* Add `BlockAnnounceValidator` trait.

* Add associated data to block announcement.

* Make tests compile.

* Move validator into `sync.rs`.

* Smaller changes.

* Update core/network/src/protocol.rs

Co-Authored-By: Kian Paimani <[email protected]>

* Update core/network/src/protocol.rs

Co-Authored-By: Bastian Köcher <[email protected]>

* Update core/network/src/test/sync.rs

Co-Authored-By: Bastian Köcher <[email protected]>

* Formatting.

* Remove assoc. data from `BlockImportNotification`.

* Use `Option<Vec<u8>>` for associated data.

* Update core/network/src/protocol/sync.rs

Co-Authored-By: Bastian Köcher <[email protected]>

* Fix type error.

* Move best_containing from Client to Backend

* Add comma for clearer diffs

Co-Authored-By: André Silva <[email protected]>

* always fetch epoch from runtime

* node integration tests don't test light nodes

* give stand-in full node a FULL role

* rejig babe APIs

* introduce next-epoch-descriptor type

* overhaul srml-BABE epoch logic

* ensure VRF outputs end up in the right epoch-randomness

* rewrite `do_initialize` to remove unnecessary loop

* begin accounting for next epoch in epoch function

* slots passes header to epoch_data

* pass slot_number to SlotWorker::epoch_data

* begin extracting epoch-change logic into its own module

* aux methods for block weight

* aux methods for genesis configuration

* comment-out most, refactor header-check pipeline

* mostly flesh out verifier again

* reinstantiate babe BlockImport implementation

* reinstate import-queue instantiation

* reintroduce slot-worker implementation

* reinstate pretty much all the rest

* move fork-choice logic to BlockImport

* fix some, but not all errors

* patch test-runtime

* make is_descendent of slightly more generic

* get skeleton compiling when passing is_descendent_of

* make descendent-of-builder more succinct

* restore ordering of authority_index / slot_number

* start fiddling with tests

* fix warnings

* improve initialization architecture and handle genesis

* tests use correct block-import

* fix BABE tests

* fix some compiler errors

* fix node-cli compilation

* all crates compile

* bump runtime versions and fix some warnings

* tweak fork-tree search implementation

* do backtracking search in fork-tree

* node-cli integration tests now work

* fix broken assumption in test_connectivity

* babe tests fail for the right reasons.

* test genesis epoch logic for epoch_changes

* test that epochs can change between blocks

* First BABE SRML test

* Testing infrastructure for BABE

Also includes a trivial additional test.

* Apply suggestions from code review

Co-Authored-By: Bastian Köcher <[email protected]>

* A little more test progress

* More work on BABE testing

* Try to get the tests working

* Implement `UintAuthorityId`-based test mocks

* Fix compilation errors

* Adjust to upstream changes

* Block numbers are ignored in BABE epoch calculation

* authority_index() should ignore invalid authorities

* Fix compile error

* Add tests that session transitions happen

* Check if BABE produces logs

It currently does not.

* Fix test suite

This was really nasty, due to a type confusion that showed up as an
off-by-1 buffer error.

* Add additional tests

Most of these were derived from the current output, so they are only
useful to guard against regressions.

* Make the tests more readable

Also bump impl_version.

* Fix excessive line width

* Remove unused imports

* Update srml/babe/src/lib.rs

Co-Authored-By: André Silva <[email protected]>

* try to fix imports

* Fix build errors in test suite

* tests did not pass

* Try to get at least one digest to be output

Currently, the code emits either no digests (if I don’t call
`Session::rotate_session()` or two digests (if I do), which is wrong.

* More tests

They still don’t work, but this should help debugging.

