Reify nfs when fs synced

live-tests/e2e/tests/test_vectors.rs

@@ -399,7 +399,7 @@ async fn create_200_block_regtest_chain_vectors() {
             // Update parent block
             parent_block_sapling_tree_size = chain_block.commitment_tree_data().sizes().sapling();
             parent_block_orchard_tree_size = chain_block.commitment_tree_data().sizes().orchard();
-            parent_chain_work = Some(*chain_block.chainwork());
+            parent_chain_work = *chain_block.chainwork();
 
             data.push((height, zebra_block, block_roots, block_treestate));
         }

live-tests/zaino-testutils/src/lib.rs

@@ -223,34 +223,33 @@ pub trait PollableTip: Status + Sync {
 
 impl PollableTip for FetchServiceSubscriber {
     async fn tip_height(&self) -> u64 {
+        // A not-yet-ready backend reports tip 0 (poll keeps waiting) rather
+        // than panicking.
         self.get_latest_block()
             .await
-            .expect("PollableTip: FetchServiceSubscriber::get_latest_block failed")
-            .height
+            .map(|block| block.height)
+            .unwrap_or(0)
     }
 }
 
 impl PollableTip for StateServiceSubscriber {
     async fn tip_height(&self) -> u64 {
         self.get_latest_block()
             .await
-            .expect("PollableTip: StateServiceSubscriber::get_latest_block failed")
-            .height
+            .map(|block| block.height)
+            .unwrap_or(0)
     }
 }
 
 impl<Source: BlockchainSource> PollableTip for NodeBackedChainIndexSubscriber<Source> {
     async fn tip_height(&self) -> u64 {
-        let snapshot = self
-            .snapshot_nonfinalized_state()
-            .await
-            .expect("PollableTip: chain-index snapshot_nonfinalized_state failed");
-        u64::from(u32::from(
-            self.best_chaintip(&snapshot)
-                .await
-                .expect("PollableTip: chain-index best_chaintip failed")
-                .height,
-        ))
+        let Ok(snapshot) = self.snapshot_nonfinalized_state().await else {
+            return 0;
+        };
+        match self.best_chaintip(&snapshot).await {
+            Ok(tip) => u64::from(u32::from(tip.height)),
+            Err(_) => 0,
+        }
     }
 }
 

packages/zaino-state/CHANGELOG.md

@@ -5,6 +5,16 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this library adheres to Rust's notion of
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased not landing in 0.4.0]
+### Added
+
+### Changed
+- `chain_index::types::BlockContext`'s chainwork field is now optional
+- `chain_index::ChainIndexSnapshot` has been completely overhauled, is now
+  a struct instead of an enum, with completely private internals. Callers
+  must now interface with it only by passing it to a ChainIndex implementor,
+  as intended.
+
 ## [Unreleased]
 
 ### Added
@@ -47,6 +57,7 @@ and this library adheres to Rust's notion of
   can no longer inflate each other's peak memory.
 ### Deprecated
 ### Removed
+- `NonFinalizedSnapshot::max_serviceable_height`
 ### Fixed
 - The finalised-state txout-set accumulator rebuild at chain tip no longer
   OOM-crashes on memory-constrained hosts. It auto-shards its in-memory spent set

packages/zaino-state/src/backends/fetch.rs

@@ -74,10 +74,7 @@ use crate::{
     utils::{get_build_info, ServiceMetadata},
     BackendType,
 };
-use crate::{
-    chain_index::{non_finalised_state::ChainIndexSnapshot, NonFinalizedSnapshot},
-    ChainIndex, NodeBackedChainIndex, NodeBackedChainIndexSubscriber,
-};
+use crate::{ChainIndex, NodeBackedChainIndex, NodeBackedChainIndexSubscriber};
 
 /// Chain fetch service backed by Zcashd's JsonRPC engine.
 ///
@@ -499,7 +496,7 @@ impl ZcashIndexer for FetchServiceSubscriber {
 
     async fn get_chain_tips(&self) -> Result<GetChainTipsResponse, Self::Error> {
         let snapshot = self.indexer.snapshot_nonfinalized_state().await?;
-        let Some(non_finalized_snapshot) = snapshot.get_nfs_snapshot() else {
+        let Some(non_finalized_snapshot) = snapshot.resolved_nfs_snapshot() else {
             return Ok(self.fetcher.get_chain_tips().await?);
         };
 
