neo-go/pkg/consensus/cache.go
Elizaveta Chichindaeva 28908aa3cf [#2442] English Check
Signed-off-by: Elizaveta Chichindaeva <elizaveta@nspcc.ru>
2022-05-04 19:48:27 +03:00

73 lines
1.3 KiB
Go

package consensus
import (
"container/list"
"sync"
"github.com/nspcc-dev/neo-go/pkg/util"
)
// relayCache is 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
}
// hashable is the type of items which can be stored in the relayCache.
type hashable interface {
Hash() util.Uint256
}
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 cache if it doesn't already exist there.
func (c *relayCache) Add(p hashable) {
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.(hashable).Hash())
}
e := c.queue.PushBack(p)
c.elems[h] = e
}
// Has checks if the item is already in cache.
func (c *relayCache) Has(h util.Uint256) bool {
c.RLock()
defer c.RUnlock()
return c.elems[h] != nil
}
// Get returns payload with the specified hash from cache.
func (c *relayCache) Get(h util.Uint256) hashable {
c.RLock()
defer c.RUnlock()
e, ok := c.elems[h]
if !ok {
return hashable(nil)
}
return e.Value.(hashable)
}