de.lmu.ifi.dbs.elki.persistent
Class ByteArrayUtil

java.lang.Object
  de.lmu.ifi.dbs.elki.persistent.ByteArrayUtil

public final class ByteArrayUtil
extends Object

Class with various utilities for manipulating byte arrays. If you find a reusable copy of this in the Java API, please tell me. Using a ByteArrayOutputStream and DataInputStream doesn't seem appropriate. C.f. DataOutputStream and ByteArrayOutputStream

Nested Class Summary

static class	ByteArrayUtil.ByteSerializer Serializer for byte objects
static class	ByteArrayUtil.DoubleSerializer Serializer for double objects
static class	ByteArrayUtil.FloatSerializer Serializer for float objects
static class	ByteArrayUtil.IntegerSerializer Serializer for integer objects
static class	ByteArrayUtil.LongSerializer Serializer for long objects
static class	ByteArrayUtil.ShortSerializer Serializer for short objects
static class	ByteArrayUtil.StringSerializer Serializer for String objects
static class	ByteArrayUtil.VarintSerializer Serializer for Integer objects using a variable size encoding

Field Summary

static ByteArrayUtil.ByteSerializer	BYTE_SERIALIZER Static instance.
static ByteArrayUtil.DoubleSerializer	DOUBLE_SERIALIZER Static instance.
static ByteArrayUtil.FloatSerializer	FLOAT_SERIALIZER Static instance.
static ByteArrayUtil.IntegerSerializer	INT_SERIALIZER Static instance.
static ByteArrayUtil.LongSerializer	LONG_SERIALIZER Static instance.
static ByteArrayUtil.ShortSerializer	SHORT_SERIALIZER Static instance.
static int	SIZE_BYTE Size of a byte in bytes.
static int	SIZE_DOUBLE Size of a double in bytes.
static int	SIZE_FLOAT Size of a float in bytes.
static int	SIZE_INT Size of an integer in bytes.
static int	SIZE_LONG Size of a long in bytes.
static int	SIZE_SHORT Size of a short in bytes.
static ByteArrayUtil.StringSerializer	STRING_SERIALIZER Static instance.
static ByteArrayUtil.VarintSerializer	VARINT_SERIALIZER Static instance.

Constructor Summary

ByteArrayUtil()

Method Summary

static int	getSignedVarintLongSize(long val) Compute the size of the varint encoding for this signed integer
static int	getSignedVarintSize(int val) Compute the size of the varint encoding for this signed integer
static int	getUnsignedVarintLongSize(long obj) Compute the size of the varint encoding for this unsigned integer
static int	getUnsignedVarintSize(int obj) Compute the size of the varint encoding for this unsigned integer
static double	readDouble(byte[] array, int offset) Read a double from the byte array at the given offset.
static float	readFloat(byte[] array, int offset) Read a float from the byte array at the given offset.
static int	readInt(byte[] array, int offset) Read an integer from the byte array at the given offset.
static long	readLong(byte[] array, int offset) Read a long from the byte array at the given offset.
static short	readShort(byte[] array, int offset) Read a short from the byte array at the given offset.
static int	readSignedVarint(ByteBuffer buffer) Read a signed integer.
static long	readSignedVarintLong(ByteBuffer buffer) Read a signed long.
static int	readUnsignedShort(byte[] array, int offset) Read an unsigned short from the byte array at the given offset.
static int	readUnsignedVarint(ByteBuffer buffer) Read an unsigned integer.
static long	readUnsignedVarintLong(ByteBuffer buffer) Read an unsigned long.
static void	unmapByteBuffer(MappedByteBuffer map) Unmap a byte buffer.
static int	writeDouble(byte[] array, int offset, double v) Write a double to the byte array at the given offset.
static int	writeFloat(byte[] array, int offset, float v) Write a float to the byte array at the given offset.
static int	writeInt(byte[] array, int offset, int v) Write an integer to the byte array at the given offset.
static int	writeLong(byte[] array, int offset, long v) Write a long to the byte array at the given offset.
static int	writeShort(byte[] array, int offset, int v) Write a short to the byte array at the given offset.
static void	writeSignedVarint(ByteBuffer buffer, int val) Write an signed integer using a variable-length encoding.
static void	writeSignedVarintLong(ByteBuffer buffer, long val) Write a signed long using a variable-length encoding.
static void	writeUnsignedVarint(ByteBuffer buffer, int val) Write an unsigned integer using a variable-length encoding.
static void	writeUnsignedVarintLong(ByteBuffer buffer, long val) Write an unsigned long using a variable-length encoding.