@@ -758,7 +755,9 @@ impl ZcashIndexer for FetchServiceSubscriber {
         let (height, confirmations, block_hash, in_best_chain) = match best_chain_location {
             Some(types::BestChainLocation::Block(block_hash, height)) => {
                 let confirmations = snapshot
-                    .max_serviceable_height()
+                    .get_nfs_snapshot()
+                    .best_tip
+                    .height
                     .0
                     .saturating_sub(height.0)
                     .saturating_add(1);
@@ -815,7 +814,9 @@ impl ZcashIndexer for FetchServiceSubscriber {
             self.indexer
                 .snapshot_nonfinalized_state()
                 .await?
-                .max_serviceable_height()
+                .get_nfs_snapshot()
+                .best_tip
+                .height
                 .0,
         ))
     }
@@ -896,18 +897,8 @@ impl ZcashIndexer for FetchServiceSubscriber {
 impl LightWalletIndexer for FetchServiceSubscriber {
     /// Return the height of the tip of the best chain
     async fn get_latest_block(&self) -> Result<BlockId, Self::Error> {
-        match self.indexer.snapshot_nonfinalized_state().await? {
-            ChainIndexSnapshot::NonFinalizedStateExists {
-                non_finalized_snapshot,
-            } => Ok(non_finalized_snapshot.best_tip.to_wire()),
-            ChainIndexSnapshot::StillSyncingFinalizedState { .. } => {
-                // TODO: This probably shouldn't be an error.
-                // this is an improvement over previous behaviour of reporting
-                // the genesis block
-                Err(FetchServiceError::UnavailableNotSyncedEnough)
-            }
-        }
-        // dbg!(&tip);
+        let snapshot = self.indexer.snapshot_nonfinalized_state().await?;
+        Ok(snapshot.get_nfs_snapshot().best_tip.to_wire())
     }
 
     /// Return the compact block corresponding to the given block identifier
@@ -938,12 +929,7 @@ impl LightWalletIndexer for FetchServiceSubscriber {
             }
         };
 
-        let Some(non_finalized_snapshot) = snapshot.get_nfs_snapshot() else {
-            // TODO: This probably shouldn't be an error.
-            // this is an improvement over previous behaviour of
-            // acting as if we are only synced to the genesis block
-            return Err(FetchServiceError::UnavailableNotSyncedEnough);
-        };
+        let non_finalized_snapshot = snapshot.get_nfs_snapshot();
 
         match self
             .indexer
@@ -1018,12 +1004,7 @@ impl LightWalletIndexer for FetchServiceSubscriber {
                 }
             }
         };
-        let Some(non_finalized_snapshot) = snapshot.get_nfs_snapshot() else {
-            // TODO: This probably shouldn't be an error.
-            // this is an improvement over previous behaviour of
-            // acting as if we are only synced to the genesis block
-            return Err(FetchServiceError::UnavailableNotSyncedEnough);
-        };
+        let non_finalized_snapshot = snapshot.get_nfs_snapshot();
         match self
             .indexer
             .get_compact_block(
@@ -1119,20 +1100,7 @@ impl LightWalletIndexer for FetchServiceSubscriber {
             let timeout_result = timeout(
                 time::Duration::from_secs((service_timeout * 4) as u64),
                 async {
-                    let Some(non_finalized_snapshot) = snapshot.get_nfs_snapshot() else {
-                        // TODO: This probably shouldn't be an error.
-                        // this is an improvement over previous behaviour of
-                        // acting as if we are only synced to the genesis block
-                        if let Err(e) = channel_tx
-                            .send(Err(tonic::Status::failed_precondition(
-                                "zaino not yet synced".to_string(),
-                            )))
-                            .await
-                        {
-                            warn!(%e, "GetBlockRange channel closed unexpectedly");
-                        };
-                        return;
-                    };
+                    let non_finalized_snapshot = snapshot.get_nfs_snapshot();
                     // Use the snapshot tip directly, as this function doesn't support passthrough
                     let chain_height = non_finalized_snapshot.best_tip.height.0;
 
@@ -1252,20 +1220,7 @@ impl LightWalletIndexer for FetchServiceSubscriber {
             let timeout_result = timeout(
                 time::Duration::from_secs((service_timeout * 4) as u64),
                 async {
-                    let Some(non_finalized_snapshot) = snapshot.get_nfs_snapshot() else {
-                        // TODO: This probably shouldn't be an error.
-                        // this is an improvement over previous behaviour of
-                        // acting as if we are only synced to the genesis block
-                        if let Err(e) = channel_tx
-                            .send(Err(tonic::Status::failed_precondition(
-                                "zaino not yet synced".to_string(),
-                            )))
-                            .await
-                        {
-                            warn!(%e, "GetBlockRangeNullifiers channel closed unexpectedly");
-                        };
-                        return;
-                    };
+                    let non_finalized_snapshot = snapshot.get_nfs_snapshot();
 
