Package org.apache.drill.exec.util.filereader

Class BufferedDirectBufInputStream

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

org.apache.drill.exec.util.filereader.DirectBufInputStream

org.apache.drill.exec.util.filereader.BufferedDirectBufInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public class BufferedDirectBufInputStream
extends DirectBufInputStream
implements Closeable

BufferedDirectBufInputStream reads from the underlying InputStream in blocks of data, into an internal buffer. The internal buffer is a direct memory backed buffer. The implementation is similar to the BufferedInputStream class except that the internal buffer is a Drillbuf and not a byte array. The mark and reset methods of the underlying InputStreamare not supported.

Field Summary

Fields

Modifier and Type	Field	Description
protected int	count	The number of valid bytes in internalBuffer.
protected int	curPosInBuffer	The current read position in the buffer; the index of the next character to be read from the internalBuffer array.
protected long	curPosInStream
protected DrillBuf	internalBuffer	The internal buffer to keep data read from the underlying inputStream.

Fields inherited from class org.apache.drill.exec.util.filereader.DirectBufInputStream

allocator, enableHints, enforceTotalByteSize, startOffset, streamId, totalByteSize

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

Constructors

Constructor	Description
BufferedDirectBufInputStream(InputStream in, BufferAllocator allocator, String id, long startOffset, long totalByteSize, boolean enforceTotalByteSize, boolean enableHints)	Creates a BufferedDirectBufInputStream with the default (8 MiB) buffer size.
BufferedDirectBufInputStream(InputStream in, BufferAllocator allocator, String id, long startOffset, long totalByteSize, int bufSize, boolean enforceTotalByteSize, boolean enableHints)	Creates a BufferedDirectBufInputStream with the specified buffer size.

Method Summary

Modifier and Type	Method	Description
int	available()
void	close()
long	getPos()
void	init()
void	mark(int readlimit)
boolean	markSupported()
int	read()	Implements the read method of InputStream.
int	read(byte[] b)
int	read(byte[] buf, int off, int len)
int	read(DrillBuf buf, int off, int len)	Has the same contract as InputStream.read(byte[], int, int) Except with DrillBuf
void	reset()
long	skip(long n)	Has the same contract as InputStream.skip(long) Skips upto the next n bytes.

Methods inherited from class org.apache.drill.exec.util.filereader.DirectBufInputStream

checkInputStreamState, checkStreamSupportsByteBuffer, fadviseIfAvailable, getInputStream, getNext, hasRemainder

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

internalBuffer

protected volatile DrillBuf internalBuffer

The internal buffer to keep data read from the underlying inputStream. internalBuffer[0] through internalBuffer[count-1] contains data read from the underlying input stream.

count

protected int count

The number of valid bytes in internalBuffer. count is always in the range [0,internalBuffer.capacity] internalBuffer[count-1] is the last valid byte in the buffer.

curPosInBuffer

protected int curPosInBuffer

The current read position in the buffer; the index of the next character to be read from the internalBuffer array.

This value is always in the range [0,count]. If curPosInBuffer is equal to count> then we have read all the buffered data and the next read (or skip) will require more data to be read from the underlying input stream.

curPosInStream

protected long curPosInStream

Constructor Details

BufferedDirectBufInputStream

public BufferedDirectBufInputStream(InputStream in,
 BufferAllocator allocator,
 String id,
 long startOffset,
 long totalByteSize,
 boolean enforceTotalByteSize,
 boolean enableHints)

Creates a BufferedDirectBufInputStream with the default (8 MiB) buffer size.

BufferedDirectBufInputStream

public BufferedDirectBufInputStream(InputStream in,
 BufferAllocator allocator,
 String id,
 long startOffset,
 long totalByteSize,
 int bufSize,
 boolean enforceTotalByteSize,
 boolean enableHints)

Creates a BufferedDirectBufInputStream with the specified buffer size.

Method Details

init

public void init()
          throws UnsupportedOperationException,
IOException

Overrides:

init in class DirectBufInputStream

Throws:

UnsupportedOperationException

IOException

read

public int read()
         throws IOException

Implements the read method of InputStream. returns one more byte or -1 if end of stream is reached.

Overrides:

read in class DirectBufInputStream

Throws:

IOException

read

public int read(DrillBuf buf,
 int off,
 int len)
         throws IOException

Has the same contract as InputStream.read(byte[], int, int) Except with DrillBuf

Overrides:

read in class DirectBufInputStream

Throws:

IOException

read

public int read(byte[] b)
         throws IOException

Overrides:

read in class FilterInputStream

Throws:

IOException

read

public int read(byte[] buf,
 int off,
 int len)
         throws IOException

Overrides:

read in class FilterInputStream

Throws:

IOException

skip

public long skip(long n)
          throws IOException

Has the same contract as InputStream.skip(long) Skips upto the next n bytes. Skip may return with less than n bytes skipped

Overrides:

skip in class FilterInputStream

Throws:

IOException

available

public int available()
              throws IOException

Overrides:

available in class FilterInputStream

Throws:

IOException

mark

public void mark(int readlimit)

Overrides:

mark in class FilterInputStream

reset

public void reset()
           throws IOException

Overrides:

reset in class FilterInputStream

Throws:

IOException

markSupported

public boolean markSupported()

Overrides:

markSupported in class FilterInputStream

getPos

public long getPos()
            throws IOException

Overrides:

getPos in class DirectBufInputStream

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class DirectBufInputStream

Throws:

IOException