protected static Angle clampAngle(Angle a, Angle min, Angle max) {
   double degrees = a.degrees;
   double minDegrees = min.degrees;
   double maxDegrees = max.degrees;
   return Angle.fromDegrees(
       degrees < minDegrees ? minDegrees : (degrees > maxDegrees ? maxDegrees : degrees));
 }
 static Angle computeRowLatitude(int row, Angle delta) {
   if (delta == null) {
     String msg = Logging.getMessage("nullValue.AngleIsNull");
     Logging.logger().severe(msg);
     throw new IllegalArgumentException(msg);
   }
   return Angle.fromDegrees(-90d + delta.getDegrees() * row);
 }
 static Angle computeColumnLongitude(int column, Angle delta) {
   if (delta == null) {
     String msg = Logging.getMessage("nullValue.AngleIsNull");
     Logging.logger().severe(msg);
     throw new IllegalArgumentException(msg);
   }
   return Angle.fromDegrees(-180 + delta.getDegrees() * column);
 }
/**
 * @author Paul Collins
 * @version $Id: PlaceNameLayer.java 13201 2010-03-12 01:59:03Z tgaskins $
 */
public class PlaceNameLayer extends AbstractLayer implements BulkRetrievable {
  private final PlaceNameServiceSet placeNameServiceSet;
  private PriorityBlockingQueue<Runnable> requestQ = new PriorityBlockingQueue<Runnable>(64);
  private Vec4 referencePoint;
  protected final Object fileLock = new Object();
  private boolean cullNames = false;

  protected static final double LEVEL_A = 0x1 << 25;
  protected static final double LEVEL_B = 0x1 << 24;
  protected static final double LEVEL_C = 0x1 << 23;
  protected static final double LEVEL_D = 0x1 << 22;
  protected static final double LEVEL_E = 0x1 << 21;
  protected static final double LEVEL_F = 0x1 << 20;
  protected static final double LEVEL_G = 0x1 << 19;
  protected static final double LEVEL_H = 0x1 << 18;
  protected static final double LEVEL_I = 0x1 << 17;
  protected static final double LEVEL_J = 0x1 << 16;
  protected static final double LEVEL_K = 0x1 << 15;
  protected static final double LEVEL_L = 0x1 << 14;
  protected static final double LEVEL_M = 0x1 << 13;
  protected static final double LEVEL_N = 0x1 << 12;
  protected static final double LEVEL_O = 0x1 << 11;
  protected static final double LEVEL_P = 0x1 << 10;
  protected static final LatLon GRID_1x1 =
      new LatLon(Angle.fromDegrees(180d), Angle.fromDegrees(360d));
  protected static final LatLon GRID_4x8 =
      new LatLon(Angle.fromDegrees(45d), Angle.fromDegrees(45d));
  protected static final LatLon GRID_8x16 =
      new LatLon(Angle.fromDegrees(22.5d), Angle.fromDegrees(22.5d));
  protected static final LatLon GRID_16x32 =
      new LatLon(Angle.fromDegrees(11.25d), Angle.fromDegrees(11.25d));
  protected static final LatLon GRID_36x72 =
      new LatLon(Angle.fromDegrees(5d), Angle.fromDegrees(5d));
  protected static final LatLon GRID_72x144 =
      new LatLon(Angle.fromDegrees(2.5d), Angle.fromDegrees(2.5d));
  protected static final LatLon GRID_144x288 =
      new LatLon(Angle.fromDegrees(1.25d), Angle.fromDegrees(1.25d));
  protected static final LatLon GRID_288x576 =
      new LatLon(Angle.fromDegrees(0.625d), Angle.fromDegrees(0.625d));

  protected List<NavigationTile> navTiles = new ArrayList<NavigationTile>();
  // top navigation tiles for each service

  /**
   * @param placeNameServiceSet the set of PlaceNameService objects that PlaceNameLayer will render.
   * @throws IllegalArgumentException if {@link
   *     gov.nasa.worldwind.layers.placename.PlaceNameServiceSet} is null
   */
  public PlaceNameLayer(PlaceNameServiceSet placeNameServiceSet) {
    if (placeNameServiceSet == null) {
      String message = Logging.getMessage("nullValue.PlaceNameServiceSetIsNull");
      Logging.logger().fine(message);
      throw new IllegalArgumentException(message);
    }

    //
    this.placeNameServiceSet = placeNameServiceSet.deepCopy();
    for (int i = 0; i < this.placeNameServiceSet.getServiceCount(); i++) {
      // todo do this for long as well and pick min
      int calc1 =
          (int)
              (PlaceNameService.TILING_SECTOR.getDeltaLatDegrees()
                  / this.placeNameServiceSet
                      .getService(i)
                      .getTileDelta()
                      .getLatitude()
                      .getDegrees());
      int numLevels = (int) Math.log(calc1);
      navTiles.add(
          new NavigationTile(
              this.placeNameServiceSet.getService(i),
              PlaceNameService.TILING_SECTOR,
              numLevels,
              "top"));
    }

    if (!WorldWind.getMemoryCacheSet().containsCache(Tile.class.getName())) {
      long size = Configuration.getLongValue(AVKey.PLACENAME_LAYER_CACHE_SIZE, 2000000L);
      MemoryCache cache = new BasicMemoryCache((long) (0.85 * size), size);
      cache.setName("Placename Tiles");
      WorldWind.getMemoryCacheSet().addCache(Tile.class.getName(), cache);
    }
  }

  public boolean isCullNames() {
    return cullNames;
  }

  public void setCullNames(boolean cullNames) {
    this.cullNames = cullNames;
    placeNameRenderer.setCullTextEnabled(cullNames);
  }

  public final PlaceNameServiceSet getPlaceNameServiceSet() {
    return this.placeNameServiceSet;
  }

  private PriorityBlockingQueue<Runnable> getRequestQ() {
    return this.requestQ;
  }

