org.verapdf.as.filters.io

Class ASBufferedInFilter

java.lang.Object

java.io.InputStream

org.verapdf.as.io.ASInputStream

org.verapdf.as.filters.ASInFilter

org.verapdf.as.filters.io.ASBufferedInFilter

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

COSFilterAESDecryptionDefault, COSFilterASCII85Decode, COSFilterASCIIHexDecode, COSFilterFlateDecode, COSFilterLZWDecode, COSFilterRC4DecryptionDefault, COSPredictorDecode, EexecFilterDecode

public class ASBufferedInFilter
extends ASInFilter

Class provides buffered input from input stream. It has two uses. If the ASBufferedInFilter object is used as a buffered stream (e. g. in unseekable parsers) then the buffer holds DECODED bytes read from inlaying stream. Before using the ASBufferedInFilter in this make sure to call initialize() method. In filter classes that are inherited from ASBufferedInFilter the buffer holds ENCODED bytes that are processed into decoded bytes on read() method calls.

Author:

Sergey Shemyakov

Field Summary

Fields

Modifier and Type	Field and Description
static int	BF_BUFFER_SIZE
protected byte[]	buffer
static int	START_BUFFER_SIZE

Fields inherited from class org.verapdf.as.io.ASInputStream

isClosed, isSourceClosed, resourceUsers

Constructor Summary

Constructors

Constructor and Description
ASBufferedInFilter(ASInputStream stream)
ASBufferedInFilter(ASInputStream stream, int buffCapacity)

Method Summary

Modifier and Type	Method and Description
long	addToBuffer(int bytesToAdd) Reads next portion of data from the underlying stream and appends it to the end of data, contained in internal buffer.
byte	bufferPop() Returns the character pointed by buffer begin marker and advances it.
int	bufferPopArray(byte[] buffer, int read) Reads data from internal buffer into passed byte array and advances begin marker.
int	bufferSize()
void	closeResource() Closes stream resource.
static byte[]	concatenate(byte[] one, int lengthOne, byte[] two, int lengthTwo)
long	feedBuffer(int bytesToRead) Reads next portion of data from the underlying stream to the internal buffer, updates begin and end pointers and returns number of bytes actually placed in buffer.
int	getBufferBegin()
int	getBufferCapacity()
int	getBufferEnd()
int	getReadCounter()
ASInputStream	getStream(int length) Gets a stream that is a piece of this stream.
ASInputStream	getStreamUntilToken(byte[] token) Gets a stream that is a piece of this stream.
void	initialize() This method should be called before using ASBufferedInFilter as buffered stream.
boolean	isEOF()
byte	peek()
byte	peek(int i)
int	processBuffer(int bytesToProcess) Shifts begin marker by up to bytesToProceed bytes to the right of to the end of the buffer if bytesToProceed is too big.
int	read(byte[] buffer)
int	read(byte[] buffer, int size)
byte	readByte()
void	reset()
void	resetReadCounter()
int	skip(int size) Skips given number of decoded bytes in stream.
void	unread()
void	unread(int i)

Methods inherited from class org.verapdf.as.filters.ASInFilter

close, decrementResourceUsers, getInputStream, incrementResourceUsers, read, setInputStream

Methods inherited from class org.verapdf.as.io.ASInputStream

createStreamFromStream

Methods inherited from class java.io.InputStream

available, mark, markSupported, read, skip

Methods inherited from class java.lang.Object

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

Field Detail

START_BUFFER_SIZE

public static final int START_BUFFER_SIZE

See Also:

Constant Field Values

BF_BUFFER_SIZE

public static final int BF_BUFFER_SIZE

See Also:

Constant Field Values

buffer

protected byte[] buffer

Constructor Detail

ASBufferedInFilter

public ASBufferedInFilter(ASInputStream stream)
                   throws IOException

Throws:

IOException

ASBufferedInFilter

public ASBufferedInFilter(ASInputStream stream,
                          int buffCapacity)

Method Detail

initialize

public void initialize()
                throws IOException

This method should be called before using ASBufferedInFilter as buffered stream.

