0
+        result_to_yield = None
+        for findkey in self.buffer_elements.keys():
+            if len(self.buffer_elements[findkey]) > biggest_size:
+                biggest_size = len(self.buffer_elements[findkey])
+                biggest_key = findkey
+
+        if self.guaranteed_group_size is not None and biggest_size < self.guaranteed_group_size and not self.drop_remaining:
+            raise RuntimeError('Failed to group items', str(self.buffer_elements[biggest_key]))
+
+        if self.guaranteed_group_size is None or biggest_size >= self.guaranteed_group_size:
+            result_to_yield = self.buffer_elements[biggest_key]
+
+        self.curr_buffer_size -= biggest_size
+        del self.buffer_elements[biggest_key]
+
+        return result_to_yield
+
+    def __iter__(self):
+        for x in self.datapipe:
+            key = self.group_key_fn(x)
+
+            self.buffer_elements[key].append(x)
+            self.curr_buffer_size += 1
+
+            if self.group_size is not None and self.group_size == len(self.buffer_elements[key]):
+                result: DataChunk[Any] = self.wrapper_class(self.buffer_elements[key])
+                yield (key, result) if self.keep_key else result
+                self.curr_buffer_size -= len(self.buffer_elements[key])
+                del self.buffer_elements[key]
+
+            if self.curr_buffer_size == self.max_buffer_size:
+                result_to_yield = self._remove_biggest_key()
+                if result_to_yield is not None:
+                    result = self.wrapper_class(result_to_yield)
+                    yield (key, result) if self.keep_key else result
+
+        for key in tuple(self.buffer_elements.keys()):
+            result = self.wrapper_class(self.buffer_elements.pop(key))
+            self.curr_buffer_size -= len(result)
+            yield (key, result) if self.keep_key else result
+
+    def reset(self) -> None:
+        self.curr_buffer_size = 0
+        self.buffer_elements = defaultdict(list)
+
+    def __getstate__(self):
+        state = (
+            self.datapipe,
+            self.group_key_fn,
+            self.keep_key,
+            self.max_buffer_size,
+            self.group_size,
+            self.guaranteed_group_size,
+            self.drop_remaining,
+            self.wrapper_class,
+            self._valid_iterator_id,
+            self._number_of_samples_yielded,
+        )
+        if IterDataPipe.getstate_hook is not None:
+            return IterDataPipe.getstate_hook(state)
+        return state
+
+    def __setstate__(self, state):
+        (
+            self.datapipe,
+            self.group_key_fn,
+            self.keep_key,
+            self.max_buffer_size,
+            self.group_size,
+            self.guaranteed_group_size,
+            self.drop_remaining,
+            self.wrapper_class,
+            self._valid_iterator_id,
+            self._number_of_samples_yielded,
+        ) = state
+        self.curr_buffer_size = 0
+        self.buffer_elements = defaultdict(list)
+
+    def __del__(self):
+        self.buffer_elements.clear()

venv/lib/python3.10/site-packages/torch/utils/data/datapipes/iter/routeddecoder.py

@@ -0,0 +1,66 @@
+from io import BufferedIOBase
+from typing import Any, Callable, Iterable, Iterator, Sized, Tuple
+
+from torch.utils.data.datapipes._decorator import functional_datapipe
+from torch.utils.data.datapipes.datapipe import IterDataPipe
+from torch.utils.data.datapipes.utils.common import _deprecation_warning
+from torch.utils.data.datapipes.utils.decoder import (
+    Decoder,
+    basichandlers as decoder_basichandlers,
+    imagehandler as decoder_imagehandler,
+    extension_extract_fn
+)
+
+__all__ = ["RoutedDecoderIterDataPipe", ]
+
+
+@functional_datapipe('routed_decode')
+class RoutedDecoderIterDataPipe(IterDataPipe[Tuple[str, Any]]):
+    r"""
+    Decodes binary streams from input DataPipe, yields pathname and decoded data in a tuple.
+
+    (functional name: ``routed_decode``)
+
+    Args:
+        datapipe: Iterable datapipe that provides pathname and binary stream in tuples
+        handlers: Optional user defined decoder handlers. If ``None``, basic and image decoder
+            handlers will be set as default. If multiple handles are provided, the priority
+            order follows the order of handlers (the first handler has the top priority)
+        key_fn: Function for decoder to extract key from pathname to dispatch handlers.
+            Default is set to extract file extension from pathname
+
+    Note:
+        When ``key_fn`` is specified returning anything other than extension, the default
+        handler will not work and users need to specify custom handler. Custom handler
+        could use regex to determine the eligibility to handle data.
+    """
+
+    def __init__(self,
+                 datapipe: Iterable[Tuple[str, BufferedIOBase]],
+                 *handlers: Callable,
+                 key_fn: Callable = extension_extract_fn) -> None:
+        super().__init__()
+        self.datapipe: Iterable[Tuple[str, BufferedIOBase]] = datapipe
+        if not handlers:
+            handlers = (decoder_basichandlers, decoder_imagehandler('torch'))
+        self.decoder = Decoder(*handlers, key_fn=key_fn)
+        _deprecation_warning(
+            type(self).__name__,
+            deprecation_version="1.12",
+            removal_version="1.13",
+            old_functional_name="routed_decode",
+        )
+
+    def add_handler(self, *handler: Callable) -> None:
+        self.decoder.add_handler(*handler)
+
+    def __iter__(self) -> Iterator[Tuple[str, Any]]:
+        for data in self.datapipe:
+            pathname = data[0]
+            result = self.decoder(data)
+            yield (pathname, result[pathname])
+
+    def __len__(self) -> int:
+        if isinstance(self.datapipe, Sized):
+            return len(self.datapipe)
+        raise TypeError(f"{type(self).__name__} instance doesn't have valid length")