* header MMR in use within txhashset itself
works with fast sync
not yet in place for initial header sync
* add the (currently unused) sync_head mmr
* use sync MMR during fast sync
rebuild header MMR after we validate full txhashset after download
* support missing header MMR (rebuild as necessary) for legacy nodes
* rustfmt
* comments/docs
* rustfmt
* cleanup DBBackend
* cleanup DBBackend
* cleanup
* rename to HashOnly
* rustfmt
* cleanup backend.append()
* simply pmmr append api
no need to pass position when appending
* cleanup
* simplify vec_backend to match simpler append api
* rustfmt
* docs/comments
* rustfmt
* cleanup
* First pass at secondary proof of work difficulty adjustments
* Core and chain test fixes
* Next difficulty calc now needs a height. Scaling calculation fixes. Setting scaling on mined block.
* Change factor to u32 instead of u64.
* Cleanup structs used by next_difficulty
* Fix header size calc with u32 scaling
* change keychain to use bip32 paths
* convert keychain to use bip32
* change identifier to be serialisation of 4-level bip32 path
* wallet changes compiling, pass parent key into all wallet functions
* rustfmt
* fix tests in chain
* rustfmt
* core tests passing
* rustfmt
* pool tests
* rustfmt
* fixing wallet tests
* rustfmt
* remove file wallet
* wallet tests compiling
* rustfmt
* remove db_migrate
* successful tx exchange test using BIP32 paths
* rustfmt
* fix wallet derivation paths to m/0/0/0
* wallet test fixed again, working with default path
* rustfmt
* fix server tests
* rustfmt
* make parent_id a trait on walletbackend
* rustfmt
* add ability for wallet to switch between multiple named accounts, and tests (not complete)
* rustfmt
* account switching tests in place and passing
* rustfmt
* compile and test with latest libsecp changes
* added public key sum to calculated e for aggsig
* rustfmt
* Update secp to 26
* bulletproof bip32 path integration
* rustfmt
* wallet restore updated with bip32 paths, also restores accounts
* rustfmt
* rustfmt
* remove old extkey
* remove old extkey
* rustfmt
* add wallet account commands
* rustfmt
* update wallet documentation
* rustfmt
* merge from master
* update libsecp tag
* merge from upstream and fix server test
* rustfmt
* rustfmt
* merge from master
* update latest libsecp merge
* fix commitment to zero value generation
When processing a new block, attemps to make the scope of the
corresponding `txhashet` lock as small as possible. The idea is
to avoid bad interactions with orphan locks or block post
processing (i.e. adapter events, etc)
* Go back to db for head and header_head
* Use batch consistently for db access
* Pass active txhashset and batch in the ctx
* Only update head in db if total work increases
* Only updated header_head if total work (on header chain) increases
* cuck placeholder
* rustfmt
* cuckatoo, early days
* rustfmt
* data structures are in place, siphash key creation is consistent with @tromp
* solver in place, (not yet working)
* cuckatoo test solver working with test nonce
* rustfmt
* update solver to remove adjacency list removals
* verifier functioning
* rustfmt
* Proper error handing in Cuckatoo module, couple of tests
* modify cuckoo/cuckatoo solvers and verifiers to function identically, in advance of trait refactoring
* rustfmt
* refactor PoW context into trait, default to using cuckoo context
* rustfmt
* create macros for integer casting/unwraps
* don't instantiate structs when just verifying, add test validation vector for cuckatoo 29
* rustfmt
* don't init cuckoo structs if just validating
* test fix
* ensure BH hashing for POW is only done within miner/validators
* introduce rewindable_kernel_view
cleanup header in extension
* cleanup and docs/comments
* txhashset does not need to be mutable here
* pull validate_kernel_history out into fn
* block_sums and full kernel sum verification
* rustfmt
* add docs/comments
* docs
* rustfmt
* comment on fact total_kernel_sum is redundant now
* make sure we setup block_sums correctly on a fork
* rustfmt
* replace those asserts with errors
* rustfmt
* Move Proof and Difficulty types to pow module. Difficulty scaling calculation.
