org.nd4j.linalg.dataset.api.iterator.fetcher.DataSetFetcher Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2015-2018 Skymind, Inc.
*
* This program and the accompanying materials are made available under the
* terms of the Apache License, Version 2.0 which is available at
* https://www.apache.org/licenses/LICENSE-2.0.
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
* SPDX-License-Identifier: Apache-2.0
******************************************************************************/
package org.nd4j.linalg.dataset.api.iterator.fetcher;
import org.nd4j.linalg.dataset.DataSet;
import java.io.Serializable;
/**
* A low level interface for loading datasets in to memory.
*
* This is used by an {@link org.nd4j.linalg.dataset.api.iterator.DataSetIterator} to
*
* handle the specifics of loading data in to memory.
*
* @author Adam Gibson
*/
public interface DataSetFetcher extends Serializable {
/**
* Whether the dataset has more to load
*
* @return whether the data applyTransformToDestination has more to load
*/
boolean hasMore();
/**
* Returns the next data applyTransformToDestination
*
* @return the next dataset
*/
DataSet next();
/**
* Fetches the next dataset. You need to call this
* to getFromOrigin a new dataset, otherwise {@link #next()}
* just returns the last data applyTransformToDestination fetch
*
* @param numExamples the number of examples to fetch
*/
void fetch(int numExamples);
/**
* The number of labels for a dataset
*
* @return the number of labels for a dataset
*/
int totalOutcomes();
/**
* The length of a feature vector for an individual example
*
* @return the length of a feature vector for an individual example
*/
int inputColumns();
/**
* The total number of examples
*
* @return the total number of examples
*/
int totalExamples();
/**
* Returns the fetcher back to the beginning of the dataset
*/
void reset();
/**
* Direct access to a number represenative of iterating through a dataset
*
* @return a cursor similar to an index
*/
int cursor();
}