/**
   * Offlined handling for cases where there was no buffered token to return, and the token read
   * next could not be returned as-is, at least not yet, but where we have not yet established that
   * buffering is needed.
   */
  protected final JsonToken _nextToken2() throws IOException {
    main_loop:
    while (true) {
      JsonToken t = delegate.nextToken();
      if (t == null) { // is this even legal?
        return (_currToken = t);
      }
      TokenFilter f;

      switch (t.id()) {
        case ID_START_ARRAY:
          f = _itemFilter;
          if (f == TokenFilter.INCLUDE_ALL) {
            _headContext = _headContext.createChildArrayContext(f, true);
            return (_currToken = t);
          }
          if (f == null) { // does this occur?
            delegate.skipChildren();
            continue main_loop;
          }
          // Otherwise still iffy, need to check
          f = _headContext.checkValue(f);
          if (f == null) {
            delegate.skipChildren();
            continue main_loop;
          }
          if (f != TokenFilter.INCLUDE_ALL) {
            f = f.filterStartArray();
          }
          _itemFilter = f;
          if (f == TokenFilter.INCLUDE_ALL) {
            _headContext = _headContext.createChildArrayContext(f, true);
            return (_currToken = t);
          }
          _headContext = _headContext.createChildArrayContext(f, false);
          // but if we didn't figure it out yet, need to buffer possible events
          if (_includePath) {
            t = _nextTokenWithBuffering(_headContext);
            if (t != null) {
              _currToken = t;
              return t;
            }
          }
          continue main_loop;

        case ID_START_OBJECT:
          f = _itemFilter;
          if (f == TokenFilter.INCLUDE_ALL) {
            _headContext = _headContext.createChildObjectContext(f, true);
            return (_currToken = t);
          }
          if (f == null) { // does this occur?
            delegate.skipChildren();
            continue main_loop;
          }
          // Otherwise still iffy, need to check
          f = _headContext.checkValue(f);
          if (f == null) {
            delegate.skipChildren();
            continue main_loop;
          }
          if (f != TokenFilter.INCLUDE_ALL) {
            f = f.filterStartObject();
          }
          _itemFilter = f;
          if (f == TokenFilter.INCLUDE_ALL) {
            _headContext = _headContext.createChildObjectContext(f, true);
            return (_currToken = t);
          }
          _headContext = _headContext.createChildObjectContext(f, false);
          if (_includePath) {
            t = _nextTokenWithBuffering(_headContext);
            if (t != null) {
              _currToken = t;
              return t;
            }
          }
          continue main_loop;

        case ID_END_ARRAY:
        case ID_END_OBJECT:
          {
            boolean returnEnd = _headContext.isStartHandled();
            f = _headContext.getFilter();
            if ((f != null) && (f != TokenFilter.INCLUDE_ALL)) {
              f.filterFinishArray();
            }
            _headContext = _headContext.getParent();
            _itemFilter = _headContext.getFilter();
            if (returnEnd) {
              return (_currToken = t);
            }
          }
          continue main_loop;

        case ID_FIELD_NAME:
          {
            final String name = delegate.getCurrentName();
            f = _headContext.setFieldName(name);
            if (f == TokenFilter.INCLUDE_ALL) {
              _itemFilter = f;
              return (_currToken = t);
            }
            if (f == null) { // filter out the value
              delegate.nextToken();
              delegate.skipChildren();
              continue main_loop;
            }
            f = f.includeProperty(name);
            if (f == null) { // filter out the value
              delegate.nextToken();
              delegate.skipChildren();
              continue main_loop;
            }
            _itemFilter = f;
            if (f == TokenFilter.INCLUDE_ALL) {
              if (_includePath) {
                return (_currToken = t);
              }
              //                        if (_includeImmediateParent) { ...
              continue main_loop;
            }
            if (_includePath) {
              t = _nextTokenWithBuffering(_headContext);
              if (t != null) {
                _currToken = t;
                return t;
              }
            }
          }
          continue main_loop;

        default: // scalar value
          f = _itemFilter;
          if (f == TokenFilter.INCLUDE_ALL) {
            return (_currToken = t);
          }
          if (f != null) {
            f = _headContext.checkValue(f);
            if ((f == TokenFilter.INCLUDE_ALL) || ((f != null) && f.includeValue(delegate))) {
              return (_currToken = t);
            }
          }
          // Otherwise not included (leaves must be explicitly included)
          break;
      }
    }
  }
  /** Method called when a new potentially included context is found. */
  protected final JsonToken _nextTokenWithBuffering(final TokenFilterContext buffRoot)
      throws IOException {
    main_loop:
    while (true) {
      JsonToken t = delegate.nextToken();
      if (t == null) { // is this even legal?
        return t;
      }
      TokenFilter f;