* Diffculty scaling and size shift for 2nd PoW
* Backport e7eb26ee
* Test compilation fixes
* Scaling only need to go one way, as @tromp pointed out
* document what we do during pipe::apply_block()
* rustfmt
* wip
* rustfmt
* wip
* additional check_known_store and check_known_mmr checks in process_block
* rustfmt
* cleanup coinbase maturity check in process_block
* consolidate the "check in store" logic
add TODOs around the 50 block OldBlock logic
* rustfmt
* cleanup
* fix: if block in orphans queue has a forked parent, cause infinite loop in check_orphans()
* process all orphans at a given height before go to next height
* refactor txhashset to only take a single header
no need to pass in current head_header each time
* rustfmt
* fix bug introduced in rewind with LMDB
* rustfmt
* add some comments
* Check txhashset content before zip/unzip
* Add header in txhashset verification
* Add copy function and test
* Add file util
* Now check and remove unexpected files instead of just crashing
* improve: time crate flagged as deprecated, switch to actively maintained chrono crate
* improve: complete the switching from deprecated time crate to chrono crate, for all the tests part
* improve: complete switching to chrono crate, for the left tests in 'chain' and 'wallet'
* Refactor hash cache handling to add properly. Only add to cache if the block is definitevely accepted or rejected.
* Dedup of header processing now looks like premature optimization. Very fast anyway. Removing the header hash cache.
* Remove now unnecessary txhashset write lock
* Ring buffer of hashes the chain has already processed
* Specifically report too old blocks as peer should be banned
* Move sync check for block relay, clean TODO
* No use processing transactions when syncing
* Ignore blocks older than horizon in pruning nodes
* fix misbehaving simulnet fastsync test
cleanup redundant cutoff vs bitmap params is rewind and check_compact
* make sure we do not verify full kernel history on a writeable txhashset extension
rework simulnet simulate_fast_sync test to be more robust
* fixup store tests
* sleep for a bit longer to give nodes time to update
their sync_state correctly
* tweak timing of simulate_block_propagation
* Handle SIGINT and SIGTERM (#1180)
* Handle SIGINT and SIGTERM
* pin croaring to version 0.3.2 until we get the clang conflict sorted out (#1183)
* document proposals for - (#1190)
* conditional timelocked outputs, and
* conditional relative timelocked outputs
* problem with validation on rewind
* update difficulty scenarios to display much more data
* correct average sum output
* update pre-genesis block padding to just use previous block's data
Only rewind kernels to avoid requiring proper bitmap extraction. Also avoids maintaining bitmap data for kernels by introducing a "prunable" flag on PMMR backend.
* A new sync status enum encapsulated in a state struct allows tracking of where sync is at. Leveraging it in the TUI to provide more helpful messages.
* Percentage progression for most sync steps
* Added sizeshift to proof of work and encoding as VLQ
* Fix some loose ends to get things to compile
* Rename sizehift to min_sizeshift
* Pipeline checks for PoW Cuckoo Cycle size shift and adjustment
factor before difficulty comparison.
* Working delta+VLQ encoding of u64 PoW, unfortunately still a
little larger than u32, at least for Cuckoo30.
* Changed binary encoding of proof of work to a sequence of exact
compact bit representation of each nonce. Somewhat simpler,
shorter and matches the data to be hashed.
* Few fixes based on @tromp feedback:
* Max nonce is 2^(N-1)
* Need a separate constant for reference sizeshift
* Cuckoo implementation now conserves sizeshift. Test providing a
block at higher sizeshift.
* Last small overflow protection
* we do not need Merkle proofs to spend coinbase outputs
we only need the output_mmr_size from the block header
* tests working with no Merkle proofs in inputs
* Migrate main node store to LMDB
In preparation to using LMDB as a wallet database, migrate the
node db. There's no point in having 2 key-value stores.
In addition LMDB provides a few advantages as a node db, namely a
much faster build (compared to RocksDb), lesser dependencies and
transactions.
* Migrated p2p store to lmdb, stuff compiles
* More fixes, chain tests starting to pass
* Fixed txhashset rollback messing with block save and general batch delimitation. Chain tests passing.
* rustfmt
* LMDB max map size of 10MB isn't really workable. Half TB seems reasonable.
* Fix wallet tests
* Rather crucial commit was missing
* rustfmt
* Fixing new merged tests following lmdb changes
* rustfmt
* * Make txhashset validation read-only on fast sync to avoid having
a really long open transaction.
* Fix deadlock in new block processing, batch should always be
created within a txhashset lock (when they interact).