  // ============== Tile Assembly ======================= //
  // ============== Tile Assembly ======================= //
  // ============== Tile Assembly ======================= //

  protected class NavigationTile {
    String id;
    protected PlaceNameService placeNameService;
    public Sector navSector;
    protected List<NavigationTile> subNavTiles = new ArrayList<NavigationTile>();
    private List<String> tileKeys = new ArrayList<String>();
    protected int level;

    NavigationTile(PlaceNameService placeNameService, Sector sector, int levels, String id) {
      this.placeNameService = placeNameService;
      this.id = id;
      this.navSector = sector;
      level = levels;
    }

    protected void buildSubNavTiles() {
      if (level > 0) {
        // split sector, create a navTile for each quad
        Sector[] subSectors = this.navSector.subdivide();
        for (int j = 0; j < subSectors.length; j++) {
          subNavTiles.add(
              new NavigationTile(placeNameService, subSectors[j], level - 1, this.id + "." + j));
        }
      }
    }

    public List<NavigationTile> navTilesVisible(
        DrawContext dc, double minDistSquared, double maxDistSquared) {
      ArrayList<NavigationTile> navList = new ArrayList<NavigationTile>();
      if (this.isNavSectorVisible(dc, minDistSquared, maxDistSquared)) {
        if (this.level > 0 && !this.hasSubTiles()) this.buildSubNavTiles();

        if (this.hasSubTiles()) {
          for (NavigationTile nav : subNavTiles) {
            navList.addAll(nav.navTilesVisible(dc, minDistSquared, maxDistSquared));
          }
        } else // at bottom level navigation tile
        {
          navList.add(this);
        }
      }

      return navList;
    }

    public boolean hasSubTiles() {
      return !subNavTiles.isEmpty();
    }

    protected boolean isNavSectorVisible(
        DrawContext dc, double minDistanceSquared, double maxDistanceSquared) {
      if (!navSector.intersects(dc.getVisibleSector())) return false;

      View view = dc.getView();
      Position eyePos = view.getEyePosition();
      if (eyePos == null) return false;

      // check for eyePos over globe
      if (Double.isNaN(eyePos.getLatitude().getDegrees())
          || Double.isNaN(eyePos.getLongitude().getDegrees())) return false;

      Angle lat =
          clampAngle(eyePos.getLatitude(), navSector.getMinLatitude(), navSector.getMaxLatitude());
      Angle lon =
          clampAngle(
              eyePos.getLongitude(), navSector.getMinLongitude(), navSector.getMaxLongitude());
      Vec4 p = dc.getGlobe().computePointFromPosition(lat, lon, 0d);
      double distSquared = dc.getView().getEyePoint().distanceToSquared3(p);
      //noinspection RedundantIfStatement
      if (minDistanceSquared > distSquared || maxDistanceSquared < distSquared) return false;

      return true;
    }

    public List<Tile> getTiles() {
      if (tileKeys.isEmpty()) {
        Tile[] tiles = buildTiles(this.placeNameService, this);
        // load tileKeys
        for (Tile t : tiles) {
          tileKeys.add(t.getFileCachePath());
          WorldWind.getMemoryCache(Tile.class.getName()).add(t.getFileCachePath(), t);
        }
        return Arrays.asList(tiles);
      } else {
        List<Tile> dataTiles = new ArrayList<Tile>();
        for (String s : tileKeys) {
          Tile t = (Tile) WorldWind.getMemoryCache(Tile.class.getName()).getObject(s);
          if (t != null) {
            dataTiles.add(t);
          }
        }
        return dataTiles;
      }
    }
  }

  protected static class Tile implements Cacheable {
    protected final PlaceNameService placeNameService;
    protected final Sector sector;
    protected final int row;
    protected final int column;
    private Integer hashInt = null;
    // Computed data.
    protected String fileCachePath = null;
    protected double extentVerticalExaggeration = Double.MIN_VALUE;
    protected double priority = Double.MAX_VALUE; // Default is minimum priority
    protected PlaceNameChunk dataChunk = null;

    Tile(PlaceNameService placeNameService, Sector sector, int row, int column) {
      this.placeNameService = placeNameService;
      this.sector = sector;
      this.row = row;
      this.column = column;
      this.fileCachePath = this.placeNameService.createFileCachePathFromTile(this.row, this.column);
      this.hashInt = this.computeHash();
    }

    public void setDataChunk(PlaceNameChunk chunk) {
      dataChunk = chunk;
    }

    public PlaceNameChunk getDataChunk() {
      return dataChunk;
    }

    public long getSizeInBytes() {

      long result = 32; // references

      result += this.getSector().getSizeInBytes();
      if (this.getFileCachePath() != null) result += this.getFileCachePath().length();

      if (dataChunk != null) {
        result += dataChunk.estimatedMemorySize;
      }

