Firstly, `Step.duration_remaining` casts it to u32, unnecesarily
limiting it to 2^32. While theoretically this is "good enough" (at 3
seconds steps it provides room for a little over 400 years), it is
still a lossy way to calculate the remaining time until the next step.
Secondly, step duration might be zero, triggering division by zero
in `Step.calibrate`
Solution: rework the code around the fact that duration is
typically in single digits and never grows, hence, it can be represented
by a much narrower range (u16) and this highlights the fact that
multiplying u64 by u16 will only result in an overflow in even further
future, at which point we should panic informatively (if anybody's
still around)
Similarly, panic when it is detected that incrementing the step
counter wrapped around on the overflow of usize.
As for the division by zero, prevent it by making zero an invalid
value for step duration. This will make AuRa log the constraint
mismatch and panic (after all, what purpose would zero step duration
serve? it makes no sense within the definition of the protocol,
as finality can only be achieved as per the specification
if messages are received within the step duration, which would violate
the speed of light and other physical laws in this case).
* Bump version.
* Fix RPC crate.
* Fix BoxFuture in crates.
* Compiles and passes tests!
* Get rid of .boxed()
* Fixing issues with the UI.
* Remove minihttp. Support threads.
* Reimplement files serving to do it in chunks.
* Increase chunk size.
* Remove some unecessary copying.
* Fix tests.
* Fix stratum warning and ipfs todo.
* Switch to proper branch of jsonrpc.
* Update Cargo.lock.
* Update docs.
* Include dapps-glue in workspace.
* fixed merge artifacts
* Fix test compilation.
* move common forks and parameters to common params
* port specs over to new format
* fix RPC tests
* parity-machine skeleton
* remove block type
* extract out ethereum-specific methods into EthereumMachine
* beginning to integrate Machine into engines. dealing with stale transitions in Ethash
* initial porting to machine
* move block reward back into engine
* abstract block reward logic
* move last hash and DAO HF logic into machine
* begin making engine function parameters generic
* abstract epoch verifier and ethash block reward logic
* instantiate special ethereummachine for ethash in spec
* optional full verification in verify_block_family
* re-instate tx_filter in a way that works for all engines
* fix warnings
* fix most tests, further generalize engine trait
* uncomment nullengine, get ethcore tests compiling
* fix warnings
* update a bunch of specs
* re-enable engine signer, validator set, and transition handler
* migrate basic_authority engine
* move last hashes into executedblock
* port tendermint
* make all ethcore tests pass
* json-tests compilation
* fix RPC tests: change in gas limit for new block changed PoW hash
* fix minor grumbles
* validate chainspecs
* fix broken import
* fix transaction verification for pre-homestead
* Rebase and fix compilation errors (tests not yet fixed)
* Use `debug_assert` over `assert`
* Fix tests
* Assert safety, clean up
* Fix up stale cache removal, move one assert to debug_assert
* Remove printlns
* Add licenses
* Fix benches
* Inline some no-ops in a hot loop that weren't being inlined
* Add spooky comment to make sure no-one removes the inlining annotations
* Minor cleanup
* Add option to switch between mmap and ram
* Flag ethash to use less memory when running light client
* Fix tests
* Remove todo comment (it's done)
* Replace assertion with error return
* Fix indentation
* Use union instead of `transmute`
* Fix benches
* Extract to constants
* Clean up and fix soundness holes
* Fix formatting
* Ignore missing-file errors
* Make incorrect cache size an error condition instead of a panic, remove dead code
* Fix compilation errors from rebase
* Fix compilation errors in tests
* Fix compilation errors in tests
