org.apache.flume.serialization
Class ResettableInputStream

java.lang.Object
  org.apache.flume.serialization.ResettableInputStream

All Implemented Interfaces:

Closeable, Resettable, Seekable

Direct Known Subclasses:

ResettableFileInputStream

@InterfaceAudience.Public
@InterfaceStability.Unstable
public abstract class ResettableInputStream
extends Object
implements Resettable, Seekable, Closeable

This abstract class defines an interface for which the stream may be marked and reset with no limit to the number of bytes which may have been read between the calls.

Any implementation of this interface guarantees that the mark position will not be invalidated by reading any number of bytes.

Warning: We reserve the right to add public methods to this class in the future. Third-party subclasses beware.

Constructor Summary

ResettableInputStream()

Method Summary

abstract void	close()
abstract void	mark() Marks the current position in this input stream.
abstract int	read() Read a single byte of data from the stream.
abstract int	read(byte[] b, int off, int len) Read multiple bytes of data from the stream.
abstract int	readChar() Read a single character.
abstract void	reset() Reset stream position to that set by mark()
abstract void	seek(long position) Seek to the specified byte position in the stream.
abstract long	tell() Tell the current byte position.

Methods inherited from class java.lang.Object

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

Constructor Detail

ResettableInputStream

public ResettableInputStream()

Method Detail

read

public abstract int read()
                  throws IOException

Read a single byte of data from the stream.

Returns:

the next byte of data, or -1 if the end of the stream has been reached.

Throws:

IOException

read

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

Read multiple bytes of data from the stream.

Parameters:

b - the buffer into which the data is read.

off - Offset into the array b at which the data is written.

len - the maximum number of bytes to read.

Returns:

the total number of bytes read into the buffer, or -1 if the end of the stream has been reached.

Throws:

IOException

readChar

public abstract int readChar()
                      throws IOException

Read a single character.

Note that this may lead to returning only one character in a 2-char surrogate pair sequence. When this happens, the underlying implementation should never persist a mark between two chars of a two-char surrogate pair sequence.

Returns:

The character read, as an integer in the range 0 to 65535 (0x00-0xffff), or -1 if the end of the stream has been reached

Throws:

IOException

mark

public abstract void mark()
                   throws IOException

Marks the current position in this input stream. A subsequent call to the reset method repositions this stream at the last marked position so that subsequent reads re-read the same bytes.

Marking a closed stream should not have any effect on the stream.

Specified by:

mark in interface Resettable

Throws:

IOException - If there is an error while setting the mark position.

See Also:

InputStream.mark(int), InputStream.reset()

reset

public abstract void reset()
                    throws IOException

Reset stream position to that set by mark()

Specified by:

reset in interface Resettable

Throws:

IOException

seek

public abstract void seek(long position)
                   throws IOException

Seek to the specified byte position in the stream.

Specified by:

seek in interface Seekable

Parameters:

position - Absolute byte offset to seek to

Throws:

IOException

tell

public abstract long tell()
                   throws IOException

Tell the current byte position.

Specified by:

tell in interface Seekable

Returns:

the current absolute byte position in the stream

Throws:

IOException

close

public abstract void close()
                    throws IOException

Specified by:

close in interface Closeable

Throws:

IOException