* fix silly error

* Don’t even try to compile a broken test

* remove broken check_epoch test and add one for genesis epoch

* Check that the length of the pre-digests is correct

* Bump `impl_version`

* use epoch_for_descendent_of even for genesis

* account for competing block 1s

* finish srml-babe docs

Co-Authored-By: André Silva <[email protected]>

* address grumbles

* blockchain cache pruning strategy

* added some internal docs to cache_pruning_strategy

* Update core/client/db/src/cache/mod.rs

Co-Authored-By: DemiMarie-parity <[email protected]>

* multiple remote values in single message

* keys_str: String ->keys_str: closure

* do not panic during execution proof check

* Update core/state-machine/src/lib.rs

Co-Authored-By: DemiMarie-parity <[email protected]>

* Update core/state-machine/src/lib.rs

Co-Authored-By: DemiMarie-parity <[email protected]>

* Update core/state-machine/src/lib.rs

Co-Authored-By: DemiMarie-parity <[email protected]>

* BackendTrustLevel enum

* up runtime version

* Update core/state-machine/src/lib.rs

Co-Authored-By: DemiMarie-parity <[email protected]>

* Update core/state-machine/src/lib.rs

Co-Authored-By: DemiMarie-parity <[email protected]>

* fixed some grumbles

* Update core/state-machine/src/testing.rs

Co-Authored-By: Gavin Wood <[email protected]>

* Update core/state-machine/src/lib.rs

Co-Authored-By: Gavin Wood <[email protected]>

* mov where

* spaces -> tabs (to restart build)

* Start refactoring state-machine crate

* More improvement to state-machine

* Fix tests compilation on master and remove warnings

* Fix compilation

* Apply suggestions from code review

Co-Authored-By: Sergei Pepyakin <[email protected]>

* Update core/state-machine/src/basic.rs

Co-Authored-By: DemiMarie-parity <[email protected]>

* Line width

* Update core/primitives/src/storage.rs

Co-Authored-By: Benjamin Kampmann <[email protected]>

* Update core/state-machine/src/error.rs

Co-Authored-By: Benjamin Kampmann <[email protected]>

* Review feedback

* Add transactions from retracted blocks back to the pool

* Line width

* Reverse retracted

* changes tries build cache

added CT build cache test

* fix lines width

* fixed some grumbles

* clear cache when: digests disabled, top-level or skewed digest is built

* cached_changed_keys -> with_cached_changed_keys

* client: only report block import to telemetry if new best

* grandpa: fix tests

* consensus: derive Default for ImportedAux

* network: fix test

cheme authored Sep 02, 2019 and Svyatoslav Nikolsky committed Sep 02, 2019

* Initial implementation, some redundancy is awkward and there is
some useless computation (but there is a pending pr for that).
Next are tests.

* Minimal tests and fix extend child.

* implement iterator for change child trie.

* prune child trie.

* Fix pruning test.

* bump spec version.

* Avoid empty child trie (could also be checked before)

* tabs.

* Fix child digest overriding each others.

* Restore doc deleted on merge.

* Check correct child value on extrinsics build.

* Revert runtime version update.

* chain+state RPCs are async now

* wrapped too long lines

* create full/light RPC impls from service

* use ordering

* post-merge fix

* generalize tree_root to remove client.backend dependency

* replace client.backend.blockchain.header with client.header

* move used_state_cache_size into client info

* Create intermediate Setup State. Fixes #1134

* remove client.backend from finality proof

* update node-template

* move memory backend into test helper mode

* move test helper into client

* starting the big refactor, remove unused functions

* apply_finality

* apply_finality

* replacing more .backend from environment with client directly

* remove .backend from grandpa by using traits

* remove .backend from babe

* remove .backend from tests where it is not needed

* remove .backend from tests

* fixing tests

* fixing tests

* fixing more tests

* fixing tests

* fix all forks test

* fix style

* fixing unnecessary allocation

* remove old test.

* fix service docs

* apply suggestion

* minor clean ups

* turns out the test-helper features actually is being used!

* fixing line length.

* fix line length

* minor cleaning

* Apply suggestions from code review

thanks, @Basti

Co-Authored-By: Bastian Köcher <[email protected]>

* address grumbles

* simplify finalize block on client

* move block back into inner function

* Apply suggestions from code review

Co-Authored-By: DemiMarie-parity <[email protected]>

* use as.ref instead of match

* Update core/client/src/backend.rs

Co-Authored-By: DemiMarie-parity <[email protected]>

* CT config methods are accepting zero

* intrduce && use configuration range in CT

* Update core/client/db/src/lib.rs

Co-Authored-By: cheme <[email protected]>

* full PR URI

* updated next_max_level_digest_range comment

* added skewed digest description

* added comment for loop

* call next_max_level_digest_range from prev_max_level_digest_block

* more test cases

* Update core/state-machine/src/changes_trie/surface_iterator.rs

Co-Authored-By: cheme <[email protected]>

* updated comment

* Introduce capabilities filtering for calls.

* Bump impl version.

