com.facebook.presto.hive.zorder

Class ZOrder

java.lang.Object

com.facebook.presto.hive.zorder.ZOrder

public class ZOrder
extends Object

The ZOrder class provides functions to map data from multiple columns of a table to a single dimensional z-address (encode) and vice versa (decode), while preserving data locality for multidimensional value combinations.

Field Summary

Fields

Modifier and Type	Field and Description
static int	MAX_INPUT_DIMENSIONS

Constructor Summary

Constructors

Constructor and Description
ZOrder(List<Integer> encodingBits)
ZOrder(List<Integer> encodingBits, boolean positiveIntegersOnly) Class constructor specifying the number of bits each value will take up for encoding and decoding.

Method Summary

Modifier and Type	Method and Description
List<Integer>	decode(byte[] address) Decodes the z-address into its corresponding input list.
List<Integer>	decode(int address) Decodes the z-address into its corresponding input list.
List<Integer>	decode(long address) Decodes the z-address into its corresponding input list.
byte[]	encodeToByteArray(List<Integer> input) Encodes the input list into its corresponding z-address and returns a byte array, with the least significant bit at index 0.
int	encodeToInteger(List<Integer> input) Encodes the input list into its corresponding z-address and returns an integer.
long	encodeToLong(List<Integer> input) Encodes the input list into its corresponding z-address and returns a long.
long	zOrderByteAddressToLong(byte[] byteAddress) Converts the byte array representation of a z-address into its long representation.
byte[]	zOrderLongToByteAddress(long address) Converts the long representation of a z-address into its byte array representation.
List<ZAddressRange<Integer>>	zOrderSearchCurveIntegers(List<ZValueRange> ranges) Searches for and outputs ranges of integer addresses within certain ranges in each dimension.
List<ZAddressRange<Long>>	zOrderSearchCurveLongs(List<ZValueRange> ranges) Searches for and outputs ranges of long addresses within certain ranges in each dimension.

Methods inherited from class java.lang.Object

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

Field Detail

MAX_INPUT_DIMENSIONS

public static final int MAX_INPUT_DIMENSIONS

See Also:

Constant Field Values

Constructor Detail

ZOrder

public ZOrder(List<Integer> encodingBits,
              boolean positiveIntegersOnly)

Class constructor specifying the number of bits each value will take up for encoding and decoding.

ZOrder

public ZOrder(List<Integer> encodingBits)

Method Detail

encodeToByteArray

public byte[] encodeToByteArray(List<Integer> input)

Encodes the input list into its corresponding z-address and returns a byte array, with the least significant bit at index 0.

encode interweaves the bit representations of the input values from the most significant bit to create the final z-address.

For example: for a list of (7, 128) = (0b00000111, 0b10000000), encode returns a z-address of 16426 = 0b0100000000101010.

Parameters:

input - the list of integer values to be encoded

Returns:

the byte array representation of the z-address

encodeToLong

public long encodeToLong(List<Integer> input)

Encodes the input list into its corresponding z-address and returns a long.

Parameters:

input - the list of integer values to be encoded

Returns:

the long representation of the z-address

encodeToInteger

public int encodeToInteger(List<Integer> input)

Encodes the input list into its corresponding z-address and returns an integer.

Parameters:

input - the list of integer values to be encoded

Returns:

the integer representation of the z-address

decode

public List<Integer> decode(byte[] address)

Decodes the z-address into its corresponding input list.

For example: for a z-address of 16426 = 0b0100000000101010, decode returns a list of (7, 128) = (0b00000111, 0b10000000).

Parameters:

address - the byte address representation of the z-address

Returns:

the list of integer values that were encoded

decode

public List<Integer> decode(long address)

Decodes the z-address into its corresponding input list.

Parameters:

address - the long representation of the z-address

Returns:

the list of integer values that were encoded

decode

public List<Integer> decode(int address)

Decodes the z-address into its corresponding input list.

Parameters:

address - the integer representation of the z-address

Returns:

the list of integer values that were encoded

zOrderByteAddressToLong

public long zOrderByteAddressToLong(byte[] byteAddress)

Converts the byte array representation of a z-address into its long representation.

Parameters:

byteAddress - the byte array representation of the z-address

Returns:

the long representation of the z-address

zOrderLongToByteAddress

public byte[] zOrderLongToByteAddress(long address)

Converts the long representation of a z-address into its byte array representation.

Parameters:

address - the long representation of the z-address

Returns:

the byte array representation of the z-address

zOrderSearchCurveLongs

public List<ZAddressRange<Long>> zOrderSearchCurveLongs(List<ZValueRange> ranges)

Searches for and outputs ranges of long addresses within certain ranges in each dimension.

zOrderSearchCurveIntegers

public List<ZAddressRange<Integer>> zOrderSearchCurveIntegers(List<ZValueRange> ranges)

Searches for and outputs ranges of integer addresses within certain ranges in each dimension.