      return result;
    }

    static int computeRow(Angle delta, Angle latitude) {
      if (delta == null || latitude == null) {
        String msg = Logging.getMessage("nullValue.AngleIsNull");
        Logging.logger().severe(msg);
        throw new IllegalArgumentException(msg);
      }
      return (int) ((latitude.getDegrees() + 90d) / delta.getDegrees());
    }

    static int computeColumn(Angle delta, Angle longitude) {
      if (delta == null || longitude == null) {
        String msg = Logging.getMessage("nullValue.AngleIsNull");
        Logging.logger().severe(msg);
        throw new IllegalArgumentException(msg);
      }
      return (int) ((longitude.getDegrees() + 180d) / delta.getDegrees());
    }

    static Angle computeRowLatitude(int row, Angle delta) {
      if (delta == null) {
        String msg = Logging.getMessage("nullValue.AngleIsNull");
        Logging.logger().severe(msg);
        throw new IllegalArgumentException(msg);
      }
      return Angle.fromDegrees(-90d + delta.getDegrees() * row);
    }

    static Angle computeColumnLongitude(int column, Angle delta) {
      if (delta == null) {
        String msg = Logging.getMessage("nullValue.AngleIsNull");
        Logging.logger().severe(msg);
        throw new IllegalArgumentException(msg);
      }
      return Angle.fromDegrees(-180 + delta.getDegrees() * column);
    }

    public Integer getHashInt() {
      return hashInt;
    }

    int computeHash() {
      return this.getFileCachePath() != null ? this.getFileCachePath().hashCode() : 0;
    }

    @Override
    public boolean equals(Object o) {
      if (this == o) return true;
      if (o == null || getClass() != o.getClass()) return false;

      final Tile tile = (Tile) o;

      return !(this.getFileCachePath() != null
          ? !this.getFileCachePath().equals(tile.getFileCachePath())
          : tile.getFileCachePath() != null);
    }

    public String getFileCachePath() {
      if (this.fileCachePath == null)
        this.fileCachePath =
            this.placeNameService.createFileCachePathFromTile(this.row, this.column);

      return this.fileCachePath;
    }

    public PlaceNameService getPlaceNameService() {
      return placeNameService;
    }

    public java.net.URL getRequestURL() throws java.net.MalformedURLException {
      return this.placeNameService.createServiceURLFromSector(this.sector);
    }

    public Sector getSector() {
      return sector;
    }

    public int hashCode() {
      return this.hashInt;
    }

    protected boolean isTileInMemoryWithData() {
      Tile t =
          (Tile) WorldWind.getMemoryCache(Tile.class.getName()).getObject(this.getFileCachePath());
      return !(t == null || t.getDataChunk() == null);
    }

    public double getPriority() {
      return priority;
    }

    public void setPriority(double priority) {
      this.priority = priority;
    }
  }

  protected Tile[] buildTiles(PlaceNameService placeNameService, NavigationTile navTile) {
    final Angle dLat = placeNameService.getTileDelta().getLatitude();
    final Angle dLon = placeNameService.getTileDelta().getLongitude();

    // Determine the row and column offset from the global tiling origin for the southwest tile
    // corner
    int firstRow = Tile.computeRow(dLat, navTile.navSector.getMinLatitude());
    int firstCol = Tile.computeColumn(dLon, navTile.navSector.getMinLongitude());
    int lastRow = Tile.computeRow(dLat, navTile.navSector.getMaxLatitude().subtract(dLat));
    int lastCol = Tile.computeColumn(dLon, navTile.navSector.getMaxLongitude().subtract(dLon));

    int nLatTiles = lastRow - firstRow + 1;
    int nLonTiles = lastCol - firstCol + 1;

    Tile[] tiles = new Tile[nLatTiles * nLonTiles];

    Angle p1 = Tile.computeRowLatitude(firstRow, dLat);
    for (int row = 0; row <= lastRow - firstRow; row++) {
      Angle p2;
      p2 = p1.add(dLat);

      Angle t1 = Tile.computeColumnLongitude(firstCol, dLon);
      for (int col = 0; col <= lastCol - firstCol; col++) {
        Angle t2;
        t2 = t1.add(dLon);
        // Need offset row and column to correspond to total ro/col numbering
        tiles[col + row * nLonTiles] =
            new Tile(placeNameService, new Sector(p1, p2, t1, t2), row + firstRow, col + firstCol);
        t1 = t2;
      }
      p1 = p2;
    }

    return tiles;
  }

  // ============== Place Name Data Structures ======================= //
  // ============== Place Name Data Structures ======================= //
  // ============== Place Name Data Structures ======================= //

  protected static class PlaceNameChunk implements Cacheable {
    protected final PlaceNameService placeNameService;
    protected final CharBuffer textArray;
    protected final int[] textIndexArray;
    protected final double[] latlonArray;
    protected final int numEntries;
    protected final long estimatedMemorySize;

    protected PlaceNameChunk(
        PlaceNameService service,
        CharBuffer text,
        int[] textIndices,
        double[] positions,
        int numEntries) {
      this.placeNameService = service;
      this.textArray = text;
      this.textIndexArray = textIndices;
      this.latlonArray = positions;
      this.numEntries = numEntries;
      this.estimatedMemorySize = this.computeEstimatedMemorySize();
    }

    protected long computeEstimatedMemorySize() {
      long result = 0;
      if (!textArray.isDirect()) result += (Character.SIZE / 8) * textArray.capacity();
      result += (Integer.SIZE / 8) * textIndexArray.length;
      result += (Double.SIZE / 8) * latlonArray.length;
      return result;
    }

