org.apache.flink.runtime.io.disk.iomanager

接口 BlockChannelReader<T>

所有超级接口:

FileIOChannel

所有已知实现类:

AsynchronousBlockReader

public interface BlockChannelReader<T>
extends FileIOChannel

A reader that reads data in blocks from a file channel. The reader reads the blocks into a MemorySegment. To support asynchronous implementations, the read method does not immediately return the full memory segment, but rather adds it to a blocking queue of finished read operations.

嵌套类概要

从接口继承的嵌套类/接口 org.apache.flink.runtime.io.disk.iomanager.FileIOChannel

FileIOChannel.Enumerator, FileIOChannel.ID

方法概要

限定符和类型	方法和说明
T	getNextReturnedBlock() Gets the next memory segment that has been filled with data by the reader.
LinkedBlockingQueue<T>	getReturnQueue() Gets the queue in which the full memory segments are queued after the read is complete.
void	readBlock(T segment) Issues a read request, which will fill the given segment with the next block in the underlying file channel.
void	seekToPosition(long position)

从接口继承的方法 org.apache.flink.runtime.io.disk.iomanager.FileIOChannel

close, closeAndDelete, deleteChannel, getChannelID, getNioFileChannel, getSize, isClosed

方法详细资料

readBlock

void readBlock(T segment)
        throws IOException

Issues a read request, which will fill the given segment with the next block in the underlying file channel. Once the read request is fulfilled, the segment will be added to this reader's return queue.

参数:

segment - The segment to read the block into.

抛出:

IOException - Thrown, when the reader encounters an I/O error.

seekToPosition

void seekToPosition(long position)
             throws IOException

抛出:

IOException

getNextReturnedBlock

T getNextReturnedBlock()
                throws IOException

Gets the next memory segment that has been filled with data by the reader. This method blocks until such a segment is available, or until an error occurs in the reader, or the reader is closed.

WARNING: If this method is invoked without any segment ever returning (for example, because the readBlock(T) method has not been invoked appropriately), the method may block forever.

返回:

The next memory segment from the reader's return queue.

抛出:

IOException - Thrown, if an I/O error occurs in the reader while waiting for the request to return.

getReturnQueue

LinkedBlockingQueue<T> getReturnQueue()

Gets the queue in which the full memory segments are queued after the read is complete.

返回:

The queue with the full memory segments.