Remove prune state (#4680)

* Rm prune state
* Merge branch 'master' into rm-prune-state

beacon-chain/db/kv/BUILD.bazel

@@ -14,7 +14,6 @@ go_library(
         "kv.go",
         "operations.go",
         "powchain.go",
-        "prune_states.go",
         "schema.go",
         "slashings.go",
         "state.go",

beacon-chain/db/kv/kv.go

@@ -1,7 +1,6 @@
 package kv
 
 import (
-	"context"
 	"os"
 	"path"
 	"time"
@@ -112,10 +111,6 @@ func NewKVStore(dirPath string) (*Store, error) {
 		return nil, err
 	}
 
-	if err := kv.pruneStates(context.TODO()); err != nil {
-		return nil, err
-	}
-
 	err = prometheus.Register(createBoltCollector(kv.db))
 
 	return kv, err

beacon-chain/db/kv/prune_states.go

@@ -1,71 +0,0 @@
-package kv
-
-import (
-	"bytes"
-	"context"
-
-	"github.com/boltdb/bolt"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/beacon-chain/db/filters"
-	"github.com/sirupsen/logrus"
-)
-
-var pruneStatesKey = []byte("prune-states")
-
-func (k *Store) pruneStates(ctx context.Context) error {
-	var pruned bool
-
-	k.db.View(func(tx *bolt.Tx) error {
-		bkt := tx.Bucket(migrationBucket)
-		v := bkt.Get(pruneStatesKey)
-		pruned = len(v) == 1 && v[0] == 0x01
-		return nil
-	})
-
-	if pruned {
-		return nil
-	}
-
-	log := logrus.WithField("prefix", "kv")
-	log.Info("Pruning states before last finalized check point. This might take a while...")
-
-	roots, err := k.rootsToPrune(ctx)
-	if err != nil {
-		return err
-	}
-
-	if err := k.DeleteStates(ctx, roots); err != nil {
-		return err
-	}
-
-	return k.db.Update(func(tx *bolt.Tx) error {
-		bkt := tx.Bucket(migrationBucket)
-		return bkt.Put(pruneStatesKey, []byte{0x01})
-	})
-}
-
-// This retrieves the key roots needed to prune states
-// * Get last finalized check point
-// * Rewind end slot until it's not finalized root
-// * return roots between slot 1 and end slot
-func (k *Store) rootsToPrune(ctx context.Context) ([][32]byte, error) {
-	cp, err := k.FinalizedCheckpoint(ctx)
-	if err != nil {
-		return nil, err
-	}
-	f := filters.NewFilter().SetStartSlot(1).SetEndSlot(helpers.StartSlot(cp.Epoch))
-	roots, err := k.BlockRoots(ctx, f)
-	if err != nil {
-		return nil, err
-	}
-	// Ensure we don't delete finalized root
-	i := 0
-	if len(roots) > 1 {
-		i = len(roots) - 1
-		for bytes.Equal(roots[i][:], cp.Root) {
-			i--
-		}
-	}
-
-	return roots[:i], nil
-}