Methods inherited from class java.lang.Object

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

Field Detail

SIZE_BYTE

public static final int SIZE_BYTE

Size of a byte in bytes.

See Also:

Constant Field Values

SIZE_SHORT

public static final int SIZE_SHORT

Size of a short in bytes.

See Also:

Constant Field Values

SIZE_INT

public static final int SIZE_INT

Size of an integer in bytes.

See Also:

Constant Field Values

SIZE_LONG

public static final int SIZE_LONG

Size of a long in bytes.

See Also:

Constant Field Values

SIZE_FLOAT

public static final int SIZE_FLOAT

Size of a float in bytes.

See Also:

Constant Field Values

SIZE_DOUBLE

public static final int SIZE_DOUBLE

Size of a double in bytes.

See Also:

Constant Field Values

BYTE_SERIALIZER

public static final ByteArrayUtil.ByteSerializer BYTE_SERIALIZER

Static instance.

SHORT_SERIALIZER

public static final ByteArrayUtil.ShortSerializer SHORT_SERIALIZER

Static instance.

INT_SERIALIZER

public static final ByteArrayUtil.IntegerSerializer INT_SERIALIZER

Static instance.

LONG_SERIALIZER

public static final ByteArrayUtil.LongSerializer LONG_SERIALIZER

Static instance.

FLOAT_SERIALIZER

public static final ByteArrayUtil.FloatSerializer FLOAT_SERIALIZER

Static instance.

DOUBLE_SERIALIZER

public static final ByteArrayUtil.DoubleSerializer DOUBLE_SERIALIZER

Static instance.

STRING_SERIALIZER

public static final ByteArrayUtil.StringSerializer STRING_SERIALIZER

Static instance.

VARINT_SERIALIZER

public static final ByteArrayUtil.VarintSerializer VARINT_SERIALIZER

Static instance.

Constructor Detail

ByteArrayUtil

public ByteArrayUtil()

Method Detail

writeShort

public static final int writeShort(byte[] array,
                                   int offset,
                                   int v)

Write a short to the byte array at the given offset.

Parameters:

array - Array to write to

offset - Offset to write to

v - data

Returns:

number of bytes written

writeInt

public static final int writeInt(byte[] array,
                                 int offset,
                                 int v)

Write an integer to the byte array at the given offset.

Parameters:

array - Array to write to

offset - Offset to write to

v - data

Returns:

number of bytes written

writeLong

public static final int writeLong(byte[] array,
                                  int offset,
                                  long v)

Write a long to the byte array at the given offset.

Parameters:

array - Array to write to

offset - Offset to write to

v - data

Returns:

number of bytes written

writeFloat

public static final int writeFloat(byte[] array,
                                   int offset,
                                   float v)

Write a float to the byte array at the given offset.

Parameters:

array - Array to write to

offset - Offset to write to

v - data

Returns:

number of bytes written

writeDouble

public static final int writeDouble(byte[] array,
                                    int offset,
                                    double v)

Write a double to the byte array at the given offset.

Parameters:

array - Array to write to

offset - Offset to write to

v - data

Returns:

number of bytes written

readShort

public static final short readShort(byte[] array,
                                    int offset)

Read a short from the byte array at the given offset.

Parameters:

array - Array to read from

offset - Offset to read at

Returns:

(signed) short

readUnsignedShort

public static final int readUnsignedShort(byte[] array,
                                          int offset)

Read an unsigned short from the byte array at the given offset.