    protected Position getPosition(int index) {
      int latlonIndex = 2 * index;
      return Position.fromDegrees(latlonArray[latlonIndex], latlonArray[latlonIndex + 1], 0);
    }

    protected PlaceNameService getPlaceNameService() {
      return this.placeNameService;
    }

    protected CharSequence getText(int index) {
      int beginIndex = textIndexArray[index];
      int endIndex = (index + 1 < numEntries) ? textIndexArray[index + 1] : textArray.length();
      return this.textArray.subSequence(beginIndex, endIndex);
    }

    public long getSizeInBytes() {
      return this.estimatedMemorySize;
    }

    private Iterable<GeographicText> makeIterable(DrawContext dc) {
      // get dispay dist for this service for use in label annealing
      double maxDisplayDistance = this.getPlaceNameService().getMaxDisplayDistance();
      ArrayList<GeographicText> list = new ArrayList<GeographicText>();
      for (int i = 0; i < this.numEntries; i++) {
        CharSequence str = getText(i);
        Position pos = getPosition(i);
        GeographicText text = new UserFacingText(str, pos);
        text.setFont(this.placeNameService.getFont());
        text.setColor(this.placeNameService.getColor());
        text.setBackgroundColor(this.placeNameService.getBackgroundColor());
        text.setVisible(isNameVisible(dc, this.placeNameService, pos));
        text.setPriority(maxDisplayDistance);
        list.add(text);
      }
      return list;
    }
  }

  // ============== Rendering ======================= //
  // ============== Rendering ======================= //
  // ============== Rendering ======================= //

  private final GeographicTextRenderer placeNameRenderer = new GeographicTextRenderer();

  @Override
  protected void doRender(DrawContext dc) {
    this.referencePoint = this.computeReferencePoint(dc);

    int serviceCount = this.placeNameServiceSet.getServiceCount();
    for (int i = 0; i < serviceCount; i++) {
      PlaceNameService placeNameService = this.placeNameServiceSet.getService(i);
      if (!isServiceVisible(dc, placeNameService)) continue;

      double minDistSquared =
          placeNameService.getMinDisplayDistance() * placeNameService.getMinDisplayDistance();
      double maxDistSquared =
          placeNameService.getMaxDisplayDistance() * placeNameService.getMaxDisplayDistance();

      if (isSectorVisible(
          dc, placeNameService.getMaskingSector(), minDistSquared, maxDistSquared)) {
        ArrayList<Tile> baseTiles = new ArrayList<Tile>();
        NavigationTile navTile = this.navTiles.get(i);
        // drill down into tiles to find bottom level navTiles visible
        List<NavigationTile> list = navTile.navTilesVisible(dc, minDistSquared, maxDistSquared);
        for (NavigationTile nt : list) {
          baseTiles.addAll(nt.getTiles());
        }

        for (Tile tile : baseTiles) {
          try {
            drawOrRequestTile(dc, tile, minDistSquared, maxDistSquared);
          } catch (Exception e) {
            Logging.logger()
                .log(
                    Level.FINE,
                    Logging.getMessage("layers.PlaceNameLayer.ExceptionRenderingTile"),
                    e);
          }
        }
      }
    }

    this.sendRequests();
    this.requestQ.clear();
  }

  protected Vec4 computeReferencePoint(DrawContext dc) {
    if (dc.getViewportCenterPosition() != null)
      return dc.getGlobe().computePointFromPosition(dc.getViewportCenterPosition());

    java.awt.geom.Rectangle2D viewport = dc.getView().getViewport();
    int x = (int) viewport.getWidth() / 2;
    for (int y = (int) (0.5 * viewport.getHeight()); y >= 0; y--) {
      Position pos = dc.getView().computePositionFromScreenPoint(x, y);
      if (pos == null) continue;

      return dc.getGlobe().computePointFromPosition(pos.getLatitude(), pos.getLongitude(), 0d);
    }

    return null;
  }

  protected Vec4 getReferencePoint() {
    return this.referencePoint;
  }

  protected void drawOrRequestTile(
      DrawContext dc,
      Tile tile,
      double minDisplayDistanceSquared,
      double maxDisplayDistanceSquared) {
    if (!isTileVisible(dc, tile, minDisplayDistanceSquared, maxDisplayDistanceSquared)) return;

    if (tile.isTileInMemoryWithData()) {
      PlaceNameChunk placeNameChunk = tile.getDataChunk();
      if (placeNameChunk.numEntries > 0) {
        Iterable<GeographicText> renderIter = placeNameChunk.makeIterable(dc);
        this.placeNameRenderer.render(dc, renderIter);
      }
      return;
    }

    // Tile's data isn't available, so request it
    if (!tile.getPlaceNameService()
        .isResourceAbsent(tile.getPlaceNameService().getTileNumber(tile.row, tile.column))) {
      this.requestTile(dc, tile);
    }
  }

  protected static boolean isServiceVisible(DrawContext dc, PlaceNameService placeNameService) {
    //noinspection SimplifiableIfStatement
    if (!placeNameService.isEnabled()) return false;

    return (dc.getVisibleSector() != null)
        && placeNameService.getMaskingSector().intersects(dc.getVisibleSector());
    //
    //        return
    // placeNameService.getExtent(dc).intersects(dc.getView().getFrustumInModelCoordinates());
  }

  protected static boolean isSectorVisible(
      DrawContext dc, Sector sector, double minDistanceSquared, double maxDistanceSquared) {

