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SciJava Common is a shared library for SciJava software. It provides a plugin framework, with an extensible mechanism for service discovery, backed by its own annotation processor, so that plugins can be loaded dynamically. It is used by downstream projects in the SciJava ecosystem, such as ImageJ and SCIFIO.
/*
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* SciJava Common shared library for SciJava software.
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package org.scijava.object;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
/**
* Data structure for managing sorted lists of registered objects.
*
* This data structure is the same as a vanilla {@link ObjectIndex} except that
* each type list is kept in sorted order; hence, the items managed must
* implement the {@link Comparable} interface. When adding a single item (i.e.,
* with {@link #add(Object)}), a binary search is used to insert it in the
* correct position (O(log n) + O(n) time per item). When adding multiple items
* at once (i.e., with {@link #addAll(Collection)}), the items are appended and
* the list is then resorted (O(n log n) time for all items).
*
*
* @author Curtis Rueden
*/
public class SortedObjectIndex> extends
ObjectIndex
{
public SortedObjectIndex(final Class baseClass) {
super(baseClass);
}
// -- Collection methods --
@Override
public boolean contains(final Object o) {
final int index = findInList(o, getAll());
return index < 0;
}
@Override
public boolean containsAll(final Collection c) {
for (final Object o : c) {
if (!contains(o)) return false;
}
return true;
}
@Override
public boolean addAll(final Collection c) {
if (c.size() > 1) {
mergeAfterSorting(c);
return c.size() > 0;
}
if (c.size() == 1) {
// add single item normally, to avoid resorting the lists
return add(c.iterator().next());
}
final boolean changed = super.addAll(c);
if (changed) sort();
return changed;
}
// -- Internal methods --
@Override
protected boolean addToList(final E obj, final List list,
final boolean batch)
{
if (batch) {
// adding multiple values; append to end of list, and sort afterward
return super.addToList(obj, list, batch);
}
// search for the correct location to insert the object
final int result = Collections.binarySearch(list, obj);
// NB: The objects' natural ordering may not be consistent with equals.
// Hence, the index reported may indicate a match with an unequal object
// (i.e., obj.compareTo(match) == 0 but !obj.equals(match)).
// But since we allow duplicate items in the index, this situation is fine;
// either way, we want to insert the object at the given point.
final int index = result < 0 ? -result - 1 : result;
// insert object at the appropriate location
list.add(index, obj);
return true;
}
// -- Helper methods --
private void sort() {
for (final List list : hoard.values()) {
Collections.sort(list);
}
}
private int findInList(final Object o, final List list) {
if (!getBaseClass().isAssignableFrom(o.getClass())) {
// wrong type
return list.size();
}
@SuppressWarnings("unchecked")
final E typedObj = (E) o;
return Collections.binarySearch(list, typedObj);
}
private void mergeAfterSorting(final Collection c) {
final List listToMerge = new ArrayList<>(c);
Collections.sort(listToMerge);
final Map, List> map = new HashMap<>();
for (final E e : listToMerge) {
for (final Class clazz : getTypes(getType(e))) {
final List list = retrieveList(clazz);
List list2 = map.get(clazz);
if (list2 == null) {
list2 = list.size() == 0 ? (List)list : new ArrayList<>();
map.put(clazz, list2);
}
list2.add(e);
}
}
for (final Entry, List> entry : map.entrySet()) {
final Class clazz = entry.getKey();
final List into = retrieveList(clazz);
final List sorted = map.get(clazz);
if (into != sorted) mergeInto(sorted, into);
}
}
private void mergeInto(final List sorted, final List into) {
if (sorted == into) return;
final int count = sorted.size();
if (count == 0) return;
if (into.size() == 0) {
into.addAll(sorted);
return;
}
int index1 = into.size() - 1;
int index2 = sorted.size() - 1;
for (int i = 0; i < count; i++) into.add(null);
int writeIndex = into.size() - 1;
E e1 = into.get(index1);
E e2 = sorted.get(index2);
while (writeIndex > index1) {
if (e1.compareTo(e2) < 0) {
into.set(writeIndex--, e2);
if (--index2 < 0) break;
e2 = sorted.get(index2);
} else {
into.set(writeIndex--, e1);
if (--index1 < 0) break;
e1 = into.get(index1);
}
}
while (index2 >= 0) {
into.set(writeIndex--, sorted.get(index2--));
}
}
}