Documentation
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Index ¶
- func OptimalK(fpRate float64) uint
- func OptimalM(n uint, fpRate float64) uint
- type Buckets
- func (b *Buckets) Count() uint
- func (b *Buckets) Get(bucket uint) uint32
- func (b *Buckets) GobDecode(data []byte) error
- func (b *Buckets) GobEncode() ([]byte, error)
- func (b *Buckets) Increment(bucket uint, delta int32) *Buckets
- func (b *Buckets) MaxBucketValue() uint8
- func (b *Buckets) ReadFrom(stream io.Reader) (int64, error)
- func (b *Buckets) Reset() *Buckets
- func (b *Buckets) Set(bucket uint, value uint8) *Buckets
- func (b *Buckets) WriteTo(stream io.Writer) (int64, error)
- type CountingBloomFilter
- func (c *CountingBloomFilter) Add(data []byte) Filter
- func (c *CountingBloomFilter) Capacity() uint
- func (c *CountingBloomFilter) Count() uint
- func (c *CountingBloomFilter) K() uint
- func (c *CountingBloomFilter) Reset() *CountingBloomFilter
- func (c *CountingBloomFilter) SetHash(h hash.Hash64)
- func (c *CountingBloomFilter) Test(data []byte) bool
- func (c *CountingBloomFilter) TestAndAdd(data []byte) bool
- func (c *CountingBloomFilter) TestAndRemove(data []byte) bool
- type Filter
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
Types ¶
type Buckets ¶
type Buckets struct {
// contains filtered or unexported fields
}
Buckets is a fast, space-efficient array of buckets where each bucket can store up to a configured maximum value.
func NewBuckets ¶
NewBuckets creates a new Buckets with the provided number of buckets where each bucket is the specified number of bits.
func (*Buckets) Increment ¶
Increment will increment the value in the specified bucket by the provided delta. A bucket can be decremented by providing a negative delta. The value is clamped to zero and the maximum bucket value. Returns itself to allow for chaining.
func (*Buckets) MaxBucketValue ¶
MaxBucketValue returns the maximum value that can be stored in a bucket.
func (*Buckets) ReadFrom ¶
ReadFrom reads a binary representation of Buckets (such as might have been written by WriteTo()) from an i/o stream. It returns the number of bytes read.
func (*Buckets) Reset ¶
Reset restores the Buckets to the original state. Returns itself to allow for chaining.
type CountingBloomFilter ¶
type CountingBloomFilter struct {
// contains filtered or unexported fields
}
func NewCountingBloomFilter ¶
func NewCountingBloomFilter(n uint, b uint8, fpRate float64) *CountingBloomFilter
NewCountingBloomFilter creates a new Counting Bloom Filter optimized to store n items with a specified target false-positive rate and bucket size. If you don't know how many bits to use for buckets, use NewDefaultCountingBloomFilter for a sensible default.
func NewDefaultCountingBloomFilter ¶
func NewDefaultCountingBloomFilter(n uint, fpRate float64) *CountingBloomFilter
NewDefaultCountingBloomFilter creates a new Counting Bloom Filter optimized to store n items with a specified target false-positive rate. Buckets are allocated four bits.
func (*CountingBloomFilter) Add ¶
func (c *CountingBloomFilter) Add(data []byte) Filter
Add will add the data to the Bloom filter. It returns the filter to allow for chaining.
func (*CountingBloomFilter) Capacity ¶
func (c *CountingBloomFilter) Capacity() uint
Capacity returns the Bloom filter capacity, m.
func (*CountingBloomFilter) Count ¶
func (c *CountingBloomFilter) Count() uint
Count returns the number of items in the filter.
func (*CountingBloomFilter) K ¶
func (c *CountingBloomFilter) K() uint
K returns the number of hash functions.
func (*CountingBloomFilter) Reset ¶
func (c *CountingBloomFilter) Reset() *CountingBloomFilter
Reset restores the Bloom filter to its original state. It returns the filter to allow for chaining.
func (*CountingBloomFilter) SetHash ¶
func (c *CountingBloomFilter) SetHash(h hash.Hash64)
SetHash sets the hashing function used in the filter. For the effect on false positive rates see: https://github.com/tylertreat/BoomFilters/pull/1
func (*CountingBloomFilter) Test ¶
func (c *CountingBloomFilter) Test(data []byte) bool
Test will test for membership of the data and returns true if it is a member, false if not. This is a probabilistic test, meaning there is a non-zero probability of false positives and false negatives.
func (*CountingBloomFilter) TestAndAdd ¶
func (c *CountingBloomFilter) TestAndAdd(data []byte) bool
TestAndAdd is equivalent to calling Test followed by Add. It returns true if the data is a member, false if not.
func (*CountingBloomFilter) TestAndRemove ¶
func (c *CountingBloomFilter) TestAndRemove(data []byte) bool
TestAndRemove will test for membership of the data and remove it from the filter if it exists. Returns true if the data was a member, false if not.
type Filter ¶
type Filter interface {
// Test will test for membership of the data and returns true if it is a
// member, false if not.
Test([]byte) bool
// Add will add the data to the Bloom filter. It returns the filter to
// allow for chaining.
Add([]byte) Filter
// TestAndAdd is equivalent to calling Test followed by Add. It returns
// true if the data is a member, false if not.
TestAndAdd([]byte) bool
}
Filter is a probabilistic data structure which is used to test the membership of an element in a set.
Source Files