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Rename gcsFilter type to GCSFilter to export it.

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Alex 2017-01-17 14:42:41 -07:00 committed by Olaoluwa Osuntokun
parent 3069dcf175
commit 684cf07725
1 changed files with 12 additions and 12 deletions
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24
gcs/gcs.go
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@ -34,7 +34,7 @@ const (
KeySize = 16 KeySize = 16
) )
// gcsFilter describes an immutable filter that can be built from // GCSFilter describes an immutable filter that can be built from
// a set of data elements, serialized, deserialized, and queried // a set of data elements, serialized, deserialized, and queried
// in a thread-safe manner. The serialized form is compressed as // in a thread-safe manner. The serialized form is compressed as
// a Golomb Coded Set (GCS), but does not include N or P to allow // a Golomb Coded Set (GCS), but does not include N or P to allow
@ -42,7 +42,7 @@ const (
// hash function used is SipHash, a keyed function; the key used // hash function used is SipHash, a keyed function; the key used
// in building the filter is required in order to match filter // in building the filter is required in order to match filter
// values and is not included in the serialized form. // values and is not included in the serialized form.
type gcsFilter struct { type GCSFilter struct {
n uint32 n uint32
p uint8 p uint8
modulusP uint64 modulusP uint64
@ -54,7 +54,7 @@ type gcsFilter struct {
// `1/(2**P)`, key `key`, and including every `[]byte` in `data` as a member of // `1/(2**P)`, key `key`, and including every `[]byte` in `data` as a member of
// the set. // the set.
func BuildGCSFilter(P uint8, key [KeySize]byte, func BuildGCSFilter(P uint8, key [KeySize]byte,
data [][]byte) (*gcsFilter, error) { data [][]byte) (*GCSFilter, error) {
// Some initial parameter checks: make sure we have data from which to // Some initial parameter checks: make sure we have data from which to
// build the filter, and make sure our parameters will fit the hash // build the filter, and make sure our parameters will fit the hash
@ -70,7 +70,7 @@ func BuildGCSFilter(P uint8, key [KeySize]byte,
} }
// Create the filter object and insert metadata. // Create the filter object and insert metadata.
f := gcsFilter{ f := GCSFilter{
n: uint32(len(data)), n: uint32(len(data)),
p: P, p: P,
} }
@ -119,7 +119,7 @@ func BuildGCSFilter(P uint8, key [KeySize]byte,
// FromBytes deserializes a GCS filter from a known N, P, and serialized // FromBytes deserializes a GCS filter from a known N, P, and serialized
// filter as returned by Bytes(). // filter as returned by Bytes().
func FromBytes(N uint32, P uint8, d []byte) (*gcsFilter, error) { func FromBytes(N uint32, P uint8, d []byte) (*GCSFilter, error) {
// Basic sanity check. // Basic sanity check.
if P > 32 { if P > 32 {
@ -127,7 +127,7 @@ func FromBytes(N uint32, P uint8, d []byte) (*gcsFilter, error) {
} }
// Create the filter object and insert metadata. // Create the filter object and insert metadata.
f := &gcsFilter{ f := &GCSFilter{
n: N, n: N,
p: P, p: P,
} }
@ -142,7 +142,7 @@ func FromBytes(N uint32, P uint8, d []byte) (*gcsFilter, error) {
// Bytes returns the serialized format of the GCS filter, which does not // Bytes returns the serialized format of the GCS filter, which does not
// include N or P (returned by separate methods) or the key used by SipHash. // include N or P (returned by separate methods) or the key used by SipHash.
func (f *gcsFilter) Bytes() []byte { func (f *GCSFilter) Bytes() []byte {
filterData := make([]byte, len(f.filterData)) filterData := make([]byte, len(f.filterData))
copy(filterData, f.filterData) copy(filterData, f.filterData)
return filterData return filterData
@ -150,18 +150,18 @@ func (f *gcsFilter) Bytes() []byte {
// P returns the filter's collision probability as a negative power of 2 (that // P returns the filter's collision probability as a negative power of 2 (that
// is, a collision probability of `1/2**20` is represented as 20). // is, a collision probability of `1/2**20` is represented as 20).
func (f *gcsFilter) P() uint8 { func (f *GCSFilter) P() uint8 {
return f.p return f.p
} }
// N returns the size of the data set used to build the filter. // N returns the size of the data set used to build the filter.
func (f *gcsFilter) N() uint32 { func (f *GCSFilter) N() uint32 {
return f.n return f.n
} }
// Match checks whether a []byte value is likely (within collision // Match checks whether a []byte value is likely (within collision
// probability) to be a member of the set represented by the filter. // probability) to be a member of the set represented by the filter.
func (f *gcsFilter) Match(key [KeySize]byte, data []byte) (bool, error) { func (f *GCSFilter) Match(key [KeySize]byte, data []byte) (bool, error) {
// Create a filter bitstream. // Create a filter bitstream.
filterData := f.Bytes() filterData := f.Bytes()
@ -195,7 +195,7 @@ func (f *gcsFilter) Match(key [KeySize]byte, data []byte) (bool, error) {
// MatchAny returns checks whether any []byte value is likely (within // MatchAny returns checks whether any []byte value is likely (within
// collision probability) to be a member of the set represented by the // collision probability) to be a member of the set represented by the
// filter faster than calling Match() for each value individually. // filter faster than calling Match() for each value individually.
func (f *gcsFilter) MatchAny(key [KeySize]byte, data [][]byte) (bool, error) { func (f *GCSFilter) MatchAny(key [KeySize]byte, data [][]byte) (bool, error) {
// Basic sanity check. // Basic sanity check.
if len(data) == 0 { if len(data) == 0 {
@ -252,7 +252,7 @@ func (f *gcsFilter) MatchAny(key [KeySize]byte, data [][]byte) (bool, error) {
// readFullUint64 reads a value represented by the sum of a unary multiple // readFullUint64 reads a value represented by the sum of a unary multiple
// of the filter's P modulus (`2**P`) and a big-endian P-bit remainder. // of the filter's P modulus (`2**P`) and a big-endian P-bit remainder.
func (f *gcsFilter) readFullUint64(b *bstream.BStream) (uint64, error) { func (f *GCSFilter) readFullUint64(b *bstream.BStream) (uint64, error) {
var v uint64 var v uint64
// Count the 1s until we reach a 0. // Count the 1s until we reach a 0.