org.nd4j.linalg.dataset.api.iterator.BaseDatasetIterator 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;
import org.nd4j.linalg.dataset.DataSet;
import org.nd4j.linalg.dataset.api.DataSetPreProcessor;
import org.nd4j.linalg.dataset.api.iterator.fetcher.DataSetFetcher;
import java.util.List;
import java.util.NoSuchElementException;
/**
* Baseline implementation includes
* control over the data fetcher and some basic
* getters for metadata
*
* @author Adam Gibson
*/
public class BaseDatasetIterator implements DataSetIterator {
private static final long serialVersionUID = -116636792426198949L;
protected int batch, numExamples;
protected DataSetFetcher fetcher;
protected DataSetPreProcessor preProcessor;
public BaseDatasetIterator(int batch, int numExamples, DataSetFetcher fetcher) {
this.batch = batch;
if (numExamples < 0)
numExamples = fetcher.totalExamples();
this.numExamples = numExamples;
this.fetcher = fetcher;
}
@Override
public boolean hasNext() {
return fetcher.hasMore() && fetcher.cursor() < numExamples;
}
@Override
public DataSet next() {
if(!hasNext())
throw new NoSuchElementException("No next element - hasNext() == false");
int next = Math.min(batch, numExamples - fetcher.cursor());
fetcher.fetch(next);
return fetcher.next();
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
@Override
public int inputColumns() {
return fetcher.inputColumns();
}
@Override
public int totalOutcomes() {
return fetcher.totalOutcomes();
}
@Override
public boolean resetSupported() {
return true;
}
@Override
public boolean asyncSupported() {
return true;
}
@Override
public void reset() {
fetcher.reset();
}
@Override
public int batch() {
return batch;
}
/**
* Set a pre processor
*
* @param preProcessor a pre processor to set
*/
@Override
public void setPreProcessor(DataSetPreProcessor preProcessor) {
this.preProcessor = preProcessor;
}
@Override
public DataSetPreProcessor getPreProcessor() {
return preProcessor;
}
@Override
public List getLabels() {
return null;
}
@Override
public DataSet next(int num) {
fetcher.fetch(num);
DataSet next = fetcher.next();
if (preProcessor != null)
preProcessor.preProcess(next);
return next;
}
}