PipelineChunkIterator does not provide the correct length

[adrianeboyd]

System Info

• transformers version: 4.28.1
• PyTorch version (GPU?): 2.0.0+cu117 (True)

Who can help?

@Narsil

Information

• [ ] The official example scripts
• [ ] My own modified scripts

Tasks

• [ ] An officially supported task in the examples folder (such as GLUE/SQuAD, ...)
• [ ] My own task or dataset (give details below)

Reproduction

Relatively minor in the scheme of things, but I looked into it a bit to make sure it wasn't an issue with batching.

from transformers import pipeline
pipe = pipeline("token-classification")
pipe(["New York " * 600] * 2, stride=0)

Leads to noisy warnings from torch:

/tmp/venv/lib/python3.8/site-packages/torch/utils/data/dataloader.py:646: UserWarning: Length of IterableDataset <transformers.pipelines.pt_utils.PipelineChunkIterator object at 0x7f084a9bce50> was reported to be 2 (when accessing len(dataloader)), but 3 samples have been fetched. 
  warnings.warn(warn_msg)
/tmp/venv/lib/python3.8/site-packages/torch/utils/data/dataloader.py:646: UserWarning: Length of IterableDataset <transformers.pipelines.pt_utils.PipelineChunkIterator object at 0x7f084a9bce50> was reported to be 2 (when accessing len(dataloader)), but 4 samples have been fetched. 
  warnings.warn(warn_msg)
/tmp/venv/lib/python3.8/site-packages/torch/utils/data/dataloader.py:646: UserWarning: Length of IterableDataset <transformers.pipelines.pt_utils.PipelineChunkIterator object at 0x7f084a9bce50> was reported to be 2 (when accessing len(dataloader)), but 5 samples have been fetched. 
  warnings.warn(warn_msg)
/tmp/venv/lib/python3.8/site-packages/torch/utils/data/dataloader.py:646: UserWarning: Length of IterableDataset <transformers.pipelines.pt_utils.PipelineChunkIterator object at 0x7f084a9bce50> was reported to be 2 (when accessing len(dataloader)), but 6 samples have been fetched. 
  warnings.warn(warn_msg)

Expected behavior

PipelineChunkIterator provides the intended length, no noisy warnings.