org.apache.commons.io.input

Class ReadAheadInputStream

  • All Implemented Interfaces:
    Closeable, AutoCloseable

    public class ReadAheadInputStream
    extends InputStream
    Implements InputStream to asynchronously read ahead from an underlying input stream when a specified amount of data has been read from the current buffer. It does so by maintaining two buffers: an active buffer and a read ahead buffer. The active buffer contains data which should be returned when a read() call is issued. The read ahead buffer is used to asynchronously read from the underlying input stream. When the current active buffer is exhausted, we flip the two buffers so that we can start reading from the read ahead buffer without being blocked by disk I/O.

    This class was ported and adapted from Apache Spark commit 933dc6cb7b3de1d8ccaf73d124d6eb95b947ed19.

    Since:
    2.9.0
    • Constructor Detail

      • ReadAheadInputStream

        public ReadAheadInputStream(InputStream inputStream,
                                    int bufferSizeInBytes)
        Creates an instance with the specified buffer size and read-ahead threshold
        Parameters:
        inputStream - The underlying input stream.
        bufferSizeInBytes - The buffer size.
      • ReadAheadInputStream

        public ReadAheadInputStream(InputStream inputStream,
                                    int bufferSizeInBytes,
                                    ExecutorService executorService)
        Creates an instance with the specified buffer size and read-ahead threshold
        Parameters:
        inputStream - The underlying input stream.
        bufferSizeInBytes - The buffer size.
        executorService - An executor service for the read-ahead thread.

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