RouterV2 #117
RouterV2 #117
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Co-authored-by: Grzegorz Gawryał <[email protected]>
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One general idea (as discussed offline): it seems that caching in the current form is largely unnecessary and adds complexity - since we get AccountId in each Step path anyway there should be no need to keep a permissioned record of pools (as long as we are able to distinguish between pair and stable pool using on-chain data eg making a cross-contract call).
It might be advantageous to create an automatic cache, which role would be to limit number of cross-contract calls, but would not require contract owner and would be simple on the implementation side.
For adding liquidity to pair contract we can create an interface that takes Option<AccountId> of the pool - if None, then new pair would be created.
@ggawryal what do you think?
amm/traits/router_v2.rs
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| /// | ||
| /// Starts with `amount_in` and token address under `path[0].token_in`. | ||
| /// | ||
| /// If `path[i].pool_id` is `None`, it attemps the swap through |
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From what I see Step now has no Option field
| let wazero = wazero::setup(&mut session); | ||
| let router = router_v2::setup(&mut session, factory.into(), wazero.into()); | ||
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| let initial_reserves = vec![100000 * ONE_USDT, 100000 * ONE_USDC]; |
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Would suggest to create constants instead of using numerical values directly whenever possible
| vec![], | ||
| ); | ||
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| _ = session |
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Suggestion: not to use _ = , if it's an error then it should be checked/unwrapped, if it's just an unused value then ignore it altogether
| _ = session | |
| session |
Agreed. Decoding the pool type might be a bit harder, but even if we had to add an extra flag to the
It might, but currently cache doesn't limit anything, it only helps to find the correct pool address for a given pair of tokens, right? If so, I wouldn't bother. |
Allow adding liquidity to StablePools via Router.
The
RouterV2contract supports swaps along paths that includePairandStablePooltypes of pools.Swap Path
Each
swap*method takes as the argumentspath: Vec<Step>andtoken_out: AccountId, except for theswap*_for_native- here we know that thetoken_outis always thewrapped_nativetoken.The
Stepstruct has two fields:Step { token_in: AccountId, pool_id: AccountId }. A valid path must consist of at least oneStep.E.g
path: [Step(token_a, pool_1) , Step(token_b, pool_2) ], token_out: token_ccan be visualized like this:pool_1 pool_2 / \ / \ token_a -> token_b -> token_cCompatibility
The old Router had a "pair caching" mechanism which allowed caching custom
Paircontracts. Also, when adding liquidity to a non-existent pair, the pair was created via theFactorycontract.In the new Router, when adding liquidity to a
Pairpool, the caller has an option to provide thePairaddress. If the address is not provided, the contract calls theFactoryto create a new Pair. It fails ifPairfor given tokens already exists.The new Router caches pools solely for optimization purposes. It is allowed to swap through any valid pool contract (
PairorStablePool). The pools are cached when swapping through or managing liquidity in a valid pool (permissionless).