public char[] increaseFreeSpace(/*int size*/ char[] buffer) {
int size = buffer.length; // double size of buffer
// increase buffer
buffer = Arrays.copyOf(buffer, buffer.length * 2);
// actual suspended location
if (suspendedLength > 0) {
int suspendedOffset = suspendedSegments.peekLast().start;
// move suspended data to the end of the buffer
System.arraycopy(
buffer, suspendedOffset, buffer, buffer.length - suspendedLength, suspendedLength);
}
this.freeLength += size;
this.size += size;
for (Iterator<Segment<T>> it = suspendedSegments.iterator(); it.hasNext(); ) {
Segment<T> segment = it.next();
segment.start += size;
}
return buffer;
}
static <T> Segment<T> newSegment(T source, int start, int length) {
Segment segment = new Segment();
segment.source = source;
segment.start = start;
segment.length = length;
return segment;
}
public void reset(int pos, char[] buffer) {
if (pos < 0 && activeSegments.size() == 1) {
return;
}
while (true) {
Segment<T> lastActiveSegment = activeSegments.peekLast();
if (pos < lastActiveSegment.start - 1) {
// segment is removed if root, and last suspended segment is merged
// with last active segment if it is the same source
if (lastActiveSegment.root) {
activeSegments.removeLast();
activeLength -= lastActiveSegment.length;
freeLength += lastActiveSegment.length;
lastActiveSegment = activeSegments.peekLast();
Segment<T> lastSuspendedSegment = suspendedSegments.peekLast();
if (lastSuspendedSegment != null
&& lastSuspendedSegment.source.equals(lastActiveSegment.source)) {
lastActiveSegment.length += lastSuspendedSegment.length;
// move data in buffer : suspended space -> active space
System.arraycopy(
buffer,
lastSuspendedSegment.start,
buffer,
activeLength,
lastSuspendedSegment.length);
suspendedSegments.removeLast();
activeLength += lastSuspendedSegment.length;
suspendedLength -= lastSuspendedSegment.length;
}
continue;
}
// segment is suspended if not root
activeSegments.removeLast();
suspendedSegments.addLast(lastActiveSegment);
int startInSuspendedSpace = size - suspendedLength - lastActiveSegment.length;
// move data in buffer : active space -> suspended space
System.arraycopy(
buffer,
lastActiveSegment.start,
buffer,
startInSuspendedSpace,
lastActiveSegment.length);
lastActiveSegment.start = startInSuspendedSpace;
activeLength -= lastActiveSegment.length;
suspendedLength += lastActiveSegment.length;
} else {
break;
}
}
}
public void restoreLastSuspendedSegment(int position, char[] buffer) {
Segment<T> lastSuspendedSegment = suspendedSegments.pollLast();
if (lastSuspendedSegment != null) {
System.arraycopy(
buffer, lastSuspendedSegment.start, buffer, activeLength, lastSuspendedSegment.length);
activeSegments.add(lastSuspendedSegment);
lastSuspendedSegment.start = activeLength;
activeLength += lastSuspendedSegment.length;
suspendedLength -= lastSuspendedSegment.length;
}
}
public void consume(int size) {
this.activeLength -= size;
this.freeLength += size;
// remove from active segments
int removed = 0;
for (Iterator<Segment<T>> it = activeSegments.iterator(); it.hasNext(); ) {
Segment<T> segment = it.next();
int remaining = size - removed;
int sizeToRemove = Math.min(remaining, segment.length);
segment.length -= sizeToRemove;
segment.start -= removed;
removed += sizeToRemove;
if (segment.length == 0 && activeSegments.size() > 1) {
it.remove();
}
}
}