* Comment about batch and txhashset interlacing
* Fix store tests to use batch
* Externalize wallet config and seed
* Converted direct read access to file outputs map to an iterator
* Cleaned up and simplified wallet Backend trait:
* No more direct mutable access to internal structures (HashMap)
* Batch interface for all writes
* Remove unneeded read wrapper (read_wallet)
* rustfmt
* First (incomplete) pass at wallet LMDB backend
* Progressing on lmdb backent iml
* Added batch impl for LMDB wallet backend. Pretty much done with it, but not sure how to deal with commit (owned).
* rustfmt
* Wrapping LMDB batch around a refcell to work around borrow rules
* Compilation up to grin chain
* Add kernel commitments sum and kernel and output MMR sizes to block header
* Sum a block without including previous sums, cleanup. Blocks are now summed and validated based on their own totals and not the totals since genesis. This allows to get rid of BlockSum and simplified the setting of a new block's roots, kernel sum and MMR sizes. Fixes#116
* Additional kernel MMR validation to check all prior header roots successively
* Wallet tests fix
* only store leaves in rm_log
* cleanup
* commit
* add failing test to cover case where we compact
an already compacted data file
* fix the logic for pruning the data file
* rm_log only contains leaves
prunelist only contains non-leaf subtree roots
* cleanup
* commit
* bitmap impl running in parallel
* rustfmt
* this is better - rewind unremoves outpu pos spent by rewound inputs
* commit
* commit
* pass bitmap around when rewinding
* store and retrieve input bitmap per block from the db
* Replace the RemoveLog with the UTXO set.
* utxo set starting to pass tests
* stuff works...
* split store types out
added some tests to compare the performance of the rm_log and the proposed utxo_set
* pull prune_list out into standalone file
* cleanup, get rid of unused height param
* cleanup and add doc comments
* add support for migrating rm_log to utxo_set
* take snapshot of utxo file during fast sync
implement migration of rm_log -> utxo_set
* rename rewound_copy to snapshot
* fixup pmmr tests to reflect cutoff_pos
* cleanup unused import
* check_compact needs to rewind the utxo_set as appropriate
* fix pool tests
* fixup core tests
* cache block_input_bitmaps via LruCache in store
* cache block header on initial write to db
* rename utxo_set -> leaf_set
and remove references to "spent" in grin_store
* better document the rewind behavior
* First pass at restructuring the keychain crate and introducing a Keychain trait
* Parameterized everything that had to. Stuff compiles.
* More stuff compiles, fix most tests
* Big merge, pushing down opening the keychain forced adding factory methods on trait
* Test fixes for pool and servers crate
Small refactoring of one folder, if it makes sense I could extend the scope.
* Remove some cloning (real and just verbosity in the code)
* Naming conventions like to/into*
* Some Clippy's suggestions
I found that we don't use field init shorthand syntax, so I didn't touch this part, was it discussed before?
* verify a tx like we verify a block (experimental)
* first minimal_pool test up and running but not testing what we need to
* rework tx_pool validation to use txhashset extension
* minimal tx pool wired up but rough
* works locally (rough statew though)
delete "legacy" pool and graph code
* rework the new pool into TransactionPool and Pool impls
* rework pool to store pool entries
with associated timer and source etc.
* all_transactions
* extra_txs so we can validate stempool against existing txpool
* rework reconcile_block
* txhashset apply_raw_tx can now rewind to a checkpoint (prev raw tx)
* wip - txhashset tx tests
* more flexible rewind on MMRs
* add tests to cover apply_raw_txs on txhashset extension
* add_to_stempool and add_to_txpool
* deaggregate multi kernel tx when adding to txpoool
* handle freshness in stempool
handle propagation of stempool txs via dandelion monitor
* patience timer and fluff if we cannot propagate
to next relay
* aggregate and fluff stempool is we have no relay
* refactor coinbase maturity
* rewrote basic tx pool tests to use a real txhashset via chain adapter
* rework dandelion monitor to reflect recent discussion
works locally but needs a cleanup
* refactor dandelion_monitor - split out phases
* more pool test coverage
* remove old test code from pool (still wip)
* block_building and block_reconciliation tests
* tracked down chain test failure...
* fix test_coinbase_maturity
* dandelion_monitor now runs...
* refactor dandelion config, shared across p2p and pool components
* fix pool tests with new config
* fix p2p tests
* rework tx pool to deal with duplicate commitments (testnet2 limitation)
* cleanup and address some PR feedback
* add big comment about pre_tx...
