// License: GPL. For details, see LICENSE file.
package org.openstreetmap.josm.data.osm;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import org.openstreetmap.josm.Main;
import org.openstreetmap.josm.data.coor.LatLon;
import org.openstreetmap.josm.data.coor.QuadTiling;
/**
* Note: bbox of primitives added to QuadBuckets has to stay the same. In case of coordinate change, primitive must
* be removed and readded.
*
* This class is (no longer) thread safe.
*
*/
public class QuadBuckets<T extends OsmPrimitive> implements Collection<T> {
private static final boolean consistency_testing = false;
private static final int NW_INDEX = 1;
private static final int NE_INDEX = 3;
private static final int SE_INDEX = 2;
private static final int SW_INDEX = 0;
static void abort(String s) {
throw new AssertionError(s);
}
public static final int MAX_OBJECTS_PER_LEVEL = 16;
static class QBLevel<T extends OsmPrimitive> {
private final int level;
private final int index;
private final BBox bbox;
private final long quad;
private final QBLevel<T> parent;
private boolean isLeaf = true;
private List<T> content;
// child order by index is sw, nw, se, ne
private QBLevel<T> nw, ne, sw, se;
private final QuadBuckets<T> buckets;
private QBLevel<T> getChild(int index) {
switch (index) {
case NE_INDEX:
if (ne == null) {
ne = new QBLevel<>(this, index, buckets);
}
return ne;
case NW_INDEX:
if (nw == null) {
nw = new QBLevel<>(this, index, buckets);
}
return nw;
case SE_INDEX:
if (se == null) {
se = new QBLevel<>(this, index, buckets);
}
return se;
case SW_INDEX:
if (sw == null) {
sw = new QBLevel<>(this, index, buckets);
}
return sw;
default:
return null;
}
}
@SuppressWarnings("unchecked")
private QBLevel<T>[] getChildren() {
return new QBLevel[] {sw, nw, se, ne};
}
@Override
public String toString() {
return super.toString() + "[" + level + "]: " + bbox();
}
/**
* Constructor for root node
*/
public QBLevel(final QuadBuckets<T> buckets) {
level = 0;
index = 0;
quad = 0;
parent = null;
bbox = new BBox(-180, 90, 180, -90);
this.buckets = buckets;
}
public QBLevel(QBLevel<T> parent, int parent_index, final QuadBuckets<T> buckets) {
this.parent = parent;
this.level = parent.level + 1;
this.index = parent_index;
this.buckets = buckets;
int shift = (QuadTiling.NR_LEVELS - level) * 2;
long mult = 1;
// Java blows the big one. It seems to wrap when you shift by > 31
if (shift >= 30) {
shift -= 30;
mult = 1 << 30;
}
long this_quadpart = mult * (parent_index << shift);
this.quad = parent.quad | this_quadpart;
this.bbox = calculateBBox(); // calculateBBox reference quad
}
private BBox calculateBBox() {
LatLon bottom_left = this.coor();
double lat = bottom_left.lat() + parent.height() / 2;
double lon = bottom_left.lon() + parent.width() / 2;
return new BBox(bottom_left.lon(), bottom_left.lat(), lon, lat);
}
QBLevel<T> findBucket(BBox bbox) {
if (!hasChildren())
return this;
else {
int idx = bbox.getIndex(level);
if (idx == -1)
return this;
return getChild(idx).findBucket(bbox);
}
}
boolean remove_content(T o) {
// If two threads try to remove item at the same time from different buckets of this QBLevel,
// it might happen that one thread removes bucket but don't remove parent because it still sees
// another bucket set. Second thread do the same. Due to thread memory caching, it's possible that
// changes made by threads will show up in children array too late, leading to QBLevel with all children
// set to null
if (content == null)
return false;
boolean ret = this.content.remove(o);
if (this.content.isEmpty()) {
this.content = null;
}
if (this.canRemove()) {
this.remove_from_parent();
}
return ret;
}
/*
* There is a race between this and qb.nextContentNode().
* If nextContentNode() runs into this bucket, it may
* attempt to null out 'children' because it thinks this
* is a dead end.