* Allow RichOffchainCall to only read offchain db.

* Fix code.

* Panic on invalid calls.

* Merge execution contexts and expose capabilities.

* Fix repr

* Re-enable keystore for offchain calls.

* client: don't import blocks that revert finality

* client: test import of blocks that revert finality

* client: replace tempdir with tempfile in test

* Cache idle state

* Display import error by default

* Include uncles

* Filter missing uncles

* Moved inherent registration to a new crate

* Ignore invalid inherent encoding

* Add Call type to extensible transactions.

Cleanup some naming

* Merge Resource and BlockExhausted into just Exhausted

* Fix

* Another fix

* Call

* Some fixes

* Fix srml tests.

* Fix all tests.

* Refactor crypto so each application of it has its own type.

* Introduce new AuthorityProvider API into Aura

This will eventually allow for dynamic determination of authority
keys and avoid having to set them directly on CLI.

* Introduce authority determinator for Babe.

Experiment with modular consensus API.

* Work in progress to introduce KeyTypeId and avoid polluting API
with validator IDs

* Finish up drafting imonline

* Rework offchain workers API.

* Rework API implementation.

* Make it compile for wasm, simplify app_crypto.

* Fix compilation of im-online.

* Fix compilation of im-online.

* Fix more compilation errors.

* Make it compile.

* Fixing tests.

* Rewrite `keystore`

* Fix session tests

* Bring back `TryFrom`'s'

* Fix `srml-grandpa`

* Fix `srml-aura`

* Fix consensus babe

* More fixes

* Make service generate keys from dev_seed

* Build fixes

* Remove offchain tests

* More fixes and cleanups

* Fixes finality grandpa

* Fix `consensus-aura`

* Fix cli

* Fix `node-cli`

* Fix chain_spec builder

* Fix doc tests

* Add authority getter for grandpa.

* Test fix

* Fixes

* Make keystore accessible from the runtime

* Move app crypto to its own crate

* Update `Cargo.lock`

* Make the crypto stuff usable from the runtime

* Adds some runtime crypto tests

* Use last finalized block for grandpa authority

* Fix warning

* Adds `SessionKeys` runtime api

* Remove `FinalityPair` and `ConsensusPair`

* Minor governance tweaks to get it inline with docs.

* Make the governance be up to date with the docs.

* Build fixes.

* Generate the inital session keys

* Failing keystore is a hard error

* Make babe work again

* Fix grandpa

* Fix tests

* Disable `keystore` in consensus critical stuff

* Build fix.

* ImOnline supports multiple authorities at once.

* Update core/application-crypto/src/ed25519.rs

* Merge branch 'master' into gav-in-progress

* Remove unneeded code for now.

* Some `session` testing

* Support querying the public keys

* Cleanup offchain

* Remove warnings

* More cleanup

* Apply suggestions from code review

Co-Authored-By: Benjamin Kampmann <[email protected]>

* More cleanups

* JSONRPC API for setting keys.

Also, rename traits::KeyStore* -> traits::BareCryptoStore*

* Bad merge

* Fix integration tests

* Fix test build

* Test fix

* Fixes

* Warnings

* Another warning

* Bump version.

* WIP: update codec

* WIP

* compiling

* WIP

* rename parity-scale-codec to codec

* WIP

* fix

* remove old comments

* use published crates

* fix expected error msg

* bump version

* fmt and fix

* remove old comment

* fix wrong decoding impl

* implement encode like for structures

* undo removal of old pending changes

* trailingzeroinput

* Apply suggestions from code review

Co-Authored-By: Bastian Köcher <[email protected]>
Co-Authored-By: DemiMarie-parity <[email protected]>

* update codec

* fmt

* version is 1.0.0

* show more error

* fmt

* switch to simple codec, trie broken for now

* Actualy use trie_root_noext

* align some hash, failing test on EMCH comment

* Fix trie code over layout instead of hash, revert legacy code for legacy
mainnet ??

* stub behind LayOut

* fix no_std

* temp solution for legacy trie behind feature legacy-key in various crate

* use remote project

* rc client db need prefix

* update trie deps

* bum spec runtime version

* Removing legacy as default.

* Switch mode to non legacy.

* bump runtime version

* Remove legacy trie compatibility features.

* fix warning

* bump version

* change hash on new test.

