com.levigo.jadice.document.io
Class SubfileSeekableInputStream

java.lang.Object
  java.io.InputStream
      com.levigo.jadice.document.io.SeekableInputStream
          com.levigo.jadice.document.io.SubfileSeekableInputStream

All Implemented Interfaces:

Closeable, DataInput, ImageInputStream

Direct Known Subclasses:

UncloseableSubfileSeekableInputStream

public class SubfileSeekableInputStream
extends SeekableInputStream

A wrapper for a SeekableInputStream which is able to provide a view of a specific part of the wrapped stream. Read accesses to the wrapped stream are synchronized, so that users of this stream need to deal with synchronization against other users of the same instance, but not against other users of the wrapped stream.

Field Summary

Fields inherited from class com.levigo.jadice.document.io.SeekableInputStream

bitOffset, byteOrder, flushedPos

Constructor Summary

SubfileSeekableInputStream(SeekableInputStream stream, long start, long length)
Creates a seekable stream part access

SubfileSeekableInputStream(SeekableInputStream stream, long start, long length, boolean propagateClose)
Creates a seekable stream part access

Method Summary

void	close() Closes this seekable input stream.
boolean	doPropagateClose() Boolean flag indicating whether if this stream is closed the closing of the warpped stream should be forced.
int	getReadAhead()
long	getSizeEstimate() A rough estimated size for this stream instance, which is used for internal cache management.
long	getStreamPosition()
long	length() Returns the length of this stream contents, if available.
int	read() Reads a single byte from the stream and returns it as an int between 0 and 255.
int	read(byte[] b, int off, int len) Reads up to len bytes from the stream, and stores them into b starting at index off.
void	seek(long pos) Sets the current stream position, measured from the beginning of this data stream, at which the next read occurs.
void	setReadAhead(int readAhead)

Methods inherited from class com.levigo.jadice.document.io.SeekableInputStream

checkClosed, finalize, flush, flushBefore, getBitOffset, getByteOrder, getFlushedPosition, isCached, isCachedFile, isCachedMemory, mark, mark, read, readBit, readBits, readBoolean, readByte, readBytes, readChar, readDouble, readFloat, readFully, readFully, readFully, readFully, readFully, readFully, readFully, readFully, readInt, readInt, readLine, readLong, readShort, readUnsignedByte, readUnsignedInt, readUnsignedInt, readUnsignedShort, readUTF, reset, resetToInitialState, setBitOffset, setByteOrder, skip, skipBytes, skipBytes

Methods inherited from class java.io.InputStream

available, markSupported

Methods inherited from class java.lang.Object

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

Constructor Detail

SubfileSeekableInputStream

public SubfileSeekableInputStream(SeekableInputStream stream,
                                  long start,
                                  long length)

Creates a seekable stream part access

Parameters:

stream - the SeekableInputStream

start - the start offset of the partial view

length - the length of the partial view to be read

SubfileSeekableInputStream

public SubfileSeekableInputStream(SeekableInputStream stream,
                                  long start,
                                  long length,
                                  boolean propagateClose)

Creates a seekable stream part access

Parameters:

stream - the SeekableInputStream

start - the start offset of the partial view

length - the length of the partial view to be read

propagateClose - propagate close to wrapped stream

Method Detail

getStreamPosition

public long getStreamPosition()
                       throws IOException

Throws:

IOException

See Also:

ImageInputStream.getStreamPosition()

close

public void close()
           throws IOException

Description copied from class: SeekableInputStream

Closes this seekable input stream. Further attempts to read from it will throw IOExceptions. Additional attempts to SeekableInputStream.close(), however, have no effect.

Specified by:

close in interface Closeable

Specified by:

close in interface ImageInputStream

Overrides:

close in class SeekableInputStream

Throws:

IOException

See Also:

InputStream.close()

read

public int read()
         throws IOException

Description copied from class: SeekableInputStream

Reads a single byte from the stream and returns it as an int between 0 and 255. If EOF is reached, -1 is returned.

Subclasses must provide an implementation for this method. The subclass implementation should update the stream position before exiting.

The bit offset within the stream must be reset to zero before the read occurs.

Specified by:

read in interface ImageInputStream

Specified by:

read in class SeekableInputStream

Returns:

the value of the next byte in the stream, or -1 if EOF is reached.

Throws:

IOException - if the stream has been closed.

See Also:

InputStream.read()

read

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

Description copied from class: SeekableInputStream

Reads up to len bytes from the stream, and stores them into b starting at index off. If no bytes can be read because the end of the stream has been reached, -1 is returned.

The bit offset within the stream must be reset to zero before the read occurs.

Subclasses must provide an implementation for this method. The subclass implementation should update the stream position before exiting.

Specified by:

read in interface ImageInputStream

Specified by:

read in class SeekableInputStream

Parameters:

b - an array of bytes to be written to.

off - the starting position within b to write to.

len - the maximum number of bytes to read.

Returns:

the number of bytes actually read, or -1 to indicate EOF.

Throws:

IOException - if an I/O error occurs.

See Also:

InputStream.read(byte[], int, int)

length

public long length()
            throws IOException

Description copied from class: SeekableInputStream

Returns the length of this stream contents, if available. Otherwise -1L will be returned.

Specified by:

length in interface ImageInputStream

Specified by:

length in class SeekableInputStream

Returns:

the length, measured in bytes or -1L if unknown.

Throws:

IOException - if an I/O error occurs.

See Also:

ImageInputStream.length()

seek

public void seek(long pos)
          throws IOException

Description copied from class: SeekableInputStream

Sets the current stream position, measured from the beginning of this data stream, at which the next read occurs. The offset may be set beyond the end of this data stream. Setting the offset beyond the end does not change the data length, an EOFException will be thrown only if a read is performed. The bit offset is set to 0.

An IndexOutOfBoundsException will be thrown if pos is smaller than the flushed position (as returned by getflushedPosition).

It is legal to seek past the end of the file; an EOFException will be thrown only if a read is performed.

Specified by:

seek in interface ImageInputStream

Specified by:

seek in class SeekableInputStream

Parameters:

pos - a long containing the desired file pointer position.

Throws:

IOException - if any other I/O error occurs.

See Also:

ImageInputStream.seek(long)

doPropagateClose

public boolean doPropagateClose()

Boolean flag indicating whether if this stream is closed the closing of the warpped stream should be forced.

Returns:

boolean flag

getSizeEstimate

public long getSizeEstimate()

Description copied from class: SeekableInputStream

A rough estimated size for this stream instance, which is used for internal cache management.

Specified by:

getSizeEstimate in class SeekableInputStream

Returns:

an estimated size

getReadAhead

public int getReadAhead()

Returns:

the readAhead

setReadAhead

public void setReadAhead(int readAhead)

Parameters:

readAhead - the readAhead to set