update to v3 contract and derive debug/eq for BlockCommitment

examples/token-stats/core/Cargo.toml

@@ -6,3 +6,4 @@ edition = "2021"
 [dependencies]
 alloy-primitives = { workspace = true }
 alloy-sol-types = { workspace = true }
+risc0-steel = { workspace = true }

examples/token-stats/core/src/lib.rs

@@ -1,13 +1,22 @@
 use alloy_primitives::{address, Address};
 use alloy_sol_types::sol;
+use risc0_steel::BlockCommitment;
 
 /// Address of Compound USDC.
-pub const CONTRACT: Address = address!("39aa39c021dfbae8fac545936693ac917d5e7563");
+pub const CONTRACT: Address = address!("c3d688B66703497DAA19211EEdff47f25384cdc3");
 
 sol! {
     /// Simplified interface of Uniswap pair contract using only what is needed.
     interface CToken {
-        function supplyRatePerBlock() external view returns (uint);
+        function getSupplyRate(uint utilization) virtual public view returns (uint64);
         function getUtilization() public view returns (uint);
     }
 }
+
+sol! {
+    #[derive(Debug, PartialEq, Eq)]
+    struct APRCommitment {
+        BlockCommitment commitment;
+        uint64 annualSupplyRate;
+    }
+}

examples/token-stats/host/src/main.rs

@@ -12,12 +12,12 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use alloy_sol_types::{SolCall, SolValue};
+use alloy_sol_types::SolValue;
 use anyhow::{Context, Result};
 use clap::Parser;
-use core::{CToken, CONTRACT};
+use core::{APRCommitment, CToken, CONTRACT};
 use methods::TOKEN_STATS_ELF;
-use risc0_steel::{config::ETH_MAINNET_CHAIN_SPEC, ethereum::EthViewCallEnv, EvmHeader, ViewCall};
+use risc0_steel::{config::ETH_MAINNET_CHAIN_SPEC, ethereum::EthViewCallEnv, ViewCall};
 use risc0_zkvm::{default_executor, ExecutorEnv};
 use tracing_subscriber::EnvFilter;
 
@@ -41,19 +41,13 @@ fn main() -> Result<()> {
     // chain configuration.
     let mut env =
         EthViewCallEnv::from_rpc(&args.rpc_url, None)?.with_chain_spec(&ETH_MAINNET_CHAIN_SPEC);
-    let number = env.header().number();
-    let commitment = env.block_commitment();
+    let block_commitment = env.block_commitment();
 
     // Preflight the view call to construct the input that is required to execute the function in
     // the guest. It also returns the result of the call.
-    let returns = env.preflight(ViewCall::new(CToken::supplyRatePerBlockCall {}, CONTRACT))?;
+    let utilization = env.preflight(ViewCall::new(CToken::getUtilizationCall {}, CONTRACT))?._0;
+    env.preflight(ViewCall::new(CToken::getSupplyRateCall { utilization }, CONTRACT))?._0;
     let input = env.into_zkvm_input()?;
-    println!(
-        "For block {} `{}` returns: {}",
-        number,
-        CToken::supplyRatePerBlockCall::SIGNATURE,
-        returns._0,
-    );
 
     println!("Running the guest with the constructed input:");
     let session_info = {
@@ -66,9 +60,12 @@ fn main() -> Result<()> {
         exec.execute(env, TOKEN_STATS_ELF).context("failed to run executor")?
     };
 
-    // extract the proof from the session info and validate it
-    let bytes = session_info.journal.as_ref();
-    assert_eq!(&bytes[..64], &commitment.abi_encode());
+    let apr_commit = APRCommitment::abi_decode(&session_info.journal.bytes, true)?;
+    assert_eq!(block_commitment, apr_commit.commitment);
+
+    // Calculation is handling `/ 10^18 * 100` to match precision for a percentage.
+    let apr = apr_commit.annualSupplyRate as f64 / 10f64.powi(16);
+    println!("Proven APR calculated is: {}%", apr);
 
     Ok(())
 }

examples/token-stats/methods/guest/src/main.rs

@@ -12,13 +12,12 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#![allow(unused_doc_comments)]
-
 use alloy_sol_types::SolValue;
+use core::{APRCommitment, CToken, CONTRACT};
 use risc0_steel::{config::ETH_MAINNET_CHAIN_SPEC, ethereum::EthViewCallInput, ViewCall};
 use risc0_zkvm::guest::env;
 
-use core::{CToken, CONTRACT};
+const SECONDS_PER_YEAR: u64 = 60 * 60 * 24 * 365;
 
 fn main() {
     // Read the input from the guest environment.
@@ -28,16 +27,27 @@ fn main() {
     // to specify the chain configuration. It checks that the state matches the state root in the
     // header provided in the input.
     let mut view_call_env = input.into_env().with_chain_spec(&ETH_MAINNET_CHAIN_SPEC);
-    // Commit the block hash and number used when deriving `view_call_env` to the journal.
-    env::commit_slice(&view_call_env.block_commitment().abi_encode());
 
     // Execute the view call; it returns the result in the type generated by the `sol!` macro.
-    let returns = view_call_env.execute(ViewCall::new(CToken::supplyRatePerBlockCall {}, CONTRACT));
+    let utilization =
+        view_call_env.execute(ViewCall::new(CToken::getUtilizationCall {}, CONTRACT))._0;
+    let supply_rate: u64 = view_call_env
+        .execute(ViewCall::new(CToken::getSupplyRateCall { utilization }, CONTRACT))
+        ._0;
 
-    // TODO calculate supply APR
+    // The formula for APR in percentage is the following:
     // Seconds Per Year = 60 * 60 * 24 * 365
     // Utilization = getUtilization()
     // Supply Rate = getSupplyRate(Utilization)
     // Supply APR = Supply Rate / (10 ^ 18) * Seconds Per Year * 100
-    println!("View call result: {}", returns._0);
+    //
+    // And this is calculating: Supply Rate * Seconds Per Year, to avoid float calculations for
+    // precision.
+    let annual_supply_rate = supply_rate * SECONDS_PER_YEAR;
+
+    // This commits the APR at current utilization rate for this given block.
+    let commitment = view_call_env.block_commitment();
+    env::commit_slice(
+        &APRCommitment { commitment, annualSupplyRate: annual_supply_rate }.abi_encode(),
+    );
 }

steel/src/lib.rs

@@ -89,6 +89,7 @@ impl<H: EvmHeader> ViewCallInput<H> {
 
 sol! {
     /// Solidity struct representing the committed block used for validation.
+    #[derive(Debug, PartialEq, Eq)]
     struct BlockCommitment {
         bytes32 blockHash;
         uint blockNumber;