Util (beat-link 0.3.7 API)

java.lang.Object
- org.deepsymmetry.beatlink.Util

```
public class Util
extends Object
```
Provides utility functions.

Author:

James Elliott

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static long`	`addressToLong(InetAddress address)` Converts the bytes that make up an internet address into the corresponding integer value to make it easier to perform bit-masking operations on them.
`static long`	`bytesToNumber(byte[] buffer, int start, int length)` Reconstructs a number that is represented by more than one byte in a network packet in big-endian order.
`static long`	`bytesToNumberLittleEndian(byte[] buffer, int start, int length)` Reconstructs a number that is represented by more than one byte in a network packet in little-endian order, for the very few protocol values that are sent in this quirky way.
`static long`	`halfFrameToTime(long halfFrame)` Figure out the track time that corresponds to a half-frame number (75 frames per second, so 150 half-frames).
`static double`	`pitchToMultiplier(long pitch)` Convert a pitch value reported by a device to the corresponding multiplier (0.0 to 2.0, where normal, unadjusted pitch has the multiplier 1.0).
`static double`	`pitchToPercentage(long pitch)` Convert a pitch value reported by a device to the corresponding percentage (-100% to +100%, where normal, unadjusted pitch has the value 0%).
`static boolean`	`sameNetwork(int prefixLength, InetAddress address1, InetAddress address2)` Checks whether two internet addresses are on the same subnet.
`static int`	`timeToHalfFrame(long milliseconds)` Convert a track position (time) into the corresponding half-frame value (75 frames per second, so 150 half-frames).
`static int`	`unsign(byte b)` Converts a signed byte to its unsigned int equivalent in the range 0-255.
`static boolean`	`validateHeader(DatagramPacket packet, int kind, String name)` Check to see whether a packet starts with the standard header bytes, followed by a byte identifying it as the kind of packet that is expected.
`static void`	`writeFully(ByteBuffer buffer, WritableByteChannel channel)` Writes the entire remaining contents of the buffer to the channel.

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

- Method Detail
  - validateHeader
```
public static boolean validateHeader(DatagramPacket packet,
                                     int kind,
                                     String name)
```
    Check to see whether a packet starts with the standard header bytes, followed by a byte identifying it as the kind of packet that is expected.
    
    Parameters:
    
    packet - a packet that has just been received
    
    kind - the expected value of the eleventh byte, which seems to identify the packet type
    
    name - the name of the kind of packet expected, for use in logging warnings if a mismatch is found
    
    Returns:
    
    true if the packet has the right header
  - unsign
```
public static int unsign(byte b)
```
    Converts a signed byte to its unsigned int equivalent in the range 0-255.
    
    Parameters:
    
    b - a byte value to be considered an unsigned integer
    
    Returns:
    
    the unsigned version of the byte
  - bytesToNumber
```
public static long bytesToNumber(byte[] buffer,
                                 int start,
                                 int length)
```
    Reconstructs a number that is represented by more than one byte in a network packet in big-endian order.
    
    Parameters:
    
    buffer - the byte array containing the packet data
    
    start - the index of the first byte containing a numeric value
    
    length - the number of bytes making up the value
    
    Returns:
    
    the reconstructed number
  - bytesToNumberLittleEndian
```
public static long bytesToNumberLittleEndian(byte[] buffer,
                                             int start,
                                             int length)
```
    Reconstructs a number that is represented by more than one byte in a network packet in little-endian order, for the very few protocol values that are sent in this quirky way.
    
    Parameters:
    
    buffer - the byte array containing the packet data
    
    start - the index of the first byte containing a numeric value
    
    length - the number of bytes making up the value
    
    Returns:
    
    the reconstructed number
  - addressToLong
```
public static long addressToLong(InetAddress address)
```
    Converts the bytes that make up an internet address into the corresponding integer value to make it easier to perform bit-masking operations on them.
    
    Parameters:
    
    address - an address whose integer equivalent is desired
    
    Returns:
    
    the integer corresponding to that address
  - sameNetwork
```
public static boolean sameNetwork(int prefixLength,
                                  InetAddress address1,
                                  InetAddress address2)
```
    Checks whether two internet addresses are on the same subnet.
    
    Parameters:
    
    prefixLength - the number of bits within an address that identify the network
    
    address1 - the first address to be compared
    
    address2 - the second address to be compared
    
    Returns:
    
    true if both addresses share the same network bits
  - pitchToPercentage
```
public static double pitchToPercentage(long pitch)
```
    Convert a pitch value reported by a device to the corresponding percentage (-100% to +100%, where normal, unadjusted pitch has the value 0%).
    
    Parameters:
    
    pitch - the reported device pitch
    
    Returns:
    
    the pitch as a percentage
  - pitchToMultiplier
```
public static double pitchToMultiplier(long pitch)
```
    Convert a pitch value reported by a device to the corresponding multiplier (0.0 to 2.0, where normal, unadjusted pitch has the multiplier 1.0).
    
    Parameters:
    
    pitch - the reported device pitch
    
    Returns:
    
    the implied pitch multiplier
  - writeFully
```
public static void writeFully(ByteBuffer buffer,
                              WritableByteChannel channel)
                       throws IOException
```
    Writes the entire remaining contents of the buffer to the channel. May complete in one operation, but the documentation is vague, so this keeps going until we are sure.
    
    Parameters:
    
    buffer - the data to be written
    
    channel - the channel to which we want to write data
    
    Throws:
    
    IOException - if there is a problem writing to the channel
  - halfFrameToTime
```
public static long halfFrameToTime(long halfFrame)
```
    Figure out the track time that corresponds to a half-frame number (75 frames per second, so 150 half-frames).
    
    Parameters:
    
    halfFrame - the half-frame that we are interested in knowing the time for
    
    Returns:
    
    the number of milliseconds into a track that the specified half-frame begins
  - timeToHalfFrame
```
public static int timeToHalfFrame(long milliseconds)
```
    Convert a track position (time) into the corresponding half-frame value (75 frames per second, so 150 half-frames).
    
    Parameters:
    
    milliseconds - how long a track has been playing for
    
    Returns:
    
    the half-frame that contains that part of the track

Class Util

Method Summary

Methods inherited from class java.lang.Object

Method Detail

validateHeader

unsign

bytesToNumber

bytesToNumberLittleEndian

addressToLong

sameNetwork

pitchToPercentage

pitchToMultiplier

writeFully

halfFrameToTime

timeToHalfFrame