Class BitReader

java.lang.Object

com.itextpdf.io.codec.brotli.dec.BitReader

final class BitReader
extends Object

Bit reading helpers.

Field Summary

Fields

Modifier and Type	Field	Description
(package private) long	accumulator	Pre-fetched bits.
(package private) int	bitOffset	Current bit-reading position in accumulator.
private static final int	BYTE_BUFFER_SIZE
private static final int	BYTE_READ_SIZE
private final byte[]	byteBuffer
private static final int	CAPACITY	Input byte buffer, consist of a ring-buffer and a "slack" region where bytes from the start of the ring-buffer are copied.
private boolean	endOfStreamReached	Input stream is finished.
private InputStream	input
private static final int	INT_BUFFER_SIZE
private final int[]	intBuffer
private int	intOffset	Offset of next item in intBuffer.
private final IntReader	intReader
private static final int	SLACK
private int	tailBytes

Constructor Summary

Constructors

Constructor	Description
BitReader()

Method Summary

Modifier and Type	Method	Description
(package private) static void	checkHealth(BitReader br, boolean endOfStream)
(package private) static void	close(BitReader br)
(package private) static void	copyBytes(BitReader br, byte[] data, int offset, int length)
(package private) static void	fillBitWindow(BitReader br)	Advances the Read buffer by 5 bytes to make room for reading next 24 bits.
(package private) static void	init(BitReader br, InputStream input)	Initialize bit reader.
(package private) static int	intAvailable(BitReader br)
(package private) static void	jumpToByteBoundary(BitReader br)
private static void	prepare(BitReader br)
(package private) static int	readBits(BitReader br, int n)	Reads the specified number of bits from Read Buffer.
(package private) static void	readMoreInput(BitReader br)	Fills up the input buffer.
(package private) static void	reload(BitReader br)

Methods inherited from class Object

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

Field Details

CAPACITY

private static final int CAPACITY

Input byte buffer, consist of a ring-buffer and a "slack" region where bytes from the start of the ring-buffer are copied.

See Also:

• Constant Field Values

SLACK

private static final int SLACK

See Also:

• Constant Field Values

INT_BUFFER_SIZE

private static final int INT_BUFFER_SIZE

See Also:

• Constant Field Values

BYTE_READ_SIZE

private static final int BYTE_READ_SIZE

See Also:

• Constant Field Values

BYTE_BUFFER_SIZE

private static final int BYTE_BUFFER_SIZE

See Also:

• Constant Field Values

byteBuffer

private final byte[] byteBuffer

intBuffer

private final int[] intBuffer

intReader

private final IntReader intReader

input

private InputStream input

endOfStreamReached

private boolean endOfStreamReached

Input stream is finished.

accumulator

long accumulator

Pre-fetched bits.

bitOffset

int bitOffset

Current bit-reading position in accumulator.

intOffset

private int intOffset

Offset of next item in intBuffer.

tailBytes

private int tailBytes

Constructor Details

BitReader

BitReader()

Method Details

readMoreInput

static void readMoreInput(BitReader br)

Fills up the input buffer.

No-op if there are at least 36 bytes present after current position.

After encountering the end of the input stream, 64 additional zero bytes are copied to the buffer.

checkHealth

static void checkHealth(BitReader br,
 boolean endOfStream)

fillBitWindow

static void fillBitWindow(BitReader br)

Advances the Read buffer by 5 bytes to make room for reading next 24 bits.

readBits

static int readBits(BitReader br,
 int n)

Reads the specified number of bits from Read Buffer.

init

static void init(BitReader br,
 InputStream input)

Initialize bit reader.

Initialisation turns bit reader to a ready state. Also a number of bytes is prefetched to accumulator. Because of that this method may block until enough data could be read from input.

Parameters:

br - BitReader POJO

input - data source

prepare

private static void prepare(BitReader br)

reload

static void reload(BitReader br)

close

static void close(BitReader br)
           throws IOException

Throws:

IOException

jumpToByteBoundary

static void jumpToByteBoundary(BitReader br)

intAvailable

static int intAvailable(BitReader br)

copyBytes

static void copyBytes(BitReader br,
 byte[] data,
 int offset,
 int length)