org.apache.hadoop.record
Class Utils

java.lang.Object
  org.apache.hadoop.record.Utils

public class Utils
extends Object

Various utility functions for Hadooop record I/O runtime.

Field Summary

static char[]

hexchars

Method Summary

static int	compareBytes(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2) Lexicographic order of binary data.
static int	getVIntSize(long i) Get the encoded length if an integer is stored in a variable-length format
static double	readDouble(byte[] bytes, int start) Parse a double from a byte array.
static float	readFloat(byte[] bytes, int start) Parse a float from a byte array.
static int	readVInt(byte[] bytes, int start) Reads a zero-compressed encoded integer from a byte array and returns it.
static int	readVInt(DataInput in) Reads a zero-compressed encoded integer from a stream and returns it.
static long	readVLong(byte[] bytes, int start) Reads a zero-compressed encoded long from a byte array and returns it.
static long	readVLong(DataInput in) Reads a zero-compressed encoded long from a stream and return it.
static void	writeVInt(DataOutput stream, int i) Serializes an int to a binary stream with zero-compressed encoding.
static void	writeVLong(DataOutput stream, long i) Serializes a long to a binary stream with zero-compressed encoding.

Methods inherited from class java.lang.Object

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

Field Detail

hexchars

public static final char[] hexchars

Method Detail

readFloat

public static float readFloat(byte[] bytes,
                              int start)

Parse a float from a byte array.

readDouble

public static double readDouble(byte[] bytes,
                                int start)

Parse a double from a byte array.

readVLong

public static long readVLong(byte[] bytes,
                             int start)
                      throws IOException

Reads a zero-compressed encoded long from a byte array and returns it.

Parameters:

bytes - byte array with decode long

start - starting index

Returns:

deserialized long

Throws:

IOException

readVInt

public static int readVInt(byte[] bytes,
                           int start)
                    throws IOException

Reads a zero-compressed encoded integer from a byte array and returns it.

Parameters:

bytes - byte array with the encoded integer

start - start index

Returns:

deserialized integer

Throws:

IOException

readVLong

public static long readVLong(DataInput in)
                      throws IOException

Reads a zero-compressed encoded long from a stream and return it.

Parameters:

in - input stream

Returns:

deserialized long

Throws:

IOException

readVInt

public static int readVInt(DataInput in)
                    throws IOException

Reads a zero-compressed encoded integer from a stream and returns it.

Parameters:

in - input stream

Returns:

deserialized integer

Throws:

IOException

getVIntSize

public static int getVIntSize(long i)

Get the encoded length if an integer is stored in a variable-length format

Returns:

the encoded length

writeVLong

public static void writeVLong(DataOutput stream,
                              long i)
                       throws IOException

Serializes a long to a binary stream with zero-compressed encoding. For -112 <= i <= 127, only one byte is used with the actual value. For other values of i, the first byte value indicates whether the long is positive or negative, and the number of bytes that follow. If the first byte value v is between -113 and -120, the following long is positive, with number of bytes that follow are -(v+112). If the first byte value v is between -121 and -128, the following long is negative, with number of bytes that follow are -(v+120). Bytes are stored in the high-non-zero-byte-first order.

Parameters:

stream - Binary output stream

i - Long to be serialized

Throws:

IOException

writeVInt

public static void writeVInt(DataOutput stream,
                             int i)
                      throws IOException

Serializes an int to a binary stream with zero-compressed encoding.

Parameters:

stream - Binary output stream

i - int to be serialized

Throws:

IOException

compareBytes

public static int compareBytes(byte[] b1,
                               int s1,
                               int l1,
                               byte[] b2,
                               int s2,
                               int l2)

Lexicographic order of binary data.