Specify size of dataset when created with generator function

[zsoltkebel]

I would like to add the ability to specify size of the dataset when creating from a generator function as e.g. const dataset = tf.data.generator(() => {...}, 65000), with the resulting dataset having a size of 65000. Currently you can't specify dataset size even if the generator function only runs a maximum of known iterations. The feature is already implemented in the underlying datasetFromIteratorFn definition so the change is very minimal. I use a generator because a large dataset is handled, but total count of elements is known.

System information

• TensorFlow.js version (you are using): 4.22.0
• Are you willing to contribute it (Yes/No): Yes

Will this change the current api? How?
The feature would add an optional size parameter to the tf.data.generator function.

Who will benefit with this feature?
Thos who create datasets of known size from generator functions.

[shmishra99]

Thank you for your contribution to TFJS. I'll be working on it and will keep you informed of the process.