trie: fix concurrent usage of secKeyBuf, ref #20920

This commit is contained in:
Martin Holst Swende 2020-04-15 11:07:29 +02:00
parent 00064ddcfb
commit af4080b4b7
No known key found for this signature in database
GPG Key ID: 683B438C05A5DDF0

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@ -59,8 +59,11 @@ var (
// secureKeyPrefix is the database key prefix used to store trie node preimages.
var secureKeyPrefix = []byte("secure-key-")
// secureKeyPrefixLength is the length of the above prefix
const secureKeyPrefixLength = 11
// secureKeyLength is the length of the above prefix + 32byte hash.
const secureKeyLength = 11 + 32
const secureKeyLength = secureKeyPrefixLength + 32
// Database is an intermediate write layer between the trie data structures and
// the disk database. The aim is to accumulate trie writes in-memory and only
@ -79,7 +82,6 @@ type Database struct {
newest common.Hash // Newest tracked node, flush-list tail
preimages map[common.Hash][]byte // Preimages of nodes from the secure trie
seckeybuf [secureKeyLength]byte // Ephemeral buffer for calculating preimage keys
gctime time.Duration // Time spent on garbage collection since last commit
gcnodes uint64 // Nodes garbage collected since last commit
@ -445,15 +447,15 @@ func (db *Database) preimage(hash common.Hash) ([]byte, error) {
return preimage, nil
}
// Content unavailable in memory, attempt to retrieve from disk
return db.diskdb.Get(db.secureKey(hash[:]))
return db.diskdb.Get(secureKey(hash))
}
// secureKey returns the database key for the preimage of key, as an ephemeral
// buffer. The caller must not hold onto the return value because it will become
// invalid on the next call.
func (db *Database) secureKey(key []byte) []byte {
buf := append(db.seckeybuf[:0], secureKeyPrefix...)
buf = append(buf, key...)
// secureKey returns the database key for the preimage of key (as a newly
// allocated byte-slice)
func secureKey(hash common.Hash) []byte {
buf := make([]byte, secureKeyLength)
copy(buf, secureKeyPrefix)
copy(buf[secureKeyPrefixLength:], hash[:])
return buf
}
@ -596,12 +598,18 @@ func (db *Database) Cap(limit common.StorageSize) error {
size := db.dirtiesSize + common.StorageSize((len(db.dirties)-1)*cachedNodeSize)
size += db.childrenSize - common.StorageSize(len(db.dirties[common.Hash{}].children)*(common.HashLength+2))
// We reuse an ephemeral buffer for the keys. The batch Put operation
// copies it internally, so we can reuse it.
var keyBuf [secureKeyLength]byte
copy(keyBuf[:], secureKeyPrefix)
// If the preimage cache got large enough, push to disk. If it's still small
// leave for later to deduplicate writes.
flushPreimages := db.preimagesSize > 4*1024*1024
if flushPreimages {
for hash, preimage := range db.preimages {
if err := batch.Put(db.secureKey(hash[:]), preimage); err != nil {
copy(keyBuf[secureKeyPrefixLength:], hash[:])
if err := batch.Put(keyBuf[:], preimage); err != nil {
log.Error("Failed to commit preimage from trie database", "err", err)
return err
}
@ -692,9 +700,15 @@ func (db *Database) Commit(node common.Hash, report bool) error {
start := time.Now()
batch := db.diskdb.NewBatch()
// We reuse an ephemeral buffer for the keys. The batch Put operation
// copies it internally, so we can reuse it.
var keyBuf [secureKeyLength]byte
copy(keyBuf[:], secureKeyPrefix)
// Move all of the accumulated preimages into a write batch
for hash, preimage := range db.preimages {
if err := batch.Put(db.secureKey(hash[:]), preimage); err != nil {
copy(keyBuf[secureKeyPrefixLength:], hash[:])
if err := batch.Put(keyBuf[:], preimage); err != nil {
log.Error("Failed to commit preimage from trie database", "err", err)
return err
}