/**
* @return all the id Sequences that are missing from this set that are not in between the range
* provided.
*/
public List<Sequence> getMissing(long first, long last) {
ArrayList<Sequence> rc = new ArrayList<Sequence>();
if (first > last) {
throw new IllegalArgumentException("First cannot be more than last");
}
if (isEmpty()) {
// We are missing all the messages.
rc.add(new Sequence(first, last));
return rc;
}
Sequence sequence = getHead();
while (sequence != null && first <= last) {
if (sequence.contains(first)) {
first = sequence.last + 1;
} else {
if (first < sequence.first) {
if (last < sequence.first) {
rc.add(new Sequence(first, last));
return rc;
} else {
rc.add(new Sequence(first, sequence.first - 1));
first = sequence.last + 1;
}
}
}
sequence = sequence.getNext();
}
if (first <= last) {
rc.add(new Sequence(first, last));
}
return rc;
}
/**
* Removes the given value from the Sequence set, splitting a contained sequence if necessary.
*
* @param value The value that should be removed from the SequenceSet.
* @return true if the value was removed from the set, false if there was no sequence in the set
* that contained the given value.
*/
public boolean remove(long value) {
Sequence sequence = getHead();
while (sequence != null) {
if (sequence.contains(value)) {
if (sequence.range() == 1) {
sequence.unlink();
return true;
} else if (sequence.getFirst() == value) {
sequence.setFirst(value + 1);
return true;
} else if (sequence.getLast() == value) {
sequence.setLast(value - 1);
return true;
} else {
sequence.linkBefore(new Sequence(sequence.first, value - 1));
sequence.linkAfter(new Sequence(value + 1, sequence.last));
sequence.unlink();
return true;
}
}
sequence = sequence.getNext();
}
return false;
}
/**
* checks if a list of sequences contain a sequence
*
* @param sequences - list of sequences
* @param seq - sequence to be checked
* @return true or false
*/
public static boolean ListContains(ArrayList<Sequence> sequences, Sequence seq) {
boolean contains = false;
for (Sequence s : sequences) {
if (s.contains(seq)) {
contains = true;
break;
}
}
return contains;
}
/**
* Returns true if the value given is contained within one of the sequences held in this set.
*
* @param value The value to search for in the set.
* @return true if the value is contained in the set.
*/
public boolean contains(long value) {
if (isEmpty()) {
return false;
}
Sequence sequence = getHead();
while (sequence != null) {
if (sequence.contains(value)) {
return true;
}
sequence = sequence.getNext();
}
return false;
}
/**
* @param value the value to add to the list
* @return false if the value was a duplicate.
*/
public boolean add(long value) {
if (isEmpty()) {
addFirst(new Sequence(value));
return true;
}
// check for append
Sequence sequence = getTail();
if (sequence.isAdjacentToLast(value)) {
sequence.last = value;
return true;
}
sequence = getHead();
while (sequence != null) {
if (sequence.isAdjacentToLast(value)) {
// grow the sequence...
sequence.last = value;
// it might connect us to the next sequence..
if (sequence.getNext() != null) {
Sequence next = sequence.getNext();
if (next.isAdjacentToFirst(value)) {
// Yep the sequence connected.. so join them.
sequence.last = next.last;
next.unlink();
}
}
return true;
}
if (sequence.isAdjacentToFirst(value)) {
// grow the sequence...
sequence.first = value;
// it might connect us to the previous
if (sequence.getPrevious() != null) {
Sequence prev = sequence.getPrevious();
if (prev.isAdjacentToLast(value)) {
// Yep the sequence connected.. so join them.
sequence.first = prev.first;
prev.unlink();
}
}
return true;
}
// Did that value land before this sequence?
if (value < sequence.first) {
// Then insert a new entry before this sequence item.
sequence.linkBefore(new Sequence(value));
return true;
}
// Did that value land within the sequence? The it's a duplicate.
if (sequence.contains(value)) {
return false;
}
sequence = sequence.getNext();
}
// Then the value is getting appended to the tail of the sequence.
addLast(new Sequence(value));
return true;
}
