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authorDeterminant <[email protected]>2020-09-15 23:55:34 -0400
committerDeterminant <[email protected]>2020-09-15 23:55:34 -0400
commit78745551c077bf54151202138c2629f288769561 (patch)
tree2b628e99fd110617089778fa91235ecd2888f4ef /core/state/snapshot/wipe.go
parent7d1388c743b4ec8f4a86bea95bfada785dee83f7 (diff)
WIP: geth-tavum
Diffstat (limited to 'core/state/snapshot/wipe.go')
-rw-r--r--core/state/snapshot/wipe.go131
1 files changed, 131 insertions, 0 deletions
diff --git a/core/state/snapshot/wipe.go b/core/state/snapshot/wipe.go
new file mode 100644
index 0000000..853a1a7
--- /dev/null
+++ b/core/state/snapshot/wipe.go
@@ -0,0 +1,131 @@
+// Copyright 2019 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package snapshot
+
+import (
+ "bytes"
+ "time"
+
+ "github.com/ava-labs/coreth/core/rawdb"
+ "github.com/ethereum/go-ethereum/common"
+ "github.com/ethereum/go-ethereum/ethdb"
+ "github.com/ethereum/go-ethereum/log"
+)
+
+// wipeSnapshot starts a goroutine to iterate over the entire key-value database
+// and delete all the data associated with the snapshot (accounts, storage,
+// metadata). After all is done, the snapshot range of the database is compacted
+// to free up unused data blocks.
+func wipeSnapshot(db ethdb.KeyValueStore, full bool) chan struct{} {
+ // Wipe the snapshot root marker synchronously
+ if full {
+ rawdb.DeleteSnapshotRoot(db)
+ }
+ // Wipe everything else asynchronously
+ wiper := make(chan struct{}, 1)
+ go func() {
+ if err := wipeContent(db); err != nil {
+ log.Error("Failed to wipe state snapshot", "err", err) // Database close will trigger this
+ return
+ }
+ close(wiper)
+ }()
+ return wiper
+}
+
+// wipeContent iterates over the entire key-value database and deletes all the
+// data associated with the snapshot (accounts, storage), but not the root hash
+// as the wiper is meant to run on a background thread but the root needs to be
+// removed in sync to avoid data races. After all is done, the snapshot range of
+// the database is compacted to free up unused data blocks.
+func wipeContent(db ethdb.KeyValueStore) error {
+ if err := wipeKeyRange(db, "accounts", rawdb.SnapshotAccountPrefix, len(rawdb.SnapshotAccountPrefix)+common.HashLength); err != nil {
+ return err
+ }
+ if err := wipeKeyRange(db, "storage", rawdb.SnapshotStoragePrefix, len(rawdb.SnapshotStoragePrefix)+2*common.HashLength); err != nil {
+ return err
+ }
+ // Compact the snapshot section of the database to get rid of unused space
+ start := time.Now()
+
+ log.Info("Compacting snapshot account area ")
+ end := common.CopyBytes(rawdb.SnapshotAccountPrefix)
+ end[len(end)-1]++
+
+ if err := db.Compact(rawdb.SnapshotAccountPrefix, end); err != nil {
+ return err
+ }
+ log.Info("Compacting snapshot storage area ")
+ end = common.CopyBytes(rawdb.SnapshotStoragePrefix)
+ end[len(end)-1]++
+
+ if err := db.Compact(rawdb.SnapshotStoragePrefix, end); err != nil {
+ return err
+ }
+ log.Info("Compacted snapshot area in database", "elapsed", common.PrettyDuration(time.Since(start)))
+
+ return nil
+}
+
+// wipeKeyRange deletes a range of keys from the database starting with prefix
+// and having a specific total key length.
+func wipeKeyRange(db ethdb.KeyValueStore, kind string, prefix []byte, keylen int) error {
+ // Batch deletions together to avoid holding an iterator for too long
+ var (
+ batch = db.NewBatch()
+ items int
+ )
+ // Iterate over the key-range and delete all of them
+ start, logged := time.Now(), time.Now()
+
+ it := db.NewIterator(prefix, nil)
+ for it.Next() {
+ // Skip any keys with the correct prefix but wrong length (trie nodes)
+ key := it.Key()
+ if !bytes.HasPrefix(key, prefix) {
+ break
+ }
+ if len(key) != keylen {
+ continue
+ }
+ // Delete the key and periodically recreate the batch and iterator
+ batch.Delete(key)
+ items++
+
+ if items%10000 == 0 {
+ // Batch too large (or iterator too long lived, flush and recreate)
+ it.Release()
+ if err := batch.Write(); err != nil {
+ return err
+ }
+ batch.Reset()
+ seekPos := key[len(prefix):]
+ it = db.NewIterator(prefix, seekPos)
+
+ if time.Since(logged) > 8*time.Second {
+ log.Info("Deleting state snapshot leftovers", "kind", kind, "wiped", items, "elapsed", common.PrettyDuration(time.Since(start)))
+ logged = time.Now()
+ }
+ }
+ }
+ it.Release()
+ if err := batch.Write(); err != nil {
+ return err
+ }
+ log.Info("Deleted state snapshot leftovers", "kind", kind, "wiped", items, "elapsed", common.PrettyDuration(time.Since(start)))
+ return nil
+}