* relax attestation validation when attestation is incoming but make it
more strict when adding to block
* share attestation validation logic between attestation pool and state
transition
* remove a bunch of redundant logging
* fix potential underflow in attestation delay checking
* fix committee used for attestation shard selection when attesting
* fix attestation data construction
* working justification, 1 node, 64 validators
* closer to tn1 params: 256 validators
* more debugging output; switch to minimum test case
* working justification and finalization in local network simulation
* fix currently incorrect state transition/attestation test assumption
* State sim compiles and run
* Works on libp2p testnet1
* Successfully update the state transition tests
* naive update of attestation pool (failing attstations can arrive in any order)
* Remove an official assert to allow attestation reordering
* include both static and dynamic check for invariants to ensure that get_crosslink_committee(...) can access all committees by ensure that SHARD_COUNT >= SLOTS_PER_EPOCH
* add state_sim to CI, to ensure that it also doesn't break SHARD_COUNT/SLOTS_PER_EPOCH assumptions, along with just in general not breaking
* rename get_genesis_beacon_state(...) to initialize_beacon_state_from_eth1(...); remove unused vestiges get_temporary_block_header(...) and get_empty_block(...); partly align initialize_beacon_state_from_eth1(...) with 0.8.0 version; implement CompactCommittee object type; update process_final_updates(...) to 0.8.0
* mark get_shard_delta(...) as 0.8.0
* mark get_total_active_balance(...) and epoch transition helper functions as 0.8.0
* move FORK_CHOICE_BALANCE_INCREMENT, not in spec anymore, to sole user in fork_choice
* remove some low-hanging perf silliness from get_winning_crosslink_and_attesting_indices(...) and switch inner/outer loop nesting order to get 10-15x function speedup for 128 and 512 validator cases by avoiding accidentally quadratic behavior, while keeping function signature unchanged and allowing easy ongoing verification of correctness of optimization
* avoid memory allocation with an openarray rather than seq
* update get_crosslink_deltas(...) to 0.8.0
* move non-spec ValidatorSetDeltaFlags from datatypes.nim to sync_protocol; fix mainnet MIN_ATTESTATION_INCLUSION_DELAY preset; update get_attestation_deltas(...) to 0.8.0; for 512 validators, get 90x speedup for get_attestation_deltas(...) from 179s to 2s
* explain purpose of when false portions, so they can be removed once accomplished
* replace BeaconState.finalized_{epoch,root} with BeaconState.finalized_checkpoint; rename get_delayed_activation_exit_epoch(...) to compute_activation_exit_epoch(...) and mark as 0.8.0; update get_churn_limit(...)/get_validator_churn_limit(...) to 0.8.0; update process_registry_updates(...) to 0.8.0
* update process_crosslinks(...) to 0.8.0; mark compute_start_slot_of_epoch(...) and get_committee_count(...) as 0.8.0
* mark Fork, is_slashable_validator(...), and get_beacon_proposer_index(...) as 0.8.0
* rename LATEST_SLASHED_EXIT_LENGTH to EPOCHS_PER_SLASHINGS_VECTOR; update process_slashings(...) to 0.8.0; remove pointless type conversion warning in get_previous_epoch(...)
* convert remaining references to finalized_epoch to finalized_checkpoint.epoch
* update slash_validator(...) to 0.8.0; mark inital value, Gwei, and time constants as 0.8.0; mark hash(...) and processBlockHeader(...) as 0.8.0
* rename WHISTLEBLOWING_REWARD_QUOTIENT to WHISTLEBLOWER_REWARD_QUOTIENT; rename LATEST_ACTIVE_INDEX_ROOTS_LENGTH to EPOCHS_PER_HISTORICAL_VECTOR (randao will also get merged into this); remove get_active_index_root(...); mark time parameter, signature domain types, and max operations per block constants as 0.8.0; update rewards and penalties constants to 0.8.0
* update is_valid_indexed_attestation(...) to 0.8.0; mark process_slot(...) as 0.8.0
* replace BeaconState.{current,previous}_justified_{epoch,root} with BeaconState.{current,previous}_justified_checkpoint
* rename slot_to_epoch(...) to compute_epoch_of_slot(...)
