org.abstracthorizon.mercury.maildir.file
Class SharedInputStreamImpl

java.lang.Object
  java.io.InputStream
      org.abstracthorizon.mercury.maildir.file.SharedInputStreamImpl

All Implemented Interfaces:

Closeable, javax.mail.internet.SharedInputStream

public class SharedInputStreamImpl
extends InputStream
implements javax.mail.internet.SharedInputStream

SharedInputStream implementation

Author:

Daniel Sendula

Field Summary

protected byte[]	buffer Stream's buffer
static int	BUFFER_SIZE Stream's buffer size
protected int	buflen Stream's buffer content len
protected long	bufptr Stream's buffer start pointer
protected long	end Stream end offset
protected FileProvider	fileProvider File provider reference
protected long	fileSize Cached value of file's size
protected int	id Unique Id - needed for debug purposes only
protected long	lastAccessed Timestamp this stream's file is accessed last time
protected long	mark Mark
protected static int	num Next Unique Id - needed for debug purposes only
protected SharedInputStreamPool	parent Pool that created this object
protected long	ptr Stream's pointer
protected RandomAccessFile	raf Random access file reference
protected long	start Stream start offset

Constructor Summary

SharedInputStreamImpl(SharedInputStreamPool parent, FileProvider fileProvider, long start, long end)
Constructor.

Method Summary

int	available() Returns number of available bytes in stream (to end of stream).
protected void	checkOpened() Checks if underlaying file is opened.
void	close() Closes the stream and releases allocated resources.
void	closeImpl() This method actually releases the resources (random access file)
protected long	getFileSize() Returns file's size.
long	getPosition() Returns current pointer in stream
void	mark(int readlimit) Sets mark.
boolean	markSupported() Returns true
InputStream	newStream(long pos, long end) Creates new stream from this stream.
int	read() Reads one byte or returns -1 if EOF is reached (end of stream really).
int	read(byte[] buf) Reads whole buffer.
int	read(byte[] buf, int off, int len) Reads bytes from the underlaying file.
boolean	ready() Returns true
void	reset() Resets stream to the mark
long	skip(long n) Skips number of bytes

Methods inherited from class java.lang.Object

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

Field Detail

num

protected static int num

Next Unique Id - needed for debug purposes only

id

protected int id

Unique Id - needed for debug purposes only

start

protected long start

Stream start offset

end

protected long end

Stream end offset

ptr

protected long ptr

Stream's pointer

mark

protected long mark

Mark

BUFFER_SIZE

public static final int BUFFER_SIZE

Stream's buffer size

See Also:

Constant Field Values

buffer

protected byte[] buffer

Stream's buffer

bufptr

protected long bufptr

Stream's buffer start pointer

buflen

protected int buflen

Stream's buffer content len

fileSize

protected long fileSize

Cached value of file's size

fileProvider

protected FileProvider fileProvider

File provider reference

raf

protected RandomAccessFile raf

Random access file reference

parent

protected SharedInputStreamPool parent

Pool that created this object

lastAccessed

protected long lastAccessed

Timestamp this stream's file is accessed last time

Constructor Detail

SharedInputStreamImpl

public SharedInputStreamImpl(SharedInputStreamPool parent,
                             FileProvider fileProvider,
                             long start,
                             long end)

Constructor.

Parameters:

parent - pool that is creating this stream

fileProvider - file provider

start - stream start

end - stream end

Method Detail

read

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

Reads bytes from the underlaying file. It opens it if it wasn't open at the moment of call. Also, uses internal buffer too.

Overrides:

read in class InputStream

Parameters:

buf - buffer to be read into

off - offset in buffer

len - length to be read

Returns:

number of actually read bytes

Throws:

IOException

read

public int read(byte[] buf)
         throws IOException

Reads whole buffer.

Overrides:

read in class InputStream

Parameters:

buf - buffer to be read into

Returns:

number of actually read bytes

Throws:

IOException

read

public int read()
         throws IOException

Reads one byte or returns -1 if EOF is reached (end of stream really).

Specified by:

read in class InputStream

Returns:

read byte

Throws:

IOException

available

public int available()
              throws IOException

Returns number of available bytes in stream (to end of stream).

Overrides:

available in class InputStream

Returns:

number of available bytes

Throws:

IOException

close

public void close()
           throws IOException

Closes the stream and releases allocated resources.

Specified by:

close in interface Closeable

Overrides:

close in class InputStream

Throws:

IOException

closeImpl

public void closeImpl()
               throws IOException

This method actually releases the resources (random access file)

Throws:

IOException

markSupported

public boolean markSupported()

Returns true

Overrides:

markSupported in class InputStream

Returns:

true

mark

public void mark(int readlimit)

Sets mark.

Overrides:

mark in class InputStream

Parameters:

readlimit - ignored

reset

public void reset()
           throws IOException

Resets stream to the mark

Overrides:

reset in class InputStream

Throws:

IOException

ready

public boolean ready()

Returns true

Returns:

true

skip

public long skip(long n)
          throws IOException

Skips number of bytes

Overrides:

skip in class InputStream

Parameters:

n - number of bytes to be skipped

Returns:

current pointer in stream

Throws:

IOException

getPosition

public long getPosition()

Returns current pointer in stream

Specified by:

getPosition in interface javax.mail.internet.SharedInputStream

Returns:

current pointer in stream

newStream

public InputStream newStream(long pos,
                             long end)

Creates new stream from this stream.

Specified by:

newStream in interface javax.mail.internet.SharedInputStream

Parameters:

pos - new relative start position

end - new relative end position

Returns:

new instance with given start and end.

checkOpened

protected void checkOpened()
                    throws IOException

Checks if underlaying file is opened. It uses FileProvider to obtain file.

Throws:

IOException

getFileSize

protected long getFileSize()

Returns file's size. If not cached then caches it using FileProvider

Returns:

file's size.