perf: store code in Bytes

[mooori]

In #448 it is pointed out that storing code in Bytes rather than Rc<Vec<u8>> avoids an extra indirection in opcode fetch. This change is implemented in this PR.

Public interfaces

Machine::new() and Runtime::new() are changed to have parameter code: Bytes instead of code: Rc<Vec<u8>>. Without this change, NEAR gas usage increases as constructing Bytes then would require cloning the Vec inside the Rc. (See numbers below.)

While this doesn't break aurora-engine, it might break other things. For example, jsontests would require an update to run on this fork.

NEAR gas usage

Including this change in aurora-engine leads to test failures due to NEAR gas usage which is lower than expected:

---- tests::repro::repro_8ru7VEA stdout ----
thread 'tests::repro::repro_8ru7VEA' panicked at 'assertion failed: `(left == right)`
  left: `242`,
 right: `241`', engine-tests/src/tests/repro.rs:146:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

---- tests::repro::repro_D98vwmi stdout ----
thread 'tests::repro::repro_D98vwmi' panicked at 'assertion failed: `(left == right)`
  left: `199`,
 right: `198`', engine-tests/src/tests/repro.rs:146:5

---- tests::repro::repro_5bEgfRQ stdout ----
thread 'tests::repro::repro_5bEgfRQ' panicked at 'assertion failed: `(left == right)`
  left: `706`,
 right: `705`', engine-tests/src/tests/repro.rs:146:5

---- tests::repro::repro_GdASJ3KESs stdout ----
thread 'tests::repro::repro_GdASJ3KESs' panicked at 'assertion failed: `(left == right)`
  left: `133`,
 right: `132`', engine-tests/src/tests/repro.rs:146:5

---- tests::uniswap::test_uniswap_input_multihop stdout ----
thread 'tests::uniswap::test_uniswap_input_multihop' panicked at 'assertion failed: `(left == right)`
  left: `123`,
 right: `122`', engine-tests/src/tests/uniswap.rs:41:5

NEAR gas usage if public interface are not changed and instead `Vec` is cloned:

---- tests::repro::repro_8ru7VEA stdout ----
thread 'tests::repro::repro_8ru7VEA' panicked at 'assertion failed: `(left == right)`
  left: `242`,
 right: `247`', engine-tests/src/tests/repro.rs:146:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

---- tests::repro::repro_D98vwmi stdout ----
thread 'tests::repro::repro_D98vwmi' panicked at 'assertion failed: `(left == right)`
  left: `199`,
 right: `205`', engine-tests/src/tests/repro.rs:146:5

---- tests::repro::repro_5bEgfRQ stdout ----
thread 'tests::repro::repro_5bEgfRQ' panicked at 'assertion failed: `(left == right)`
  left: `706`,
 right: `705`', engine-tests/src/tests/repro.rs:146:5

---- tests::repro::repro_FRcorNv stdout ----
thread 'tests::repro::repro_FRcorNv' panicked at 'assertion failed: `(left == right)`
  left: `197`,
 right: `202`', engine-tests/src/tests/repro.rs:146:5

---- tests::repro::repro_GdASJ3KESs stdout ----
thread 'tests::repro::repro_GdASJ3KESs' panicked at 'assertion failed: `(left == right)`
  left: `133`,
 right: `136`', engine-tests/src/tests/repro.rs:146:5

---- tests::uniswap::test_uniswap_exact_output stdout ----
thread 'tests::uniswap::test_uniswap_exact_output' panicked at '34 Tgas is not equal to 33 Tgas', engine-tests/src/test_utils/mod.rs:842:5

---- tests::uniswap::test_uniswap_input_multihop stdout ----
thread 'tests::uniswap::test_uniswap_input_multihop' panicked at 'assertion failed: `(left == right)`
  left: `123`,
 right: `125`', engine-tests/src/tests/uniswap.rs:41:5

---- tests::one_inch::test_1inch_liquidity_protocol stdout ----
thread 'tests::one_inch::test_1inch_liquidity_protocol' panicked at '26 Tgas is not equal to 25 Tgas', engine-tests/src/test_utils/mod.rs:842:5

Question

Does this change make sense given that it requires breaking public interfaces for rather small improvements in NEAR gas usage?

[birchmd]

Thanks for looking into this @mooori . In my opinion, it is not worth making a breaking change for a less than 1% savings.