UniswapV3Pool::simulate_swap_mut overdrafts pools

[fabianbergmark]

amms UniswapV3Pool::simulate_swap_mut succeeds to swap from IC to Weth on a pool with very small weth balance (0x30C777EFb634759D235F3aAdBf562a4945ec7F6a), where output amount is larger than the current weth balance of the pool.

Is there a way I can verify that this is not a sync issue by inspection of the UniswapV3Pool struct?

[0xOsiris]

Can you share the quantities and block you are simulating on. Maybe write an example test of the scenario?

[fabianbergmark]

Before I dig deeper, I suspect this might be caused by an issue with how I sync the pool state from logs. I'm running a geth node, which iiuc is sufficient for v2pools but maybe not v3?

Alternatively it could be due to #105. What would be needed to support syncing v3 from a checkpoint?

[0xOsiris]

Before I dig deeper, I suspect this might be caused by an issue with how I sync the pool state from logs. I'm running a geth node, which iiuc is sufficient for v2pools but maybe not v3?

Alternatively it could be due to #105. What would be needed to support syncing v3 from a checkpoint?

IIRC we would need to synchronize the Tick bitmaps of the v3 pools by syncing the mint/burn logs from the last synced block on the checkpoint to the chain head. Which is not currently implemented. So, the liquidity positions might be outdated when pulling from a checkpoint, and therefore could lead to overflow/underflow when syncing the mint/burn logs from the chain head onwards.

[fabianbergmark]

I've been doing some digging into a specific contract: 0xbbd2d2f1c729156f128bd2401477e59256d4da9b.
The reserves I log is from calculate_virtual_reserves. What I find strange is that the last burn event doesn't affect the reserves at all.

19136418 creation block
    
19136418 mint event MintFilter { sender: 0xc36442b4a4522e871399cd717abdd847ab11fe88, owner: 0xc36442b4a4522e871399cd717abdd847ab11fe88, tick_lower: 280320, tick_upper: 280380, amount: 6814308178012212284, amount_0: 0, amount_1: 24999999999999999998302 }
reserves before log Err(UniswapV3MathError(R))
reserves after log Err(UniswapV3MathError(R))

swap event SwapFilter { sender: 0x3fc91a3afd70395cd496c647d5a6cc9d4b2b7fad, recipient: 0xab491a6cced1c277ae3f2ddba0995a1c7ca5ece3, amount_0: 8057809913, amount_1: -12034426644211325774520, sqrt_price_x96: 96899797195315228613501546353885045, liquidity: 6814308178012212284, tick: 280351 }
reserves before log Err(UniswapV3MathError(R))
reserves after log Ok((5571620438407, 8334163545102383462135234))

19137748 swap event SwapFilter { sender: 0x0b8a49d816cc709b6eadb09498030ae3416b66dc, recipient: 0xa88800cd213da5ae406ce248380802bd53b47647, amount_0: 1030384105, amount_1: -1536387654224908997417, sqrt_price_x96: 96881934021596932143520717412713476, liquidity: 6814308178012212284, tick: 280347 }
reserves before log Ok((5571620438407, 8334163545102383462135234))
reserves after log Ok((5572734818211, 8332496962384934696093510))

19137749 swap event SwapFilter { sender: 0x3fc91a3afd70395cd496c647d5a6cc9d4b2b7fad, recipient: 0xa8961eb3bfb918edd20d1b81678a7855fae77f16, amount_0: 5751770283, amount_1: -8565967860927147218039, sqrt_price_x96: 96782339774308945015944204737030145, liquidity: 6814308178012212284, tick: 280326 }
reserves before log Ok((5572734818211, 8332496962384934696093510))
reserves after log Ok((5578588969959, 8323752869224038604935005))

19137775 swap event SwapFilter { sender: 0x3fc91a3afd70395cd496c647d5a6cc9d4b2b7fad, recipient: 0x848650cd11e3f3e2d69ab421c3eae75ac7b80211, amount_0: 1838765148, amount_1: -2734713200654965485608, sqrt_price_x96: 96750543985766461035989159181923180, liquidity: 6814308178012212284, tick: 280320 }
reserves before log Ok((5578588969959, 8323752869224038604935005))
reserves after log Ok((5580262714013, 8321256242705219796492288))

19138212 swap event SwapFilter { sender: 0x3fc91a3afd70395cd496c647d5a6cc9d4b2b7fad, recipient: 0x6b6cfdf92a4bf115b56b542bf59160b62e4a55ac, amount_0: 21000000, amount_1: -31221983305126378005, sqrt_price_x96: 96750180976007774456156643280560554, liquidity: 6814308178012212284, tick: 280320 }
reserves before log Ok((5580262714013, 8321256242705219796492288))
reserves after log Ok((5580262714013, 8321256242705219796492288))

19138858 swap event SwapFilter { sender: 0x01bd2da640345f1c29831b7cef9a434298408172, recipient: 0xdf71525e5c7435ef860909547d1589e53c004f03, amount_0: 65433618, amount_1: -97282655966123558516, sqrt_price_x96: 96749049896245110764756950763719153, liquidity: 6814308178012212284, tick: 280320 }
reserves before log Ok((5580262714013, 8321256242705219796492288))
reserves after log Ok((5580262714013, 8321256242705219796492288))

19140957 burn event BurnFilter { owner: 0xc36442b4a4522e871399cd717abdd847ab11fe88, tick_lower: 280320, tick_upper: 280380, amount: 6814308178012212284, amount_0: 16714867575, amount_1: 710402586194 }
reserves before log Ok((5580262714013, 8321256242705219796492288))
reserves after log Ok((5580262714013, 8321256242705219796492288))

[fabianbergmark]

Could it be that this check should be using >= and <=?

amms-rs/src/amm/uniswap_v3/mod.rs

Line 811 in 739a823

if self.tick > tick_lower && self.tick < tick_upper {

[0xOsiris]

hmm, can you share a repro?