Add DynamicEmbedding to Keras

PiperOrigin-RevId: 556908566

keras/BUILD

@@ -143,6 +143,7 @@ py_library(
         "//keras/protobuf:projector_config_proto_py_pb2",
         "//keras/utils:engine_utils",
         "//keras/utils:mode_keys",
+        "//keras/utils:timed_threads",
     ],
 )
 

keras/api/golden/v1/tensorflow.keras.callbacks.-update-embedding-callback.pbtxt

@@ -0,0 +1,99 @@
+path: "tensorflow.keras.callbacks.UpdateEmbeddingCallback"
+tf_class {
+  is_instance: "<class \'keras.callbacks.UpdateEmbeddingCallback\'>"
+  is_instance: "<class \'keras.utils.timed_threads.TimedThread\'>"
+  is_instance: "<class \'keras.callbacks.Callback\'>"
+  is_instance: "<type \'object\'>"
+  member_method {
+    name: "__init__"
+    argspec: "args=[\'self\', \'dynamic_embedding_layer\', \'interval\'], varargs=None, keywords=None, defaults=None"
+  }
+  member_method {
+    name: "is_alive"
+    argspec: "args=[\'self\'], varargs=None, keywords=None, defaults=None"
+  }
+  member_method {
+    name: "on_batch_begin"
+    argspec: "args=[\'self\', \'batch\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_batch_end"
+    argspec: "args=[\'self\', \'batch\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_epoch_begin"
+    argspec: "args=[\'self\', \'epoch\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_epoch_end"
+    argspec: "args=[\'self\', \'epoch\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_interval"
+    argspec: "args=[\'self\'], varargs=None, keywords=None, defaults=None"
+  }
+  member_method {
+    name: "on_predict_batch_begin"
+    argspec: "args=[\'self\', \'batch\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_predict_batch_end"
+    argspec: "args=[\'self\', \'batch\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_predict_begin"
+    argspec: "args=[\'self\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_predict_end"
+    argspec: "args=[\'self\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_test_batch_begin"
+    argspec: "args=[\'self\', \'batch\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_test_batch_end"
+    argspec: "args=[\'self\', \'batch\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_test_begin"
+    argspec: "args=[\'self\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_test_end"
+    argspec: "args=[\'self\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_train_batch_begin"
+    argspec: "args=[\'self\', \'batch\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_train_batch_end"
+    argspec: "args=[\'self\', \'batch\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_train_begin"
+    argspec: "args=[\'self\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_train_end"
+    argspec: "args=[\'self\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "set_model"
+    argspec: "args=[\'self\', \'model\'], varargs=None, keywords=None, defaults=None"
+  }
+  member_method {
+    name: "set_params"
+    argspec: "args=[\'self\', \'params\'], varargs=None, keywords=None, defaults=None"
+  }
+  member_method {
+    name: "start"
+    argspec: "args=[\'self\'], varargs=None, keywords=None, defaults=None"
+  }
+  member_method {
+    name: "stop"
+    argspec: "args=[\'self\'], varargs=None, keywords=None, defaults=None"
+  }
+}

keras/api/golden/v1/tensorflow.keras.callbacks.pbtxt

@@ -60,4 +60,8 @@ tf_module {
     name: "TerminateOnNaN"
     mtype: "<type \'type\'>"
   }
+  member {
+    name: "UpdateEmbeddingCallback"
+    mtype: "<type \'type\'>"
+  }
 }

keras/api/golden/v2/tensorflow.keras.callbacks.-update-embedding-callback.pbtxt

@@ -0,0 +1,99 @@
+path: "tensorflow.keras.callbacks.UpdateEmbeddingCallback"
+tf_class {
+  is_instance: "<class \'keras.callbacks.UpdateEmbeddingCallback\'>"
+  is_instance: "<class \'keras.utils.timed_threads.TimedThread\'>"
+  is_instance: "<class \'keras.callbacks.Callback\'>"
+  is_instance: "<type \'object\'>"
+  member_method {
+    name: "__init__"
+    argspec: "args=[\'self\', \'dynamic_embedding_layer\', \'interval\'], varargs=None, keywords=None, defaults=None"
+  }
+  member_method {
+    name: "is_alive"
+    argspec: "args=[\'self\'], varargs=None, keywords=None, defaults=None"
+  }
+  member_method {
+    name: "on_batch_begin"
+    argspec: "args=[\'self\', \'batch\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_batch_end"
+    argspec: "args=[\'self\', \'batch\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_epoch_begin"
+    argspec: "args=[\'self\', \'epoch\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_epoch_end"
+    argspec: "args=[\'self\', \'epoch\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_interval"
+    argspec: "args=[\'self\'], varargs=None, keywords=None, defaults=None"
+  }
+  member_method {
+    name: "on_predict_batch_begin"
+    argspec: "args=[\'self\', \'batch\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_predict_batch_end"
+    argspec: "args=[\'self\', \'batch\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_predict_begin"
+    argspec: "args=[\'self\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_predict_end"
+    argspec: "args=[\'self\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_test_batch_begin"
+    argspec: "args=[\'self\', \'batch\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_test_batch_end"
+    argspec: "args=[\'self\', \'batch\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_test_begin"
+    argspec: "args=[\'self\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_test_end"
+    argspec: "args=[\'self\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_train_batch_begin"
+    argspec: "args=[\'self\', \'batch\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_train_batch_end"
+    argspec: "args=[\'self\', \'batch\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_train_begin"
+    argspec: "args=[\'self\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "on_train_end"
+    argspec: "args=[\'self\', \'logs\'], varargs=None, keywords=None, defaults=[\'None\'], "
+  }
+  member_method {
+    name: "set_model"
+    argspec: "args=[\'self\', \'model\'], varargs=None, keywords=None, defaults=None"
+  }
+  member_method {
+    name: "set_params"
+    argspec: "args=[\'self\', \'params\'], varargs=None, keywords=None, defaults=None"
+  }
+  member_method {
+    name: "start"
+    argspec: "args=[\'self\'], varargs=None, keywords=None, defaults=None"
+  }
+  member_method {
+    name: "stop"
+    argspec: "args=[\'self\'], varargs=None, keywords=None, defaults=None"
+  }
+}