* beginning to refactor keychain into wallet lib
* rustfmt
* more refactor of aggsig lib, simplify aggsig context manager, hold instance statically for now
* clean some warnings
* clean some warnings
* fix wallet send test a bit
* fix core tests, move wallet dependent tests into integration tests
* repair chain tests
* refactor/fix pool tests
* fix wallet tests, moved from keychain
* add wallet tests
* block sums and reworked block validation
read and write block_sums
refactor validate on both block and txhashset
write block_sum on fast sync
we store the kernel_sum (need to account for the offset)
* block_sums
* rustfmt
* cleanup
* wip BlockMarker struct, get rid of PMMRMetadata
* use rewind to init the txhashet correctly on startup, we do not need to track pos via metadata (we have block markers), we do not need to open the txhashset with specific pos (we have rewind)
* better logging on init
* keep rewinding and validating on init, to find a good block
* use validate_roots on chain init
* Beginning to remove in-process miner
* rustfmt
* rustfmt
* rustfmt
* rustfmt
* remove pow crate and put remnants into core
* rustfmt
* fix test compilation in core and chain
* rustfmt
* Updating server tests to use test miner
* rustfmt
* rustfmt
* remove pow from test matrix
* adding basic stratum stats to TUI
* run stratum server at all times, and halt messages while syncing
* fix core tests
* add ability to run internal test miner for cuckoo 16 testing
* modify build instructions
* commit
* rustfmt
* only fast sync once
then treat as full sync
* commit
* add some debug logging so we can track progress when verifying rangeproofs
* rustfmt
This PR adresses #166
Error handling in wallet was ported to failure in https://github.com/mimblewimble/grin/pull/713
Using the same error model makes wallet code simpler and may simplify migration to Hyper.
This PR fixes#953 by introducing a lock for txhashet_write. It's not enough
to synchronize access to in memory data, files also needs to be protected, so
a general txhashset lock was introduced.
* update pmmr to get batch of elements by insertion position
* update pmmr to get batch of elements by insertion position
* add api + chain calls to get traversed outputs back out
* add api + chain calls to get traversed outputs back out
* first pass getting wallet restore to work again with updated utxo-walking api
* documentation and spelling
* unused values in tests; just .unwrap()
* unneeded macro_use (router)
* unneeded macro_use and use-imports
* unused value -> .unwrap
* unused variables
* clarify that " is required (see 107ea3c4dd)
* first steps to dig into #933 test_p2p issues
* less simulnet build warnings
Our chain orphans data structure now does:
* Eviction based on a max total number of orphaned blocks
* Evicts further away first, then too old
* Avoids all cloning (blocks can be big)
This allows sync to be a little more stupid, only reducing the
number of blocks it requests when orphans get nearly full.
Fixes#897
* Fix and cleanup of fast sync triggering logic
* New txhashset on fast sync has to be applied, not rolled back
* Do not block if peer send buffer is full, fixes#912
* add hint for gcc-5 for building CUDA plugin
* add N_BLOCks comment for >=6GB GPU cards
* minor logging cleanup
* mark to be kept + reformat as "@ height [hash]"
* show CuckooNN + better wording
* Bump up crates versions
* Finally add a Cargo.lock to avoid dependency breakages
* Build doc update for testnet2
* Fix test framework not really using its mining config
* Testnet2 genesis, best so far at 128 difficulty (a nice number)
* Minor build doc update
* move some debug! to trace!
