1 files changed, 51 insertions, 0 deletions
diff --git a/ledger/ledgercore/misc.go b/ledger/ledgercore/misc.go
new file mode 100644
index 000000000..f4fd21f50
--- /dev/null
+++ b/ledger/ledgercore/misc.go
@@ -0,0 +1,51 @@
+// Copyright (C) 2019-2021 Algorand, Inc.
+// This file is part of go-algorand
+//
+// go-algorand is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// go-algorand 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 Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with go-algorand.  If not, see <https://www.gnu.org/licenses/>.
+
+package ledgercore
+
+import (
+	"fmt"
+
+	"github.com/algorand/go-algorand/crypto"
+	"github.com/algorand/go-algorand/data/basics"
+	"github.com/algorand/go-algorand/data/bookkeeping"
+)
+
+// ParticipantsArray implements merklearray.Array and is used to commit
+// to a Merkle tree of online accounts.
+//msgp:ignore ParticipantsArray
+type ParticipantsArray []basics.Participant
+
+// Length returns the ledger of the array.
+func (a ParticipantsArray) Length() uint64 {
+	return uint64(len(a))
+}
+
+// GetHash returns the hash for the given position.
+func (a ParticipantsArray) GetHash(pos uint64) (crypto.Digest, error) {
+	if pos >= uint64(len(a)) {
+		return crypto.Digest{}, fmt.Errorf("array ParticipantsArray.Get(%d) out of bounds %d", pos, len(a))
+	}
+
+	return crypto.HashObj(a[pos]), nil
+}
+
+// InitState structure defines blockchain init params
+type InitState struct {
+	Block       bookkeeping.Block
+	Accounts    map[basics.Address]basics.AccountData
+	GenesisHash crypto.Digest
+}