Crate essential_vm

The essential VM implementation.

Reading State

The primary entrypoint for this crate is the Vm type.

The Vm allows for executing arbitrary essential ASM ops. The primary use-case is executing Programs that make up a Predicate’s program graph during Solution validation.

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.

Re-exports

• pub use essential_types as types;

Modules

• asm
  Assembly for the Essential VM.
• bytecode
  Items related to bytecode representation for the VM assembly.
• error
  The types of errors that might occur throughout execution.
• sync
  Items related to stepping forward VM execution by synchronous operations.

Structs

• Access
  All necessary solution access required to check an individual predicate.
• ExecFuture
  A future that when polled attempts to make progress on VM execution.
• GasLimit
  Gas limits.
• LazyCache
  Lazily cache expensive to compute values.
• Memory
  Memory for temporary storage of words.
• OpAsync
  The set of operations that are performed asynchronously.
• Repeat
  A stack of repeat counters.
• Stack
  The VM’s Stack, i.e. a Vec of Words updated during each step of execution.
• Vm
  The operation execution state of the VM.

Enums

• Op
  All operations available to the Essential VM execution.
• OpSync
  The set of operations that are performed synchronously.
• ProgramControlFlow
  Update the program to a new position or halt it.

Traits

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

Functions

• mut_keys
  A helper for collecting all mutable keys that are proposed for mutation for the predicate at the given index.
• mut_keys_set
  Get the contract of mutable keys for this predicate.
• mut_keys_slices
  Get the mutable keys as slices

Type Aliases

• BytecodeMapped
  Shorthand for the BytecodeMapped type representing a mapping to/from 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.