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ray-project--ray/python/ray/train/tensorflow/keras.py
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2026-07-13 13:17:40 +08:00

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7.2 KiB
Python

import shutil
from abc import abstractmethod
from typing import Dict, List, Optional, Union
from tensorflow.keras.callbacks import Callback as KerasCallback
import ray
from ray.train.tensorflow import TensorflowCheckpoint
from ray.util.annotations import PublicAPI
class _Callback(KerasCallback):
"""Base class for Ray Train's Keras callbacks."""
_allowed = [
"epoch_begin",
"epoch_end",
"train_batch_begin",
"train_batch_end",
"test_batch_begin",
"test_batch_end",
"predict_batch_begin",
"predict_batch_end",
"train_begin",
"train_end",
"test_begin",
"test_end",
"predict_begin",
"predict_end",
]
def __init__(self, on: Union[str, List[str]] = "validation_end"):
super(_Callback, self).__init__()
if not isinstance(on, list):
on = [on]
if any(w not in self._allowed for w in on):
raise ValueError(
"Invalid trigger time selected: {}. Must be one of {}".format(
on, self._allowed
)
)
self._on = on
def _handle(self, logs: Dict, when: str):
raise NotImplementedError
def on_epoch_begin(self, epoch, logs=None):
if "epoch_begin" in self._on:
self._handle(logs, "epoch_begin")
def on_epoch_end(self, epoch, logs=None):
if "epoch_end" in self._on:
self._handle(logs, "epoch_end")
def on_train_batch_begin(self, batch, logs=None):
if "train_batch_begin" in self._on:
self._handle(logs, "train_batch_begin")
def on_train_batch_end(self, batch, logs=None):
if "train_batch_end" in self._on:
self._handle(logs, "train_batch_end")
def on_test_batch_begin(self, batch, logs=None):
if "test_batch_begin" in self._on:
self._handle(logs, "test_batch_begin")
def on_test_batch_end(self, batch, logs=None):
if "test_batch_end" in self._on:
self._handle(logs, "test_batch_end")
def on_predict_batch_begin(self, batch, logs=None):
if "predict_batch_begin" in self._on:
self._handle(logs, "predict_batch_begin")
def on_predict_batch_end(self, batch, logs=None):
if "predict_batch_end" in self._on:
self._handle(logs, "predict_batch_end")
def on_train_begin(self, logs=None):
if "train_begin" in self._on:
self._handle(logs, "train_begin")
def on_train_end(self, logs=None):
if "train_end" in self._on:
self._handle(logs, "train_end")
def on_test_begin(self, logs=None):
if "test_begin" in self._on:
self._handle(logs, "test_begin")
def on_test_end(self, logs=None):
if "test_end" in self._on:
self._handle(logs, "test_end")
def on_predict_begin(self, logs=None):
if "predict_begin" in self._on:
self._handle(logs, "predict_begin")
def on_predict_end(self, logs=None):
if "predict_end" in self._on:
self._handle(logs, "predict_end")
class RayReportCallback(_Callback):
def __init__(
self,
checkpoint_on: Union[str, List[str]] = "epoch_end",
report_metrics_on: Union[str, List[str]] = "epoch_end",
metrics: Optional[Union[str, List[str], Dict[str, str]]] = None,
):
if isinstance(checkpoint_on, str):
checkpoint_on = [checkpoint_on]
if isinstance(report_metrics_on, str):
report_metrics_on = [report_metrics_on]
on = list(set(checkpoint_on + report_metrics_on))
super().__init__(on=on)
self._checkpoint_on: List[str] = checkpoint_on
self._report_metrics_on: List[str] = report_metrics_on
self._metrics = metrics
def _get_reported_metrics(self, logs: Dict) -> Dict:
assert isinstance(self._metrics, (type(None), str, list, dict))
if self._metrics is None:
reported_metrics = logs
elif isinstance(self._metrics, str):
reported_metrics = {self._metrics: logs[self._metrics]}
elif isinstance(self._metrics, list):
reported_metrics = {metric: logs[metric] for metric in self._metrics}
elif isinstance(self._metrics, dict):
reported_metrics = {
key: logs[metric] for key, metric in self._metrics.items()
}
assert isinstance(reported_metrics, dict)
return reported_metrics
@abstractmethod
def _save_and_report_checkpoint(
self, metrics: Dict, checkpoint: TensorflowCheckpoint
):
"""Save checkpoint and report metrics corresonding to this checkpoint."""
raise NotImplementedError
@abstractmethod
def _report_metrics(self, metrics: Dict):
"""Report metrics."""
raise NotImplementedError
def _handle(self, logs: Dict, when: str):
assert when in self._checkpoint_on or when in self._report_metrics_on
metrics = self._get_reported_metrics(logs)
should_checkpoint = when in self._checkpoint_on
if should_checkpoint:
checkpoint = TensorflowCheckpoint.from_model(self.model)
self._save_and_report_checkpoint(metrics, checkpoint)
# Clean up temporary checkpoint
shutil.rmtree(checkpoint.path, ignore_errors=True)
else:
self._report_metrics(metrics)
@PublicAPI(stability="alpha")
class ReportCheckpointCallback(RayReportCallback):
"""Keras callback for Ray Train reporting and checkpointing.
.. note::
Metrics are always reported with checkpoints, even if the event isn't specified
in ``report_metrics_on``.
Example:
.. testcode:: python
############# Using it in TrainSession ###############
from ray.air.integrations.keras import ReportCheckpointCallback
def train_loop_per_worker():
strategy = tf.distribute.MultiWorkerMirroredStrategy()
with strategy.scope():
model = build_model()
model.fit(dataset_shard, callbacks=[ReportCheckpointCallback()])
Args:
metrics: Metrics to report. If this is a list, each item describes
the metric key reported to Keras, and it's reported under the
same name. If this is a dict, each key is the name reported
and the respective value is the metric key reported to Keras.
If this is None, all Keras logs are reported.
report_metrics_on: When to report metrics. Must be one of
the Keras event hooks (less the ``on_``), e.g.
"train_start" or "predict_end". Defaults to "epoch_end".
checkpoint_on: When to save checkpoints. Must be one of the Keras event hooks
(less the ``on_``), e.g. "train_start" or "predict_end". Defaults to
"epoch_end".
"""
def _save_and_report_checkpoint(
self, metrics: Dict, checkpoint: TensorflowCheckpoint
):
"""Save checkpoint and report metrics corresonding to this checkpoint."""
ray.train.report(metrics, checkpoint=checkpoint)
def _report_metrics(self, metrics: Dict):
"""Report metrics."""
ray.train.report(metrics, checkpoint=None)