org.apache.parquet.bytes

Class BytesUtils

java.lang.Object

org.apache.parquet.bytes.BytesUtils

public class BytesUtils
extends Object

utility methods to deal with bytes

Field Summary

Fields

Modifier and Type	Field and Description
static Charset	UTF8

Constructor Summary

Constructors

Constructor and Description
BytesUtils()

Method Summary

Modifier and Type	Method and Description
static byte[]	booleanToBytes(boolean value)
static boolean	bytesToBool(byte[] bytes)
static int	bytesToInt(byte[] bytes)
static long	bytesToLong(byte[] bytes)
static int	getWidthFromMaxInt(int bound) give the number of bits needed to encode an int given the max value
static byte[]	intToBytes(int value)
static byte[]	longToBytes(long value)
static int	paddedByteCountFromBits(int bitLength)
static int	readIntLittleEndian(byte[] in, int offset) reads an int in little endian at the given position
static int	readIntLittleEndian(ByteBuffer in, int offset) reads an int in little endian at the given position
static int	readIntLittleEndian(InputStream in)
static int	readIntLittleEndianOnOneByte(InputStream in)
static int	readIntLittleEndianOnThreeBytes(InputStream in)
static int	readIntLittleEndianOnTwoBytes(InputStream in)
static int	readIntLittleEndianPaddedOnBitWidth(InputStream in, int bitWidth)
static int	readUnsignedVarInt(InputStream in)
static long	readUnsignedVarLong(InputStream in)
static int	readZigZagVarInt(InputStream in) uses a trick mentioned in https://developers.google.com/protocol-buffers/docs/encoding to read zigZag encoded data
static long	readZigZagVarLong(InputStream in) uses a trick mentioned in https://developers.google.com/protocol-buffers/docs/encoding to read zigZag encoded data TODO: the implementation is compatible with readZigZagVarInt.
static void	writeIntLittleEndian(OutputStream out, int v)
static void	writeIntLittleEndianOnOneByte(OutputStream out, int v)
static void	writeIntLittleEndianOnThreeBytes(OutputStream out, int v)
static void	writeIntLittleEndianOnTwoBytes(OutputStream out, int v)
static void	writeIntLittleEndianPaddedOnBitWidth(OutputStream out, int v, int bitWidth) Write a little endian int to out, using the the number of bytes required by bit width
static void	writeUnsignedVarInt(int value, ByteBuffer dest)
static void	writeUnsignedVarInt(int value, OutputStream out)
static void	writeUnsignedVarLong(long value, OutputStream out)
static void	writeZigZagVarInt(int intValue, OutputStream out)
static void	writeZigZagVarLong(long longValue, OutputStream out)

Methods inherited from class java.lang.Object

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

Field Detail

UTF8

public static final Charset UTF8

Constructor Detail

BytesUtils

public BytesUtils()

Method Detail

getWidthFromMaxInt

public static int getWidthFromMaxInt(int bound)

give the number of bits needed to encode an int given the max value

Parameters:

bound - max int that we want to encode

Returns:

the number of bits required

readIntLittleEndian

public static int readIntLittleEndian(ByteBuffer in,
                                      int offset)
                               throws IOException

reads an int in little endian at the given position

Parameters:

in - a byte buffer

offset - an offset into the byte buffer

Returns:

the integer at position offset read using little endian byte order

Throws:

IOException - if there is an exception reading from the byte buffer

readIntLittleEndian

public static int readIntLittleEndian(byte[] in,
                                      int offset)
                               throws IOException

reads an int in little endian at the given position

Parameters:

in - a byte array

offset - an offset into the byte array

Returns:

the integer at position offset read using little endian byte order

Throws:

IOException - if there is an exception reading from the byte array

readIntLittleEndian

public static int readIntLittleEndian(InputStream in)
                               throws IOException

Throws:

IOException

readIntLittleEndianOnOneByte

public static int readIntLittleEndianOnOneByte(InputStream in)
                                        throws IOException

Throws:

IOException

readIntLittleEndianOnTwoBytes

public static int readIntLittleEndianOnTwoBytes(InputStream in)
                                         throws IOException

Throws:

IOException

readIntLittleEndianOnThreeBytes

public static int readIntLittleEndianOnThreeBytes(InputStream in)
                                           throws IOException

Throws:

IOException

readIntLittleEndianPaddedOnBitWidth

public static int readIntLittleEndianPaddedOnBitWidth(InputStream in,
                                                      int bitWidth)
                                               throws IOException

Throws:

IOException

writeIntLittleEndianOnOneByte

public static void writeIntLittleEndianOnOneByte(OutputStream out,
                                                 int v)
                                          throws IOException

Throws:

IOException

writeIntLittleEndianOnTwoBytes

public static void writeIntLittleEndianOnTwoBytes(OutputStream out,
                                                  int v)
                                           throws IOException

Throws:

IOException

writeIntLittleEndianOnThreeBytes

public static void writeIntLittleEndianOnThreeBytes(OutputStream out,
                                                    int v)
                                             throws IOException

Throws:

IOException

writeIntLittleEndian

public static void writeIntLittleEndian(OutputStream out,
                                        int v)
                                 throws IOException

Throws:

IOException

writeIntLittleEndianPaddedOnBitWidth

public static void writeIntLittleEndianPaddedOnBitWidth(OutputStream out,
                                                        int v,
                                                        int bitWidth)
                                                 throws IOException

Write a little endian int to out, using the the number of bytes required by bit width

Parameters:

out - an output stream

v - an int value

bitWidth - bit width for padding

Throws:

IOException - if there is an exception while writing

readUnsignedVarInt

public static int readUnsignedVarInt(InputStream in)
                              throws IOException

Throws:

IOException

readZigZagVarInt

public static int readZigZagVarInt(InputStream in)
                            throws IOException

uses a trick mentioned in https://developers.google.com/protocol-buffers/docs/encoding to read zigZag encoded data

Parameters:

in - an input stream

Returns:

the value of a zig-zag varint read from the current position in the stream

Throws:

IOException - if there is an exception while reading

writeUnsignedVarInt

public static void writeUnsignedVarInt(int value,
                                       OutputStream out)
                                throws IOException

Throws:

IOException

writeUnsignedVarInt

public static void writeUnsignedVarInt(int value,
                                       ByteBuffer dest)
                                throws IOException

Throws:

IOException

writeZigZagVarInt

public static void writeZigZagVarInt(int intValue,
                                     OutputStream out)
                              throws IOException

Throws:

IOException

readZigZagVarLong

public static long readZigZagVarLong(InputStream in)
                              throws IOException

uses a trick mentioned in https://developers.google.com/protocol-buffers/docs/encoding to read zigZag encoded data TODO: the implementation is compatible with readZigZagVarInt. Is there a need for different functions?

Parameters:

in - an input stream

Returns:

the value of a zig-zag var-long read from the current position in the stream

Throws:

IOException - if there is an exception while reading

readUnsignedVarLong

public static long readUnsignedVarLong(InputStream in)
                                throws IOException

Throws:

IOException

writeUnsignedVarLong

public static void writeUnsignedVarLong(long value,
                                        OutputStream out)
                                 throws IOException

Throws:

IOException

writeZigZagVarLong

public static void writeZigZagVarLong(long longValue,
                                      OutputStream out)
                               throws IOException

Throws:

IOException

paddedByteCountFromBits

public static int paddedByteCountFromBits(int bitLength)

Parameters:

bitLength - a count of bits

Returns:

the corresponding byte count padded to the next byte

intToBytes

public static byte[] intToBytes(int value)

bytesToInt

public static int bytesToInt(byte[] bytes)

longToBytes

public static byte[] longToBytes(long value)

bytesToLong

public static long bytesToLong(byte[] bytes)

booleanToBytes

public static byte[] booleanToBytes(boolean value)

bytesToBool

public static boolean bytesToBool(byte[] bytes)