def setMinPartitions(sc: SparkContext, context: JobContext, minPartitions: Int) {
val defaultMaxSplitBytes = sc.getConf.get(config.FILES_MAX_PARTITION_BYTES)
val openCostInBytes = sc.getConf.get(config.FILES_OPEN_COST_IN_BYTES)
val defaultParallelism = sc.defaultParallelism
val files = listStatus(context).asScala
val totalBytes = files.filterNot(_.isDirectory).map(_.getLen + openCostInBytes).sum
val bytesPerCore = totalBytes / defaultParallelism
val maxSplitSize = Math.min(defaultMaxSplitBytes, Math.max(openCostInBytes, bytesPerCore))
super.setMaxSplitSize(maxSplitSize)