    View view = dc.getView();
    Position eyePos = view.getEyePosition();
    if (eyePos == null) return false;

    Angle lat = clampAngle(eyePos.getLatitude(), sector.getMinLatitude(), sector.getMaxLatitude());
    Angle lon =
        clampAngle(eyePos.getLongitude(), sector.getMinLongitude(), sector.getMaxLongitude());
    Vec4 p = dc.getGlobe().computePointFromPosition(lat, lon, 0d);
    double distSquared = dc.getView().getEyePoint().distanceToSquared3(p);
    //noinspection RedundantIfStatement
    if (minDistanceSquared > distSquared || maxDistanceSquared < distSquared) return false;

    return true;
  }

  protected static boolean isTileVisible(
      DrawContext dc, Tile tile, double minDistanceSquared, double maxDistanceSquared) {
    if (!tile.getSector().intersects(dc.getVisibleSector())) return false;

    View view = dc.getView();
    Position eyePos = view.getEyePosition();
    if (eyePos == null) return false;

    Angle lat =
        clampAngle(
            eyePos.getLatitude(),
            tile.getSector().getMinLatitude(),
            tile.getSector().getMaxLatitude());
    Angle lon =
        clampAngle(
            eyePos.getLongitude(),
            tile.getSector().getMinLongitude(),
            tile.getSector().getMaxLongitude());
    Vec4 p = dc.getGlobe().computePointFromPosition(lat, lon, 0d);
    double distSquared = dc.getView().getEyePoint().distanceToSquared3(p);
    //noinspection RedundantIfStatement
    if (minDistanceSquared > distSquared || maxDistanceSquared < distSquared) return false;

    return true;
  }

  protected static boolean isNameVisible(
      DrawContext dc, PlaceNameService service, Position namePosition) {
    double elevation = dc.getVerticalExaggeration() * namePosition.getElevation();
    Vec4 namePoint =
        dc.getGlobe()
            .computePointFromPosition(
                namePosition.getLatitude(), namePosition.getLongitude(), elevation);
    Vec4 eyeVec = dc.getView().getEyePoint();

    double dist = eyeVec.distanceTo3(namePoint);
    return dist >= service.getMinDisplayDistance() && dist <= service.getMaxDisplayDistance();
  }

  protected static Angle clampAngle(Angle a, Angle min, Angle max) {
    double degrees = a.degrees;
    double minDegrees = min.degrees;
    double maxDegrees = max.degrees;
    return Angle.fromDegrees(
        degrees < minDegrees ? minDegrees : (degrees > maxDegrees ? maxDegrees : degrees));
  }

  // ============== Image Reading and Downloading ======================= //
  // ============== Image Reading and Downloading ======================= //
  // ============== Image Reading and Downloading ======================= //

  protected void requestTile(DrawContext dc, Tile tile) {
    Vec4 centroid = dc.getGlobe().computePointFromPosition(tile.getSector().getCentroid(), 0);
    if (this.getReferencePoint() != null)
      tile.setPriority(centroid.distanceTo3(this.getReferencePoint()));

    RequestTask task = new RequestTask(tile, this);
    this.getRequestQ().add(task);
  }

  protected void sendRequests() {
    Runnable task = this.requestQ.poll();
    while (task != null) {
      if (!WorldWind.getTaskService().isFull()) {
        WorldWind.getTaskService().addTask(task);
      }
      task = this.requestQ.poll();
    }
  }

  protected static class RequestTask implements Runnable, Comparable<RequestTask> {
    protected final PlaceNameLayer layer;
    protected final Tile tile;

    RequestTask(Tile tile, PlaceNameLayer layer) {
      this.layer = layer;
      this.tile = tile;
    }

    public void run() {
      if (this.tile.isTileInMemoryWithData()) return;

      final java.net.URL tileURL =
          this.layer.getDataFileStore().findFile(tile.getFileCachePath(), false);
      if (tileURL != null) {
        if (this.layer.loadTile(this.tile, tileURL)) {
          tile.getPlaceNameService()
              .unmarkResourceAbsent(
                  tile.getPlaceNameService().getTileNumber(tile.row, tile.column));
          this.layer.firePropertyChange(AVKey.LAYER, null, this);
          return;
        }
      }

      this.layer.downloadTile(this.tile);
    }

    /**
     * @param that the task to compare
     * @return -1 if <code>this</code> less than <code>that</code>, 1 if greater than, 0 if equal
     * @throws IllegalArgumentException if <code>that</code> is null
     */
    public int compareTo(RequestTask that) {
      if (that == null) {
        String msg = Logging.getMessage("nullValue.RequestTaskIsNull");
        Logging.logger().severe(msg);
        throw new IllegalArgumentException(msg);
      }
      return this.tile.getPriority() == that.tile.getPriority()
          ? 0
          : this.tile.getPriority() < that.tile.getPriority() ? -1 : 1;
    }

    public boolean equals(Object o) {
      if (this == o) return true;
      if (o == null || getClass() != o.getClass()) return false;

      final RequestTask that = (RequestTask) o;

