Text memmap dataset

[michalivne]

Signed-off-by: Micha Livne mlivne@nvidia.com

What does this PR do ?

Has mechanism to retire older ind files by updating internal idx version.

Indexing speed of 1443990774 samples in 147 files using 6 workers

Loading speed

[NeMo I 2022-04-29 00:23:22 text_memmap_dataset:85] Time loading 147 mem-mapped files: 0:00:04.395558

In [9]: len(ds)
Out[9]: 1443990774
# Timing without tokenizer
In [10]: %timeit -n 1000  ds[np.random.randint(len(ds))]
555 µs ± 16.9 µs per loop (mean ± std. dev. of 7 runs, 1,000 loops each)
# TIming with 'byte-level' tokenizer
In [20]: %timeit -n 1000  ds[np.random.randint(len(ds))]
724 µs ± 19.8 µs per loop (mean ± std. dev. of 7 runs, 1,000 loops each)

Add a one line overview of what this PR aims to accomplish.

Collection: [Note which collection this PR will affect]

Changelog

• Added TextMemMapDataset
• Added CSVMemMapDataset
• Retired MegatronDataset
• Added nemo/collections/nlp/data/language_modeling/text_memmap_dataset.py to preprocess indices (else happs on the fly at first run)
• Added nemo/collections/nlp/data/machine_translation/sequence_to_sequence_dataset.py
• Added scripts/nlp_language_modeling/build_index_memmap_data.py

Usage

Example for caching index files:

NeMo/scripts/nlp_language_modeling/build_index_memmap_data.py *.txt

Index files will be created when instantiating a memory mapped dataset if missing.

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Additional Information

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[lgtm-com]

This pull request fixes 1 alert when merging 61daef3 into d97e0d3 - view on LGTM.com

fixed alerts:

• 1 for `__init__` method calls overridden method

[lgtm-com]

This pull request introduces 1 alert and fixes 1 when merging 77cbd9b into d97e0d3 - view on LGTM.com

new alerts:

• 1 for Syntax error

fixed alerts:

• 1 for `__init__` method calls overridden method

[lgtm-com]

This pull request introduces 1 alert and fixes 1 when merging 061beeb into da1b56c - view on LGTM.com

new alerts:

• 1 for Syntax error

fixed alerts:

• 1 for `__init__` method calls overridden method

[lgtm-com]

This pull request introduces 4 alerts and fixes 1 when merging 535a2f9 into 0d052c8 - view on LGTM.com

new alerts:

• 3 for Unused import
• 1 for Syntax error

fixed alerts:

• 1 for `__init__` method calls overridden method

[lgtm-com]

This pull request introduces 7 alerts and fixes 1 when merging 0b09a96 into 0d052c8 - view on LGTM.com

new alerts:

• 5 for Unused import
• 2 for Unused local variable

fixed alerts:

• 1 for `__init__` method calls overridden method

[lgtm-com]

This pull request introduces 7 alerts and fixes 1 when merging 0f3810c into 70d9687 - view on LGTM.com

new alerts:

• 5 for Unused import
• 2 for Unused local variable

fixed alerts:

• 1 for `__init__` method calls overridden method

[lgtm-com]

This pull request introduces 7 alerts and fixes 1 when merging 865d8c8 into 70d9687 - view on LGTM.com

new alerts:

• 5 for Unused import
• 2 for Unused local variable

fixed alerts:

• 1 for `__init__` method calls overridden method

[lgtm-com]

This pull request introduces 7 alerts and fixes 1 when merging fbc977f into 70d9687 - view on LGTM.com

new alerts:

• 5 for Unused import
• 2 for Unused local variable

fixed alerts:

• 1 for `__init__` method calls overridden method

[lgtm-com]

This pull request introduces 2 alerts when merging fe85c7b into 1d64497 - view on LGTM.com

new alerts:

• 1 for Unused import
• 1 for `__init__` method calls overridden method

[lgtm-com]

This pull request introduces 1 alert when merging a014a2f into 1d64497 - view on LGTM.com

new alerts:

• 1 for `__init__` method calls overridden method

[lgtm-com]

This pull request introduces 1 alert when merging f0b0d0e into 3816254 - view on LGTM.com

new alerts:

• 1 for `__init__` method calls overridden method

[lgtm-com]

This pull request introduces 3 alerts when merging f4cba69 into 3816254 - view on LGTM.com

new alerts:

• 1 for Unused import
• 1 for Explicit export is not defined
• 1 for `__init__` method calls overridden method

[lgtm-com]

This pull request introduces 2 alerts when merging f207758 into 3816254 - view on LGTM.com

new alerts:

• 1 for Unused import
• 1 for `__init__` method calls overridden method

[MaximumEntropy]

LGTM! Great PR!

[lgtm-com]

This pull request introduces 1 alert when merging c5b4c61 into 3816254 - view on LGTM.com

new alerts:

• 1 for `__init__` method calls overridden method