| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| package org.apache.uima.cas.impl; |
| |
| import java.util.Comparator; |
| import java.util.NoSuchElementException; |
| |
| import org.apache.uima.cas.FSIterator; |
| import org.apache.uima.cas.FeatureStructure; |
| import org.apache.uima.jcas.cas.TOP; |
| |
| /** |
| * Wraps FSIterator<T>, limits results to n gets. Moving the iterator around does not count towards |
| * the limit. |
| */ |
| class FsIterator_limited<T extends FeatureStructure> implements LowLevelIterator<T> { |
| |
| final private LowLevelIterator<T> iterator; // not just for single-type iterators |
| final private int limit; |
| |
| private int count = 0; |
| private boolean limitReached = false; |
| |
| FsIterator_limited(FSIterator<T> iterator, int limit) { |
| this.iterator = (LowLevelIterator<T>) iterator; |
| this.limit = limit; |
| this.limitReached = limit <= count; |
| } |
| |
| private void maybeMakeInvalid() { |
| if (count < 0 || count == limit) { |
| limitReached = true; |
| } |
| } |
| |
| @Override |
| public T getNvc() { |
| maybeMakeInvalid(); |
| if (limitReached) { |
| throw new NoSuchElementException(); |
| } |
| T r = iterator.get(); // not getNvc because of above maybeMakeInvalid |
| return r; |
| } |
| |
| @Override |
| public void moveToNextNvc() { |
| maybeMakeInvalid(); |
| if (limitReached) { |
| return; |
| } |
| iterator.moveToNext(); // not getNvc because of above maybeMakeInvalid |
| count++; |
| } |
| |
| @Override |
| public void moveToPreviousNvc() { |
| count--; |
| maybeMakeInvalid(); |
| if (limitReached) { |
| return; |
| } |
| iterator.moveToPrevious(); // not getNvc because of above maybeMakeInvalid |
| } |
| |
| @Override |
| public void moveToFirstNoReinit() { |
| iterator.moveToFirstNoReinit(); |
| count = 0; |
| this.limitReached = limit <= count; |
| } |
| |
| @Override |
| public void moveToLastNoReinit() { |
| if (count >= 0 && limitReached && iterator.isValid()) { |
| iterator.moveToPrevious(); |
| count--; |
| } else { |
| moveToFirstNoReinit(); |
| } |
| |
| while (count < limit - 1 && iterator.isValid()) { |
| iterator.moveToNextNvc(); |
| if (!iterator.isValid()) { |
| iterator.moveToLastNoReinit(); |
| break; |
| } else { |
| count++; |
| } |
| } |
| this.limitReached = limit <= count; |
| } |
| |
| @Override |
| public void moveToNoReinit(FeatureStructure fs) { |
| // If the iterator is not valid, then we make it valid by moving to the start |
| if (!isValid()) { |
| moveToFirstNoReinit(); |
| } |
| |
| // Now we seek... we cannot make proper use of the binary search here because we do not know |
| // now many elements the binary search skips and whether we stay inside the limit. Hopefully, |
| // the limit is not too big so that it might actually be faster to seek instead of doing the |
| // binary search. |
| Comparator<TOP> cmp = iterator.getComparator(); |
| boolean skippedMatch = false; |
| boolean movedForward = false; |
| while (isValid()) { |
| T current = get(); |
| |
| int c = cmp.compare((TOP) current, (TOP) fs); |
| |
| // We seek to the first match in index order. Because we move backwards, we need to skip over |
| // matches in order to do so and then potentially back-up at the end of the move process. |
| if (c == 0) { |
| if (movedForward) { |
| // We reached the first match by seeking forward, so we can stop here |
| break; |
| } |
| |
| moveToPreviousNvc(); |
| skippedMatch = true; |
| continue; |
| } |
| |
| if (skippedMatch) { |
| break; |
| } |
| |
| if (c < 0) { |
| moveToNextNvc(); |
| movedForward = true; |
| continue; |
| } |
| |
| if (c > 0) { |
| moveToPreviousNvc(); |
| } |
| } |
| |
| if (skippedMatch) { |
| if (!isValid()) { |
| moveToFirstNoReinit(); |
| } else { |
| moveToNextNvc(); |
| } |
| } |
| } |
| |
| // @Override |
| // public void moveToExactNoReinit(FeatureStructure fs) { |
| // iterator.moveToExactNoReinit(fs); |
| // maybeMakeInvalid(); |
| // } |
| |
| @Override |
| public FSIterator<T> copy() { |
| FsIterator_limited<T> copy = new FsIterator_limited<>(iterator.copy(), limit); |
| copy.count = count; |
| copy.limitReached = limitReached; |
| return copy; |
| } |
| |
| @Override |
| public boolean isValid() { |
| maybeMakeInvalid(); |
| return !limitReached && iterator.isValid(); |
| } |
| |
| @Override |
| public int ll_indexSizeMaybeNotCurrent() { |
| return iterator.ll_indexSizeMaybeNotCurrent(); |
| } |
| |
| @Override |
| public int ll_maxAnnotSpan() { |
| return iterator.ll_maxAnnotSpan(); |
| } |
| |
| @Override |
| public LowLevelIndex<T> ll_getIndex() { |
| return iterator.ll_getIndex(); |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.apache.uima.cas.impl.LowLevelIterator#isIndexesHaveBeenUpdated() |
| */ |
| @Override |
| public boolean isIndexesHaveBeenUpdated() { |
| return iterator.isIndexesHaveBeenUpdated(); |
| } |
| |
| @Override |
| public boolean maybeReinitIterator() { |
| return iterator.maybeReinitIterator(); |
| } |
| |
| @Override |
| public Comparator<TOP> getComparator() { |
| return iterator.getComparator(); |
| } |
| |
| @Override |
| public int size() { |
| return Math.min(limit, iterator.size()); |
| } |
| } |