      // Don't include layer in comparison so that requests are shared among layers
      return !(tile != null ? !tile.equals(that.tile) : that.tile != null);
    }

    public int hashCode() {
      return (tile != null ? tile.hashCode() : 0);
    }

    public String toString() {
      return this.tile.toString();
    }
  }

  protected boolean loadTile(Tile tile, java.net.URL url) {
    if (WWIO.isFileOutOfDate(url, this.placeNameServiceSet.getExpiryTime())) {
      // The file has expired. Delete it then request download of newer.
      this.getDataFileStore().removeFile(url);
      String message = Logging.getMessage("generic.DataFileExpired", url);
      Logging.logger().fine(message);
      return false;
    }

    PlaceNameChunk tileData;
    synchronized (this.fileLock) {
      tileData = readTileData(tile, url);
    }

    if (tileData == null) {
      // Assume that something's wrong with the file and delete it.
      this.getDataFileStore().removeFile(url);
      tile.getPlaceNameService()
          .markResourceAbsent(tile.getPlaceNameService().getTileNumber(tile.row, tile.column));
      String message = Logging.getMessage("generic.DeletedCorruptDataFile", url);
      Logging.logger().fine(message);
      return false;
    }

    tile.setDataChunk(tileData);
    WorldWind.getMemoryCache(Tile.class.getName()).add(tile.getFileCachePath(), tile);
    return true;
  }

  protected static PlaceNameChunk readTileData(Tile tile, java.net.URL url) {
    java.io.InputStream is = null;

    try {
      String path = url.getFile();
      path =
          path.replaceAll(
              "%20", " "); // TODO: find a better way to get a path usable by FileInputStream

      java.io.FileInputStream fis = new java.io.FileInputStream(path);
      java.io.BufferedInputStream buf = new java.io.BufferedInputStream(fis);
      is = new java.util.zip.GZIPInputStream(buf);

      GMLPlaceNameSAXHandler handler = new GMLPlaceNameSAXHandler();
      javax.xml.parsers.SAXParserFactory.newInstance().newSAXParser().parse(is, handler);
      return handler.createPlaceNameChunk(tile.getPlaceNameService());
    } catch (Exception e) {
      // todo log actual error
      Logging.logger()
          .log(
              Level.FINE,
              Logging.getMessage(
                  "layers.PlaceNameLayer.ExceptionAttemptingToReadFile", url.toString()),
              e);
    } finally {
      try {
        if (is != null) is.close();
      } catch (java.io.IOException e) {
        Logging.logger()
            .log(
                Level.FINE,
                Logging.getMessage(
                    "layers.PlaceNameLayer.ExceptionAttemptingToReadFile", url.toString()),
                e);
      }
    }

    return null;
  }

  protected static CharBuffer newCharBuffer(int numElements) {
    ByteBuffer bb = ByteBuffer.allocateDirect((Character.SIZE / 8) * numElements);
    bb.order(ByteOrder.nativeOrder());
    return bb.asCharBuffer();
  }

  protected static class GMLPlaceNameSAXHandler extends org.xml.sax.helpers.DefaultHandler {
    protected static final String GML_FEATURE_MEMBER = "gml:featureMember";
    protected static final String TOPP_FULL_NAME_ND = "topp:full_name_nd";
    protected static final String TOPP_LATITUDE = "topp:latitude";
    protected static final String TOPP_LONGITUDE = "topp:longitude";
    protected final LinkedList<String> internedQNameStack = new LinkedList<String>();
    protected boolean inBeginEndPair = false;
    protected StringBuilder latBuffer = new StringBuilder();
    protected StringBuilder lonBuffer = new StringBuilder();

    StringBuilder textArray = new StringBuilder();
    int[] textIndexArray = new int[16];
    double[] latlonArray = new double[16];
    int numEntries = 0;

    protected GMLPlaceNameSAXHandler() {}

    protected PlaceNameChunk createPlaceNameChunk(PlaceNameService service) {
      int numChars = this.textArray.length();
      CharBuffer textBuffer = newCharBuffer(numChars);
      textBuffer.put(this.textArray.toString());
      textBuffer.rewind();
      return new PlaceNameChunk(
          service, textBuffer, this.textIndexArray, this.latlonArray, this.numEntries);
    }

    protected void beginEntry() {
      int textIndex = this.textArray.length();
      this.textIndexArray = append(this.textIndexArray, this.numEntries, textIndex);
      this.inBeginEndPair = true;
    }

    protected void endEntry() {
      double lat = this.parseDouble(this.latBuffer);
      double lon = this.parseDouble(this.lonBuffer);
      int numLatLon = 2 * this.numEntries;
      this.latlonArray = this.append(this.latlonArray, numLatLon, lat);
      numLatLon++;
      this.latlonArray = this.append(this.latlonArray, numLatLon, lon);

      this.latBuffer.delete(0, this.latBuffer.length());
      this.lonBuffer.delete(0, this.lonBuffer.length());
      this.inBeginEndPair = false;
      this.numEntries++;
    }

    protected double parseDouble(StringBuilder sb) {
      double value = 0;
      try {
        value = Double.parseDouble(sb.toString());
      } catch (NumberFormatException e) {
        Logging.logger()
            .log(
                Level.FINE,
                Logging.getMessage("layers.PlaceNameLayer.ExceptionAttemptingToReadFile", ""),
                e);
      }
      return value;
    }

    protected int[] append(int[] array, int index, int value) {
      if (index >= array.length) array = this.resizeArray(array);
      array[index] = value;
      return array;
    }

    protected int[] resizeArray(int[] oldArray) {
      int newSize = 2 * oldArray.length;
      int[] newArray = new int[newSize];
      System.arraycopy(oldArray, 0, newArray, 0, oldArray.length);
      return newArray;
    }

    protected double[] append(double[] array, int index, double value) {
      if (index >= array.length) array = this.resizeArray(array);
      array[index] = value;
      return array;
    }

    protected double[] resizeArray(double[] oldArray) {
      int newSize = 2 * oldArray.length;
      double[] newArray = new double[newSize];
      System.arraycopy(oldArray, 0, newArray, 0, oldArray.length);
      return newArray;
    }

