neoneo-go/pkg/consensus/cache.go
2019-11-13 17:27:25 +03:00

60 lines
1 KiB
Go

package consensus
import (
"container/list"
"sync"
"github.com/CityOfZion/neo-go/pkg/util"
)
// relayCache is a payload cache which is used to store
// last consensus payloads.
type relayCache struct {
*sync.RWMutex
maxCap int
elems map[util.Uint256]*list.Element
queue *list.List
}
func newFIFOCache(capacity int) *relayCache {
return &relayCache{
RWMutex: new(sync.RWMutex),
maxCap: capacity,
elems: make(map[util.Uint256]*list.Element),
queue: list.New(),
}
}
// Add adds payload into a cache if it doesn't already exist.
func (c *relayCache) Add(p *Payload) {
c.Lock()
defer c.Unlock()
h := p.Hash()
if c.elems[h] != nil {
return
}
if c.queue.Len() >= c.maxCap {
first := c.queue.Front()
c.queue.Remove(first)
delete(c.elems, first.Value.(*Payload).Hash())
}
e := c.queue.PushBack(p)
c.elems[h] = e
}
// Get returns payload with the specified hash from cache.
func (c *relayCache) Get(h util.Uint256) *Payload {
c.RLock()
defer c.RUnlock()
e, ok := c.elems[h]
if !ok {
return nil
}
return e.Value.(*Payload)
}