From a0d8218eb1e8997ad2886b56bf3771e9bb18475a Mon Sep 17 00:00:00 2001
From: Bryan Stitt <bryan@llamanodes.com>
Date: Tue, 16 May 2023 18:18:56 -0700
Subject: [PATCH] best block num has to check has_block_data

---
 web3_proxy/src/rpcs/consensus.rs | 73 +++++++++++++++++++++++++++-----
 web3_proxy/src/rpcs/many.rs      |  6 +--
 2 files changed, 66 insertions(+), 13 deletions(-)

diff --git a/web3_proxy/src/rpcs/consensus.rs b/web3_proxy/src/rpcs/consensus.rs
index 31ffe385..5a943f67 100644
--- a/web3_proxy/src/rpcs/consensus.rs
+++ b/web3_proxy/src/rpcs/consensus.rs
@@ -7,10 +7,10 @@ use derive_more::Constructor;
 use ethers::prelude::{H256, U64};
 use hashbrown::{HashMap, HashSet};
 use itertools::{Itertools, MinMaxResult};
-use log::{trace, warn};
+use log::{debug, trace, warn};
 use moka::future::Cache;
 use serde::Serialize;
-use std::cmp::Reverse;
+use std::cmp::{Ordering, Reverse};
 use std::collections::BTreeMap;
 use std::fmt;
 use std::sync::Arc;
@@ -115,24 +115,76 @@ impl ConsensusWeb3Rpcs {
         self.best_rpcs.len()
     }
 
-    pub fn best_block_num(&self, skip_rpcs: &[Arc<Web3Rpc>]) -> Option<&U64> {
-        if self.best_rpcs.iter().all(|rpc| skip_rpcs.contains(rpc)) {
+    pub fn best_block_num(
+        &self,
+        needed_block_num: Option<&U64>,
+        skip_rpcs: &[Arc<Web3Rpc>],
+    ) -> Option<&U64> {
+        // TODO: dry this up with `filter`?
+        fn _best_block_num_filter(
+            x: &ConsensusWeb3Rpcs,
+            rpc: &Arc<Web3Rpc>,
+            needed_block_num: Option<&U64>,
+            skip_rpcs: &[Arc<Web3Rpc>],
+        ) -> bool {
+            // return true if this rpc will never work for us. "false" is good
+            if skip_rpcs.contains(rpc) {
+                // if rpc is skipped, it must have already been determined it is unable to serve the request
+                true
+            } else if let Some(needed_block_num) = needed_block_num {
+                if let Some(rpc_data) = x.rpc_data.get(rpc).as_ref() {
+                    match rpc_data.head_block_num.cmp(needed_block_num) {
+                        Ordering::Less => {
+                            // rpc is not synced. let it catch up
+                            false
+                        }
+                        Ordering::Greater | Ordering::Equal => {
+                            // rpc is synced past the needed block. make sure the block isn't too old for it
+                            !x.has_block_data(rpc, needed_block_num)
+                        }
+                    }
+                } else {
+                    // no rpc data for this rpc. thats not promising
+                    true
+                }
+            } else {
+                false
+            }
+        }
+
+        if self
+            .best_rpcs
+            .iter()
+            .all(|rpc| _best_block_num_filter(self, rpc, needed_block_num, skip_rpcs))
+        {
             // all of the consensus rpcs are skipped
             // iterate the other rpc tiers to find the next best block
-            let mut best_block = None;
+            let mut best_num = None;
             for (next_ranking, next_rpcs) in self.other_rpcs.iter() {
-                if next_rpcs.iter().all(|rpc| skip_rpcs.contains(rpc)) {
-                    // everything in this ranking is skipped
+                if next_rpcs
+                    .iter()
+                    .all(|rpc| _best_block_num_filter(self, rpc, needed_block_num, skip_rpcs))
+                {
+                    // TODO: too verbose
+                    debug!("everything in this ranking ({:?}) is skipped", next_ranking);
                     continue;
                 }
 
-                best_block = best_block.max(next_ranking.head_num.as_ref());
+                best_num = best_num.max(next_ranking.head_num.as_ref());
             }
 
-            best_block
+            // TODO: too verbose
+            debug!("best (old) block: {:?}", best_num);
+
+            best_num
         } else {
             // not all the best synced rpcs are skipped yet. use the best head block
-            Some(self.head_block.number())
+            let best_num = self.head_block.number();
+
+            // TODO: too verbose
+            debug!("best (head) block: {}", best_num);
+
+            Some(best_num)
         }
     }
 
@@ -143,6 +195,7 @@ impl ConsensusWeb3Rpcs {
             .unwrap_or(false)
     }
 
+    // TODO: better name for this
     pub fn filter(
         &self,
         skip: &[Arc<Web3Rpc>],
diff --git a/web3_proxy/src/rpcs/many.rs b/web3_proxy/src/rpcs/many.rs
index e761f691..cf8e7f1c 100644
--- a/web3_proxy/src/rpcs/many.rs
+++ b/web3_proxy/src/rpcs/many.rs
@@ -1933,12 +1933,12 @@ async fn watch_for_block(
     skip_rpcs: &[Arc<Web3Rpc>],
     watch_consensus_rpcs: &mut watch::Receiver<Option<Arc<ConsensusWeb3Rpcs>>>,
 ) -> Web3ProxyResult<bool> {
-    info!("waiting for {:?}", needed_block_num);
+    debug!("waiting for {:?}", needed_block_num);
 
     let mut best_block_num: Option<U64> = watch_consensus_rpcs
         .borrow_and_update()
         .as_ref()
-        .and_then(|x| x.best_block_num(skip_rpcs).copied());
+        .and_then(|x| x.best_block_num(needed_block_num, skip_rpcs).copied());
 
     match (needed_block_num, best_block_num.as_ref()) {
         (Some(x), Some(best)) => {
@@ -1977,7 +1977,7 @@ async fn watch_for_block(
 
         best_block_num = consensus_rpcs
             .as_ref()
-            .and_then(|x| x.best_block_num(skip_rpcs).copied());
+            .and_then(|x| x.best_block_num(needed_block_num, skip_rpcs).copied());
     }
 
     Ok(true)