Package org.apache.flink.runtime.operators.resettable

Class NonReusingBlockResettableIterator<T>

java.lang.Object
org.apache.flink.runtime.operators.resettable.NonReusingBlockResettableIterator<T>
All Implemented Interfaces:
Iterator<T>, MemoryBlockIterator, ResettableIterator<T>
Direct Known Subclasses:
ReusingBlockResettableIterator
public class NonReusingBlockResettableIterator<T> extends Object implements ResettableIterator<T>
Implementation of an iterator that fetches a block of data into main memory and offers resettable access to the data in that block.

  • Field Details

    • LOG

      public static final org.slf4j.Logger LOG

    • input

      protected Iterator<T> input

    • nextElement

      protected T nextElement

    • leftOverElement

      protected T leftOverElement

    • readPhase

      protected boolean readPhase

    • noMoreBlocks

      protected boolean noMoreBlocks

    • readView

      protected final RandomAccessInputView readView

    • collectingView

      protected final SimpleCollectingOutputView collectingView

    • serializer

      protected final org.apache.flink.api.common.typeutils.TypeSerializer<T> serializer

    • numRecordsInBuffer

      protected int numRecordsInBuffer

    • numRecordsReturned

      protected int numRecordsReturned

    • emptySegments

      protected final ArrayList<org.apache.flink.core.memory.MemorySegment> emptySegments

    • fullSegments

      protected final ArrayList<org.apache.flink.core.memory.MemorySegment> fullSegments

    • closed

      protected volatile boolean closed

  • Constructor Details

  • Method Details

    • reopen

      public void reopen(Iterator<T> input) throws IOException
      Throws:
      IOException

    • hasNext

      public boolean hasNext()
      Specified by:
      hasNext in interface Iterator<T>

    • next

      public T next()
      Specified by:
      next in interface Iterator<T>

    • remove

      public void remove()
      Specified by:
      remove in interface Iterator<T>

    • reset

      public void reset()
      Description copied from interface: ResettableIterator
      Resets the iterator.
      Specified by:
      reset in interface ResettableIterator<T>

    • nextBlock

      public boolean nextBlock() throws IOException
      Description copied from interface: MemoryBlockIterator
      Move the iterator to the next memory block. The next memory block starts at the first element that was not in the block before. A special case is when no record was in the block before, which happens when this function is invoked two times directly in a sequence, without calling hasNext() or next in between. Then the block moves one element.
      Specified by:
      nextBlock in interface MemoryBlockIterator
      Returns:
      True if a new memory block was loaded, false if there were no further records and hence no further memory block.
      Throws:
      IOException - Thrown, when advancing to the next block failed.

    • hasFurtherInput

      public boolean hasFurtherInput()
      Checks, whether the input that is blocked by this iterator, has further elements available. This method may be used to forecast (for example at the point where a block is full) whether there will be more data (possibly in another block).
      Returns:
      True, if there will be more data, false otherwise.

    • close

      public void close()
      This method closes the iterator and releases all resources. This method works both as a regular shutdown and as a canceling method. The method may be called multiple times and will not produce an error.

    • open

      public void open()

    • writeNextRecord

      protected boolean writeNextRecord(T record) throws IOException
      Throws:
      IOException

    • getNextRecord

      protected T getNextRecord(T reuse) throws IOException
      Throws:
      IOException

    • getNextRecord

      protected T getNextRecord() throws IOException
      Throws:
      IOException