tech.mlsql.tool

Class ZOrderingBytesUtil

java.lang.Object

tech.mlsql.tool.ZOrderingBytesUtil

public class ZOrderingBytesUtil
extends Object

所有列都表示为为8byte 我们限制z-ordering最大支持1024byte, 这意味着一个z-ordering 索引最多1024/8=128个字段。

Field Summary

Fields

Modifier and Type	Field and Description
static int	SIZEOF_LONG

Constructor Summary

Constructors

Constructor and Description
ZOrderingBytesUtil()

Method Summary

Modifier and Type	Method and Description
static int	compareTo(byte[] buffer1, int offset1, int length1, byte[] buffer2, int offset2, int length2)
static byte[]	doubleTo8Byte(double a) 1.先得到byte[]表示。 2.如果是正数，翻转第一个bit 3.如果是负数，翻转所有的bit 此时可以自然排序
static byte[]	interleave8Byte(byte[] buffer1, byte[] buffer2) buffer1,buffer2 必须是8字节，最后输出是16字节 buffer2的值在奇数位
static byte[]	interleaveByte(byte x, byte y) x在奇数位,y在偶数位
static byte[]	interleaveMulti8Byte(byte[][] buffer)
static byte[]	intTo8Byte(int a)
static byte[]	longTo8Byte(long a)
static byte[]	toBytes(double d)
static byte[]	toBytes(int val)
static byte[]	toBytes(long val)
static String	toString(byte[] b)
static byte	updatePos(byte a, int apos, byte b, int bpos)
static byte[]	utf8To8Byte(String a)

Methods inherited from class java.lang.Object

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

Field Detail

SIZEOF_LONG

public static final int SIZEOF_LONG

See Also:

Constant Field Values

Constructor Detail

ZOrderingBytesUtil

public ZOrderingBytesUtil()

Method Detail

toBytes

public static byte[] toBytes(int val)

toBytes

public static byte[] toBytes(long val)

intTo8Byte

public static byte[] intTo8Byte(int a)

longTo8Byte

public static byte[] longTo8Byte(long a)

toBytes

public static byte[] toBytes(double d)

doubleTo8Byte

public static byte[] doubleTo8Byte(double a)

1.先得到byte[]表示。 2.如果是正数，翻转第一个bit 3.如果是负数，翻转所有的bit 此时可以自然排序

utf8To8Byte

public static byte[] utf8To8Byte(String a)

interleave8Byte

public static byte[] interleave8Byte(byte[] buffer1,
                                     byte[] buffer2)

buffer1,buffer2 必须是8字节，最后输出是16字节 buffer2的值在奇数位

updatePos

public static byte updatePos(byte a,
                             int apos,
                             byte b,
                             int bpos)

interleaveMulti8Byte

public static byte[] interleaveMulti8Byte(byte[][] buffer)

interleaveByte

public static byte[] interleaveByte(byte x,
                                    byte y)

x在奇数位,y在偶数位

toString

public static String toString(byte[] b)

compareTo

public static int compareTo(byte[] buffer1,
                            int offset1,
                            int length1,
                            byte[] buffer2,
                            int offset2,
                            int length2)