This will allow us to deduplicate network simulations in tests for the
different algorithms. More generally, it facilitates writing general
tools and applying them to all distributed algorithms.
This also contains a few fixes for the `common_subset` module:
* Rename `common_subset::Output` to `Message` to avoid confusing it
with the value that the algorithm outputs as a result.
* Implement dispatch of messages to the right instance within
`CommonSubset`, in a way that is transparent to the user.
This fixes several issues with the broadcast algorithm and enables the
previously ignored tests that now pass:
* Don't decide on a root hash based on anyone's `Echo` message.
* Work around the `merkle` crate's inability to produce the proof of the
`i`-th leaf for a given index `i`.
* Ignore messages from unknown nodes.
* Avoid decoding multiple times.
* Document the full algorithm.
* Don't count multiple `Echo` or `Ready` messages coming from the same
node.
* Fix index computation for a given proof.
* Move `BroadcastMessage` into `broadcast` to make the module more
self-contained.
The example now only executes a single broadcast instance, expecting the
first node (the one with the lexicographically lowest address) to
propose a value. A shell script is added that runs for example nodes.
Use env_logger instead of simple_logger, so the log level can be controlled
with an environment variable. You can e.g. log all output from the broadcast
test and the crate itself in debug mode with:
RUST_LOG=hbbft=debug,broadcast=debug
Some debugging messages are more concise now and use hexadecimal
notation instead of printing arrays of decimal values.
An indentation error in the Travis script is also fixed.
Andreas Fackler
Vladimir Komendantskiy
Peter van Nostrand