* rename aggregation_bitfield/custody_bitfield fields to aggregation_bits/custody_bits; rename convert_to_indexed(...) to get_indexed_attestation(...); mark BeaconBlockHeader as 0.8.0; update minimal preset MIN_ATTESTATION_INCLUSION_DELAY/time parameters in general to 0.8
* fix beacon node compilation; it used slightly different capitalizations of slot_to_epoch/slotToEpoch
* mark integer_squareroot(...), Deposit, VoluntaryExit, and Transfer as 0.8.0; rename get_epoch_start_slot(...) to compute_start_slot_of_epoch(...)
* add new Domain alias for uint64; rename bls_domain(...) to compute_domain(...), MAX_INDICES_PER_ATTESTATION to MAX_VALIDATORS_PER_COMMITTEE, and SignatureDomain to DomainType; update get_domain(...) to 0.8.0
* update/mark initiate_validator_exit(...) and Crosslink as 0.8.0; rename BeaconState.latest_block_roots -> BeaconState.block_roots; mark HistoricalBatch as 0.8.0
* migrate attestation pool tests from get_crosslink_committees_at_slot(...) to get_crosslink_committee(...)
* rm obsolete, unused get_crosslink_committees_at_slot_cached(...) and migrate tests/test_state_transition from get_crosslink_committees_at_slot(...) to get_crosslink_committee(...)
* migrate tests/testutil from get_crosslink_committees_at_slot(...) to get_crosslink_committee(...)
* use more pervasive caching infrastructure, initially of compute_committee; remove buggy (and per-index) shuffling to fix research/state_sim, which was noticing validators on multiple shard committees; rm now-unused specific get_attesting_balance_cached
* add some get_active_validator_index caching
* rm obsolete/unused get_attesting_indices_cached
* rm get_crosslink_committees_at_slot(...)
* some more 0.7 changes -- some of which can't be completed pending some data structure updates -- and shard handling changes to offset with epoch start shards
* update Deposit and BeaconBlockHeader to 0.7.0
* update get_total_balance(...) and get_base_reward(...) to 0.7.0
* rename initial value constant BLS_WITHDRAWAL_PREFIX_BYTE to BLS_WITHDRAWAL_PREFIX
* mark minimal presets as entirely migrated to 0.7.0; update process_rewards_and_penalties(...) to 0.7.0
* specify that targeting 0.7.0; adopt 0.7.0 refactoring of bls_domain/get_domain to update get_domain(...) to 0.7.0; mark that mainnet constant presets and block header processing are 0.7.0-consistent; update process_justification_and_finalization to 0.7.0 to fix potential underflow errors
* address mratsim's comment to copy whole spec comment
* 0.7.0 updates which don't change semantics; mostly comment changes
* mark get_attesting_indices, bls_verify, ProposerSlashing, BeaconBlockBody, deposit contract constants, state list length constants, compute_committee, get_crosslink_committee, is_slashable_attestation_data, processAttesterSlashings as 0.7.0; rename BASE_REWARD_QUOTIENT to BASE_REWARD_FACTOR
* complete marking unchanged-in-0.7.0 datatypes as such; a few more have trivial field renamings, etc
* update IndexedAttestation, verify_slashable_attestation/verify_indexed_attestation, and attester slashing processing to 0.6.3
* rm debug scaffolding
* rename Attestation.aggregate_signature -> Attestation.signature; convert various references to AttestationData.slot to get_attestation_slot; implement convert_to_indexed; update checkAttestation and processAttestations to 0.6.3; remove spurious assertion in beacon node related to invalid attestations
* replace 0.5 get_winning_root_and_participants with 0.6 get_winning_crosslink_and_attesting_indices; update process_crosslinks to 0.6.3
* mark both remaining 0.6.0 spec implementations as 0.6.3
* clear out all remaining spec version 0.6.1 refs
* GENESIS_SLOT and GENESIS_EPOCH are 0
* rm 0.5 get_attestation_participants in favor of 0.6 get_attesting_indices
* address mratsim's comment
* time can be equal to genesis
* fix invalid block assertions; those were essentially spurious
* allow toBeaconTime to handle time before genesis (in accordance with now(...) which states time can exist before GENESIS)
* Proto changes to facilitate backward sync
* Update to latest spec types in sync proto
* Use blockpool for more straightforward block headers collection
* Added BlockPool.getRef
* Update beacon_chain/sync_protocol.nim
Co-Authored-By: Jacek Sieka <arnetheduck@gmail.com>
* update process_justification_and_finalization to 0.6.2; mark AttesterSlashing as 0.6.2
