public class ReadAheadInputStream extends InputStream
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.
Constructor and Description |
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ReadAheadInputStream(InputStream inputStream,
int bufferSizeInBytes)
Creates an instance with the specified buffer size and read-ahead threshold
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ReadAheadInputStream(InputStream inputStream,
int bufferSizeInBytes,
ExecutorService executorService)
Creates an instance with the specified buffer size and read-ahead threshold
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Modifier and Type | Method and Description |
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int |
available() |
void |
close() |
int |
read() |
int |
read(byte[] b,
int offset,
int len) |
long |
skip(long n) |
mark, markSupported, read, reset
public ReadAheadInputStream(InputStream inputStream, int bufferSizeInBytes)
inputStream
- The underlying input stream.bufferSizeInBytes
- The buffer size.public ReadAheadInputStream(InputStream inputStream, int bufferSizeInBytes, ExecutorService executorService)
inputStream
- The underlying input stream.bufferSizeInBytes
- The buffer size.executorService
- An executor service for the read-ahead thread.public int available() throws IOException
available
in class InputStream
IOException
public void close() throws IOException
close
in interface Closeable
close
in interface AutoCloseable
close
in class InputStream
IOException
public int read() throws IOException
read
in class InputStream
IOException
public int read(byte[] b, int offset, int len) throws IOException
read
in class InputStream
IOException
public long skip(long n) throws IOException
skip
in class InputStream
IOException
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