*/
void __split() {
List<T> tmpcontent = content;
content = null;
for (T o : tmpcontent) {
int idx = o.getBBox().getIndex(level);
if (idx == -1) {
__add_content(o);
} else {
getChild(idx).doAdd(o);
}
}
isLeaf = false; // It's not enough to check children because all items could end up in this level (index == -1)
}
boolean __add_content(T o) {
boolean ret = false;
// The split_lock will keep two concurrent calls from overwriting content
if (content == null) {
content = new ArrayList<>();
}
ret = content.add(o);
return ret;
}
boolean matches(final T o, final BBox search_bbox) {
if (o instanceof Node){
final LatLon latLon = ((Node)o).getCoor();
// node without coords -> bbox[0,0,0,0]
return search_bbox.bounds(latLon != null ? latLon : LatLon.ZERO);
}
return o.getBBox().intersects(search_bbox);
}
private void search_contents(BBox search_bbox, List<T> result) {
/*
* It is possible that this was created in a split
* but never got any content populated.
*/
if (content == null)
return;
for (T o : content) {
if (matches(o, search_bbox)) {
result.add(o);
}
}
}
/*
* This is stupid. I tried to have a QBLeaf and QBBranch
* class descending from a QBLevel. It's more than twice
* as slow. So, this throws OO out the window, but it
* is fast. Runtime type determination must be slow.
*/
boolean isLeaf() {
return isLeaf;
}
boolean hasChildren() {
return nw != null || ne != null || sw != null || se != null;
}
QBLevel<T> next_sibling() {
return (parent == null) ? null : parent.firstSiblingOf(this);
}
boolean hasContent() {
return content != null;
}
QBLevel<T> nextSibling() {
QBLevel<T> next = this;
QBLevel<T> sibling = next.next_sibling();
// Walk back up the tree to find the
// next sibling node. It may be either
// a leaf or branch.
while (sibling == null) {
next = next.parent;
if (next == null) {
break;
}
sibling = next.next_sibling();
}
next = sibling;
return next;
}
QBLevel<T> firstChild() {
if (sw != null)
return sw;
if (nw != null)
return nw;
if (se != null)
return se;
return ne;
}
QBLevel<T> firstSiblingOf(final QBLevel<T> child) {
switch (child.index) {
case SW_INDEX:
if (nw != null)
return nw;
case NW_INDEX:
if (se != null)
return se;
case SE_INDEX:
return ne;
}
return null;
}
QBLevel<T> nextNode() {
if (!this.hasChildren())
return this.nextSibling();
return this.firstChild();
}
QBLevel<T> nextContentNode() {
QBLevel<T> next = this.nextNode();
if (next == null)
return next;
if (next.hasContent())
return next;
return next.nextContentNode();
}
void doAdd(T o) {
if (consistency_testing) {
if (!matches(o, this.bbox())) {
o.getBBox().getIndex(level);
o.getBBox().getIndex(level - 1);
abort("\nobject " + o + " does not belong in node at level: " + level + " bbox: " + this.bbox());
}
}
__add_content(o);
if (isLeaf() && content.size() > MAX_OBJECTS_PER_LEVEL && level < QuadTiling.NR_LEVELS) {
__split();
}
}
void add(T o) {
findBucket(o.getBBox()).doAdd(o);
}
private void search(BBox search_bbox, List<T> result) {
if (!this.bbox().intersects(search_bbox))
return;
else if (bbox().bounds(search_bbox)) {
buckets.search_cache = this;
}
if (this.hasContent()) {
search_contents(search_bbox, result);
}
//TODO Coincidence vector should be calculated here and only buckets that match search_bbox should be checked
if (nw != null) {
nw.search(search_bbox, result);
}
if (ne != null) {
ne.search(search_bbox, result);
}
if (se != null) {
se.search(search_bbox, result);
}
if (sw != null) {
sw.search(search_bbox, result);
}
}
public String quads() {
return Long.toHexString(quad);
}
int index_of(QBLevel<T> find_this) {
QBLevel<T>[] children = getChildren();
for (int i = 0; i < QuadTiling.TILES_PER_LEVEL; i++) {
if (children[i] == find_this)
return i;
}
return -1;
}
double width() {
return bbox.width();
}
double height() {
return bbox.height();
}
public BBox bbox() {
return bbox;
}
/*
* This gives the coordinate of the bottom-left
* corner of the box
*/
final LatLon coor() {
return QuadTiling.tile2LatLon(this.quad);
}
void remove_from_parent() {
if (parent == null)
return;
if (!canRemove()) {
abort("attempt to remove non-empty child: " + this.content + " " + Arrays.toString(this.getChildren()));
}
if (parent.nw == this) {
parent.nw = null;
} else if (parent.ne == this) {
parent.ne = null;
} else if (parent.sw == this) {
parent.sw = null;
} else if (parent.se == this) {
parent.se = null;
}
if (parent.canRemove()) {
parent.remove_from_parent();
}
}
boolean canRemove() {
if (content != null && !content.isEmpty())
return false;
if (this.hasChildren())
return false;
return true;
}
}
private QBLevel<T> root;
private QBLevel<T> search_cache;
private int size;
/**
* Constructs a new {@code QuadBuckets}.
