public T lower(long sequence, boolean inclusive) {
Entry<Long, T> lower = index.floorEntry(sequence);
if (lower == null) {
return null;
}
if (inclusive) {
return lower.getValue();
}
if (lower.getKey() == sequence) {
return lower.getValue().prev;
} else {
return lower.getValue();
}
}
public T upper(long sequence, boolean inclusive) {
if (head == null || head.prev.getSequence() < sequence) {
return null;
}
Entry<Long, T> upper = index.ceilingEntry(sequence);
if (upper == null) {
return null;
}
if (inclusive) {
return upper.getValue();
}
if (upper.getKey() == sequence) {
return upper.getValue().next;
} else {
return upper.getValue();
}
}
public void add(T node) {
T prev = null;
if (head != null) {
// Optimize for case where this is at tail:
if (head.prev.getSequence() < node.getSequence()) {
prev = head.prev;
} else {
Entry<Long, T> entry = index.lowerEntry(node.getSequence());
if (entry != null) {
prev = entry.getValue();
}
}
}
// T prev = index.lower(node);
// If this the lowest then the new head is this.
if (prev == null) {
node.linkToHead(this);
} else {
prev.linkAfter(node);
}
}
/** @param sequence The sequence number of the element to get. */
public T get(long sequence) {
return index.get(sequence);
}
public void clear() {
while (head != null) {
head.unlink();
}
index.clear();
}