Crate essential_check::state_read_vm

The essential state read VM implementation.

Reading State

The primary entrypoint for this crate is the Vm type.

The Vm allows for executing operations that read state and apply any necessary operations in order to form the final, expected state slot layout within the VM’s [Memory]. The Vm’s memory can be accessed directly from the Vm, or the Vm can be consumed and state slots returned with Vm::into_state_slots.

Executing Ops

There are three primary methods available for executing operations:

• Vm::exec_ops
• Vm::exec_bytecode
• Vm::exec_bytecode_iter

Each have slightly different performance implications, so be sure to read the docs before selecting a method.

Execution Future

The Vm::exec_* functions all return Futures that not only yield on async operations, but yield based on a user-specified gas limit too. See the ExecFuture docs for further details on the implementation.

Modules

• asm
  Assembly for state read operations.
• constraint
  The essential constraint checking implementation.
• error
  The types of errors that might occur throughout state read execution.

Structs

• Access
  All necessary solution data and state access required to check an individual predicate.
• ExecFuture
  A future that when polled attempts to make progress on VM execution.
• GasLimit
  Gas limits.
• SolutionAccess
  All necessary solution data access required to check an individual predicate.
• Stack
  The VM’s Stack, i.e. a Vec of Words updated during each step of execution.
• StateSlots
  The pre and post mutation state slot values for the predicate being solved.
• StateSlotsMut
  A type representing the VM’s mutable state slots.
• Vm
  The operation execution state of the State Read VM.

Traits

• OpAccess
  Types that provide access to operations.
• OpGasCost
  A mapping from an operation to its gas cost.
• StateRead
  Access to state required by the state read VM.

Type Aliases

• BytecodeMapped
  Shorthand for the BytecodeMapped type representing a mapping to/from state read Ops.
• BytecodeMappedLazy
  Shorthand for the BytecodeMappedLazy type for mapping Ops.
• BytecodeMappedSlice
  Shorthand for the BytecodeMappedSlice type for mapping Ops.
• Gas
  Unit used to measure gas.
• OpAsyncResult
  Shorthand for a Result where the error type is an OpAsyncError.
• OpResult
  Shorthand for a Result where the error type is an OpError.
• OpSyncResult
  Shorthand for a Result where the error type is an OpSyncError.
• StateReadResult
  Shorthand for a Result where the error type is a StateReadError.
• StateSlotSlice
  The state slots declared within the predicate.
• StateSlotsResult
  Shorthand for a Result where the error type is a StateSlotsError.