added JumpDest interface + basic map implementation

core/vm/jumpdests.go

@@ -0,0 +1,51 @@
+// Copyright 2024 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 vm
+
+import "github.com/ethereum/go-ethereum/common"
+
+// JumpDests is an interface for managing the jumpdest analysis cache.
+// It provides methods to store and retrieve the results of JUMPDEST analysis
+// for contract bytecode, which is used to determine valid jump destinations.
+type JumpDests interface {
+	// Load retrieves the cached jumpdest analysis for the given code hash.
+	// Returns the BitVec and true if found, or nil and false if not cached.
+	Load(codeHash common.Hash) (BitVec, bool)
+
+	// Store saves the jumpdest analysis for the given code hash.
+	Store(codeHash common.Hash, vec BitVec)
+}
+
+// mapJumpDests is the default implementation of JumpDests using a map.
+// This implementation is not thread-safe and is meant to be used per EVM instance.
+type mapJumpDests map[common.Hash]BitVec
+
+// newMapJumpDests creates a new map-based JumpDests implementation.
+func newMapJumpDests() JumpDests {
+	return make(mapJumpDests)
+}
+
+// Load retrieves the cached jumpdest analysis for the given code hash.
+func (j mapJumpDests) Load(codeHash common.Hash) (BitVec, bool) {
+	vec, ok := j[codeHash]
+	return vec, ok
+}
+
+// Store saves the jumpdest analysis for the given code hash.
+func (j mapJumpDests) Store(codeHash common.Hash, vec BitVec) {
+	j[codeHash] = vec
+}