The calculation overflow fix in #1068 did not account for XMR < 1 which
resulted in truncation when dividing by the PICO_OFFSET.
This commit uses `Decimal` to do the calculation at fixed precision and
adds a number of test values to verify the calculation.
Closes#1084
In testing, ASB panicked in `max_bitcoin_for_price` when the Monero
balance x Bitcoin price was enough to overflow `u64`.
This commit changes the function to do the piconero offset division
first, and then to use `checked_mul` to return None if the calculation
would overflow. This required changing the function return
signature to an `Option`. Additional tests for the function were also added.
MONERO_FEE was changed from 0.000030 to 0.000016, which is still
double the current median transaction fee listed at
https://www.monero.how/monero-transaction-fees as of 2022-07-28.
Having `spot_price` and `execution_setup` as separate protocols did not bring any advantages, but was problematic because we had to ensure that `execution_setup` would be triggered after `spot_price`. Because of this dependency it is better to combine the protocols into one.
Combining the protocols also allows a refactoring to get rid of the `libp2p-async-await` dependency.
Alice always listens for the `swap_setup` protocol. When Bob opens a substream on that protocol the spot price is communicated, and then all execution setup messages (swap-id and signature exchange).
When a CLI requests a spot price have some errors that are expected, where we can provide a proper error message for the CLI:
- Balance of ASB too low
- Buy amount sent by CLI exceeds maximum buy amount accepted by ASB
- ASB is running in maintenance mode and does not accept incoming swap requests
All of these errors returns a proper error to the CLI and prints a warning in the ASB logs.
Any other unexpected error will result in closing the channel with the CLI and printing an error in the ASB logs.
To achieve this, we decompose `watch_for_locked_xmr` into two parts:
1. A non-self-consuming function to construct a `WatchRequest`
2. A state transition that can now consume `self` again because
it is only called once within the whole select! expression.
Ideally, we would move more logic onto this state transition (like
comparing the actual amounts and fail the transition if it is not
valid). Doing so would have an unfortunate side-effect: We would
always wait for the full confirmations before checking whether or
not we actually receive enough XMR.
This allows us to have state transitions that consume self.
First, we tell the user that we are now waiting for Alice to lock
the monero. Additionally, we tell them once we received the
transfer proof which will lead directly into the
"waiting for confirmations" function.
This reduces the overall amount of LoC that imports take up in our
codebase by almost 100.
It also makes merge-conflicts less likely because there is less
grouping together of imports that may lead to layout changes which
in turn can cause merge conflicts.
The wallet is an instance of a wallet that has a name.
When we use `CreateWalletForOutputThenReloadWallet` we actually unload the wallet.
It would be cleaner to create a new instance that does that swap, but I did not go that far.
If the monero wallet rpc has not already been downloaded we download the monero cli package and extract the wallet rpc. The unneeded files are cleaned up. The monero wallet rpc is started on a random port which is provided to the swap cli.
We added a fork of tokio-tar via a git subtree because we needed a tokio-tar version that was compatible with tokio 1.0. Remove this subtree in favor of a regular cargo dependency when this PR merges: https://github.com/vorot93/tokio-tar/pull/3.
In order to ensure that we can atomically generate_from_keys and then reload a wallet,
we have to wrap the client of the monero wallet RPC inside a mutex.
When introducing the Mutex I noticed that several inner RPC calls were leaking to the
swap crate monero wallet. As this is a violation of boundaries I introduced the traits
`GetAddress`, `WalletBlockHeight` and `Refresh`.
Note that the monero wallet could potentially know its own public view key and
public spend key. If we refactor the wallet to include this information upon wallet
creation we can also generate addresses using `monero::Address::standard`.
Rust fmt automatically groups the imports (from top to bottom) as `pub use` `use crate` and `use`.
There is no need to introduce sections which cause annoyance when auto importing using the IDE.
Created network, storage and protocol modules. Organised
files into the modules where the belong.
xmr_btc crate moved into isolated modulein swap crate.
Remove the xmr_btc module and integrate into swap crate.
Consolidate message related code
Reorganise imports
Remove unused parent Message enum
Remove unused parent State enum
Remove unused dependencies from Cargo.toml
Also use cosntant backoff retry strategy as opposed to exponential
backoff. This is in case retrying several times quickly causes the
retry intervals to become large enough that the test is very slow
and/or the Bitcoin lock transaction expires.
The current problem occurs on the last message i.e. Bob sending
tx_redeem_encsig to Alice. The action is yielded for Bob to do it, but
Alice appears to never receive it (unconfirmed claim, requires more
logging).