* Move dependency (#11 trie PR) patched to a parity repo.
Bench reverted to correct hasher.
Some renaming and doc improvments.

* ChildBitmap renaming to BitMap.

* Renaming of LayOut to Layout.

* formatting.

* Removing abreviation such as _ix nb_ or bm.

* Update deps and apply renaming 'Buff' -> 'Buffer'.

* Align to latest trie crates naming changes.

* Update trie dependency.

* Update trie dependency.

* change block_import test hash

* update trie deps (trie use new scale codec but it does not seems to be
an issue).

* update to use latest trie version (no mgmt of multiple radix).

* tabify

* Restoring test to 10 000.

* Use published crate, trie bench is currently down until publishing
(require another pr to update version).

* Update trie-bench.

* Check the genesis hash in transactions regardless of era.

* Fix check-fees, too.

* Undo.

* Subkey supports new signing.

* Remove unneeded type param.

* Bump tx version

* Build.

* Another build fix

* Build again

* Cleanup

* Another fix.

* Fix

* Fixes

* 6 second blocks.

* Fixes

* Build fix

* Fix

* Fix.

* Reorg test

* Fixed informant misreporting reorgs

* Update cache when reorg is caused by applying finality

* Test for finality reorg

* Simplified test

* Typo

Co-Authored-By: André Silva <[email protected]>

* refactor sr_primitives.

* Fix try build error.

* Line-width

* Ui test.

* Final fixes.

* Fix build again.

* bring back ui test.

* Fix unsigned import.

* Another ui fix.

* Also refactor substrate-primitives

* Fix benchmarks.

* Fix doc test.

* fix doc tests

DemiMarie-parity authored Jul 23, 2019 and asynchronous rob committed Jul 23, 2019

* Add `epoch` field to `SlotInfo`

* Add slot calculations

* More work on epochs in BABE

* Apply suggestions from code review

Co-Authored-By: Bastian Köcher <[email protected]>

* Typo: `/` not `%` for division

* Delete useless `LastSlotInEpoch::put(false)`

* Bump `spec_version`

* Make test suite pass again

* Implement BABE epoch randomness signing

* Try to fix compilation

Currently causes a stack overflow in the compiler

* Fix rustc stack overflow

* Add missing `PartialEq` and `Eq` implementations

* Fix compile errors in test suite

* Another silly compile error

* Clone `epoch`

* Fix compile error in benchmarks

* Implement `clone` for `Epoch`

* Merge master

* AUTHORING TEST PASSES!!!

* Fix compilation

* Bump `spec_version`

* Fix compilation

* Fix compilation (again)

* Remove an outdated FIXME

* Fix run.sh and move it to scripts/

* Delete commented-out code

* Fix documentation

Co-Authored-By: André Silva <[email protected]>

* Fix BABE initialization and refactor

* Respond to review

* typo

* Remove useless data in `CheckedHeader::Deferred`

* Remove `slot_number` from Epoch

It is not needed, and only served to waste space and cause confusion.

* Remove epoch from BABE digests

* Move digest.rs to primitives

* Fix incorrect warning names

* Fix compile error

* Consistent field naming for BABE digests

* More compiler error fixex

* Unbound variable

* more compile errors

* another compile error

* Fix compile errors in runtime

* another compile error

* Another compile error

* Fix wasm build

* missing import

* Fix more compile errors

* yet another compile error

* compile fix in test runtime

* Fix and simplify the BABE runtime

The BABE runtime was massively overcomplicated and also wrong.  It
assumed it needed to:

1. delay new authorities taking effect until the next epoch
2. not delay emitting `Consensus` digests to mark epoch changes

However, the first is handled by the `srml_session` crate, and the
second is flat-out incorrect: `Consensus` digests take effect
immediately.  Furthermore, `srml_babe` tried to duplicate the
functionality of `srml_session::PeriodicSession`, but did it both
clumsily and incorrectly.  Fortunately, the new code is simpler and far
more likely to be correct.

* Use `system` to get the test authorities

The genesis block used by tests defines no authorities.  Only the test
suite is affected.

* Fix test runtime impl for BabeApi::epoch() with std

* Fix compilation

* Cached authorities are in the form of an epoch

not a `Vec<AuthorityId>`.

* `slots_per_epoch` is not fixed in general

The BABE code previously assumed `slots_per_epoch` to be a constant,
but that assumption is false in general.  Furthermore, removing this
assumption also allows a lot of code to go away.

