pyth2wormhole-client:should_resend(): optimize interval-only batches (#338)

* pyth2wormhole-client:should_resend(): optimize interval-only batches

Most attestation conditions in prod are interval-only. This change
ensures that interval-only batches don't waste time on the on-chain
state lookup request.

* pyth2wormhole: Fix build error, redundant new_symbol_states decl

* pyth2wormhole-client: is_onchain -> needs_onchain_lookup

* pyth2wormhole-client: typo

Author: Stanisław Drozd

solana/pyth2wormhole/client/src/attestation_cfg.rs

@@ -144,6 +144,22 @@ pub struct AttestationConditions {
     pub publish_time_min_delta_secs: Option<u64>,
 }
 
+impl AttestationConditions {
+    /// Used by should_resend() to check if it needs to make the expensive RPC request
+    pub fn need_onchain_lookup(&self) -> bool {
+        // Bug trap for new fields that also need to be included in
+        // the returned expression
+        let AttestationConditions {
+            min_interval_secs: _min_interval_secs,
+            max_batch_jobs: _max_batch_jobs,
+            price_changed_pct,
+            publish_time_min_delta_secs,
+        } = self;
+
+        price_changed_pct.is_some() || publish_time_min_delta_secs.is_some()
+    }
+}
+
 impl Default for AttestationConditions {
     fn default() -> Self {
         Self {

solana/pyth2wormhole/client/src/batch_state.rs

@@ -57,35 +57,6 @@ impl<'a> BatchState<'a> {
         let sym_count = self.symbols.len();
         let pubkeys: Vec<_> = self.symbols.iter().map(|s| s.price_addr).collect();
 
-        // Always learn the current on-chain state for each symbol, use None values if lookup fails
-        let mut new_symbol_states: Vec<Option<PriceAccount>> = match c
-            .get_multiple_accounts(&pubkeys)
-            .await
-        {
-            Ok(acc_opts) => {
-                acc_opts
-                    .into_iter()
-                    .enumerate()
-                    .map(|(idx, opt)| {
-                        // Take each Some(acc), make it None and log on load_price_account() error
-                        opt.and_then(|acc| {
-                            pyth_sdk_solana::state::load_price_account(&acc.data)
-                                .cloned() // load_price_account() transmutes the data reference into another reference, and owning acc_opts is not enough
-                                .map_err(|e| {
-                                    warn!("Could not parse symbol {}/{}: {}", idx, sym_count, e);
-                                    e
-                                })
-                                .ok() // Err becomes None
-                        })
-                    })
-                    .collect()
-            }
-            Err(e) => {
-                warn!("Could not look up any symbols on-chain: {}", e);
-                vec![None; sym_count]
-            }
-        };
-
         // min interval
         if self.last_job_finished_at.elapsed()
             > Duration::from_secs(self.conditions.min_interval_secs)
@@ -96,14 +67,47 @@ impl<'a> BatchState<'a> {
             ));
         }
 
-        for (idx, old_new_tup) in self
-            .last_known_symbol_states
-            .iter_mut() // Borrow mutably to make the update easier
-            .zip(new_symbol_states.iter())
-            .enumerate()
-        {
-            //  Only evaluate this symbol if a triggering condition is not already met
-            if ret.is_none() {
+        // Only lookup and compare symbols if the conditions require
+        if self.conditions.need_onchain_lookup() {
+            let mut new_symbol_states: Vec<Option<PriceAccount>> =
+                match c.get_multiple_accounts(&pubkeys).await {
+                    Ok(acc_opts) => {
+                        acc_opts
+                            .into_iter()
+                            .enumerate()
+                            .map(|(idx, opt)| {
+                                // Take each Some(acc), make it None and log on load_price_account() error
+                                opt.and_then(|acc| {
+                                    pyth_sdk_solana::state::load_price_account(&acc.data)
+                                        .cloned() // load_price_account() transmutes the data reference into another reference, and owning acc_opts is not enough
+                                        .map_err(|e| {
+                                            warn!(
+                                                "Could not parse symbol {}/{}: {}",
+                                                idx, sym_count, e
+                                            );
+                                            e
+                                        })
+                                        .ok() // Err becomes None
+                                })
+                            })
+                            .collect()
+                    }
+                    Err(e) => {
+                        warn!("Could not look up any symbols on-chain: {}", e);
+                        vec![None; sym_count]
+                    }
+                };
+
+            for (idx, old_new_tup) in self
+                .last_known_symbol_states
+                .iter_mut() // Borrow mutably to make the update easier
+                .zip(new_symbol_states.iter())
+                .enumerate()
+            {
+                //  Only evaluate this symbol if a triggering condition is not already met
+                if ret.is_some() {
+                    break;
+                }
                 match old_new_tup {
                     (Some(old), Some(new)) => {
                         // publish_time_changed
@@ -143,19 +147,18 @@ impl<'a> BatchState<'a> {
                     }
                 }
             }
-        }
-
-        // Update with newer state only if a condition was met. We
-        // don't want to shadow changes that may happen over a larger
-        // period between state lookups.
-        if ret.is_some() {
-            for (old, new) in self
-                .last_known_symbol_states
-                .iter_mut()
-                .zip(new_symbol_states.into_iter())
-            {
-                if new.is_some() {
-                    *old = new;
+            // Update with newer state only if a condition was met. We
+            // don't want to shadow changes that may happen over a larger
+            // period between state lookups.
+            if ret.is_some() {
+                for (old, new) in self
+                    .last_known_symbol_states
+                    .iter_mut()
+                    .zip(new_symbol_states.into_iter())
+                {
+                    if new.is_some() {
+                        *old = new;
+                    }
                 }
             }
         }