*/
public QuadBuckets() {
clear();
}
@Override
public final void clear() {
root = new QBLevel<>(this);
search_cache = null;
size = 0;
}
@Override
public boolean add(T n) {
root.add(n);
size++;
return true;
}
@Override
public boolean retainAll(Collection<?> objects) {
for (T o : this) {
if (objects.contains(o)) {
continue;
}
if (!this.remove(o))
return false;
}
return true;
}
@Override
public boolean removeAll(Collection<?> objects) {
boolean changed = false;
for (Object o : objects) {
changed = changed | remove(o);
}
return changed;
}
@Override
public boolean addAll(Collection<? extends T> objects) {
boolean changed = false;
for (T o : objects) {
changed = changed | this.add(o);
}
return changed;
}
@Override
public boolean containsAll(Collection<?> objects) {
for (Object o : objects) {
if (!this.contains(o))
return false;
}
return true;
}
@Override
public boolean remove(Object o) {
@SuppressWarnings("unchecked")
T t = (T) o;
search_cache = null; // Search cache might point to one of removed buckets
QBLevel<T> bucket = root.findBucket(t.getBBox());
if (bucket.remove_content(t)) {
size--;
return true;
} else
return false;
}
@Override
public boolean contains(Object o) {
@SuppressWarnings("unchecked")
T t = (T) o;
QBLevel<T> bucket = root.findBucket(t.getBBox());
return bucket != null && bucket.content != null && bucket.content.contains(t);
}
public ArrayList<T> toArrayList() {
ArrayList<T> a = new ArrayList<>();
for (T n : this) {
a.add(n);
}
return a;
}
@Override
public Object[] toArray() {
return this.toArrayList().toArray();
}
@Override
public <A> A[] toArray(A[] template) {
return this.toArrayList().toArray(template);
}
class QuadBucketIterator implements Iterator<T> {
QBLevel<T> current_node;
int content_index;
int iterated_over;
final QBLevel<T> next_content_node(QBLevel<T> q) {
if (q == null)
return null;
QBLevel<T> orig = q;
QBLevel<T> next;
next = q.nextContentNode();
if (orig == next) {
abort("got same leaf back leaf: " + q.isLeaf());
}
return next;
}
public QuadBucketIterator(QuadBuckets<T> qb) {
if (!qb.root.hasChildren() || qb.root.hasContent()) {
current_node = qb.root;
} else {
current_node = next_content_node(qb.root);
}
iterated_over = 0;
}
@Override
public boolean hasNext() {
if (this.peek() == null)
return false;
return true;
}
T peek() {
if (current_node == null)
return null;
while ((current_node.content == null) || (content_index >= current_node.content.size())) {
content_index = 0;
current_node = next_content_node(current_node);
if (current_node == null) {
break;
}
}
if (current_node == null || current_node.content == null)
return null;
return current_node.content.get(content_index);
}
@Override
public T next() {
T ret = peek();
content_index++;
iterated_over++;
return ret;
}
@Override
public void remove() {
// two uses
// 1. Back up to the thing we just returned
// 2. move the index back since we removed
// an element
content_index--;
T object = peek();
current_node.remove_content(object);
}
}
@Override
public Iterator<T> iterator() {
return new QuadBucketIterator(this);
}
@Override
public int size() {
return size;
}
@Override
public boolean isEmpty() {
if (this.size() == 0)
return true;
return false;
}
public List<T> search(BBox search_bbox) {
List<T> ret = new ArrayList<>();
// Doing this cuts down search cost on a real-life data set by about 25%
boolean cache_searches = true;
if (cache_searches) {
if (search_cache == null) {
search_cache = root;
}
// Walk back up the tree when the last search spot can not cover the current search
while (search_cache != null && !search_cache.bbox().bounds(search_bbox)) {
search_cache = search_cache.parent;
}
if (search_cache == null) {
search_cache = root;
Main.info("bbox: " + search_bbox + " is out of the world");
}
} else {
search_cache = root;
}
// Save parent because search_cache might change during search call
QBLevel<T> tmp = search_cache.parent;
search_cache.search(search_bbox, ret);
// A way that spans this bucket may be stored in one
// of the nodes which is a parent of the search cache
while (tmp != null) {
tmp.search_contents(search_bbox, ret);
tmp = tmp.parent;
}
return ret;
}
}