ethereumjs-monorepo

@ethereumjs/vm

---

@ethereumjs/vm / VM

Class: VM

Defined in: vm/src/vm.ts:21

The VM is a state transition machine that executes EVM bytecode and updates the state. It can be used to execute transactions, blocks, individual transactions, or snippets of EVM bytecode.

A VM can be created with the constructor method:

• createVM

Constructors

Constructor

new VM(opts?): VM

Defined in: vm/src/vm.ts:68

Instantiates a new VM Object.

Parameters

opts?

VMOpts = {}

Returns

VM

Deprecated

Use createVM instead — async initialization avoids side effects from partially constructed instances.

Properties

blockchain

readonly blockchain: EVMMockBlockchainInterface

Defined in: vm/src/vm.ts:30

The blockchain the VM operates on

---

common

readonly common: Common

Defined in: vm/src/vm.ts:32

---

events

readonly events: EventEmitter<VMEvent>

Defined in: vm/src/vm.ts:34

---

evm

readonly evm: EVMInterface

Defined in: vm/src/vm.ts:38

The EVM used for bytecode execution

---

stateManager

readonly stateManager: StateManagerInterface

Defined in: vm/src/vm.ts:25

The StateManager used by the VM

Methods

errorStr()

errorStr(): string

Defined in: vm/src/vm.ts:135

Return a compact error string representation of the object

Returns

string

---

shallowCopy()

shallowCopy(downlevelCaches?): Promise<VM>

Defined in: vm/src/vm.ts:110

Returns a copy of the VM instance.

Note that the returned copy will share the same db as the original for the blockchain and the statemanager.

Associated caches will be deleted and caches will be re-initialized for a more short-term focused usage, being less memory intense (the statemanager caches will switch to using an ORDERED_MAP cache data structure more suitable for short-term usage, the trie node LRU cache will not be activated at all). To fine-tune this behavior (if the shallow-copy-returned object has a longer life span e.g.) you can set the downlevelCaches option to false.

Parameters

downlevelCaches?

boolean = true

Downlevel (so: adopted for short-term usage) associated state caches (default: true)

Returns

Promise<VM>