* replace get_effective_balance(...) with state.validator_registry[idx].effective_balance; rm get_effective_balance, process_ejections, should_update_validator_registry, update_validator_registry, and update_registry_and_shuffling_data; update get_total_balance to 0.6.2; implement process_registry_updates
* rm exit_validator; implement is_slashable_attestation_data; partly update processAttesterSlashings
* mark HistoricalBatch and Eth1Data as 0.6.2; implement get_shard_delta(...); replace 0.5 finish_epoch_update with 0.6 process_final_updates
* mark increase_balance, decrease_balance, get_delayed_activation_exit_epoch, bls_aggregate_pubkeys, bls_verify_multiple, Attestation, Transfer, slot_to_epoch, Crosslink, get_current_epoch, int_to_bytes*, various constants, processEth1Data, processTransfers, and verifyStateRoot as 0.6.2; rm is_double_vote and is_surround_vote
* mark get_bitfield_bit, verify_bitfield, ProposerSlashing, DepositData, VoluntaryExit, PendingAttestation, Fork, integer_squareroot, get_epoch_start_slot, is_active_validator, generate_seed, some constants to 0.6.2; rename MIN_PENALTY_QUOTIENT to MIN_SLASHING_PENALTY_QUOTIENT
* rm get_previous_total_balance, get_current_epoch_boundary_attestations, get_previous_epoch_boundary_attestations, and get_previous_epoch_matching_head_attestations
* update BeaconState to 0.6.2; simplify legacy get_crosslink_committees_at_slot infrastructure a bit by noting that registry_change is always false; reimplment 0.5 get_crosslink_committees_at_slot in terms of 0.6 get_crosslink_committee
* mark process_deposit(...), get_block_root_at_slot(...), get_block_root(...), Deposit, BeaconBlockHeader, BeaconBlockBody, hash(...), get_active_index_root(...), various constants, get_shard_delta(...), get_epoch_start_shard(...), get_crosslink_committee(...), processRandao(...), processVoluntaryExits(...), cacheState(...) as 0.6.2
* rm removed-since-0.5 split(...), is_power_of_2(...), get_shuffling(...); rm 0.5 versions of get_active_validator_indices and get_epoch_committee_count; add a few tests for integer_squareroot
* mark bytes_to_int(...) and advanceState(...) as 0.6.2
* rm 0.5 get_attesting_indices; update get_attesting_balance to 0.6.2
* another tiny commit to poke AppVeyor to maybe not timeout at connecting to GitHub partway through CI: mark get_churn_limit(...), initiate_validator_exit(...), and Validator as 0.6.2
* mark get_attestation_slot(...), AttestationDataAndCustodyBit, and BeaconBlock as 0.6.2
* implement get_churn_limit from 0.6.1; update initiate_validator_exit and get_previous_epoch to 0.6.1; remove obsoleted/non-spec reduce_balance, replaced by decrease_balance; mark BeaconBlock as 0.6.1
* rename get_block_root to get_block_root_at_slot and introduce epoch-oriented get_block_root; implement get_attestation_slot, get_matching_source_attestations, get_matching_target_attestations, get_matching_head_attestations, 0.6.1 get_attesting_indices, get_unslashed_attesting_indices, get_attestation_deltas, process_rewards_and_penalties; rm get_inactivity_penalty
* update Validator and processVoluntaryExits to 0.6.1; rm obsolete inclusion_slots/inclusion_distances
* rm removed activate_validator; mark DepositData, misc values, Gwei values, Randao processing, state caching as 0.6.1; update GENESIS_SLOT to 64, since it doesn't quite yet work at 0
* mark BeaconBlockHeader as 0.6.1; update BeaconBlockBody to 0.6.1; rename WHISTLEBLOWER_REWARD_QUOTIENT to WHISTLEBLOWING_REWARD_QUOTIENT; update slash_validator to 0.6.1
* implement 0.6.2 is_slashable_validator; update processProposerSlashings to 0.6.2; mark state caching as 0.6.2
* mark get_total_active_balance and process_slashings as 0.6.2; update get_base_reward to 0.6.2
* rm prepare_validator_for_withdrawal, process_exit_queue; mark mainnet misc constants as 0.6.2; update process block header to 0.6.2
* address mratsim's code review comment
* Initial move constants to mainnet preset
* Bump fixtures to include shuffling with minimal preset
* Add minimal preset with shuffling test
* Add minimal preset to the full test suite
* use preset() everywhere
* initial new get_beacon_proposer_index and dependencies (get_shuffled_index, get_shard_delta, get_epoch_start_shard, get_crosslink_committee)
* more 0.6.1 updates
* clean up debugEchos and fix validator keygen to create correct indices
* Change digests to SHA2-256 (from Keccak256)
* Fix sha256 digest initialization - pass shuffling test
* Add comments + remove old shuffling tests
* Remove stale tree hashing tests
* Small toOpenArray optim + notes on in-place hashing
* Revert "Revert "Update test repo""
This reverts commit f385467cd3.
