return commitment for Envs with BlockHeaderCommit

risc0 · Dec 16, 2024 · 5599b10 · 5599b10
1 parent fcd494e
commit 5599b10
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Showing 2 changed files with 25 additions and 19 deletions.
diff --git a/examples/token-stats/host/src/main.rs b/examples/token-stats/host/src/main.rs
@@ -89,19 +89,15 @@ async fn main() -> Result<()> {
         rate
     );
 
+    let commitment = env.commitment();
+
     // Construct the input from the environment.
     let input1 = env.into_input().await?;
 
     // Create another EVM environment for that provider defaulting to the latest block.
     let mut env = EthEvmEnv::builder().provider(provider).build().await?;
     env = env.with_chain_spec(&ETH_MAINNET_CHAIN_SPEC);
 
-    // TODO: Make it easier to get the commitment from a HostEvmEnv
-    let commitment = input1
-        .clone()
-        .into_env()
-        .with_chain_spec(&ETH_MAINNET_CHAIN_SPEC)
-        .into_commitment();
     // Preflight the verification of the commitment of the previous input.
     SteelVerifier::preflight(&mut env)
         .verify(&commitment)

diff --git a/steel/src/host/mod.rs b/steel/src/host/mod.rs
@@ -25,7 +25,7 @@ use crate::{
     ethereum::{EthBlockHeader, EthEvmEnv},
     history::HistoryCommit,
     host::db::ProviderDb,
-    ComposeInput, EvmBlockHeader, EvmEnv, EvmInput,
+    BlockHeaderCommit, Commitment, ComposeInput, EvmBlockHeader, EvmEnv, EvmInput,
 };
 use alloy::eips::eip1898::{HexStringMissingPrefixError, ParseBlockNumberError};
 use alloy::{
@@ -162,6 +162,21 @@ where
     }
 }
 
+impl<D, H: EvmBlockHeader, C> HostEvmEnv<D, H, C> {
+    /// Sets the chain ID and specification ID from the given chain spec.
+    ///
+    /// This will panic when there is no valid specification ID for the current block.
+    pub fn with_chain_spec(mut self, chain_spec: &ChainSpec) -> Self {
+        self.cfg_env.chain_id = chain_spec.chain_id();
+        self.cfg_env.handler_cfg.spec_id = chain_spec
+            .active_fork(self.header.number(), self.header.timestamp())
+            .unwrap();
+        self.commit.config_id = chain_spec.digest();
+
+        self
+    }
+}
+
 impl<T, N, P, H> HostEvmEnv<AlloyDb<T, N, P>, H, ()>
 where
     T: Transport + Clone,
@@ -178,18 +193,13 @@ where
     }
 }
 
-impl<D, H: EvmBlockHeader, C> HostEvmEnv<D, H, C> {
-    /// Sets the chain ID and specification ID from the given chain spec.
-    ///
-    /// This will panic when there is no valid specification ID for the current block.
-    pub fn with_chain_spec(mut self, chain_spec: &ChainSpec) -> Self {
-        self.cfg_env.chain_id = chain_spec.chain_id();
-        self.cfg_env.handler_cfg.spec_id = chain_spec
-            .active_fork(self.header.number(), self.header.timestamp())
-            .unwrap();
-        self.commit.config_id = chain_spec.digest();
-
-        self
+impl<D, H: EvmBlockHeader, C: Clone + BlockHeaderCommit<H>> HostEvmEnv<D, H, C> {
+    /// Returns the [Commitment] used to validate the environment.
+    pub fn commitment(&self) -> Commitment {
+        self.commit
+            .inner
+            .clone()
+            .commit(&self.header, self.commit.config_id)
     }
 }