Method treeIter

src/main/java/org/mapdb/IndexTreeListJava.java:525–583

(int dirShift, long recid, Store store, int level, long indexStart)

        }
    }
    public static long[] treeIter(int dirShift, long recid, Store store, int level, long indexStart){
        if(CC.ASSERT && level<0)
            throw new DBException.DataCorruption("level too low");
        if(CC.ASSERT && indexStart<0)
            throw new AssertionError();
        if(CC.ASSERT && (dirShift<0||dirShift>maxDirShift))
            throw new AssertionError();


        long[] dir = store.get(recid, dirSer);

        boolean first = true;
        final int slot = treePos(dirShift, level, indexStart);
        int pos = dirOffsetFromSlot(dir,slot);
        if(pos<0)
            pos = -pos;
        posLoop:
        for(;
            pos<dir.length;
            pos+=2)
        {
            long oldVal = dir[pos];
            long oldIndex = dir[pos + 1]-1;

            if (oldIndex == -1) {
                if(oldVal == 0){
                    first = false;
                    //nothing here continue
                    continue posLoop;
                }

                //calculate corresponding index from our pos
                long index = first? indexStart : (
                        //upper part of level, strip out part for pos
                        indexStart & (full << ((level+1)*dirShift)) |
                        //part with current pos
                        ((long)slot)<<(dirShift*level)
                );
                // recid here, dive deeper
                long[] ret = treeIter(dirShift, oldVal, store, level-1, index);
                if (ret != null)
                    return ret;
                //nothing in this dir, continue

                //TODO PERF: add another type of iteration
                // this place  should not be reached if we collapse nodes on delete, or delete is forbidden
                // in that case we do not have to use recursion, and `dir` variable can be reused
            } else {
                if(oldIndex>=indexStart) {
                    //there is value here, return it
                    return new long[]{oldIndex, oldVal};
                }
                //this position is occupied by smaller index
            }
            first = false;
        }
        //reached end of this dir, nothing found
        return null;