     @protobuf = new Protobuf fs.readFileSync __dirname+"/../proto/vector_tile.desc"
 
   grind: (source, @destination, @callback) ->
-    @_log "[>] starting to grind"
+    @_log "[>] starting to grind #{source} into #{@destination}"
 
     @_mustExist source
     .then => @_loadMBTiles source

          stream.pause()
          paused = true

        promise = if @config.copyAboveZoom and z >= @config.copyAboveZoom
          @_loadTile z, x, y
          .then (buffer) => @_storeTile z, x, y, buffer
        else
          @_processTile z, x, y

        promise.finally =>
          queueSpots++
          if paused and queueSpots > 0
            stream.resume()

  config:
    debug: true
    output: "mbtiles"
    maxZoom: 14

  queueSize: 64