* fix compile error

* Implement epoch checker

* Fix runtime compilation

* fork-tree: add method for finding a node in the tree

* babe: register epoch transitions in fork tree and validate them

* fork-tree: add method for arbitrary pruning

* Expose the queued validator set to SRML modules

BABE needs to know not only what the current validator set is, but also
what the next validator set will be.  Expose this to clients of the
session module.

* Bump hex-literal

Hopefully this will fix the panic

* babe: prune epoch change fork tree on finality

* babe: validate epoch index on transition

* babe: persist epoch changes tree

* Fix compile error in tests

* Fix compile error in tests

* Another compile error in tests

* Fix compilation of tests

* core: move grandpa::is_descendent_of to client utils

* babe: use is_descendent_of from client utils

* babe: extract slot_number from pre_digest in import_block

* Move BABE testsuite to its own file

* Initial part of test code

* Missing `WeightMultiplierUpdate` in test-runtime

* bump `spec_version`

* Add a test that a very bogus is rejected

* Run the tests again

* Fix compiler diagnostics

* Bump `spec_version`

* Initial infrastructure for mutation testing

* Mutation testing of block import

* babe: revert epoch changes in case of block import error

* babe: fix logging target

* babe: BabeBlockImport doesn't box inner BlockImport

* babe: fix epoch check in block import

* babe: populate authorities cache on block authorship

* babe: remove unused functions

* babe: use RANDOMNESS_LENGTH const

* babe: remove unneeded config parameters

* core: revert change to hex dependency version

* cleanup gitignore

* babe: add docs to aux_schema

* babe: remove useless drops in tests

* babe: remove annoying macos smart quotes

* fork-tree: docs

* fork-tree: add tests

* babe: style

* babe: rename randomness config variable

* babe: remove randomness helper function

* babe: style fixes

* babe: add docs

* babe: fix tests

* node: bump spec_version

* babe: fix tests

* client: fix panic on decode block number as u32

* client: add test for number_index_key

* client: add another test at client level

* client: address review grumbles

* client: add tests for reorging on diverged finality

* client: mark finalized block as best if diverged from current best chain

* client: update meta on set_head

* core: add docs about SelectChain to finalize_block

* client: improve finality reorg test

* client: LongestChain doesn't return client best block

* client: LongestChain searches canonical chain

* Switch the client to new futures

* No need for compat in the client

* Fix client tests

* Address review

* SharedFinalityProofRequestBuilder -> BoxFinalityProofRequestBuilder

* SharedThings -> BoxThings

* Fix tests

* build_request_data now takes &mut self

* The other traits now also take &mut self

* More or less fix tests

* Fix tests

* Fix more tests

* Moar tests

* Don't call make_block_import multiple time

* Fix doctest

* check resulting state root on import.

* get root from last method.

* Fix test runtime (was changing state after root calculation).

* Do reset new authorities (just take before root calculation).

* bump impl runtime version.

* Update core/sr-api-macros/tests/trybuild.rs

Co-Authored-By: Bastian Köcher <[email protected]>

* do not return empty entries from state_queryStorage

* revert back None -> null change

* Revert "revert back None -> null change"

This reverts commit 318eb043.

* Draft of new sessions

* Reintroduce tuple impls

* Move staking module to new session API

* More work on staking and grandpa.

* Use iterator to avoid cloning and tuple macro

* Make runtime build again

* Polish the OpaqueKeys devex

* Move consensus logic into system & aura.

* Fix up system module

* Get build mostly going. Stuck at service.rs

* Building again

* Update srml/staking/src/lib.rs

Co-Authored-By: DemiMarie-parity <[email protected]>

* Refactoring out Consensus module, AuthorityIdOf, &c.

* Refactored out DigestItem::AuthoritiesChanged. Building.

* Remove tentative code

* Remove invalid comment

* Make Seal opaque and introduce nice methods for handling opaque items.

* Start to use proper digest for Aura authorities tracking.

* Fix up grandpa, remove system::Raw/Log

* Refactor Grandpa to use new logging infrastructure.

Also make authorityid/sessionkey static. Switch over to storing
authorities in a straight Vec.

* Building again

* Tidy up some AuthorityIds

* Expunge most of the rest of the AuthorityKey confusion.

Also, de-generify Babe and re-generify Aura.

