Class AsyncReader

Method Details

• getMaxBufferSizeInBytes

  public long getMaxBufferSizeInBytes()

  Returns the estimated size in bytes of buffered records at which the background thread pauses reading (defaults to 512 KB).

• setMaxBufferSizeInBytes

  public AsyncReader setMaxBufferSizeInBytes(long maxBufferSize)

  Sets the estimated size in bytes of buffered records at which the background thread pauses reading (defaults to 512 KB, minimum MINIMUM_BUFFER_SIZE).

• getBufferSizeInBytes

  public long getBufferSizeInBytes()

  Returns the estimated size in bytes of the records buffered but not yet read.

• getPeakBufferSizeInBytes

  public long getPeakBufferSizeInBytes()

  Returns the largest value getBufferSizeInBytes() has reached.

• getPriority

  public int getPriority()

  Returns the priority given to the background reading thread when this reader is opened (defaults to Thread.NORM_PRIORITY).

• setPriority

  public AsyncReader setPriority(int priority)

  Sets the priority given to the background reading thread when this reader is opened, from Thread.MIN_PRIORITY to Thread.MAX_PRIORITY (defaults to Thread.NORM_PRIORITY).

• getException

  public DataException getException()

  Returns the first exception thrown by the background thread or null if there was none.

• open

  public void open() throws DataException

  Description copied from class: DataEndpoint

  Makes this endpoint ready for reading or writing.

  Overrides:

  open in class ProxyReader

  Throws:

  DataException

• close

  public void close() throws DataException

  Description copied from class: DataEndpoint

  Indicates that this endpoint has finished reading or writing.

  Overrides:

  close in class ProxyReader

  Throws:

  DataException

• push

  public void push(Record record)

  Description copied from class: DataReader

  Adds a record to this DataReaders buffer. Records in the buffer will be returned by DataReader.read() before attempting to read from the underlying implementation.

  Overrides:

  push in class DataReader

  See Also:

  • DataReader.read()

• pop

  protected Record pop()

  Description copied from class: DataReader

  Removes and returns the next record in this DataReaders buffer or null if it is empty.

  Overrides:

  pop in class DataReader

  See Also:

  • DataReader.push(Record)

• available

  public int available() throws DataException

  Description copied from class: DataReader

  Returns the number of records that can probably be read without blocking.

  Overrides:

  available in class ProxyReader

  Throws:

  DataException

• fillCache

  protected void fillCache()

  Runs on the background thread, reading the nested reader into the buffer (pausing while it is full) until the input ends, this reader is closed or a read fails.

• rethrowAsyncException

  public void rethrowAsyncException()

  Rethrows the exception thrown by the internal thread or returns silently if no exception was thrown.

• readImpl

  protected Record readImpl() throws Throwable

  Description copied from class: DataReader

  Overridden by subclasses to read the next record from this DataReader. The default implementation of DataReader.read() now insures that this method will not be called again after it returns a null.

  If no record is available, null will be returned.

  Contract for subclasses (see also docs/authoring/DataReader.md):

  • Return null exactly once to signal end-of-stream.
  • Do not call this method directly — DataReader.read() is the template method that wraps exceptions, increments the record count, and tracks lineage.
  • Do not call DataEndpoint.incrementRecordCount() here; DataReader.read() already does.
  • Throw raw exceptions; DataReader.read() wraps them via exception(throwable).

  Overrides:

  readImpl in class ProxyReader

  Throws:

  Throwable

• exception

  public final DataException exception(String message, Throwable exception)

  Description copied from class: DataObject

  Converts an exception to a DataException, prefixing the original message with the specified text and adding this endpoint's properties (name-value pairs).

  The returned exception can then be thrown in the normal way.

  If the supplied exception is an instanceof DataException, it will be returned, otherwise it will be nested inside a DataException. In either case the result message will contain the new prefix along with this endpoint properties.

  Overrides:

  exception in class DataObject

• exception

  public final DataException exception(Throwable exception)

  Description copied from class: DataObject

  Converts an exception to a DataException and adds this endpoint's properties (name-value pairs).

  The returned exception can then be thrown in the normal way.

  If the supplied exception is an instanceof DataException, it will be returned, otherwise it will be nested inside a DataException. In either case the result message will contain this endpoint properties.

  Overrides:

  exception in class DataObject

• exception

  public final DataException exception(String message)

  Description copied from class: DataObject

  Creates an exception with the specified message and containing this endpoint's properties (name-value pairs).

  The returned exception can then be thrown in the normal way.

  Overrides:

  exception in class DataObject

• addExceptionProperties

  public final DataException addExceptionProperties(DataException exception)

  Description copied from class: Endpoint

  Adds this endpoint's current state to a DataException. Since this method is called whenever an exception is thrown, subclasses should override it to add their specific information.

  Overrides:

  addExceptionProperties in class ProxyReader

• addExceptionPropertiesImpl

  protected DataException addExceptionPropertiesImpl(DataException exception)

  Adds this reader's own state, but not the nested reader's (it runs on another thread), to the exception; subclasses override this instead of the final addExceptionProperties(DataException).