core, eth, les, trie: add a prefix to contract code (#21080)

core/rawdb/schema.go

@@ -18,6 +18,7 @@
 package rawdb
 
 import (
+	"bytes"
 	"encoding/binary"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -69,6 +70,7 @@ var (
 	bloomBitsPrefix       = []byte("B") // bloomBitsPrefix + bit (uint16 big endian) + section (uint64 big endian) + hash -> bloom bits
 	SnapshotAccountPrefix = []byte("a") // SnapshotAccountPrefix + account hash -> account trie value
 	SnapshotStoragePrefix = []byte("o") // SnapshotStoragePrefix + account hash + storage hash -> storage trie value
+	codePrefix            = []byte("c") // codePrefix + code hash -> account code
 
 	preimagePrefix = []byte("secure-key-")      // preimagePrefix + hash -> preimage
 	configPrefix   = []byte("ethereum-config-") // config prefix for the db
@@ -192,6 +194,20 @@ func preimageKey(hash common.Hash) []byte {
 	return append(preimagePrefix, hash.Bytes()...)
 }
 
+// codeKey = codePrefix + hash
+func codeKey(hash common.Hash) []byte {
+	return append(codePrefix, hash.Bytes()...)
+}
+
+// IsCodeKey reports whether the given byte slice is the key of contract code,
+// if so return the raw code hash as well.
+func IsCodeKey(key []byte) (bool, []byte) {
+	if bytes.HasPrefix(key, codePrefix) && len(key) == common.HashLength+len(codePrefix) {
+		return true, key[len(codePrefix):]
+	}
+	return false, nil
+}
+
 // configKey = configPrefix + hash
 func configKey(hash common.Hash) []byte {
 	return append(configPrefix, hash.Bytes()...)