    @SuppressWarnings({"StringEquality"})
    public void characters(char ch[], int start, int length) {
      if (!this.inBeginEndPair) return;

      // Top of QName stack is an interned string,
      // so we can use pointer comparison.
      String internedTopQName = this.internedQNameStack.getFirst();

      StringBuilder sb = null;
      if (TOPP_LATITUDE == internedTopQName) sb = this.latBuffer;
      else if (TOPP_LONGITUDE == internedTopQName) sb = this.lonBuffer;
      else if (TOPP_FULL_NAME_ND == internedTopQName) sb = this.textArray;

      if (sb != null) sb.append(ch, start, length);
    }

    public void startElement(
        String uri, String localName, String qName, org.xml.sax.Attributes attributes) {
      // Don't validate uri, localName or attributes because they aren't used.
      // Intern the qName string so we can use pointer comparison.
      String internedQName = qName.intern();
      //noinspection StringEquality
      if (GML_FEATURE_MEMBER == internedQName) this.beginEntry();
      this.internedQNameStack.addFirst(internedQName);
    }

    public void endElement(String uri, String localName, String qName) {
      // Don't validate uri or localName because they aren't used.
      // Intern the qName string so we can use pointer comparison.
      String internedQName = qName.intern();
      //noinspection StringEquality
      if (GML_FEATURE_MEMBER == internedQName) this.endEntry();
      this.internedQNameStack.removeFirst();
    }
  }

  protected void downloadTile(final Tile tile) {
    downloadTile(tile, null);
  }

  protected void downloadTile(final Tile tile, DownloadPostProcessor postProcessor) {
    if (!this.isNetworkRetrievalEnabled()) return;

    if (!WorldWind.getRetrievalService().isAvailable()) return;

    java.net.URL url;
    try {
      url = tile.getRequestURL();
      if (WorldWind.getNetworkStatus().isHostUnavailable(url)) return;
    } catch (java.net.MalformedURLException e) {
      Logging.logger()
          .log(
              java.util.logging.Level.SEVERE,
              Logging.getMessage("layers.PlaceNameLayer.ExceptionCreatingUrl", tile),
              e);
      return;
    }

    Retriever retriever;

    if ("http".equalsIgnoreCase(url.getProtocol()) || "https".equalsIgnoreCase(url.getProtocol())) {
      if (postProcessor == null) postProcessor = new DownloadPostProcessor(this, tile);
      retriever = new HTTPRetriever(url, postProcessor);
    } else {
      Logging.logger()
          .severe(
              Logging.getMessage("layers.PlaceNameLayer.UnknownRetrievalProtocol", url.toString()));
      return;
    }

    // Apply any overridden timeouts.
    Integer cto = AVListImpl.getIntegerValue(this, AVKey.URL_CONNECT_TIMEOUT);
    if (cto != null && cto > 0) retriever.setConnectTimeout(cto);
    Integer cro = AVListImpl.getIntegerValue(this, AVKey.URL_READ_TIMEOUT);
    if (cro != null && cro > 0) retriever.setReadTimeout(cro);
    Integer srl = AVListImpl.getIntegerValue(this, AVKey.RETRIEVAL_QUEUE_STALE_REQUEST_LIMIT);
    if (srl != null && srl > 0) retriever.setStaleRequestLimit(srl);

    WorldWind.getRetrievalService().runRetriever(retriever, tile.getPriority());
  }

  protected void saveBuffer(java.nio.ByteBuffer buffer, java.io.File outFile)
      throws java.io.IOException {
    synchronized (this.fileLock) // sychronized with read of file in RequestTask.run()
    {
      WWIO.saveBuffer(buffer, outFile);
    }
  }

  protected static class DownloadPostProcessor extends AbstractRetrievalPostProcessor {
    protected final PlaceNameLayer layer;
    protected final Tile tile;
    protected final FileStore fileStore;

    public DownloadPostProcessor(PlaceNameLayer layer, Tile tile) {
      // No arg check; the class has protected access.
      this(layer, tile, null);
    }

    public DownloadPostProcessor(PlaceNameLayer layer, Tile tile, FileStore fileStore) {
      // No arg check; the class has protected access.

      //noinspection RedundantCast
      super((AVList) layer);

      this.layer = layer;
      this.tile = tile;
      this.fileStore = fileStore;
    }

    protected FileStore getFileStore() {
      return this.fileStore != null ? this.fileStore : this.layer.getDataFileStore();
    }

    @Override
    protected void markResourceAbsent() {
      this.tile
          .getPlaceNameService()
          .markResourceAbsent(
              this.tile.getPlaceNameService().getTileNumber(this.tile.row, this.tile.column));
    }

    @Override
    protected Object getFileLock() {
      return this.layer.fileLock;
    }

    protected File doGetOutputFile() {
      return this.getFileStore().newFile(this.tile.getFileCachePath());
    }

    @Override
    protected ByteBuffer handleSuccessfulRetrieval() {
      ByteBuffer buffer = super.handleSuccessfulRetrieval();

      if (buffer != null) {
        // Fire a property change to denote that the layer's backing data has changed.
        this.layer.firePropertyChange(AVKey.LAYER, null, this);
      }

      return buffer;
    }

    @Override
    protected ByteBuffer handleXMLContent() throws IOException {
      // Check for an exception report
      String s = WWIO.byteBufferToString(this.getRetriever().getBuffer(), 1024, null);
      if (s.contains("<ExceptionReport>")) {
        // TODO: Parse the xml and include only the message text in the log message.

