hll

Documentation

Overview

• This file from
• https://github.com/addthis/stream-lib/blob/master/src/main/java/com/clearspring/analytics/hash/MurmurHash.java *
• This class modified by Scouter-Project * - original package : com.clearspring.analytics.hash *

*

• Licensed to the Apache Software Foundation (ASF) under one or more
• contributor license agreements. See the NOTICE file distributed with this
• work for additional information regarding copyright ownership. The ASF
• licenses this file to you under the Apache License, Version 2.0 (the
• "License"); you may not use this file except in compliance with the License.
• You may obtain a copy of the License at *
• http://www.apache.org/licenses/LICENSE-2.0 *
• Unless required by applicable law or agreed to in writing, software
• distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
• WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
• License for the specific language governing permissions and limitations under
• the License. *

*

• This is a very fast, non-cryptographic hash suitable for general hash-based
• lookup. See http://murmurhash.googlepages.com/ for more details.
• <p/>
• <p>
• The C version of MurmurHash 2.0 found at that site was ported to Java by
• Andrzej Bialecki (ab at getopt org).
• </p>

Index

• Constants
• func MurmurHash(o uint32) uint32
• func MurmurHashByte(data []byte) uint32
• func MurmurHashByteSeed(data []byte, seed uint32) uint32
• func MurmurHashLong(data uint64) uint32
• func MurmurHashLongByte(data []byte, length int32) uint64
• func Round(val float64) int64
• type HyperLogLog
  • func BuildHyperLogLog(bytes []byte) *HyperLogLog
  • func NewHyperLogLog(log2m uint32, registerSet *RegisterSet) *HyperLogLog
  • func NewHyperLogLogDefault() *HyperLogLog
  • func NewHyperLogLogFloat(Rsd float64) *HyperLogLog
  • func NewHyperLogLogInt(log2m uint32) *HyperLogLog
  • func (this *HyperLogLog) AddAll(other *HyperLogLog)
  • func (this *HyperLogLog) Cardinality() uint64
  • func (this *HyperLogLog) GetBytes() []byte
  • func (this *HyperLogLog) Merge(estimators ...*HyperLogLog) *HyperLogLog
  • func (this *HyperLogLog) Offer(o uint32) bool
  • func (this *HyperLogLog) OfferLong(o uint64) bool
  • func (this *HyperLogLog) Sizeof() int
• type RegisterSet
  • func NewRegisterSet(count int) *RegisterSet
  • func NewRegisterSetInit(count int, initialValues []uint32) *RegisterSet
  • func (this *RegisterSet) Bits() []uint32
  • func (this *RegisterSet) Get(position int) uint32
  • func (this *RegisterSet) Merge(that *RegisterSet)
  • func (this *RegisterSet) ReadOnlyBits() []uint32
  • func (this *RegisterSet) Set(position, value uint32)
  • func (this *RegisterSet) UpdateIfGreater(position, value uint32) bool

Constants

const (
	LOG2_BITS_PER_WORD = 6
	REGISTER_SIZE      = 5
)

Functions

func MurmurHash

func MurmurHash(o uint32) uint32

func MurmurHash(Object o) int {
       if (o == null) {
           return 0;
       }
       if (o instanceof Long) {
           return hashLong((Long) o);
       }
       if (o instanceof Integer) {
           return hashLong((Integer) o);
       }
       if (o instanceof Double) {
           return hashLong(Double.doubleToRawLongBits((Double) o));
       }
       if (o instanceof Float) {
           return hashLong(Float.floatToRawIntBits((Float) o));
       }
       if (o instanceof String) {
           return hash(((String) o).getBytes());
       }
       if (o instanceof byte[]) {
           return hash((byte[]) o);
       }

       return hash(o.toString());
   }

func MurmurHashByte

func MurmurHashByte(data []byte) uint32

func MurmurHashByteSeed

func MurmurHashByteSeed(data []byte, seed uint32) uint32

func MurmurHashLong

func MurmurHashLong(data uint64) uint32

func MurmurHashLongByte

func MurmurHashLongByte(data []byte, length int32) uint64

func MurmurHash64(Object o) int64 {
       if (o == null) {
           return 0l;
       } else if (o instanceof String) {
           final byte[] bytes = ((String) o).getBytes();
           return hash64(bytes, bytes.length);
       } else if (o instanceof byte[]) {
           final byte[] bytes = (byte[]) o;
           return hash64(bytes, bytes.length);
       }
       return hash64(o.toString());
   }