      // One simplification here: we know for a fact that the item filter is
      // neither null nor 'include all', for most cases; the only exception
      // being FIELD_NAME handling

      switch (t.id()) {
        case ID_START_ARRAY:
          f = _headContext.checkValue(_itemFilter);
          if (f == null) {
            delegate.skipChildren();
            continue main_loop;
          }
          if (f != TokenFilter.INCLUDE_ALL) {
            f = f.filterStartArray();
          }
          _itemFilter = f;
          if (f == TokenFilter.INCLUDE_ALL) {
            _headContext = _headContext.createChildArrayContext(f, true);
            return _nextBuffered(buffRoot);
          }
          _headContext = _headContext.createChildArrayContext(f, false);
          continue main_loop;

        case ID_START_OBJECT:
          f = _itemFilter;
          if (f == TokenFilter.INCLUDE_ALL) {
            _headContext = _headContext.createChildObjectContext(f, true);
            return t;
          }
          if (f == null) { // does this occur?
            delegate.skipChildren();
            continue main_loop;
          }
          // Otherwise still iffy, need to check
          f = _headContext.checkValue(f);
          if (f == null) {
            delegate.skipChildren();
            continue main_loop;
          }
          if (f != TokenFilter.INCLUDE_ALL) {
            f = f.filterStartObject();
          }
          _itemFilter = f;
          if (f == TokenFilter.INCLUDE_ALL) {
            _headContext = _headContext.createChildObjectContext(f, true);
            return _nextBuffered(buffRoot);
          }
          _headContext = _headContext.createChildObjectContext(f, false);
          continue main_loop;

        case ID_END_ARRAY:
        case ID_END_OBJECT:
          {
            // Unlike with other loops, here we know that content was NOT
            // included (won't get this far otherwise)
            f = _headContext.getFilter();
            if ((f != null) && (f != TokenFilter.INCLUDE_ALL)) {
              f.filterFinishArray();
            }
            boolean gotEnd = (_headContext == buffRoot);
            boolean returnEnd = gotEnd && _headContext.isStartHandled();

            _headContext = _headContext.getParent();
            _itemFilter = _headContext.getFilter();

            if (returnEnd) {
              return t;
            }
            // Hmmh. Do we need both checks, or should above suffice?
            if (gotEnd || (_headContext == buffRoot)) {
              return null;
            }
          }
          continue main_loop;

        case ID_FIELD_NAME:
          {
            final String name = delegate.getCurrentName();
            f = _headContext.setFieldName(name);
            if (f == TokenFilter.INCLUDE_ALL) {
              _itemFilter = f;
              return _nextBuffered(buffRoot);
            }
            if (f == null) { // filter out the value
              delegate.nextToken();
              delegate.skipChildren();
              continue main_loop;
            }
            f = f.includeProperty(name);
            if (f == null) { // filter out the value
              delegate.nextToken();
              delegate.skipChildren();
              continue main_loop;
            }
            _itemFilter = f;
            if (f == TokenFilter.INCLUDE_ALL) {
              return _nextBuffered(buffRoot);
            }
          }
          continue main_loop;

        default: // scalar value
          f = _itemFilter;
          if (f == TokenFilter.INCLUDE_ALL) {
            return _nextBuffered(buffRoot);
          }
          if (f != null) {
            f = _headContext.checkValue(f);
            if ((f == TokenFilter.INCLUDE_ALL) || ((f != null) && f.includeValue(delegate))) {
              return _nextBuffered(buffRoot);
            }
          }
          // Otherwise not included (leaves must be explicitly included)
          continue main_loop;
      }
    }
  }
  @Override
  public JsonToken nextToken() throws IOException {
    // Anything buffered?
    TokenFilterContext ctxt = _exposedContext;

    if (ctxt != null) {
      while (true) {
        JsonToken t = ctxt.nextTokenToRead();
        if (t != null) {
          _currToken = t;
          return t;
        }
        // all done with buffered stuff?
        if (ctxt == _headContext) {
          _exposedContext = null;
          if (ctxt.inArray()) {
            t = delegate.getCurrentToken();
            // Is this guaranteed to work without further checks?
            //                        if (t != JsonToken.START_ARRAY) {
            _currToken = t;
            return t;
          }

          // Almost! Most likely still have the current token;
          // with the sole exception of
          /*
          t = delegate.getCurrentToken();
          if (t != JsonToken.FIELD_NAME) {
              _currToken = t;
              return t;
          }
          */
          break;
        }
        // If not, traverse down the context chain
        ctxt = _headContext.findChildOf(ctxt);
        _exposedContext = ctxt;
        if (ctxt == null) { // should never occur
          throw _constructError("Unexpected problem: chain of filtered context broken");
        }
      }
    }