                     // Use the snapshot tip directly, as this function doesn't support passthrough
                     let chain_height = non_finalized_snapshot.best_tip.height.0;
@@ -1389,12 +1344,7 @@ impl LightWalletIndexer for FetchServiceSubscriber {
                 // Zebra returns None for mempool transactions, convert to `Mempool Height`.
                 None => {
                     let snapshot = self.indexer.snapshot_nonfinalized_state().await?;
-                    let Some(non_finalized_snapshot) = snapshot.get_nfs_snapshot() else {
-                        // TODO: This probably shouldn't be an error.
-                        // this is an improvement over previous behaviour of
-                        // acting as if we are only synced to the genesis block
-                        return Err(FetchServiceError::UnavailableNotSyncedEnough);
-                    };
+                    let non_finalized_snapshot = snapshot.get_nfs_snapshot();
                     non_finalized_snapshot.best_tip.height.0 as u64
                 }
             };
@@ -1745,20 +1695,7 @@ impl LightWalletIndexer for FetchServiceSubscriber {
             let timeout = timeout(
                 time::Duration::from_secs((service_timeout * 6) as u64),
                 async {
-                    let Some(non_finalized_snapshot) = snapshot.get_nfs_snapshot() else {
-                        // TODO: This probably shouldn't be an error.
-                        // this is an improvement over previous behaviour of
-                        // acting as if we are only synced to the genesis block
-                        if let Err(e) = channel_tx
-                            .send(Err(tonic::Status::failed_precondition(
-                                "zaino not yet synced".to_string(),
-                            )))
-                            .await
-                        {
-                            warn!(%e, "GetMempoolStream channel closed unexpectedly");
-                        };
-                        return;
-                    };
+                    let non_finalized_snapshot = snapshot.get_nfs_snapshot();
                     let mempool_height = non_finalized_snapshot.best_tip.height.0;
                     match indexer.get_mempool_stream(None) {
                         Some(mut mempool_stream) => {

packages/zaino-state/src/backends/state.rs

@@ -1,5 +1,6 @@
 //! Zcash chain fetch and tx submission service backed by Zebras [`ReadStateService`].
 
+use crate::{chain_index::types::BestChainLocation, TransactionHash};
 #[allow(deprecated)]
 use crate::{
     chain_index::{
@@ -20,10 +21,6 @@ use crate::{
     utils::{get_build_info, ServiceMetadata},
     BackendType, NodeBackedChainIndex, NodeBackedChainIndexSubscriber, State,
 };
-use crate::{
-    chain_index::{types::BestChainLocation, NonFinalizedSnapshot},
-    TransactionHash,
-};
 use tokio_stream::StreamExt as _;
 use zaino_fetch::{
     chain::{transaction::FullTransaction, utils::ParseFromSlice},
@@ -578,9 +575,8 @@ impl StateServiceSubscriber {
             let timeout_result = timeout(
             time::Duration::from_secs((service_timeout * 4) as u64),
             async {
-                // This method does not support passthrough. Just return.
-                let Some(non_finalized_snapshot) = snapshot.get_nfs_snapshot() else {return};
-                let chain_height = non_finalized_snapshot.best_tip.height.0;
+                let nfs_snapshot = snapshot.get_nfs_snapshot();
+                let chain_height = nfs_snapshot.best_tip.height.0;
 
                 match state_service_clone
                     .indexer
@@ -688,7 +684,7 @@ impl StateServiceSubscriber {
         height: u32,
     ) -> Result<CompactBlock, StateServiceError> {
         let snapshot = self.indexer.snapshot_nonfinalized_state().await?;
-        let chain_height = snapshot.max_serviceable_height().0;
+        let chain_height = snapshot.get_nfs_snapshot().best_tip.height.0;
         Err(if height >= chain_height {
             StateServiceError::TonicStatusError(tonic::Status::out_of_range(format!(
                 "Error: Height out of range [{height}]. Height requested \
@@ -1567,19 +1563,14 @@ impl ZcashIndexer for StateServiceSubscriber {
     /// tags: blockchain
     async fn get_block_count(&self) -> Result<Height, Self::Error> {
         let snapshot = self.indexer.snapshot_nonfinalized_state().await?;
-        let Some(non_finalized_snapshot) = snapshot.get_nfs_snapshot() else {
-            // TODO: This probably shouldn't be an error.
-            // this is an improvement over previous behaviour of
-            // acting as if we are only synced to the genesis block
-            return Err(StateServiceError::UnavailableNotSyncedEnough);
-        };
-        let h = non_finalized_snapshot.best_tip.height;
+        let nfs_snapshot = snapshot.get_nfs_snapshot();
+        let h = nfs_snapshot.best_tip.height;
         Ok(h.into())
     }
 
     async fn get_chain_tips(&self) -> Result<GetChainTipsResponse, Self::Error> {
         let snapshot = self.indexer.snapshot_nonfinalized_state().await?;
-        let Some(non_finalized_snapshot) = snapshot.get_nfs_snapshot() else {
+        let Some(non_finalized_snapshot) = snapshot.resolved_nfs_snapshot() else {
             return Ok(self.rpc_client.get_chain_tips().await?);
         };
 
