genlayer.std.advanced package

This module provides some “advanced” features that can be used for optimizations

Warning

If you are using something “advanced” you must know what you do

class genlayer.std.advanced.AlreadySerializedResult

Bases: bytes

If contract method returns instance of this class, calldata encoding won’t be performed. Instead stored bytes will be passed as is

static __new__(cls, *args, **kwargs)

Forwards all arguments to bytes

exception genlayer.std.advanced.ContractError

Bases: Exception

Represents “Contract error” result of a contract that is passed to validator function of genlayer.std.run_nondet()

Validating leader output and sandbox invocation are only places where contract can “handle” contract error

__init__(data: str) → None

data: str

class genlayer.std.advanced.ContractReturn

Bases: object

Represents a normal “Return” result of a contract that is passed to validator function of genlayer.std.run_nondet()

__init__(data: Any) → None

data: Any

genlayer.std.advanced.run_nondet(leader_fn: Callable[[], T], validator_fn: Callable[[ContractReturn | Rollback | ContractError], bool]) → Lazy

Most generic user-friendly api to execute a non-deterministic block

Parameters:

• leader_fn (Callable[[], T]) – function that is executed in the leader

• validator_fn (Callable[[ContractReturn | Rollback | ContractError], bool]) – function that is executed in the validator that also checks leader result

Return type:

Lazy

Uses cloudpickle to pass a “function” to sub VM

Note

If validator_fn produces an error and leader_fn produces an error, executor itself will set result of this block to “agree” and fail entire contract with leader’s error. This is done because not all errors can be caught in code itself (i.e. exit). If this behavior is not desired, just fast return False for leader error result.

Warning

All sub-vm returns go through genlayer.py.calldata encoding

genlayer.std.advanced.sandbox(fn: Callable[[], Any]) → Lazy[Any]

Runs function in the sandbox

Return type:

Lazy[Any]

genlayer.std.advanced.validator_handle_rollbacks_and_errors_default(fn: Callable[[], Any], leaders_result: ContractReturn | Rollback | ContractError) → tuple[Any, Any]

Default function to handle rollbacks and contract errors

Errors and rollbacks are always checked for strict equality, which means that it’s user responsibility to dump least possible text in there

Returns:

ContractReturn data fields as (validator, leader)` iff both results are not errors/rollbacks

Return type:

tuple[Any, Any]