    // If not, need to read more. If we got any:
    JsonToken t = delegate.nextToken();
    if (t == null) {
      // no strict need to close, since we have no state here
      return (_currToken = t);
    }

    // otherwise... to include or not?
    TokenFilter f;

    switch (t.id()) {
      case ID_START_ARRAY:
        f = _itemFilter;
        if (f == TokenFilter.INCLUDE_ALL) {
          _headContext = _headContext.createChildArrayContext(f, true);
          return (_currToken = t);
        }
        if (f == null) { // does this occur?
          delegate.skipChildren();
          break;
        }
        // Otherwise still iffy, need to check
        f = _headContext.checkValue(f);
        if (f == null) {
          delegate.skipChildren();
          break;
        }
        if (f != TokenFilter.INCLUDE_ALL) {
          f = f.filterStartArray();
        }
        _itemFilter = f;
        if (f == TokenFilter.INCLUDE_ALL) {
          _headContext = _headContext.createChildArrayContext(f, true);
          return (_currToken = t);
        }
        _headContext = _headContext.createChildArrayContext(f, false);

        // Also: only need buffering if parent path to be included
        if (_includePath) {
          t = _nextTokenWithBuffering(_headContext);
          if (t != null) {
            _currToken = t;
            return t;
          }
        }
        break;

      case ID_START_OBJECT:
        f = _itemFilter;
        if (f == TokenFilter.INCLUDE_ALL) {
          _headContext = _headContext.createChildObjectContext(f, true);
          return (_currToken = t);
        }
        if (f == null) { // does this occur?
          delegate.skipChildren();
          break;
        }
        // Otherwise still iffy, need to check
        f = _headContext.checkValue(f);
        if (f == null) {
          delegate.skipChildren();
          break;
        }
        if (f != TokenFilter.INCLUDE_ALL) {
          f = f.filterStartObject();
        }
        _itemFilter = f;
        if (f == TokenFilter.INCLUDE_ALL) {
          _headContext = _headContext.createChildObjectContext(f, true);
          return (_currToken = t);
        }
        _headContext = _headContext.createChildObjectContext(f, false);
        // Also: only need buffering if parent path to be included
        if (_includePath) {
          t = _nextTokenWithBuffering(_headContext);
          if (t != null) {
            _currToken = t;
            return t;
          }
        }
        // note: inclusion of surrounding Object handled separately via
        // FIELD_NAME
        break;

      case ID_END_ARRAY:
      case ID_END_OBJECT:
        {
          boolean returnEnd = _headContext.isStartHandled();
          f = _headContext.getFilter();
          if ((f != null) && (f != TokenFilter.INCLUDE_ALL)) {
            f.filterFinishArray();
          }
          _headContext = _headContext.getParent();
          _itemFilter = _headContext.getFilter();
          if (returnEnd) {
            return (_currToken = t);
          }
        }
        break;

      case ID_FIELD_NAME:
        {
          final String name = delegate.getCurrentName();
          // note: this will also set 'needToHandleName'
          f = _headContext.setFieldName(name);
          if (f == TokenFilter.INCLUDE_ALL) {
            _itemFilter = f;
            if (!_includePath) {
              // Minor twist here: if parent NOT included, may need to induce output of
              // surrounding START_OBJECT/END_OBJECT
              if (_includeImmediateParent && !_headContext.isStartHandled()) {
                t =
                    _headContext
                        .nextTokenToRead(); // returns START_OBJECT but also marks it handled
                _exposedContext = _headContext;
              }
            }
            return (_currToken = t);
          }
          if (f == null) {
            delegate.nextToken();
            delegate.skipChildren();
            break;
          }
          f = f.includeProperty(name);
          if (f == null) {
            delegate.nextToken();
            delegate.skipChildren();
            break;
          }
          _itemFilter = f;
          if (f == TokenFilter.INCLUDE_ALL) {
            if (_includePath) {
              return (_currToken = t);
            }
          }
          if (_includePath) {
            t = _nextTokenWithBuffering(_headContext);
            if (t != null) {
              _currToken = t;
              return t;
            }
          }
          break;
        }

      default: // scalar value
        f = _itemFilter;
        if (f == TokenFilter.INCLUDE_ALL) {
          return (_currToken = t);
        }
        if (f != null) {
          f = _headContext.checkValue(f);
          if ((f == TokenFilter.INCLUDE_ALL) || ((f != null) && f.includeValue(delegate))) {
            return (_currToken = t);
          }
        }
        // Otherwise not included (leaves must be explicitly included)
        break;
    }

    // We get here if token was not yet found; offlined handling
    return _nextToken2();
  }