Class RememberBytesInputStream

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

org.apache.derby.impl.store.raw.data.RememberBytesInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public class RememberBytesInputStream
extends FilterInputStream

A FilterInputStream that remembers read or skipped bytes.

In record mode this stream remembers all the bytes a caller reads or skips. After reading some bytes this returns a 'replay' stream to re-read them.

A caller may call getReplaySteam to get a stream to re-read the the remembered bytes. Any number of calls to getReplayStream are supported.

The clear function causes this stream to forget the remembered bytes and re-enter record mode.

Field Summary

Fields

Modifier and Type	Field	Description
(package private) ByteHolder	bh
(package private) boolean	recording
(package private) boolean	streamClosed

Fields inherited from class FilterInputStream

in

Constructor Summary

Constructors

Constructor	Description
RememberBytesInputStream(InputStream in, ByteHolder bh)	Construct a RememberBytesInputStream.

Method Summary

Modifier and Type	Method	Description
int	available()	Return the number of bytes remains in the byteHolder for reading, without setting the write/read mode.
void	clear()	Clear all the remembered bytes.
long	fillBuf(int len)	read len bytes from the input stream, and store it in the byte holder.
ByteHolder	getByteHolder()	Get the byteHolder.
InputStream	getReplayStream()	Get an input stream for re-reading the remembered bytes.
int	numBytesSaved()	Return the number of bytes that have been saved to this byte holder.
int	putBuf(OutputStream out, int len)	read len bytes from the byte holder, and write it to the output stream.
int	read()
int	read(byte[] b, int off, int len)
boolean	recording()	Return true iff this RememberBytesInputStream is in recording mode.
void	setInput(InputStream in)	Set the InputStream from which this reads.
int	shiftToFront()	remove the remaining bytes in the byteHolder to the beginning set the position to start recording just after these bytes. returns how many bytes was transfered to the beginning.
long	skip(long count)
String	toString()

Methods inherited from class FilterInputStream

close, mark, markSupported, read, reset

Methods inherited from class InputStream

nullInputStream, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo

Methods inherited from class Object

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

Field Details

bh

ByteHolder bh

recording

boolean recording

streamClosed

boolean streamClosed

Constructor Details

RememberBytesInputStream

public RememberBytesInputStream(InputStream in,
 ByteHolder bh)

Construct a RememberBytesInputStream.

Parameters:

bh - for storing the remembered bytes. (must be in writing mode.

Method Details

read

public int read()
         throws IOException

Overrides:

read in class FilterInputStream

Throws:

IOException - thrown on an io error spooling rememberd bytes to backing storage.

See Also:

• InputStream.read()

read

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

Overrides:

read in class FilterInputStream

Throws:

IOException - thrown on an io error spooling rememberd bytes to backing storage.

See Also:

• InputStream.read()

fillBuf

public long fillBuf(int len)
             throws IOException

read len bytes from the input stream, and store it in the byte holder. Note, fillBuf does not return negative values, if there are no bytes to store in the byteholder, it will return 0

Throws:

IOException - thrown on an io error spooling rememberd bytes to backing storage.

putBuf

public int putBuf(OutputStream out,
 int len)
           throws IOException

read len bytes from the byte holder, and write it to the output stream.

Throws:

IOException - thrown on an io error spooling rememberd bytes to backing storage.

skip

public long skip(long count)
          throws IOException

Overrides:

skip in class FilterInputStream

Throws:

IOException - thrown on an io error spooling rememberd bytes to backing storage.

See Also:

• InputStream.skip(long)

getReplayStream

public InputStream getReplayStream()
                            throws IOException

Get an input stream for re-reading the remembered bytes.

Throws:

IOException

getByteHolder

public ByteHolder getByteHolder()
                         throws IOException

Get the byteHolder.

Throws:

IOException

clear

public void clear()
           throws IOException

Clear all the remembered bytes. This stream will remember any bytes read after this call.

Throws:

IOException - thrown on an io error clearing backing storage.

setInput

public void setInput(InputStream in)

Set the InputStream from which this reads.

Please note this does not clear remembered bytes.

recording

public boolean recording()

Return true iff this RememberBytesInputStream is in recording mode.

available

public int available()
              throws IOException

Return the number of bytes remains in the byteHolder for reading, without setting the write/read mode.

Overrides:

available in class FilterInputStream

Throws:

IOException

numBytesSaved

public int numBytesSaved()
                  throws IOException

Return the number of bytes that have been saved to this byte holder. This result is different from available() as it is unaffected by the current read position on the ByteHolder.

Throws:

IOException

shiftToFront

public int shiftToFront()
                 throws IOException

remove the remaining bytes in the byteHolder to the beginning set the position to start recording just after these bytes. returns how many bytes was transfered to the beginning.

Throws:

IOException

toString

public String toString()

Overrides:

toString in class Object

See Also:

• Object.toString()