Пример #1
0
 /**
  * Executes the updates. Resolving text node adjacency can be skipped if adjacent text nodes are
  * not to be expected.
  *
  * @param mergeTexts adjacent text nodes are to be expected and must be merged
  */
 public void execute(final boolean mergeTexts) {
   check();
   optimize();
   applyValueUpdates();
   if (cacheDistanceUpdates) data.cache = true;
   applyStructuralUpdates();
   updateDistances();
   if (mergeTexts) resolveTextAdjacency();
   data.cache = false;
 }
Пример #2
0
  /**
   * Resolves unwanted text node adjacency which can result from structural changes in the database.
   * Adjacent text nodes are two text nodes A and B, where PRE(B)=PRE(A)+1 and PARENT(A)=PARENT(B).
   */
  private void resolveTextAdjacency() {
    // Text node merges are also gathered on a separate list to leverage optimizations.
    final AtomicUpdateList allMerges = new AtomicUpdateList(data);

    // keep track of the visited locations to avoid superfluous checks
    final IntSet s = new IntSet();
    // Text nodes have to be merged from the highest to the lowest pre value
    for (int i = 0; i < updStructural.size(); i++) {
      final BasicUpdate u = updStructural.get(i);
      final Data insseq = u.getInsertionData();
      // calculate the new location of the update, here we have to check for adjacency
      final int newLocation = u.location + u.accumulatedShifts - u.shifts;
      final int beforeNewLocation = newLocation - 1;
      // check surroundings of this location for adjacent text nodes depending on the
      // kind of update, first the one with higher PRE values (due to shifts!)
      // ... for insert/replace ...
      if (insseq != null) {
        // calculate the current following node
        final int followingNode = newLocation + insseq.meta.size;
        final int beforeFollowingNode = followingNode - 1;
        // check the nodes at the end of/after the insertion sequence
        if (!s.contains(beforeFollowingNode)) {
          final AtomicUpdateList merges = necessaryMerges(beforeFollowingNode, allMerges.data);
          mergeNodes(merges);
          allMerges.merge(merges);
          s.add(beforeFollowingNode);
        }
      }
      // check nodes for delete and for insert before the updated location
      if (!s.contains(beforeNewLocation)) {
        final AtomicUpdateList merges = necessaryMerges(beforeNewLocation, allMerges.data);
        mergeNodes(merges);
        allMerges.merge(merges);
        s.add(beforeNewLocation);
      }
    }

    allMerges.updateDistances();
    allMerges.clear();
  }