Source code for apache_beam.ml.inference.tensorflow_inference

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# pytype: skip-file

import enum
import sys
from typing import Any
from typing import Callable
from typing import Dict
from typing import Iterable
from typing import Optional
from typing import Sequence
from typing import Union

import numpy

import tensorflow as tf
import tensorflow_hub as hub
from apache_beam.ml.inference import utils
from apache_beam.ml.inference.base import ModelHandler
from apache_beam.ml.inference.base import PredictionResult

__all__ = [
    'TFModelHandlerNumpy',
    'TFModelHandlerTensor',
]

TensorInferenceFn = Callable[[
    tf.Module,
    Sequence[Union[numpy.ndarray, tf.Tensor]],
    Dict[str, Any],
    Optional[str]
],
                             Iterable[PredictionResult]]


class ModelType(enum.Enum):
  """Defines how a model file should be loaded."""
  SAVED_MODEL = 1
  SAVED_WEIGHTS = 2


def _load_model(model_uri, custom_weights, load_model_args):
  try:
    model = tf.keras.models.load_model(
        hub.resolve(model_uri), **load_model_args)
  except Exception as e:
    raise ValueError(
        "Unable to load the TensorFlow model: {exception}. Make sure you've \
        saved the model with TF2 format. Check out the list of TF2 Models on \
        TensorFlow Hub - https://tfhub.dev/s?subtype=module,placeholder&tf-version=tf2."  # pylint: disable=line-too-long
        .format(exception=e))
  if custom_weights:
    model.load_weights(custom_weights)
  return model


def _load_model_from_weights(create_model_fn, weights_path):
  model = create_model_fn()
  model.load_weights(weights_path)
  return model


def default_numpy_inference_fn(
    model: tf.Module,
    batch: Sequence[numpy.ndarray],
    inference_args: Dict[str, Any],
    model_id: Optional[str] = None) -> Iterable[PredictionResult]:
  vectorized_batch = numpy.stack(batch, axis=0)
  predictions = model(vectorized_batch, **inference_args)
  return utils._convert_to_result(batch, predictions, model_id)


def default_tensor_inference_fn(
    model: tf.Module,
    batch: Sequence[tf.Tensor],
    inference_args: Dict[str, Any],
    model_id: Optional[str] = None) -> Iterable[PredictionResult]:
  vectorized_batch = tf.stack(batch, axis=0)
  predictions = model(vectorized_batch, **inference_args)
  return utils._convert_to_result(batch, predictions, model_id)