* more informative debugs
* standardising on always showing chain tips as "cumulative difficulty @ height [hash]"
* make 2 debug outputs into a single
* "no peers" as warning (not info) to let it stand out more clearly
* move fn param (used only in this one debug line)
* clarify difficulty "units"
* rewind to header as part of txhashset validation
otherwise we risk including a new block and the roots do not match
* fix bug in rm_log rewind (wants to be inclusive of provided index)
* put block marker in the index so we can rewind correctly
during validation of the new txhashset
* rustfmt
* remove difficulty field from block_header (derive from total_difficulty)
* address feedback on PR and general cleanup
* rustfmt
* rework pow/difficulty validation in pipe::validate_header
now that we only have total_difficulty available
* cleanup various todos
* rustfmt
* rework DifficultyIterator to track header and prev_header state
* rustfmt caught some garbage syntax
* cleanup
* move from storing per block kernel_offset in the block header
to storing the total accumulated kernel offset on each block header
* rustfmt
* cleanup
* wip
* failing test for being too eager when pruning a sibling
* commit
* rustfmt
* [WIP] modified get_shift and get_leaf_shift to account for leaving "pruned but not compacted" leaves in place
Note: this currently breaks check_compact as nothing else is aware of the modified behavior
* rustfmt
* commit
* rustfmt
* basic prune/compact/shift working
* rustfmt
* commit
* rustfmt
* next_pruned_idx working (I think)
* commit
* horizon test uncovered some subtle issues - wip
* rustfmt
* cleanup
* rustfmt
* commit
* cleanup
* cleanup
* commit
* rustfmt
* contains -> binary_search
* rustfmt
* no need for height==0 special case
* wip - works for single compact, 2nd one breaks the mmr hashes
* commit
* rustfmt
* fixed it (needs a lot of cleanup)
we were not traversing all the way up to the peak if we pruned an entire tree
so rm_log and prune list were inconsistent
* multiple compact steps are working
data file not being copmacted currently (still to investigate)
* cleanup store tests
* cleanup
* cleanup up debug
* rustfmt
* take kernel offsets into account when summing kernels and outputs for full txhashset validation
validate chain state pre and post compaction
* rustfmt
* fix wallet refresh (we need block height to be refreshed on non-coinbase outputs)
otherwise we cannot spend them...
* rustfmt
* first explorations at attempting to integrate more user-friendly status screen/ui
* rustfmt
* adding some logo and color for visual interest
* formatting
* better integration with stdout, cleaner looking startup and shutdown
* rustfmt
* update to framework, and first collection of stats from server
* rustfmt
* commit of basic stat screen, think it's in a good enough state to share
* rustfmt
* fix to automated tests
* fix to automated tests
* grin.toml setting
* grin.toml setting
* grin.toml setting
* Cleanup MMRs positional indexes. Get rid of the kernel position index.
Introduced a new block marker index that keeps, for each block, the
respective positions in the output and kernel MMRs. This is now sufficient
for rewind.
* Block marker compaction
* Implementation of compaction for the chain. Single entry point on the chain triggers compaction of all MMRs as well as the cleanup of the positional index and full blocks.
* API endpoint, additional tests and more fixes for compaction
* Also prune PMMR metadata, minor bug fix
* PMMR store tests fix
* adding file position index data accessable to the chain, and allowing for storage of such within db
* missing file
* restart files at last recorded position in stored file metadata
* just use tip to store last pmmr index information
* error handling
* test fix
* family_branch() to recursively call family() up the branch
todo
- we hit a peak, then we need to get to the root somehow
- actually get the hashes to build the proof
* wip
* some additional testing around merkle tree branches
* track left/right branch for each sibling as we build the merkle path up
* MerkleProof and basic (incomplete) verify fn
* I think a MerkleProof verifies correctly now
need to test on test case with multiple peaks
* basic pmmr merkle proof working
* MerkleProof now serializable/deserializable
* coinbase maturity via merkle proof basically working
* ser/deser merkle proof into hex in api and wallet.dat
* cleanup
* wip - temporarily saving merkle proofs to the commit index
* assert merkle proof in store matches the rewound version
there are cases where it does not...
* commit
* commit
* can successfully rewind the output PMMR and generate a Merkle proof
need to fix the tests up now
and cleanup the code
and add docs for functions etc.
* core tests passing
* fixup chain tests using merkle proofs
* pool tests working with merkle proofs
* api tests working with merkle proof
* fix the broken comapct block hashing behavior
made nonce for short_ids explicit to help with this
* cleanup and comment as necessary
* cleanup variety of TODOs
* beginning to add bullet proof messages
* Updated core transaction creation to embed the output's value and switch commit hash as part of the rangeproof message
* formatting issue
* more formatting issues
* Removing conditional feature compliation.. just bulletproofs from now on
* ensure MAX_PROOF_SIZE uses bulletproof sizing instead of earlier version
* updated with switch commit committed to in extra data
* accidentally commented out bullet-proof-size feature
Due to occasional bad network conditions, a node can miss a block.
When the next one is received and detected orphaned, we should at least try a request for the
previous block, assuming it's not already an orphan in itself and we're not syncing already.
No additinal tests were implemented, test like `simulate_full_sync` test this functionality because
sync starts later. It seems to be an issue with sync test coverage. As fix I'd suggest to start sync
as soon as we get a peer connection.
