chain: Modernize EthereumAdapter.latest_block

Author: lutter

chain/ethereum/src/adapter.rs

@@ -17,7 +17,6 @@ use prost_types::Any;
 use std::cmp;
 use std::collections::{HashMap, HashSet};
 use std::fmt;
-use std::marker::Unpin;
 use thiserror::Error;
 use tiny_keccak::keccak256;
 use web3::types::{Address, Log, H256};
@@ -1082,10 +1081,7 @@ pub trait EthereumAdapter: Send + Sync + 'static {
     async fn net_identifiers(&self) -> Result<ChainIdentifier, Error>;
 
     /// Get the latest block, including full transactions.
-    fn latest_block(
-        &self,
-        logger: &Logger,
-    ) -> Box<dyn Future<Item = LightEthereumBlock, Error = bc::IngestorError> + Send + Unpin>;
+    async fn latest_block(&self, logger: &Logger) -> Result<LightEthereumBlock, bc::IngestorError>;
 
     /// Get the latest block, with only the header and transaction hashes.
     async fn latest_block_header(

chain/ethereum/src/ethereum_adapter.rs

@@ -1288,38 +1288,30 @@ impl EthereumAdapterTrait for EthereumAdapter {
             .await
     }
 
-    fn latest_block(
-        &self,
-        logger: &Logger,
-    ) -> Box<dyn Future<Item = LightEthereumBlock, Error = IngestorError> + Send + Unpin> {
+    async fn latest_block(&self, logger: &Logger) -> Result<LightEthereumBlock, IngestorError> {
         let web3 = self.web3.clone();
-        Box::new(
-            retry("eth_getBlockByNumber(latest) with txs RPC call", logger)
-                .redact_log_urls(true)
-                .no_limit()
-                .timeout_secs(ENV_VARS.json_rpc_timeout.as_secs())
-                .run(move || {
-                    let web3 = web3.cheap_clone();
-                    async move {
-                        let block_opt = web3
-                            .eth()
-                            .block_with_txs(Web3BlockNumber::Latest.into())
-                            .await
-                            .map_err(|e| {
-                                anyhow!("could not get latest block from Ethereum: {}", e)
-                            })?;
-                        block_opt
-                            .ok_or_else(|| anyhow!("no latest block returned from Ethereum").into())
-                    }
-                })
-                .map_err(move |e| {
-                    e.into_inner().unwrap_or_else(move || {
-                        anyhow!("Ethereum node took too long to return latest block").into()
-                    })
+        retry("eth_getBlockByNumber(latest) with txs RPC call", logger)
+            .redact_log_urls(true)
+            .no_limit()
+            .timeout_secs(ENV_VARS.json_rpc_timeout.as_secs())
+            .run(move || {
+                let web3 = web3.cheap_clone();
+                async move {
+                    let block_opt = web3
+                        .eth()
+                        .block_with_txs(Web3BlockNumber::Latest.into())
+                        .await
+                        .map_err(|e| anyhow!("could not get latest block from Ethereum: {}", e))?;
+                    block_opt
+                        .ok_or_else(|| anyhow!("no latest block returned from Ethereum").into())
+                }
+            })
+            .map_err(move |e| {
+                e.into_inner().unwrap_or_else(move || {
+                    anyhow!("Ethereum node took too long to return latest block").into()
                 })
-                .boxed()
-                .compat(),
-        )
+            })
+            .await
     }
 
     fn load_block(