        StringBuilder sb = new StringBuilder(this.getRetriever().getName());

        sb.append("\n");
        sb.append(WWIO.byteBufferToString(this.getRetriever().getBuffer(), 2048, null));
        Logging.logger().warning(sb.toString());

        return null;
      }

      this.saveBuffer();

      return this.getRetriever().getBuffer();
    }
  }

  // *** Bulk download ***
  // *** Bulk download ***
  // *** Bulk download ***

  /**
   * Start a new {@link BulkRetrievalThread} that downloads all placenames for a given sector and
   * resolution to the current World Wind file cache.
   *
   * <p>This method creates and starts a thread to perform the download. A reference to the thread
   * is returned. To create a downloader that has not been started, construct a {@link
   * PlaceNameLayerBulkDownloader}.
   *
   * <p>Note that the target resolution must be provided in radians of latitude per texel, which is
   * the resolution in meters divided by the globe radius.
   *
   * @param sector the sector to download data for.
   * @param resolution the target resolution, provided in radians of latitude per texel.
   * @param listener an optional retrieval listener. May be null.
   * @return the {@link PlaceNameLayerBulkDownloader} that executes the retrieval.
   * @throws IllegalArgumentException if the sector is null or the resolution is less than zero.
   * @see PlaceNameLayerBulkDownloader
   */
  public BulkRetrievalThread makeLocal(
      Sector sector, double resolution, BulkRetrievalListener listener) {
    PlaceNameLayerBulkDownloader thread =
        new PlaceNameLayerBulkDownloader(
            this, sector, resolution, this.getDataFileStore(), listener);
    thread.setDaemon(true);
    thread.start();
    return thread;
  }

  /**
   * Start a new {@link BulkRetrievalThread} that downloads all placenames for a given sector and
   * resolution to a specified file store.
   *
   * <p>This method creates and starts a thread to perform the download. A reference to the thread
   * is returned. To create a downloader that has not been started, construct a {@link
   * PlaceNameLayerBulkDownloader}.
   *
   * <p>Note that the target resolution must be provided in radians of latitude per texel, which is
   * the resolution in meters divided by the globe radius.
   *
   * @param sector the sector to download data for.
   * @param resolution the target resolution, provided in radians of latitude per texel.
   * @param fileStore the file store in which to place the downloaded elevations. If null the
   *     current World Wind file cache is used.
   * @param listener an optional retrieval listener. May be null.
   * @return the {@link PlaceNameLayerBulkDownloader} that executes the retrieval.
   * @throws IllegalArgumentException if the sector is null or the resolution is less than zero.
   * @see PlaceNameLayerBulkDownloader
   */
  public BulkRetrievalThread makeLocal(
      Sector sector, double resolution, FileStore fileStore, BulkRetrievalListener listener) {
    PlaceNameLayerBulkDownloader thread =
        new PlaceNameLayerBulkDownloader(this, sector, resolution, fileStore, listener);
    thread.setDaemon(true);
    thread.start();
    return thread;
  }

  /**
   * Get the estimated size in bytes of the placenames not in the World Wind file cache for the
   * given sector and resolution.
   *
   * <p>Note that the target resolution must be provided in radians of latitude per texel, which is
   * the resolution in meters divided by the globe radius.
   *
   * @param sector the sector to estimate.
   * @param resolution the target resolution, provided in radians of latitude per texel.
   * @return the estimated size in bytes of the missing placenames.
   * @throws IllegalArgumentException if the sector is null or the resolution is less than zero.
   */
  public long getEstimatedMissingDataSize(Sector sector, double resolution) {
    return this.getEstimatedMissingDataSize(sector, resolution, this.getDataFileStore());
  }

  /**
   * Get the estimated size in bytes of the placenames not in a specified file store for the given
   * sector and resolution.
   *
   * <p>Note that the target resolution must be provided in radians of latitude per texel, which is
   * the resolution in meters divided by the globe radius.
   *
   * @param sector the sector to estimate.
   * @param resolution the target resolution, provided in radians of latitude per texel.
   * @param fileStore the file store to examine. If null the current World Wind file cache is used.
   * @return the estimated size in byte of the missing placenames.
   * @throws IllegalArgumentException if the sector is null or the resolution is less than zero.
   */
  public long getEstimatedMissingDataSize(Sector sector, double resolution, FileStore fileStore) {
    try {
      PlaceNameLayerBulkDownloader downloader =
          new PlaceNameLayerBulkDownloader(
              this,
              sector,
              resolution,
              fileStore != null ? fileStore : this.getDataFileStore(),
              null);
      return downloader.getEstimatedMissingDataSize();
    } catch (Exception e) {
      String message =
          Logging.getMessage("generic.ExceptionDuringDataSizeEstimate", this.getName());
      Logging.logger().severe(message);
      throw new RuntimeException(message);
    }
  }
}