BitBufferHelper (openflowplugin 0.9.5-SNAPSHOT API)

java.lang.Object
- org.opendaylight.openflowplugin.libraries.liblldp.BitBufferHelper

```
public abstract class BitBufferHelper
extends Object
```
BitBufferHelper class that provides utility methods to - fetch specific bits from a serialized stream of bits - convert bits to primitive data type - like short, int, long - store bits in specified location in stream of bits - convert primitive data types to stream of bits.

Field Summary

Fields
Modifier and Type Field and Description

static long BYTE_MASK

Fields
Modifier and Type	Field and Description
`static long`	`BYTE_MASK`

Constructor Summary

Constructors
Constructor and Description

BitBufferHelper()

Constructors
Constructor and Description
`BitBufferHelper()`

Method Summary

All Methods Static Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`static void`	`checkExceptions(byte[] data, int startOffset, int numBits)` Checks for overflow and underflow exceptions.
`static byte[]`	`getBits(byte[] data, int startOffset, int numBits)` Reads the specified number of bits from the passed byte array starting to read from the specified offset The bits read are stored in a byte array which size is dictated by the number of bits to be stored.
`static byte`	`getByte(byte[] data)` Returns the first byte from the byte array.
`static int`	`getInt(byte[] data)` Returns the int value for the byte array passed.
`static int`	`getInt(byte[] data, int numBits)` Returns the int value for the last numBits of the byte array passed.
`static long`	`getLong(byte[] data)` Returns the long value for the byte array passed.
`static long`	`getLong(byte[] data, int numBits)` Returns the long value for the last numBits of the byte array passed.
`static int`	`getLSBMask(int numBits)` Returns numBits 1's in the LSB position.
`static int`	`getMSBMask(int numBits)` Returns numBits 1's in the MSB position.
`static short`	`getShort(byte[] data)` Returns the short value for the byte array passed.
`static short`	`getShort(byte[] data, int numBits)` Returns the short value for the last numBits of the byte array passed.
`static void`	`setBytes(byte[] data, byte[] input, int startOffset, int numBits)` Deprecated. Use `copyBitsFromLsb(byte[], byte[], int, int)` instead.
`static byte[]`	`shiftBitsToLSB(byte[] inputBytes, int numBits)` It aligns the first numBits bits to the right end of the byte array preceding them with numBits % 8 zero bits.
`static byte[]`	`shiftBitsToMSB(byte[] inputBytes, int numBits)` Takes an LSB aligned byte array and returned the LSB numBits in a MSB aligned byte array.
`static byte[]`	`toByteArray(Number input)` Accepts a number as input and returns its value in byte form in LSB aligned form example: input = 5000 [1001110001000] bytes = 19, -120 [00010011] [10001000].
`static byte[]`	`toByteArray(Number input, int numBits)` Accepts a number as input and returns its value in byte form in MSB aligned form example: input = 5000 [1001110001000] bytes = -114, 64 [10011100] [01000000].
`static long`	`toNumber(byte[] array)` Returns the numerical value of the byte array passed.
`static long`	`toNumber(byte[] array, int numBits)` Returns the numerical value of the last numBits (LSB bits) of the byte array passed.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - BYTE_MASK
```
public static final long BYTE_MASK
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - BitBufferHelper
```
public BitBufferHelper()
```
- Method Detail
  - getByte
```
public static byte getByte(byte[] data)
```
    Returns the first byte from the byte array.
    
    Returns:
    
    byte value
  - getShort
```
public static short getShort(byte[] data)
```
    Returns the short value for the byte array passed. Size of byte array is restricted to Short.SIZE
    
    Returns:
    
    short value
  - getShort
```
public static short getShort(byte[] data,
                             int numBits)
```
    Returns the short value for the last numBits of the byte array passed. Size of numBits is restricted to Short.SIZE
    
    Returns:
    
    short - the short value of byte array
  - getInt
```
public static int getInt(byte[] data)
```
    Returns the int value for the byte array passed. Size of byte array is restricted to Integer.SIZE
    
    Returns:
    
    int - the integer value of byte array
  - getInt
```
public static int getInt(byte[] data,
                         int numBits)
```
    Returns the int value for the last numBits of the byte array passed. Size of numBits is restricted to Integer.SIZE
    
    Returns:
    
    int - the integer value of byte array
  - getLong
```
public static long getLong(byte[] data)
```
    Returns the long value for the byte array passed. Size of byte array is restricted to Long.SIZE
    
    Returns:
    
    long - the integer value of byte array
  - getLong
```
public static long getLong(byte[] data,
                           int numBits)
```
    Returns the long value for the last numBits of the byte array passed. Size of numBits is restricted to Long.SIZE
    
