io.permazen.util

Class ByteReader

java.lang.Object

io.permazen.util.ByteReader

public class ByteReader
extends Object

Reads bytes from a buffer.

Constructor Summary

Constructors

Constructor and Description
ByteReader(byte[] buf) Constructor.
ByteReader(byte[] buf, int off) Constructor.
ByteReader(byte[] buf, int off, int len) Constructor.
ByteReader(ByteWriter writer) Constructor.
ByteReader(ByteWriter writer, int mark) Constructor.

Method Summary

Modifier and Type	Method and Description
byte[]	getBytes() Copy all the of bytes in the buffer.
byte[]	getBytes(int off) Copy a range of bytes from the given offset to the end of the buffer.
byte[]	getBytes(int off, int len) Copy a range of bytes from the buffer.
int	getMax() Get maximum offset into buffer.
int	getOffset() Get current offset into buffer.
int	mark() Mark current read position.
int	peek() Peek at next byte, if any.
int	readByte() Read the next byte.
byte[]	readBytes(int len) Read the specified number of bytes.
int	remain() Get the number of bytes remaining.
void	reset(int mark) Reset read position to a previously marked position.
void	skip(int num) Skip over bytes.
void	unread() Unread the previously read byte.
void	unread(int len) Unread the given number of previously read bytes.

Methods inherited from class java.lang.Object

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

Constructor Detail

ByteReader

public ByteReader(byte[] buf)

Constructor. The provided array is read from directly; no copy is made.

Parameters:

buf - array to read from

Throws:

NullPointerException - if buf is null

ByteReader

public ByteReader(byte[] buf,
                  int off)

Constructor. The provided array is read from directly; no copy is made.

Parameters:

buf - array to read from

off - starting offset into buf

Throws:

IndexOutOfBoundsException - if off is out of bounds

NullPointerException - if buf is null

ByteReader

public ByteReader(byte[] buf,
                  int off,
                  int len)

Constructor. The provided array is read from directly; no copy is made.

Parameters:

buf - array to read from

off - offset into buf

len - number of bytes to read

Throws:

IndexOutOfBoundsException - if off or len are out of bounds

NullPointerException - if buf is null

ByteReader

public ByteReader(ByteWriter writer)

Constructor. Takes a snapshot of the given writer's entire content.

Parameters:

writer - ByteWriter to read data from

Throws:

NullPointerException - if writer is null

ByteReader

public ByteReader(ByteWriter writer,
                  int mark)

Constructor. Takes a snapshot of the given writer's content starting at the specified position.

Parameters:

writer - ByteWriter to read data from

mark - position previously returned by ByteWriter.mark()

Throws:

IndexOutOfBoundsException - if mark is out of bounds

NullPointerException - if writer is null

Method Detail

peek

public int peek()

Peek at next byte, if any.

Returns:

next byte (0-255)

Throws:

IndexOutOfBoundsException - if there are no more bytes

readByte

public int readByte()

Read the next byte.

Returns:

next byte (0-255)

Throws:

IndexOutOfBoundsException - if there are no more bytes

unread

public void unread()

Unread the previously read byte. Equivalent to unread(1).

Throws:

IndexOutOfBoundsException - if there are no more bytes to unread

unread

public void unread(int len)

Unread the given number of previously read bytes.

Parameters:

len - the number of bytes to unread

Throws:

IndexOutOfBoundsException - if there are no more bytes to unread

readBytes

public byte[] readBytes(int len)

Read the specified number of bytes.

Parameters:

len - number of bytes to read

Returns:

bytes read

Throws:

IndexOutOfBoundsException - if there are not enough bytes

IllegalArgumentException - if len is negative

remain

public int remain()

Get the number of bytes remaining.

Returns:

bytes remaining

skip

public void skip(int num)

Skip over bytes.

Parameters:

num - the number of bytes to skip

Throws:

IndexOutOfBoundsException - if num is negative

IndexOutOfBoundsException - if less than num bytes remain

getOffset

public int getOffset()

Get current offset into buffer.

Returns:

current offset

getMax

public int getMax()

Get maximum offset into buffer.

Returns:

maximum offset

getBytes

public byte[] getBytes(int off,
                       int len)

Copy a range of bytes from the buffer. Does not change the read position.

Parameters:

off - offset into buffer

len - number of bytes

Returns:

copy of the specified byte range

Throws:

IndexOutOfBoundsException - if off and/or len is out of bounds

getBytes

public byte[] getBytes(int off)

Copy a range of bytes from the given offset to the end of the buffer. Does not change the read position.

Parameters:

off - offset into buffer

Returns:

copy of the specified byte range

Throws:

IndexOutOfBoundsException - if off is out of bounds

getBytes

public byte[] getBytes()

Copy all the of bytes in the buffer. Does not change the read position.

Returns:

copy of the entire buffer

mark

public int mark()

Mark current read position.

Returns:

the current offset

reset

public void reset(int mark)

Reset read position to a previously marked position.

Parameters:

mark - value previously returned by mark()

Throws:

IndexOutOfBoundsException - if mark is out of bounds