* Revert "Revert "Fix SIGFPE on shuffling for 0""
This reverts commit 226d380f87.
* Revert "Revert "Implement shuffling test (pending typedesc and shuffling algo fix)""
This reverts commit 813cb6fbb8.
* withEth2hash templates now needs ctx.init()
* Use init-update-finish to avoid burnMem
* signed_root -> signing_root
* implement new process_deposit; update timing parameters to 0.6.1; update Deposit to 0.6.1 and remove DepositInput
* update get_active_validator_indices and get_epoch_committee_count to 0.6.1; rm get_current_epoch_committee_count, get_previous_epoch_committee_count, and get_next_epoch_committee_count; bump state_sim default validator count a bit more
* re-introduce 0.5.1-ish get_active_validator_indices, get_epoch_committee_count as scaffolding for still-0.5.1ish shuffling
* track justified and head blocks correctly in presence of blank slots
* fix new block state root
* keep list of viable heads instead of walking children
* disable json bitfield deserializer (needs a corresponding serializer)
* fix handshake best & finalized root
* begin 0.6.0: new get_domain/increase_balance/reduce_balance, BeaconState.validator_balances -> BeaconState.balances, some renamed constants, transaction processing changes, SlashableAttestation field name changes, 0.6.0 get_beacon_proposer_index always uses given state's slot, update tests subrepo
* mark get_bitfield_bit/bls_verify_multiple/stat-list-lengths/is_active_validator/is_surround_vote/slot_to_epoch/int_to_bytes/etc as unchanged in 0.6.0; rm Eth1DataVote/maybe_reset_eth1_period and thus adjust expected tree hash test results
* mark verify_bitfield/bls_verify/deposit-contract/VoluntaryExit/PendingAttestation/Historicalbatch/Fork as 0.6.0; update DOMAIN_BEACON_BLOCK to DOMAIN_BEACON_PROPOSER
* update Crosslink to 0.6.0 (also requires tree hashing test result change, so isolate in individual commit)
* mark verify_merkle_branch/get_delayed_activation_exit_epoch/ProposerSlashing/Attestation/AttestationDataAndCustodyBit/hash/integer_squareroot/get_epoch_start_slot/is_double_vote/get_randao_mix/generate_seed as 0.6.0; update reward and penalty quotients; SlashableAttestation -> IndexedAttestation; rm get_fork_version; ATTESTATION_INCLUSION_REWARD_QUOTIENT -> PROPOSER_REWARD_QUOTIENT
* Load full state test + Add json-serialization for Bitfield
* Implement empty_block_transition test (but test is missing the end state)
* Use the provided empty block instead of mocking one
* Add failing block signing test
* Tests that can't be passed now are now "for information" + indent the "information"/hash given
* fix node.state being used unsafely across async callbacks (fixes#230)
* node.state -> node.stateCache
* fix attestation validation not to use asserts
* re-enable attestation pool tests
* prepare for resizing validator registry
* rm now-superceded shuffling cache (shuffling is only called from get_crosslinks), which was badly architected due to trying to exist in state; rm one more vestige of previous light-client regime (one more to go, from datatypes)
* fix wrong shuffling list size (active validator size, not validator size) to make consistent with 0.5.1 (will be inconsistent with testnet0); fix typo and change defaults in state_sim
* doAssert a couple of constant relationships necessary to avoid underflow; rm non-spec, unused helper function get_new_recent_block_roots
* refactor separate crosslink_committee_cache and winning_root_participants_cache(s) into StateData object; remove last vestige of previous shuffling cache
* separate out caching parts of StateData to new StateCache object
* ssz: avoid memory allocations
* a bit fishy with the 32-item stack.. this should be a smallvector
* digest: avoid another burnmem
* avoid a few allocations by using iterator
this is the beginning of tracking block-slots more precisely, so we can
the justification epoch slot bug.
