When replaying state transitions, for the slots that have a block, the
state root is taken from the block. For slots that lack a block, it's
currently calculated using hash_tree_root which is expensive.
Caching the empty slot state roots helps us avoid recalculating this
hash, meaning that for replay, hashes are never calculated. This turns
blocks into fairly lightweight "state-diffs"!
* avoid re-saving state when replaying blocks
* advance empty slots slot-by-slot and save root
* fix sim randomness
* fix sim genesis filename
* introduce `isEpoch` to check if a slot is an epoch slot
* remove incorrect/obsolete comment; deprecate BeaconState state transition functions
* remove deprecated state_transition(state: var BeaconState)
* add specific workarounds for state_transition() and process_slots() to nfuzz_block() and addTestBlock()
* Jenkins: add timeouts to testnet finalisation tests
- add nicer child process management to "launch_local_testnet.sh"
- correct a comment in "start.sh"
* the Jenkins worker's version of "timeout" doesn't support "-v"
* remove near-duplicate code paths: process_slot(), process_slots(), and state_transition() for BeaconState are now wrappers around the HashedBeaconState versions
* convert tests/test_state_transition.nim to use HashedBeaconState
* convert mocking infrastructure and spec_block/epoch_processing tests to use HashedBeaconBlock, and remove thus unused process_slot*(state: var BeaconState)
* ssz: move ref support outside
Instead of allocating ref's inside SSZ, move it to separate helper:
* makes `ref` allocations explicit
* less magic inside SSZ
* `ref` in nim generally means reference whereas SSZ was loading as
value - if a type indeed used references it would get copies instead of
references to a single value on roundtrip which is unexpected
TODO: EF tests would benefit from some refactoring since they all do the
same thing practically..
Co-authored-by: Zahary Karadjov <zahary@gmail.com>
* refactor blook pool caches to directly use TableRef to avoid SSZ decoding, which was consuming 20% of profile on mainnet eth2_network_simulation
* use table's hasKeyOrPut
* bump eth2 spec reference to v0.11.1
* cache whole StateData objects and switch from expensive clear() to cheaper new object instantiation for caching
* remove scaffolding and stop re-assigning to part of StateData object
* 80-character lines
* Create a json log named "nbc.log" only when the --dev-build option
is specified to the connect_to_testnet script.
This option is specified for the targets "testnet0", "testnet1"
and "schlesi-dev"
Please see the newly added 'schlesi-dev' Makefile target.
It demonstrates how the log level can be specified for individual topics.
Additionally, when connecting to testnets like 'schlesi' there will be
two additional log files produced in the working directory:
* json-log.txt
* text-log.txt (in the textblocks format)
In BlockPool, we keep the head state around, so it's trivial to restore
the temporary state there and keep going as if nothing happened.
This solves 3 problems:
* stack space - the state copy on mainnet is huge
* GC scanning - using stack space for state slows down the GC
significantly
* reckless copying - the copy itself takes a long time
In state_sim, we'll do the same and allocate on heap - this helps a
little with GC - without it, the collection of the temporary strings
created with `toHex` while printing the json dominates the trace.