@@ -1790,7 +1781,9 @@ impl ZcashIndexer for StateServiceSubscriber {
         let (height, confirmations, block_hash, in_best_chain) = match best_chain_location {
             Some(BestChainLocation::Block(block_hash, height)) => {
                 let confirmations = snapshot
-                    .max_serviceable_height()
+                    .get_nfs_snapshot()
+                    .best_tip
+                    .height
                     .0
                     .saturating_sub(height.0)
                     .saturating_add(1);
@@ -1905,13 +1898,8 @@ impl LightWalletIndexer for StateServiceSubscriber {
     /// Return the height of the tip of the best chain
     async fn get_latest_block(&self) -> Result<BlockId, Self::Error> {
         let snapshot = self.indexer.snapshot_nonfinalized_state().await?;
-        let Some(non_finalized_snapshot) = snapshot.get_nfs_snapshot() else {
-            // TODO: This probably shouldn't be an error.
-            // this is an improvement over previous behaviour of
-            // acting as if we are only synced to the genesis block
-            return Err(StateServiceError::UnavailableNotSyncedEnough);
-        };
-        Ok(non_finalized_snapshot.best_tip.to_wire())
+        let nfs_snapshot = snapshot.get_nfs_snapshot();
+        Ok(nfs_snapshot.best_tip.to_wire())
     }
 
     /// Return the compact block corresponding to the given block identifier
@@ -1946,13 +1934,8 @@ impl LightWalletIndexer for StateServiceSubscriber {
         {
             Ok(Some(block)) => Ok(block),
             Ok(None) => {
-                let Some(non_finalized_snapshot) = snapshot.get_nfs_snapshot() else {
-                    // TODO: This probably shouldn't be an error.
-                    // this is an improvement over previous behaviour of
-                    // acting as if we are only synced to the genesis block
-                    return Err(StateServiceError::UnavailableNotSyncedEnough);
-                };
-                let chain_height = non_finalized_snapshot.best_tip.height.0;
+                let nfs_snapshot = snapshot.get_nfs_snapshot();
+                let chain_height = nfs_snapshot.best_tip.height.0;
                 match hash_or_height {
                     HashOrHeight::Height(Height(height)) if height >= chain_height => Err(
                         StateServiceError::TonicStatusError(tonic::Status::out_of_range(format!(
@@ -1966,13 +1949,8 @@ impl LightWalletIndexer for StateServiceSubscriber {
                 }
             }
             Err(e) => {
-                let Some(non_finalized_snapshot) = snapshot.get_nfs_snapshot() else {
-                    // TODO: This probably shouldn't be an error.
-                    // this is an improvement over previous behaviour of
-                    // acting as if we are only synced to the genesis block
-                    return Err(StateServiceError::UnavailableNotSyncedEnough);
-                };
-                let chain_height = non_finalized_snapshot.best_tip.height.0;
+                let nfs_snapshot = snapshot.get_nfs_snapshot();
+                let chain_height = nfs_snapshot.best_tip.height.0;
                 match hash_or_height {
                     HashOrHeight::Height(Height(height)) if height >= chain_height => Err(
                         StateServiceError::TonicStatusError(tonic::Status::out_of_range(format!(
@@ -2400,13 +2378,8 @@ impl LightWalletIndexer for StateServiceSubscriber {
         let (channel_tx, channel_rx) =
             mpsc::channel(self.config.common.service.channel_size as usize);
         let snapshot = self.indexer.snapshot_nonfinalized_state().await?;
-        let Some(non_finalized_snapshot) = snapshot.get_nfs_snapshot() else {
-            // TODO: This probably shouldn't be an error.
-            // this is an improvement over previous behaviour of
-            // acting as if we are only synced to the genesis block
-            return Err(StateServiceError::UnavailableNotSyncedEnough);
-        };
-        let mempool_height = non_finalized_snapshot.best_tip.height.0;
+        let nfs_snapshot = snapshot.get_nfs_snapshot();
+        let mempool_height = nfs_snapshot.best_tip.height.0;
         tokio::spawn(async move {
             let timeout = timeout(
                 time::Duration::from_secs((service_timeout * 6) as u64),