Parameters:

array - Array to read from

offset - Offset to read at

Returns:

short

readInt

public static final int readInt(byte[] array,
                                int offset)

Read an integer from the byte array at the given offset.

Parameters:

array - Array to read from

offset - Offset to read at

Returns:

data

readLong

public static final long readLong(byte[] array,
                                  int offset)

Read a long from the byte array at the given offset.

Parameters:

array - Array to read from

offset - Offset to read at

Returns:

data

readFloat

public static final float readFloat(byte[] array,
                                    int offset)

Read a float from the byte array at the given offset.

Parameters:

array - Array to read from

offset - Offset to read at

Returns:

data

readDouble

public static final double readDouble(byte[] array,
                                      int offset)

Read a double from the byte array at the given offset.

Parameters:

array - Array to read from

offset - Offset to read at

Returns:

data

writeSignedVarint

public static final void writeSignedVarint(ByteBuffer buffer,
                                           int val)

Write an signed integer using a variable-length encoding. The sign bit is moved to bit 0. Data is always written in 7-bit little-endian, where the 8th bit is the continuation flag.

Parameters:

buffer - Buffer to write to

val - number to write

writeSignedVarintLong

public static final void writeSignedVarintLong(ByteBuffer buffer,
                                               long val)

Write a signed long using a variable-length encoding. The sign bit is moved to bit 0. Data is always written in 7-bit little-endian, where the 8th bit is the continuation flag.

Parameters:

buffer - Buffer to write to

val - number to write

writeUnsignedVarint

public static final void writeUnsignedVarint(ByteBuffer buffer,
                                             int val)

Write an unsigned integer using a variable-length encoding. Data is always written in 7-bit little-endian, where the 8th bit is the continuation flag.

Parameters:

buffer - Buffer to write to

val - number to write

writeUnsignedVarintLong

public static final void writeUnsignedVarintLong(ByteBuffer buffer,
                                                 long val)

Write an unsigned long using a variable-length encoding. Data is always written in 7-bit little-endian, where the 8th bit is the continuation flag. Note that for integers, this will result in the same encoding as writeUnsignedVarint(java.nio.ByteBuffer, int)

Parameters:

buffer - Buffer to write to

val - number to write

getSignedVarintSize

public static final int getSignedVarintSize(int val)

Compute the size of the varint encoding for this signed integer

Parameters:

val - integer to write

Returns:

Encoding size of this integer

getUnsignedVarintSize

public static final int getUnsignedVarintSize(int obj)

Compute the size of the varint encoding for this unsigned integer

Parameters:

obj - integer to write

Returns:

Encoding size of this integer

getSignedVarintLongSize

public static final int getSignedVarintLongSize(long val)

Compute the size of the varint encoding for this signed integer

Parameters:

val - integer to write

Returns:

Encoding size of this integer

getUnsignedVarintLongSize

public static final int getUnsignedVarintLongSize(long obj)

Compute the size of the varint encoding for this unsigned integer

Parameters:

obj - integer to write

Returns:

Encoding size of this integer

readSignedVarint

public static final int readSignedVarint(ByteBuffer buffer)

Read a signed integer.

Parameters:

buffer - Buffer to read from

Returns:

Integer value

readUnsignedVarint

public static final int readUnsignedVarint(ByteBuffer buffer)

Read an unsigned integer.

Parameters:

buffer - Buffer to read from

Returns:

Integer value

readSignedVarintLong

public static final long readSignedVarintLong(ByteBuffer buffer)

Read a signed long.

Parameters:

buffer - Buffer to read from

Returns:

long value

readUnsignedVarintLong

public static final long readUnsignedVarintLong(ByteBuffer buffer)

Read an unsigned long.

Parameters:

buffer - Buffer to read from

Returns:

long value

unmapByteBuffer

public static void unmapByteBuffer(MappedByteBuffer map)

Unmap a byte buffer.

Parameters:

map - Byte buffer to unmap.