prysm-pulse/beacon-chain/cache/checkpoint_state.go
2019-08-29 09:36:43 -05:00

115 lines
3.2 KiB
Go

package cache
import (
"errors"
"sync"
"github.com/gogo/protobuf/proto"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promauto"
pb "github.com/prysmaticlabs/prysm/proto/beacon/p2p/v1"
ethpb "github.com/prysmaticlabs/prysm/proto/eth/v1alpha1"
"github.com/prysmaticlabs/prysm/shared/hashutil"
"k8s.io/client-go/tools/cache"
)
var (
// ErrNotCheckpointState will be returned when a cache object is not a pointer to
// a CheckpointState struct.
ErrNotCheckpointState = errors.New("object is not a state by check point struct")
// maxCheckpointStateSize defines the max number of entries check point to state cache can contain.
maxCheckpointStateSize = 4
// Metrics.
checkpointStateMiss = promauto.NewCounter(prometheus.CounterOpts{
Name: "check_point_statecache_miss",
Help: "The number of check point state requests that aren't present in the cache.",
})
checkpointStateHit = promauto.NewCounter(prometheus.CounterOpts{
Name: "check_point_state_cache_hit",
Help: "The number of check point state requests that are present in the cache.",
})
)
// CheckpointState defines the active validator indices per epoch.
type CheckpointState struct {
Checkpoint *ethpb.Checkpoint
State *pb.BeaconState
}
// CheckpointStateCache is a struct with 1 queue for looking up state by checkpoint.
type CheckpointStateCache struct {
cache *cache.FIFO
lock sync.RWMutex
}
// checkpointState takes the checkpoint as the key of the resulting state.
func checkpointState(obj interface{}) (string, error) {
info, ok := obj.(*CheckpointState)
if !ok {
return "", ErrNotCheckpointState
}
h, err := hashutil.HashProto(info.Checkpoint)
if err != nil {
return "", err
}
return string(h[:]), nil
}
// NewCheckpointStateCache creates a new checkpoint state cache for storing/accessing processed state.
func NewCheckpointStateCache() *CheckpointStateCache {
return &CheckpointStateCache{
cache: cache.NewFIFO(checkpointState),
}
}
// StateByCheckpoint fetches state by checkpoint. Returns true with a
// reference to the CheckpointState info, if exists. Otherwise returns false, nil.
func (c *CheckpointStateCache) StateByCheckpoint(cp *ethpb.Checkpoint) (*pb.BeaconState, error) {
c.lock.RLock()
defer c.lock.RUnlock()
h, err := hashutil.HashProto(cp)
if err != nil {
return nil, err
}
obj, exists, err := c.cache.GetByKey(string(h[:]))
if err != nil {
return nil, err
}
if exists {
checkpointStateHit.Inc()
} else {
checkpointStateMiss.Inc()
return nil, nil
}
info, ok := obj.(*CheckpointState)
if !ok {
return nil, ErrNotCheckpointState
}
return proto.Clone(info.State).(*pb.BeaconState), nil
}
// AddCheckpointState adds CheckpointState object to the cache. This method also trims the least
// recently added CheckpointState object if the cache size has ready the max cache size limit.
func (c *CheckpointStateCache) AddCheckpointState(cp *CheckpointState) error {
c.lock.Lock()
defer c.lock.Unlock()
if err := c.cache.AddIfNotPresent(cp); err != nil {
return err
}
trim(c.cache, maxCheckpointStateSize)
return nil
}
// CheckpointStateKeys returns the keys of the state in cache.
func (c *CheckpointStateCache) CheckpointStateKeys() []string {
return c.cache.ListKeys()
}