Throws:

IOException

read

public int read(byte[] buffer,
                int size)
         throws IOException

Description copied from class: ASInFilter

Overrides:

read in class ASInFilter

Throws:

IOException

read

public int read(byte[] buffer)
         throws IOException

Description copied from class: ASInFilter

Overrides:

read in class ASInFilter

Throws:

IOException

readByte

public byte readByte()
              throws IOException

Throws:

IOException

processBuffer

public int processBuffer(int bytesToProcess)

Shifts begin marker by up to bytesToProceed bytes to the right of to the end of the buffer if bytesToProceed is too big.

Parameters:

bytesToProcess - amount of bytes to shift.

Returns:

amount of bytes actually processed.

feedBuffer

public long feedBuffer(int bytesToRead)
                throws IOException

Reads next portion of data from the underlying stream to the internal buffer, updates begin and end pointers and returns number of bytes actually placed in buffer.

Parameters:

bytesToRead - amount of bytes to read.

Returns:

amount of bytes actually placed into buffer.

Throws:

IOException

addToBuffer

public long addToBuffer(int bytesToAdd)
                 throws IOException

Reads next portion of data from the underlying stream and appends it to the end of data, contained in internal buffer.

Parameters:

bytesToAdd - amount of bytes to read.

Returns:

amount of bytes actually appended to buffer.

Throws:

IOException

getBufferBegin

public int getBufferBegin()

Returns:

beginning index of unread data in buffer.

getBufferEnd

public int getBufferEnd()

Returns:

index of the end of of valid unread data in buffer.

bufferPop

public byte bufferPop()

Returns the character pointed by buffer begin marker and advances it.

Returns:

character, pointed by buffer begin marker.

bufferPopArray

public int bufferPopArray(byte[] buffer,
                          int read)
                   throws IOException

Reads data from internal buffer into passed byte array and advances begin marker.

Parameters:

buffer - is byte array where data will be read.

read - maximal amount of bytes to read.

Returns:

amount of actually read bytes.

Throws:

IOException - if passed buffer is too small to contain necessary amount of bytes.

bufferSize

public int bufferSize()

Returns:

the number of bytes currently available in the buffer.

getBufferCapacity

public int getBufferCapacity()

Returns:

the total capacity of buffer.

closeResource

public void closeResource()
                   throws IOException

Closes stream resource. There is a difference between closing stream and closing it's resource. Several streams may have the same resource (e. g. the same file stream) and resource should be closed only after all streams using it are closed.

Overrides:

closeResource in class ASInFilter

Throws:

IOException

reset

public void reset()
           throws IOException

Overrides:

reset in class ASInFilter

Throws:

IOException

concatenate

public static byte[] concatenate(byte[] one,
                                 int lengthOne,
                                 byte[] two,
                                 int lengthTwo)

skip

public int skip(int size)
         throws IOException

Skips given number of decoded bytes in stream.

Overrides:

skip in class ASInFilter

Parameters:

size - is amount of bytes to skip.

Returns:

amount of actually skipped bytes.

Throws:

IOException - if stream-reading error occurs.

peek

public byte peek()
          throws IOException

Throws:

IOException

peek

public byte peek(int i)
          throws IOException

Throws:

IOException

unread

public void unread()
            throws IOException

Throws:

IOException

unread

public void unread(int i)
            throws IOException

Throws:

IOException

isEOF

public boolean isEOF()

resetReadCounter

public void resetReadCounter()

getReadCounter

public int getReadCounter()

getStream

public ASInputStream getStream(int length)
                        throws IOException

Gets a stream that is a piece of this stream. The next length bytes will be the data in the new stream.

Parameters:

length - is the length of new stream.

Returns:

new stream.

Throws:

IOException

getStreamUntilToken

public ASInputStream getStreamUntilToken(byte[] token)
                                  throws IOException

Gets a stream that is a piece of this stream. The data is taken from the current buffer position until the given token is not found.

Parameters:

token - is the byte array that means the end of stream.

Returns:

new stream.

Throws:

IOException