keras/api/golden/v2/tensorflow.keras.callbacks.pbtxt

@@ -64,6 +64,10 @@ tf_module {
     name: "TerminateOnNaN"
     mtype: "<type \'type\'>"
   }
+  member {
+    name: "UpdateEmbeddingCallback"
+    mtype: "<type \'type\'>"
+  }
   member {
     name: "experimental"
     mtype: "<type \'module\'>"

keras/callbacks.py

@@ -40,6 +40,7 @@
 from keras.utils.data_utils import Sequence
 from keras.utils.generic_utils import Progbar
 from keras.utils.mode_keys import ModeKeys
+from keras.utils.timed_threads import TimedThread
 
 # isort: off
 from tensorflow.python.platform import tf_logging as logging
@@ -3306,3 +3307,119 @@ def __init__(
             self.on_train_begin = on_train_begin
         if on_train_end is not None:
             self.on_train_end = on_train_end
+
+
+@keras_export("keras.callbacks.experimental.UpdateEmbeddingCallback")
+class UpdateEmbeddingCallback(TimedThread, Callback):
+    """A callback to update the DynamicEmbedding layer at specific time
+    interval.
+
+    Updating the embedding matrix  would mean that the optimizer variables will
+    be reset in this callback and this could have potential side effects. This
+    means that any existing slot variables associated with the optimizer will
+    likely be discarded when the optimizer is rebuilt. This affects optimizers
+    that rely on states of optimizer slot variables.
+
+    Example:
+      ```
+        # Generate dummy data
+        train_data = np.array([
+            ['a', 'j', 'c', 'd', 'e'],
+            ['a', 'h', 'i', 'j', 'b'],
+            ['i', 'h', 'c', 'j', 'e'],
+        ])
+        train_labels = np.array([0, 1, 2])
+        vocab = tf.constant(['a', 'b', 'c', 'd', 'e'])
+        eviction_policy = 'LFU'
+        # Define the model
+        model = tf.keras.models.Sequential([
+            DynamicEmbedding(
+                input_dim=5,
+                output_dim=2,
+                input_length=5,
+                eviction_policy=eviction_policy,
+                initial_vocabulary=vocab,
+            ),
+            tf.keras.layers.Flatten(),
+            tf.keras.layers.Dense(3, activation='softmax'),
+        ])
+
+        # Compile the model
+        model.compile(
+            optimizer='adam',
+            loss='sparse_categorical_crossentropy',
+            metrics=['accuracy'],
+        )
+        # update the vocabulary every 1 second
+        update_embedding_callback = UpdateEmbeddingCallback(
+            model.layers[0], interval=1
+        )
+        with update_embedding_callback:
+          result = model.fit(
+              train_data,
+              train_labels,
+              epochs=100,
+              batch_size=1,
+              callbacks=[update_embedding_callback],
+          )
+      ```
+    """
+
+    def __init__(self, dynamic_embedding_layer, interval):
+        """Initialize Timed Callback object.
+
+        Args:
+          dynamic_embedding_layer: The dynamic embedding
+            layer to be updated.
+          interval: the interval, in seconds, to wait between calls to the
+            thread function. The thread function here updates the embeddings
+            matrix and resets the optimizer states.
+        """
+        self._epoch = 0
+        TimedThread.__init__(self, interval)
+        Callback.__init__(self)
+        self._dynamic_embedding_layer = dynamic_embedding_layer
+        self.strategy = tf.distribute.get_strategy()
+
+    def on_interval(self):
+        try:
+            critical_section = tf.CriticalSection()
+
+            # Using `tf.CriticalSection` when updating embeddings using timed
+            # thread can help ensure thread safety and prevent race conditions
+            # in the shared variables.
+            def execute_critical_section():
+                critical_section.execute(
+                    lambda: self._dynamic_embedding_layer.update_embeddings(  # pylint: disable=g-long-lambda
+                        self.strategy
+                    )
+                )
+
+            # update embeddings across all devices if distributed training is
+            # used
+            self.strategy.run(execute_critical_section)
+            # update optimizer variables across all devices if distributed
+            # training is used.
+            self.strategy.run(
+                lambda: self._reset_optimizer()
+            )  # pylint: disable=unnecessary-lambda
+        except AttributeError:
+            logging.info(
+                "Time interval specified to the UpdateEmbeddingCallback may be"
+                " too small, please try increasing the value of `interval`."
+            )
+
+    def _reset_optimizer(self):
+        """Resetting the optimizer variables.
+
+        Resetting the optimizer variables is necessary after updating the
+        variable in the layer. This ensures that the optimizer is working with a
+        consistent internal state. This helps to prevent unexpected behavior and
+        can lead to more stable and faster training of the model.
+        """
+        for var in self.model.optimizer.variables():
+            if "dynamic_embedding" in var.name:
+                backend.set_value(var, backend.zeros_like(var))
+
+    def on_epoch_begin(self, epoch, logs=None):
+        self._epoch = epoch

keras/layers/__init__.py

@@ -73,6 +73,7 @@
 from keras.layers.core.tf_op_layer import SlicingOpLambda
 from keras.layers.core.tf_op_layer import TFOpLambda
 
+
 # Locally-connected layers.
 from keras.layers.locally_connected.locally_connected1d import (
     LocallyConnected1D,