/
kvs.go
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/
kvs.go
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//
// Copyright (C) 2019-2020 Vdaas.org Vald team ( kpango, rinx, kmrmt )
//
// Licensed 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
//
// https://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.
//
package kvs
import (
"context"
"sync"
"sync/atomic"
"unsafe"
xxhash "github.com/cespare/xxhash/v2"
)
type BidiMap interface {
Get(string) (uint32, bool)
GetInverse(uint32) (string, bool)
Set(string, uint32)
Delete(string) (uint32, bool)
DeleteInverse(uint32) (string, bool)
Range(ctx context.Context, f func(string, uint32) bool)
Len() uint64
}
type bidi struct {
ou [slen]*ou
uo [slen]*uo
l uint64
}
const (
// slen is shards length
slen = 512
// slen = 4096
// mask is slen-1 Hex value
mask = 0x1FF
// mask = 0xFFF
)
func New() BidiMap {
b := &bidi{
l: 0,
}
for i := range b.ou {
b.ou[i] = new(ou)
}
for i := range b.uo {
b.uo[i] = new(uo)
}
return b
}
func (b *bidi) Get(key string) (uint32, bool) {
return b.uo[xxhash.Sum64(*(*[]byte)(unsafe.Pointer(&key)))&mask].Load(key)
}
func (b *bidi) GetInverse(val uint32) (string, bool) {
return b.ou[val&mask].Load(val)
}
func (b *bidi) Set(key string, val uint32) {
b.uo[xxhash.Sum64(*(*[]byte)(unsafe.Pointer(&key)))&mask].Store(key, val)
b.ou[val&mask].Store(val, key)
atomic.AddUint64(&b.l, 1)
}
func (b *bidi) Delete(key string) (val uint32, ok bool) {
idx := xxhash.Sum64(*(*[]byte)(unsafe.Pointer(&key))) & mask
val, ok = b.uo[idx].Load(key)
if !ok {
return 0, false
}
b.uo[idx].Delete(key)
b.ou[val&mask].Delete(val)
atomic.AddUint64(&b.l, ^uint64(0))
return val, true
}
func (b *bidi) DeleteInverse(val uint32) (key string, ok bool) {
idx := val & mask
key, ok = b.ou[idx].Load(val)
if !ok {
return "", false
}
b.uo[xxhash.Sum64(*(*[]byte)(unsafe.Pointer(&key)))&mask].Delete(key)
b.ou[val&mask].Delete(val)
atomic.AddUint64(&b.l, ^uint64(0))
return key, true
}
func (b *bidi) Range(ctx context.Context, f func(string, uint32) bool) {
wg := new(sync.WaitGroup)
for i := range b.uo {
wg.Add(1)
go func(c context.Context, idx int) {
b.uo[idx].Range(func(uuid string, oid uint32) bool {
select {
case <-c.Done():
return false
default:
f(uuid, oid)
return true
}
})
wg.Done()
}(ctx, i)
}
wg.Wait()
}
func (b *bidi) Len() uint64 {
return atomic.LoadUint64(&b.l)
}