* Remove cruft

* Untangle last of the `AuthorityId`s.

* Sort out finality_tracker

* Refactor median getting

* Apply suggestions from code review

Co-Authored-By: Robert Habermeier <[email protected]>

* Session tests works

* Update core/sr-primitives/src/generic/digest.rs

Co-Authored-By: DemiMarie-parity <[email protected]>

* Session tests works

* Fix for staking from @dvc94ch

* log an error

* fix test runtime build

* Some test fixes

* Staking mock update to new session api.

* Fix build.

* Move OpaqueKeys to primitives.

* Use on_initialize instead of check_rotate_session.

* Update tests to new staking api.

* fixup mock

* Fix bond_extra_and_withdraw_unbonded_works.

* Fix bond_with_little_staked_value_bounded_by_slot_stake.

* Fix bond_with_no_staked_value.

* Fix change_controller_works.

* Fix less_than_needed_candidates_works.

* Fix multi_era_reward_should_work.

* Fix nominating_and_rewards_should_work.

* Fix nominators_also_get_slashed.

* Fix phragmen_large_scale_test.

* Fix phragmen_poc_works.

* Fix phragmen_score_should_be_accurate_on_large_stakes.

* Fix phragmen_should_not_overflow.

* Fix reward_destination_works.

* Fix rewards_should_work.

* Fix sessions_and_eras_should_work.

* Fix slot_stake_is_least_staked_validator.

* Fix too_many_unbond_calls_should_not_work.

* Fix wrong_vote_is_null.

* Fix runtime.

* Fix wasm runtime build.

* Update Cargo.lock

* Fix warnings.

* Fix grandpa tests.

* Fix test-runtime build.

* Fix template node build.

* Fix stuff.

* Update Cargo.lock to fix CI

* Re-add missing AuRa logs

Runtimes are required to know about every digest they receive ― they
panic otherwise.  This re-adds support for AuRa pre-runtime digests.

* Update core/consensus/babe/src/digest.rs

Co-Authored-By: DemiMarie-parity <[email protected]>

* Kill log trait and all that jazz.

* Refactor staking tests.

* Fix ci runtime wasm check.

* Line length 120.

* Make tests build again

* Remove trailing commas in function declarations

The `extern_functions!` macro doesn’t like them, perhaps due to a bug in
rustc.

* Fix type error

* Fix compilation errors

* Fix a test

* Another couple of fixes

* Fix another test

* More test fixes

* Another test fix

* Bump runtime.

* Wrap long line

* Fix build, remove redundant code.

* Issue to track TODO

* Leave the benchmark code alone.

* Fix missing `std::time::{Instant, Duration}`

* Indentation

* Aura ConsensusLog as enum

* child cache, and test failing notifications

* fix tests and no listen child on top wildcard

* remove useless method

* bump impl version

* Update core/client/src/notifications.rs

Co-Authored-By: Tomasz Drwięga <[email protected]>

* Update core/client/src/notifications.rs

Co-Authored-By: Tomasz Drwięga <[email protected]>

* Update core/client/src/notifications.rs

Co-Authored-By: Tomasz Drwięga <[email protected]>

* Update core/client/src/notifications.rs

Co-Authored-By: Tomasz Drwięga <[email protected]>

* factoring notification methods to remove some redundant code.

* test child sub removal

* HStorage implementation and some type alias.

* Remove HStorage cache: does not fit

* fix removal

* Make cache use byte length (shared) instead of number of kv

* Make use of hashes cache in rpc

* applying ratio on different lru caches

* Fix format

* break a line

* Remove per element overhead of lru cache.

* typo

* Make test-client generic over runtime.

* Make sure genesis storage is constructed correctly.

* Use prelude in tests.

* Add an example of how to use test-client with node/runtime.

* Bump version.

* Rename test-clients.

* Add different digest types for different parts of the code

* Add script to update dependencies

* Remove an old changelog

* `Inherent` → `PreRuntime`

* add light nodes to test_sync && test_consensus

* forbid light2light connections

* add light nodes to test_connectivity

* fixed light2light connection penalty

* post-merge fixes

* remove best_queued from Client info

* Drop import_lock from client, move it into backend, impl default version via static mutex

* still need to allow depcretion because of client.backend

* additional docs

* Remove default impl of get_import_lock, impl on instances

* Bump parking_lot to 0.8.0 accross the board