com.levigo.jadice.document.io
Class CarbonCopyStream

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

All Implemented Interfaces:

Closeable, DataInput, ImageInputStream

public class CarbonCopyStream
extends SeekableInputStream

A SeekableInputStream delegating all read operations to the stream given at construction time. In addition to this wholly transparent operation, all read operations performed using this stream are copied into a separate ByteArrayBuffer. This copying does not at all consider seeking, i.e. reading the same source stream segment twice using seeks will yield a buffer holding two copies of this segment.

Field Summary

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

bitOffset, byteOrder, flushedPos

Constructor Summary

CarbonCopyStream(SeekableInputStream source)
Create a CarbonCopyStream that proxies the a part of the source stream starting at current stream position of the source stream.

CarbonCopyStream(SeekableInputStream source, long start)
Create a CarbonCopyStream that proxies the a part of the source stream starting at the given start position.

Method Summary

ByteArrayBuffer	getBuffer() Return the ByteArrayBuffer holding a copy of the data read via this stream.
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.

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

checkClosed, close, 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

CarbonCopyStream

public CarbonCopyStream(SeekableInputStream source)
                 throws IOException

Create a CarbonCopyStream that proxies the a part of the source stream starting at current stream position of the source stream.

Parameters:

source -

Throws:

IOException

CarbonCopyStream

public CarbonCopyStream(SeekableInputStream source,
                        long start)
                 throws IOException

Create a CarbonCopyStream that proxies the a part of the source stream starting at the given start position. Calls to seek(long) and getStreamPosition() will take this start offset in consideration, i.e. seeking the CarbonCopyStream to offset 0 (zero) will seek the source stream to the given start position.

Parameters:

source -

start -

Throws:

IOException

Method Detail

getStreamPosition

public long getStreamPosition()
                       throws IOException

Throws:

IOException

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.

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.

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.

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.

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

getBuffer

public ByteArrayBuffer getBuffer()

Return the ByteArrayBuffer holding a copy of the data read via this stream.

Returns:

a ByteArrayBuffer