Package org.apache.commons.io.input
Class ReadAheadInputStream
- java.lang.Object
-
- java.io.InputStream
-
- org.apache.commons.io.input.ReadAheadInputStream
-
- All Implemented Interfaces:
Closeable
,AutoCloseable
public class ReadAheadInputStream extends InputStream
ImplementsInputStream
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 Summary
Constructors Constructor Description ReadAheadInputStream(InputStream inputStream, int bufferSizeInBytes)
Creates an instance with the specified buffer size and read-ahead thresholdReadAheadInputStream(InputStream inputStream, int bufferSizeInBytes, ExecutorService executorService)
Creates an instance with the specified buffer size and read-ahead threshold
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description int
available()
void
close()
int
read()
int
read(byte[] b, int offset, int len)
long
skip(long n)
-
Methods inherited from class java.io.InputStream
mark, markSupported, nullInputStream, read, readAllBytes, readNBytes, readNBytes, reset, transferTo
-
-
-
-
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.
-
-
Method Detail
-
available
public int available() throws IOException
- Overrides:
available
in classInputStream
- Throws:
IOException
-
close
public void close() throws IOException
- Specified by:
close
in interfaceAutoCloseable
- Specified by:
close
in interfaceCloseable
- Overrides:
close
in classInputStream
- Throws:
IOException
-
read
public int read() throws IOException
- Specified by:
read
in classInputStream
- Throws:
IOException
-
read
public int read(byte[] b, int offset, int len) throws IOException
- Overrides:
read
in classInputStream
- Throws:
IOException
-
skip
public long skip(long n) throws IOException
- Overrides:
skip
in classInputStream
- Throws:
IOException
-
-