[https://github.com/mimblewimble/grin/issues/705]
* beginning to remove sum
* continuing to remove sumtree sums
* finished removing sums from pmmr core
* renamed sumtree files, and completed changes+test updates in core and store
* updating grin/chain to include removelogs
* integration of flatfile structure, changes to chain/sumtree to start using them
* tests on chain, core and store passing
* cleaning up api and tests
* formatting
* flatfiles stored as part of PMMR backend instead
* all compiling and tests running
* documentation
* added remove + pruning to flatfiles
* remove unneeded enum
* adding sumtree root struct
* wip - basic tx pool lookup for kernel short ids (compact block hydration)
* use the nonce in the compact_block to correctly generate short_ids for lookup
* query the tx pool based on kernel short_ids
* tests passing
* cleanup some logging
* cleanup logging
* WIP - split the key in final tx step
store "offset" on transaction itself
* rebase
* commit
* tx with offset
* got a test tx validating successfully using a sig from a split key and the appropriate offset
* sum up the offset for the block_header
* fix size tests for blocks and compact blocks (header now includes offset)
* use txs with offsets in most of the core tests
some tests now failing
* build kernel from k1G (k2 stored on tx, sum stored on header)
* commit
* tx now has vec of kernels
rework tx and kernel validation
* add test for tx cut_through
* wip - working on splitting in aggsig
* split the key when creating the initial sender aggsig context
* cleanup
* cleanup
* code needs claning up but split keys working for sender/receiver aggsig flow
* cleanup debug logging
* fix tests
* fix merge and basic cleanup
* fix keychain tests to use new tx_id
* Util to zip and unzip directories
* First pass at sumtree request/response. Add message types, implement the exchange in the protocol, zip up the sumtree directory and stream the file over, with necessary adapter hooks.
* Implement the sumtree archive receive logicGets the sumtree archive data stream from the network and write it to a file. Unzip the file, place it at the right spot and reconstruct the sumtree data structure, rewinding where to the right spot.
* Sumtree hash structure validation
* Simplify sumtree backend buffering logic. The backend for a sumtree has to implement some in-memory buffering logic to provide a commit/rollback interface. The backend itself is an aggregate of 3 underlying storages (an append only file, a remove log and a skip list). The buffering was previously implemented both by the backend and some of the underlying storages. Now pushing back all buffering logic to the storages to keep the backend simpler.
* Add kernel append only store file to sumtrees. The chain sumtrees structure now also saves all kernels to a dedicated file. As that storage is implemented by the append only file wrapper, it's also rewind-aware.
* Full state validation. Checks that:
- MMRs are sane (hash and sum each node)
- Tree roots match the corresponding header
- Kernel signatures are valid
- Sum of all kernel excesses equals the sum of UTXO commitments
minus the supply
* Fast sync handoff to body sync. Once the fast-sync state is fully setup, get bacj in body sync
mode to get the full bodies of the last blocks we're missing.
* First fully working fast sync
* Facility in p2p conn to deal with attachments (raw binary after message).
* Re-introduced sumtree send and receive message handling using the above.
* Fixed test and finished updating all required db state after sumtree validation.
* Massaged a little bit the pipeline orphan check to still work after the new sumtrees have been setup.
* Various cleanup. Consolidated fast sync and full sync into a single function as they're very similar. Proper conditions to trigger a sumtree request and some checks on receiving it.
* first pass at allow/deny lists for hard-coded peers (not just seeds)
* commit
* add peers_allow and peers_deny examples and comments to grin.toml
* always ask for compact block
always fail to hydrate
always fallback to requesting full block
* decide to send full (empty) block over compact (empty) block
* add some randomness to the decision around broadcasting an empty block
as a block or as a compact block (so we can exercise more code paths easily)
* [wip] header first propagation
successfully propagating headers (unless we mined the block itself)
not yet asking for the block if we receive a header
* call request_block after successful processing header
* cleanup and skip asking for block if header is an orphan
* comments around error handling in receive_header
* large updates for mining, fix async mode, will list changes in PR
* reset config and build defaults
* change to difficulty calculations
* tweaking mining params and tests
* tweaking to tests
* including pre-genesis data for difficulty adjustments, adding adjustment scenario tests
* further clarifying next_difficulty function
* moving tests out of consensus.rs
* pow test fix
* changing pre-genesis generation