64 bit implementation copied from here: https://github.com/tnm/murmurhash-java *

• Generates 64 bit hash from byte array with default seed value. *
• @param data byte array to hash
• @param length length of the array to hash
• @return 64 bit hash of the given string

func Round

func Round(val float64) int64

Types

type HyperLogLog

type HyperLogLog struct {
	// contains filtered or unexported fields
}

func BuildHyperLogLog

func BuildHyperLogLog(bytes []byte) *HyperLogLog

* Initial code from HyperLogLog.Builder.build() * by Scouter-Project

func NewHyperLogLog

func NewHyperLogLog(log2m uint32, registerSet *RegisterSet) *HyperLogLog

*

• Creates a new HyperLogLog instance using the given registers. Used for

• unmarshalling a serialized instance and for merging multiple counters

• together. *

• @param registerSet

• - the initial values for the register set

  @Deprecated

func NewHyperLogLogDefault

func NewHyperLogLogDefault() *HyperLogLog

func NewHyperLogLogFloat

func NewHyperLogLogFloat(Rsd float64) *HyperLogLog

*

• Create a new HyperLogLog instance using the specified standard deviation. *
• @param rsd
• - the relative standard deviation for the counter. smaller
• values create counters that require more space.

func NewHyperLogLogInt

func NewHyperLogLogInt(log2m uint32) *HyperLogLog

*

• Create a new HyperLogLog instance. The log2m parameter defines the
• accuracy of the counter. The larger the log2m the better the accuracy.
• <p/>
• accuracy = 1.04/sqrt(2^log2m) *
• @param log2m
• - the number of bits to use as the basis for the HLL instance

func (*HyperLogLog) AddAll

func (this *HyperLogLog) AddAll(other *HyperLogLog)

*

• Add all the elements of the other set to this set.
• <p/>
• This operation does not imply a loss of precision. *
• @param other
• A compatible Hyperloglog instance (same log2m)
• @throws CardinalityMergeException
• if other is not compatible

func (*HyperLogLog) Cardinality

func (this *HyperLogLog) Cardinality() uint64

func (*HyperLogLog) GetBytes

func (this *HyperLogLog) GetBytes() []byte

* This method is modified by Souter-pcode *

func (*HyperLogLog) Merge

func (this *HyperLogLog) Merge(estimators ...*HyperLogLog) *HyperLogLog

func (*HyperLogLog) Offer

func (this *HyperLogLog) Offer(o uint32) bool

public boolean offer(Object o) {
		final int x = MurmurHash.hash(o);
		return offerHashed(x);
	}

func (*HyperLogLog) OfferLong

func (this *HyperLogLog) OfferLong(o uint64) bool

func (*HyperLogLog) Sizeof

func (this *HyperLogLog) Sizeof() int

type RegisterSet

type RegisterSet struct {
	Count int
	Size  int
	M     []uint32
}

func NewRegisterSet

func NewRegisterSet(count int) *RegisterSet

func NewRegisterSetInit

func NewRegisterSetInit(count int, initialValues []uint32) *RegisterSet

func (*RegisterSet) Bits

func (this *RegisterSet) Bits() []uint32

func (*RegisterSet) Get

func (this *RegisterSet) Get(position int) uint32

func (*RegisterSet) Merge

func (this *RegisterSet) Merge(that *RegisterSet)

func (*RegisterSet) ReadOnlyBits

func (this *RegisterSet) ReadOnlyBits() []uint32

func (*RegisterSet) Set

func (this *RegisterSet) Set(position, value uint32)

func (*RegisterSet) UpdateIfGreater

func (this *RegisterSet) UpdateIfGreater(position, value uint32) bool