example_uniswap_get_reserves/
main.rs

1//! Example of uniswap getReserves() call emulation.
2#![cfg_attr(not(test), warn(unused_crate_dependencies))]
3
4use alloy_eips::BlockId;
5use alloy_provider::ProviderBuilder;
6use alloy_sol_types::{sol, SolCall};
7use revm::{
8    context::TxEnv,
9    context_interface::result::{ExecutionResult, Output},
10    database::{AlloyDB, CacheDB},
11    database_interface::{DatabaseRef, EmptyDB, WrapDatabaseAsync},
12    primitives::{address, StorageKey, TxKind, U256},
13    Context, ExecuteEvm, MainBuilder, MainContext,
14};
15
16#[tokio::main]
17async fn main() -> anyhow::Result<()> {
18    // Initialize the Alloy provider and database
19    let rpc_url = "https://mainnet.infura.io/v3/c60b0bb42f8a4c6481ecd229eddaca27";
20    let provider = ProviderBuilder::new().connect(rpc_url).await?;
21
22    let alloy_db = WrapDatabaseAsync::new(AlloyDB::new(provider, BlockId::latest())).unwrap();
23    let cache_db = CacheDB::new(alloy_db);
24
25    // ----------------------------------------------------------- //
26    //             Storage slots of UniV2Pair contract             //
27    // =========================================================== //
28    // storage[5] = factory: address                               //
29    // storage[6] = token0: address                                //
30    // storage[7] = token1: address                                //
31    // storage[8] = (res0, res1, ts): (uint112, uint112, uint32)   //
32    // storage[9] = price0CumulativeLast: uint256                  //
33    // storage[10] = price1CumulativeLast: uint256                 //
34    // storage[11] = kLast: uint256                                //
35    // =========================================================== //
36
37    // Choose slot of storage that you would like to transact with
38    let slot = StorageKey::from(8);
39
40    // ETH/USDT pair on Uniswap V2
41    let pool_address = address!("0d4a11d5EEaaC28EC3F61d100daF4d40471f1852");
42
43    // Generate abi for the calldata from the human readable interface
44    sol! {
45        function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
46    }
47
48    // Encode abi into Bytes
49    let encoded = getReservesCall::new(()).abi_encode();
50
51    // Query basic properties of an account incl bytecode
52    let acc_info = cache_db.basic_ref(pool_address).unwrap().unwrap();
53
54    // Query value of storage slot at account address
55    let value = cache_db.storage_ref(pool_address, slot).unwrap();
56
57    // Initialise empty in-memory-db
58    let mut cache_db = CacheDB::new(EmptyDB::default());
59
60    // Insert basic account info which was generated via Web3DB with the corresponding address
61    cache_db.insert_account_info(pool_address, acc_info);
62
63    // Insert our pre-loaded storage slot to the corresponding contract key (address) in the DB
64    cache_db
65        .insert_account_storage(pool_address, slot, value)
66        .unwrap();
67
68    // Initialise an empty (default) EVM
69    let mut evm = Context::mainnet().with_db(cache_db).build_mainnet();
70
71    // Execute transaction without writing to the DB
72    let result = evm
73        .transact(TxEnv {
74            // fill in missing bits of env struct
75            // change that to whatever caller you want to be
76            caller: address!("0000000000000000000000000000000000000000"),
77            // account you want to transact with
78            kind: TxKind::Call(pool_address),
79            // calldata formed via abigen
80            data: encoded.into(),
81            // transaction value in wei
82            value: U256::from(0),
83            ..Default::default()
84        })
85        .unwrap();
86
87    // Unpack output call enum into raw bytes
88    let value = match result {
89        ExecutionResult::Success {
90            output: Output::Call(value),
91            ..
92        } => value,
93        _ => panic!("Execution failed: {result:?}"),
94    };
95
96    // Decode bytes to reserves + ts via alloy's abi decode
97    let return_vals = getReservesCall::abi_decode_returns(&value)?;
98
99    // Print emulated getReserves() call output
100    println!("Reserve0: {:#?}", return_vals.reserve0);
101    println!("Reserve1: {:#?}", return_vals.reserve1);
102    println!("Timestamp: {:#?}", return_vals.blockTimestampLast);
103
104    Ok(())
105}
example_uniswap_get_reserves/main.rs

example_uniswap_get_reserves/
main.rs
