graph, runtime: Add ethereum.decodeParams host function

graph/src/data/subgraph/api_version.rs

@@ -24,6 +24,9 @@ pub const API_VERSION_0_0_8: Version = Version::new(0, 0, 8);
 /// Enables new host function `eth_get_balance`
 pub const API_VERSION_0_0_9: Version = Version::new(0, 0, 9);
 
+/// Enables new host function `ethereum.decodeParams`
+pub const API_VERSION_0_0_10: Version = Version::new(0, 0, 10);
+
 /// Before this check was introduced, there were already subgraphs in the wild with spec version
 /// 0.0.3, due to confusion with the api version. To avoid breaking those, we accept 0.0.3 though it
 /// doesn't exist.

graph/src/env/mappings.rs

@@ -175,7 +175,7 @@ pub struct InnerMappingHandlers {
     entity_cache_dead_weight: EnvVarBoolean,
     #[envconfig(from = "GRAPH_ENTITY_CACHE_SIZE", default = "10000")]
     entity_cache_size_in_kb: usize,
-    #[envconfig(from = "GRAPH_MAX_API_VERSION", default = "0.0.9")]
+    #[envconfig(from = "GRAPH_MAX_API_VERSION", default = "0.0.10")]
     max_api_version: Version,
     #[envconfig(from = "GRAPH_MAPPING_HANDLER_TIMEOUT")]
     mapping_handler_timeout_in_secs: Option<u64>,

runtime/wasm/src/host_exports.rs

@@ -1236,6 +1236,30 @@ impl HostExports {
         ty.abi_decode(&data).context("Failed to decode")
     }
 
+    /// Like [`Self::ethereum_decode`], but decodes `data` as ABI function
+    /// parameters (the layout used by transaction calldata and event data)
+    /// rather than as a single ABI value. The two differ only for a top-level
+    /// tuple with at least one dynamic field: calldata has no leading offset
+    /// word, which `abi_decode` would otherwise expect.
+    pub(crate) fn ethereum_decode_params(
+        &self,
+        types: String,
+        data: Vec<u8>,
+        gas: &GasCounter,
+        state: &mut BlockState,
+    ) -> Result<abi::DynSolValue, anyhow::Error> {
+        Self::track_gas_and_ops(
+            gas,
+            state,
+            gas::DEFAULT_GAS_OP.with_args(complexity::Size, &data),
+            "ethereum_decode_params",
+        )?;
+
+        let ty: abi::DynSolType = types.parse().context("Failed to read types")?;
+
+        ty.abi_decode_params(&data).context("Failed to decode")
+    }
+
     pub(crate) fn yaml_from_bytes(
         &self,
         bytes: &[u8],

runtime/wasm/src/module/context.rs

@@ -1180,6 +1180,26 @@ impl WasmInstanceContext<'_> {
         }
     }
 
+    /// function decodeParams(types: String, data: Bytes): ethereum.Value | null
+    pub async fn ethereum_decode_params(
+        &mut self,
+        gas: &GasCounter,
+        types_ptr: AscPtr<AscString>,
+        data_ptr: AscPtr<Uint8Array>,
+    ) -> Result<AscPtr<AscEnum<EthereumValueKind>>, HostExportError> {
+        let types = asc_get(self, types_ptr, gas)?;
+        let data = asc_get(self, data_ptr, gas)?;
+        let host_exports = self.as_ref().ctx.host_exports.cheap_clone();
+        let ctx = &mut self.as_mut().ctx;
+        let result = host_exports.ethereum_decode_params(types, data, gas, &mut ctx.state);
+
+        // return `null` if it fails
+        match result {
+            Ok(token) => asc_new(self, &token, gas).await,
+            Err(_) => Ok(AscPtr::null()),
+        }
+    }
+
     /// function arweave.transactionData(txId: string): Bytes | null
     pub async fn arweave_transaction_data(
         &self,

runtime/wasm/src/module/instance.rs

@@ -462,6 +462,12 @@ pub(crate) fn build_linker(
 
     link!("ethereum.encode", ethereum_encode, params_ptr);
     link!("ethereum.decode", ethereum_decode, params_ptr, data_ptr);
+    link!(
+        "ethereum.decodeParams",
+        ethereum_decode_params,
+        params_ptr,
+        data_ptr
+    );
 
     link!("abort", abort, message_ptr, file_name_ptr, line, column);