* avoid asyncDiscard (swallows assertions)
* fix attestation delay
* fix several state root cache bugs
* introduce workaround for genesis epoch spec issue
* no need to pass prev_block_root when updating state
* some Slot fixes
* fix `hash_tree_root` for Slot, Epoch
* detect missing hash_tree_root type support
* remove some <0.5 state checks
* ssz: update to 0.5.1:ish
* slightly fewer seq allocations
* still a lot of potential for optimization
* fixes#174
* ssz: avoid reallocating leaves (logN merkle impl)
* update processExits to 0.5.1
* mark process_deposit, get_empty_block as 0.5.1; update get_genesis_beacon_state to 0.5.1; implement processDeposits
* hotfix via https://github.com/ethereum/eth2.0-specs/pull/821
* rm gone-in-0.5.0 Proposal, verifyBlockSignature, and slot check which moved to spec function processBlockHeader
* mark get_attestation_participants and get_epoch_committee_count as 0.5.1; finish updating processAttestations to 0.5.1; add kludgy workaround for bug relating to get_winning_roots_etc using crosslink_data_root as index when we have that as ZERO_HASH for all leading to it confusing attesters on different shards; rm BeaconState.latest_attestations, which splits into previous_epoch_attestations and current_epoch_attestations
* Fix CI due to removed latest_attestations field
* add simple bitfield type (fixes#19)
* fix bit endianess to match spec
* consolidate attestation and block logging
* cruft cleanup
* run optimizer on tests, speeds up build
* begin refactoring 0.5.0 epoch transition at justification and finalization
* update processTransfers to 0.5.0 spec
* update get_crosslink_committees_at_slot to 0.5.0 except for noted workaround for pre-0.5.0 spec bug related to epoch boundary conditions, to be flipped in more coordinated way with other epoch processing changes
* mark ejection processing as 0.5.0
* 0.5.0 epoch update finalization
* rm BEACON_CHAIN_SHARD_NUMBER to complete updating miscellaneous constants to 0.5.0
* mark verify_slashable_attestation as 0.5.0
* update process_attester_slashing to 0.5.0
* update process_slashings(...) to 0.5.0 and mark process_exit_queue as 0.5.0
* refactor epoch processing by implementing 0.5.0's update_registry_and_shuffling_data(...)
* begin 0.5.0 spec update: parent_root -> previous_block_root, BeaconState.justified_epoch -> BeaconState.current_justified_epoch, DOMAIN_PROPOSAL -> DOMAIN_BEACON_BLOCK, temporarily rename BeaconBlockHeader to BeaconBlockHeaderRLP to allow for gradual re-merging without disrupting RLP; mark a few unchanged functions and data types, implement get_temporary_block_header/get_empty_block/should_update_validator_registry/processBlockHeader/cacheState; update a few others
* a dozen or so more trivial mostly comment changes, finding more unchanged parts of 0.5.0
* several more trivial changes; goal is to reduce noise around the upcoming substantial changes (epoch processing, etc)
* remove some redundant state updates
* when attesting late, use correct state / head
* don't send out obsolete attestations
* don't propose obsolete blocks
* remove some more resundant state updates :)
* simplify block logging (experimental)
* document fork choice division
* fix some Slot / Epoch conversion warnings
* set epoch_boundary_root - chain finalizes!