[docs]class TFModelHandlerNumpy(ModelHandler[numpy.ndarray, PredictionResult, tf.Module]): def __init__( self, model_uri: str, model_type: ModelType = ModelType.SAVED_MODEL, create_model_fn: Optional[Callable] = None, *, load_model_args: Optional[Dict[str, Any]] = None, custom_weights: str = "", inference_fn: TensorInferenceFn = default_numpy_inference_fn, min_batch_size: Optional[int] = None, max_batch_size: Optional[int] = None, large_model: bool = False, **kwargs): """Implementation of the ModelHandler interface for Tensorflow. Example Usage:: pcoll | RunInference(TFModelHandlerNumpy(model_uri="my_uri")) See https://www.tensorflow.org/tutorials/keras/save_and_load for details. Args: model_uri (str): path to the trained model. model_type: type of model to be loaded. Defaults to SAVED_MODEL. create_model_fn: a function that creates and returns a new tensorflow model to load the saved weights. It should be used with ModelType.SAVED_WEIGHTS. load_model_args: a dictionary of parameters to pass to the load_model function of TensorFlow to specify custom config. custom_weights (str): path to the custom weights to be applied once the model is loaded. inference_fn: inference function to use during RunInference. Defaults to default_numpy_inference_fn. large_model: set to true if your model is large enough to run into memory pressure if you load multiple copies. Given a model that consumes N memory and a machine with W cores and M memory, you should set this to True if N*W > M. kwargs: 'env_vars' can be used to set environment variables before loading the model. **Supported Versions:** RunInference APIs in Apache Beam have been tested with Tensorflow 2.9, 2.10, 2.11. """ self._model_uri = model_uri self._model_type = model_type self._inference_fn = inference_fn self._create_model_fn = create_model_fn self._env_vars = kwargs.get('env_vars', {}) self._load_model_args = {} if not load_model_args else load_model_args self._custom_weights = custom_weights self._batching_kwargs = {} if min_batch_size is not None: self._batching_kwargs['min_batch_size'] = min_batch_size if max_batch_size is not None: self._batching_kwargs['max_batch_size'] = max_batch_size self._large_model = large_model
[docs] def load_model(self) -> tf.Module: """Loads and initializes a Tensorflow model for processing.""" if self._model_type == ModelType.SAVED_WEIGHTS: if not self._create_model_fn: raise ValueError( "Callable create_model_fn must be passed" "with ModelType.SAVED_WEIGHTS") return _load_model_from_weights(self._create_model_fn, self._model_uri) return _load_model( self._model_uri, self._custom_weights, self._load_model_args)
[docs] def update_model_path(self, model_path: Optional[str] = None): self._model_uri = model_path if model_path else self._model_uri
[docs] def run_inference( self, batch: Sequence[numpy.ndarray], model: tf.Module, inference_args: Optional[Dict[str, Any]] = None ) -> Iterable[PredictionResult]: """ Runs inferences on a batch of numpy array and returns an Iterable of numpy array Predictions. This method stacks the n-dimensional numpy array in a vectorized format to optimize the inference call. Args: batch: A sequence of numpy nd-array. These should be batchable, as this method will call `numpy.stack()` and pass in batched numpy nd-array with dimensions (batch_size, n_features, etc.) into the model's predict() function. model: A Tensorflow model. inference_args: any additional arguments for an inference. Returns: An Iterable of type PredictionResult. """ inference_args = {} if not inference_args else inference_args return self._inference_fn(model, batch, inference_args, self._model_uri)
[docs] def get_num_bytes(self, batch: Sequence[numpy.ndarray]) -> int: """ Returns: The number of bytes of data for a batch of numpy arrays. """ return sum(sys.getsizeof(element) for element in batch)
[docs] def get_metrics_namespace(self) -> str: """ Returns: A namespace for metrics collected by the RunInference transform. """ return 'BeamML_TF_Numpy'
[docs] def validate_inference_args(self, inference_args: Optional[Dict[str, Any]]): pass
[docs] def batch_elements_kwargs(self): return self._batching_kwargs
[docs] def share_model_across_processes(self) -> bool: return self._large_model
[docs]class TFModelHandlerTensor(ModelHandler[tf.Tensor, PredictionResult, tf.Module]): def __init__( self, model_uri: str, model_type: ModelType = ModelType.SAVED_MODEL, create_model_fn: Optional[Callable] = None, *, load_model_args: Optional[Dict[str, Any]] = None, custom_weights: str = "", inference_fn: TensorInferenceFn = default_tensor_inference_fn, min_batch_size: Optional[int] = None, max_batch_size: Optional[int] = None, large_model: bool = False, **kwargs): """Implementation of the ModelHandler interface for Tensorflow. Example Usage:: pcoll | RunInference(TFModelHandlerTensor(model_uri="my_uri")) See https://www.tensorflow.org/tutorials/keras/save_and_load for details. Args: model_uri (str): path to the trained model. model_type: type of model to be loaded. Defaults to SAVED_MODEL. create_model_fn: a function that creates and returns a new tensorflow model to load the saved weights. It should be used with ModelType.SAVED_WEIGHTS. load_model_args: a dictionary of parameters to pass to the load_model function of TensorFlow to specify custom config. custom_weights (str): path to the custom weights to be applied once the model is loaded. inference_fn: inference function to use during RunInference. Defaults to default_numpy_inference_fn. large_model: set to true if your model is large enough to run into memory pressure if you load multiple copies. Given a model that consumes N memory and a machine with W cores and M memory, you should set this to True if N*W > M. kwargs: 'env_vars' can be used to set environment variables before loading the model. **Supported Versions:** RunInference APIs in Apache Beam have been tested with Tensorflow 2.11. """ self._model_uri = model_uri self._model_type = model_type self._inference_fn = inference_fn self._create_model_fn = create_model_fn self._env_vars = kwargs.get('env_vars', {}) self._load_model_args = {} if not load_model_args else load_model_args self._custom_weights = custom_weights self._batching_kwargs = {} if min_batch_size is not None: self._batching_kwargs['min_batch_size'] = min_batch_size if max_batch_size is not None: self._batching_kwargs['max_batch_size'] = max_batch_size self._large_model = large_model
[docs] def load_model(self) -> tf.Module: """Loads and initializes a tensorflow model for processing.""" if self._model_type == ModelType.SAVED_WEIGHTS: if not self._create_model_fn: raise ValueError( "Callable create_model_fn must be passed" "with ModelType.SAVED_WEIGHTS") return _load_model_from_weights(self._create_model_fn, self._model_uri) return _load_model( self._model_uri, self._custom_weights, self._load_model_args)
[docs] def update_model_path(self, model_path: Optional[str] = None): self._model_uri = model_path if model_path else self._model_uri
[docs] def run_inference( self, batch: Sequence[tf.Tensor], model: tf.Module, inference_args: Optional[Dict[str, Any]] = None ) -> Iterable[PredictionResult]: """ Runs inferences on a batch of tf.Tensor and returns an Iterable of Tensor Predictions. This method stacks the list of Tensors in a vectorized format to optimize the inference call. Args: batch: A sequence of Tensors. These Tensors should be batchable, as this method will call `tf.stack()` and pass in batched Tensors with dimensions (batch_size, n_features, etc.) into the model's predict() function. model: A Tensorflow model. inference_args: Non-batchable arguments required as inputs to the model's forward() function. Unlike Tensors in `batch`, these parameters will not be dynamically batched Returns: An Iterable of type PredictionResult. """ inference_args = {} if not inference_args else inference_args return self._inference_fn(model, batch, inference_args, self._model_uri)
[docs] def get_num_bytes(self, batch: Sequence[tf.Tensor]) -> int: """ Returns: The number of bytes of data for a batch of Tensors. """ return sum(sys.getsizeof(element) for element in batch)
[docs] def get_metrics_namespace(self) -> str: """ Returns: A namespace for metrics collected by the RunInference transform. """ return 'BeamML_TF_Tensor'
[docs] def validate_inference_args(self, inference_args: Optional[Dict[str, Any]]): pass
[docs] def batch_elements_kwargs(self): return self._batching_kwargs
[docs] def share_model_across_processes(self) -> bool: return self._large_model