test_worst_returndatacopy()

Documentation for tests/benchmark/test_worst_memory.py::test_worst_returndatacopy@88e9fb8f.

Generate fixtures for these test cases for Osaka with:

fill -v tests/benchmark/test_worst_memory.py::test_worst_returndatacopy -m benchmark

Test running a block filled with RETURNDATACOPY executions.

Source code in tests/benchmark/test_worst_memory.py

@pytest.mark.parametrize(
    "size",
    [
        pytest.param(0, id="0 bytes"),
        pytest.param(100, id="100 bytes"),
        pytest.param(10 * 1024, id="10KiB"),
        pytest.param(1024 * 1024, id="1MiB"),
    ],
)
@pytest.mark.parametrize(
    "fixed_dst",
    [
        True,
        False,
    ],
)
def test_worst_returndatacopy(
    benchmark_test: BenchmarkTestFiller,
    pre: Alloc,
    size: int,
    fixed_dst: bool,
) -> None:
    """Test running a block filled with RETURNDATACOPY executions."""
    # Create the contract that will RETURN the data that will be used for
    # RETURNDATACOPY.
    # Random-ish data is injected at different points in memory to avoid
    # making the content
    # predictable. If `size` is 0, this helper contract won't be used.
    code = (
        Op.MSTORE8(0, Op.GAS)
        + Op.MSTORE8(size // 2, Op.GAS)
        + Op.MSTORE8(size - 1, Op.GAS)
        + Op.RETURN(0, size)
    )
    helper_contract = pre.deploy_contract(code=code)

    returndata_gen = Op.STATICCALL(address=helper_contract) if size > 0 else Bytecode()
    dst = 0 if fixed_dst else Op.MOD(Op.GAS, 7)

    # We create the contract that will be doing the RETURNDATACOPY multiple
    # times.
    returndata_gen = Op.STATICCALL(address=helper_contract) if size > 0 else Bytecode()
    attack_block = Op.RETURNDATACOPY(dst, Op.PUSH0, Op.RETURNDATASIZE)

    # The attack loop is constructed as:
    # ```
    # JUMPDEST(#)
    # RETURNDATACOPY(...)
    # RETURNDATACOPY(...)
    # ...
    # STATICCALL(address=helper_contract)
    # JUMP(#)
    # ```
    # The goal is that once per (big) loop iteration, the helper contract is
    # called to
    # generate fresh returndata to continue calling RETURNDATACOPY.

    benchmark_test(
        code_generator=JumpLoopGenerator(
            setup=returndata_gen, attack_block=attack_block, cleanup=returndata_gen
        ),
    )

Parametrized Test Cases

This test case is only parametrized by fork.

Fork All Forks Prague Osaka

Fixture Type All Fixture Types blockchain_test

Test ID (Abbreviated)	fixed_dst	size
...fork_Prague-blockchain_test-fixed_dst_True-0 bytes	True	0
...fork_Prague-blockchain_test-fixed_dst_True-100 bytes	True	100
...fork_Prague-blockchain_test-fixed_dst_True-10KiB	True	10240
...fork_Prague-blockchain_test-fixed_dst_True-1MiB	True	1048576
...fork_Prague-blockchain_test-fixed_dst_False-0 bytes	False	0
...fork_Prague-blockchain_test-fixed_dst_False-100 bytes	False	100
...fork_Prague-blockchain_test-fixed_dst_False-10KiB	False	10240
...fork_Prague-blockchain_test-fixed_dst_False-1MiB	False	1048576
...fork_Osaka-blockchain_test-fixed_dst_True-0 bytes	True	0
...fork_Osaka-blockchain_test-fixed_dst_True-100 bytes	True	100
...fork_Osaka-blockchain_test-fixed_dst_True-10KiB	True	10240
...fork_Osaka-blockchain_test-fixed_dst_True-1MiB	True	1048576
...fork_Osaka-blockchain_test-fixed_dst_False-0 bytes	False	0
...fork_Osaka-blockchain_test-fixed_dst_False-100 bytes	False	100
...fork_Osaka-blockchain_test-fixed_dst_False-10KiB	False	10240
...fork_Osaka-blockchain_test-fixed_dst_False-1MiB	False	1048576