* fix slotStart to offset GENESIS_SLOT
* work around bug that will be fixed by
https://github.com/ethereum/eth2.0-specs/pull/732
* compile with debug info (there was a GC-related crash in C land)
* processEpoch 5x faster, total 2x faster, with 16k validators
* don't recompute active_validator_indices as much
* remove duplicate process_ejections function
* prevent balance underflow, per spec implementation note
* verify that permutation shuffing works: add YAML dependency to be used for ingesting test cases; switch from blake2 to keccak256 to match EF test cases; remove inefficient naive-spec-version of shuffling algorithm now that protolambda's can be tested directly
* Complete scan through v0.3.0 spec; remaining known discreptancy is in bls_verify_multiple
* switch remaining slot-misuses of get_active_validator_indices to epochs
* spec workaround
* finish first 0.3.0 pass by getting slow, naive version of bls_verify_multiple running
* implement in-memory block graph
* store tail block in database
* resolve unknown parents by syncing them from peers
* introduce concept of resolved blocks and attestations - those that
follow minimal protocol rules
* update state head lazily
* log more stuff
* shortHash -> shortLog
* start 9/10 beacon nodes by default, last can be started manually
* see also #134
* fix start.sh epoch length
* convert some asserts to doAsserts to keep them in release mode builds; rename get_initial_beacon_state to get_genesis_beacon_state to track spec; switch target spec version to 0.3.0; switch references to penalize_validator to slash_validator/slashValidator to track spec; make some function returns safer by omitting 'return'
* 2x shuffling speedup by hoisting pivot calculations per https://github.com/protolambda/eth2-shuffle
* fix initial attestation pool on reordered attestations
* simplify db layer api
* load head block from database on startup, then load state
* significantly changes database format
* move subscriptions to separate proc's
* implement block replay from historical state
* avoid rescheduling epoch actions on block receipt (why?)
* make sure genesis block is created and used
* relax initial state sim parameters a bit
* switch to v0.2.0 shuffling scheme
* fix some >80 char lines; add get_total_balance helper function (used in epoch processing, etc); note intended removal of repeat_hash and users thereof; add some int_to_bytes and bytes_to_int helpers; more underflow comments; add Gwei type; adjust generate_seed to include additional entropy source; note egregious inefficiencies
* minor code cleanup
* move some general helper functions to helpers.nim and clarify little-endian comments
* s/slot_included/inclusion_slot/; s/participation_bitfield/aggregation_bitfield/; rearrange some type definitions to match spec order
* a couple more Eth1Data-related spec syncs
* s/CrosslinkRecord/Crosslink/
* {MIN,MAX}_DEPOSIT to {MIN,MAX}_DEPOSIT_AMOUNT; rm SHARD_PERSISTENT_COMMITTEE_CHANGE_PERIOD; per https://github.com/ethereum/eth2.0-specs/issues/378 and 35adc9c61a rm persistent_committees, persistent_committee_reassignments, and ShardReassignmentRecord
* complete switchover from status/ValidatorStatusCodes to status_flags/INITIATED_EXIT/WITHDRAWABLE validator representation
You'll need the latest versions of nim-eth-p2p, nim-serialization
and nim-json-serialization.
Before starting the simulation script, make sure to delete any previous
json files from the simulation folder:
```
rm tests/simulation/*.json
tests/simulation/start.sh
```
This should survive the creation of few blocks before diying with a
block validation error.
* spec updates
* balances move out to separate seq
* bunch of placeholders for proof-of-custody / phase1
* fix inclusion distance adjustment
* modify state in-place in `updateState` (tests spent over 80% time
copying state! now it's down to 25-50)
* document several conditions and conversations
* some renames here and there to follow spec
* spec updates
* random small updates
* ssz no longer sorts by field, fix enum serialization
* rewire block processing a little to avoid a few state copies
* add a state simulation tool that writes out jsons
* ssz: finish implementation
* add object support, simplify implementation
* fix extra round of hashing in tree_hash_root
* ssz: cleanups
* work around Nim range bug for Uint24, cleanups
* some minor renames
* fix some leftover block slot references (replaced by state slot)
* fix some more uint underflows
* update epoch calculations (reward et al)
* now works past 100 epochs at least with empty blocks (very slow)
* use repeat_hash from spec in randao
* add some logging to state processing
* export crypto string converters in spec insulation layer
* enable block signature verification
* ssz: add support for arrays, remove custom data type code
* correctly handle previous and new block
* add trivial block processing tests
* prefer iterative repeat_hash
* state transition mostly done
* handle most specials and slashings
* spec updates
* make several constants uint64 to help minimize casting
* document data type woes - will have to revisit these
* change comment style on fields and constants to make room for better
comments
* add BLSVerify and BLSAddPbkeys facades to insulate spec code from
milagro
* fix proof of possession type
* drop explicitly ordered container fields from ssz - there's an issue
open to sort this out before committing it to the spec
* more work on block processing
* fix some unsigned issues
* fix ssz issue when last chunk is not full
* work around empty const seq compiler bug
* XXX -> TODO