org.nd4j.common.util.Index 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.common.util;
import java.io.Serializable;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
/**
* An index is a transform of objects augmented with a list and a reverse lookup table
* for fast lookups.
* Indices are used for vocabulary in many of the natural language processing
* @author Adam Gibson
*
*/
@SuppressWarnings({"rawtypes", "unchecked"})
public class Index implements Serializable {
private static final long serialVersionUID = 1160629777026141078L;
private Map objects = new ConcurrentHashMap<>();
private Map indexes = new ConcurrentHashMap<>();
public synchronized boolean add(Object o, int idx) {
if (o instanceof String && o.toString().isEmpty()) {
throw new IllegalArgumentException("Unable to add the empty string");
}
Integer index = indexes.get(o);
if (index == null) {
index = idx;
objects.put(idx, o);
indexes.put(o, index);
return true;
}
return false;
}
public synchronized boolean add(Object o) {
if (o instanceof String && o.toString().isEmpty()) {
throw new IllegalArgumentException("Unable to add the empty string");
}
Integer index = indexes.get(o);
if (index == null) {
index = objects.size();
objects.put(index, o);
indexes.put(o, index);
return true;
}
return false;
}
public synchronized int indexOf(Object o) {
Integer index = indexes.get(o);
if (index == null) {
return -1;
} else {
return index;
}
}
public synchronized Object get(int i) {
return objects.get(i);
}
public int size() {
return objects.size();
}
@Override
public String toString() {
StringBuilder buff = new StringBuilder("[");
int sz = objects.size();
int i;
for (i = 0; i < sz; i++) {
Object e = objects.get(i);
buff.append(e);
if (i < (sz - 1))
buff.append(" , ");
}
buff.append("]");
return buff.toString();
}
@Override
public boolean equals(Object o) {
if (this == o)
return true;
if (o == null || getClass() != o.getClass())
return false;
Index index = (Index) o;
if (objects != null ? !objects.equals(index.objects) : index.objects != null)
return false;
return !(indexes != null ? !indexes.equals(index.indexes) : index.indexes != null);
}
@Override
public int hashCode() {
int result = objects != null ? objects.hashCode() : 0;
result = 31 * result + (indexes != null ? indexes.hashCode() : 0);
return result;
}
}