    Returns:
    
    long - the integer value of byte array
  - getBits
```
@Nonnull
public static byte[] getBits(byte[] data,
                                      int startOffset,
                                      int numBits)
                               throws BufferException
```
    Reads the specified number of bits from the passed byte array starting to read from the specified offset The bits read are stored in a byte array which size is dictated by the number of bits to be stored. The bits are stored in the byte array LSB aligned.
    Ex. Read 7 bits at offset 10 0 9 10 16 17 0101000010 | 0000101 | 1111001010010101011 will be returned as {0,0,0,0,0,1,0,1}
    
    Parameters:
    
    startOffset - - offset to start fetching bits from data from
    
    numBits - - number of bits to be fetched from data
    
    Returns:
    
    byte [] - LSB aligned bits
    
    Throws:
    
    BufferException - when the startOffset and numBits parameters are not congruent with the data buffer size
  - setBytes
```
@Deprecated
public static void setBytes(byte[] data,
                                        byte[] input,
                                        int startOffset,
                                        int numBits)
                                 throws BufferException
```
    Deprecated. Use copyBitsFromLsb(byte[], byte[], int, int) instead.
    
    Bits are expected to be stored in the input byte array from LSB.
    
    Parameters:
    
    data - to set the input byte
    
    input - bytes to be inserted
    
    startOffset - offset of data[] to start inserting byte from
    
    numBits - number of bits of input to be inserted into data[]
    
    Throws:
    
    BufferException - when the startOffset and numBits parameters are not congruent with data and input buffers' size
  - getMSBMask
```
public static int getMSBMask(int numBits)
```
    Returns numBits 1's in the MSB position.
  - getLSBMask
```
public static int getLSBMask(int numBits)
```
    Returns numBits 1's in the LSB position.
  - toNumber
```
public static long toNumber(byte[] array)
```
    Returns the numerical value of the byte array passed.
    
    Returns:
    
    long - numerical value of byte array passed
  - toNumber
```
public static long toNumber(byte[] array,
                            int numBits)
```
    Returns the numerical value of the last numBits (LSB bits) of the byte array passed.
    
    Returns:
    
    long - numerical value of byte array passed
  - toByteArray
```
public static byte[] toByteArray(Number input)
```
    Accepts a number as input and returns its value in byte form in LSB aligned form example: input = 5000 [1001110001000] bytes = 19, -120 [00010011] [10001000].
  - toByteArray
```
public static byte[] toByteArray(Number input,
                                 int numBits)
```
    Accepts a number as input and returns its value in byte form in MSB aligned form example: input = 5000 [1001110001000] bytes = -114, 64 [10011100] [01000000].
    
    Parameters:
    
    numBits - - the number of bits to be returned
    
    Returns:
    
    byte[]
  - shiftBitsToMSB
```
public static byte[] shiftBitsToMSB(byte[] inputBytes,
                                    int numBits)
```
    Takes an LSB aligned byte array and returned the LSB numBits in a MSB aligned byte array.
    It aligns the last numBits bits to the head of the byte array following them with numBits % 8 zero bits.
    Example: For inputbytes = [00000111][01110001] and numBits = 12 it returns: shiftedBytes = [01110111][00010000]
    
    Parameters:
    
    numBits - - number of bits to be left aligned
    
    Returns:
    
    byte[]
  - shiftBitsToLSB
```
public static byte[] shiftBitsToLSB(byte[] inputBytes,
                                    int numBits)
```
    It aligns the first numBits bits to the right end of the byte array preceding them with numBits % 8 zero bits.
    Example: For inputbytes = [01110111][00010000] and numBits = 12 it returns: shiftedBytes = [00000111][01110001]
    
    Parameters:
    
    inputBytes - input bytes
    
    numBits - - number of bits to be right aligned
    
    Returns:
    
    byte[]
  - checkExceptions
```
public static void checkExceptions(byte[] data,
                                   int startOffset,
                                   int numBits)
                            throws BufferException
```
    Checks for overflow and underflow exceptions.
    
    Throws:
    
    BufferException - when the startOffset and numBits parameters are not congruent with the data buffer's size

Class BitBufferHelper

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

BYTE_MASK

Constructor Detail

BitBufferHelper

Method Detail

getByte

getShort

getShort

getInt

getInt

getLong

getLong

getBits

setBytes

getMSBMask

getLSBMask

toNumber

toNumber

toByteArray

toByteArray

shiftBitsToMSB

shiftBitsToLSB

checkExceptions