feat(indexer): add accept_block with chain-linkage check and atomic apply

test `RISC0_DEV_MODE=1 RISC0_SKIP_BUILD=1 cargo test -p indexer_core --lib accept_tests`

lez/indexer/core/src/block_store.rs

@@ -2,10 +2,11 @@ use std::{path::Path, sync::Arc};
 
 use anyhow::{Context as _, Result};
 use common::{
-    block::{BedrockStatus, Block},
+    HashType,
+    block::{BedrockStatus, Block, BlockHeader},
     transaction::{LeeTransaction, clock_invocation},
 };
-use lee::{Account, AccountId, V03State};
+use lee::{Account, AccountId, GENESIS_BLOCK_ID, V03State};
 use lee_core::BlockId;
 use log::info;
 use logos_blockchain_core::header::HeaderId;
@@ -13,7 +14,20 @@ use logos_blockchain_zone_sdk::Slot;
 use storage::indexer::RocksDBIO;
 use tokio::sync::RwLock;
 
-use crate::chain_breaker::ChainBreaker;
+use crate::{chain_breaker::ChainBreaker, ingest_error::BlockIngestError};
+
+struct Tip {
+    block_id: u64,
+    hash: HashType,
+}
+
+/// Outcome of feeding a parsed L2 block to the validated tip.
+pub enum AcceptOutcome {
+    /// Chained and applied; tip and L1 read cursor both advance.
+    Applied,
+    /// Did not chain or failed to apply; tip stays frozen, breaker recorded.
+    Parked(BlockIngestError),
+}
 
 #[derive(Clone)]
 pub struct IndexerStore {
@@ -156,6 +170,129 @@ impl IndexerStore {
             .get_account_by_id(*account_id))
     }
 
+    /// The last successfully applied block as `{block_id, hash}`, or `None` before
+    /// any block is stored (cold start). Read fresh from the store each call.
+    fn validated_tip(&self) -> Result<Option<Tip>> {
+        let Some(block_id) = self.dbio.get_meta_last_block_id_in_db()? else {
+            return Ok(None);
+        };
+        let Some(block) = self.dbio.get_block(block_id)? else {
+            return Ok(None);
+        };
+        Ok(Some(Tip {
+            block_id,
+            hash: block.header.hash,
+        }))
+    }
+
+    /// Returns `Some(err)` if `block` is not the valid continuation of the tip:
+    /// hash integrity, then block-id continuity, then `prev_block_hash` linkage.
+    fn acceptance_error(&self, block: &Block) -> Result<Option<BlockIngestError>> {
+        let computed = block.recompute_hash();
+        if computed != block.header.hash {
+            return Ok(Some(BlockIngestError::HashMismatch {
+                computed,
+                header: block.header.hash,
+            }));
+        }
+
+        match self.validated_tip()? {
+            None => {
+                if block.header.block_id != GENESIS_BLOCK_ID {
+                    return Ok(Some(BlockIngestError::UnexpectedBlockId {
+                        expected: GENESIS_BLOCK_ID,
+                        got: block.header.block_id,
+                    }));
+                }
+            }
+            Some(tip) => {
+                let expected = tip.block_id.checked_add(1).expect("block id overflow");
+                if block.header.block_id != expected {
+                    return Ok(Some(BlockIngestError::UnexpectedBlockId {
+                        expected,
+                        got: block.header.block_id,
+                    }));
+                }
+                if block.header.prev_block_hash != tip.hash {
+                    return Ok(Some(BlockIngestError::BrokenChainLink {
+                        expected_prev: tip.hash,
+                        got_prev: block.header.prev_block_hash,
+                    }));
+                }
+            }
+        }
+        Ok(None)
+    }
+
+    /// Records the chain breaker: the first break is stored verbatim; subsequent
+    /// breaks only bump `orphans_since`, preserving the original cause.
+    fn record_break(
+        &self,
+        header: Option<&BlockHeader>,
+        l1_slot: serde_json::Value,
+        error: BlockIngestError,
+    ) -> Result<()> {
+        let breaker = match self.get_chain_breaker()? {
+            Some(mut existing) => {
+                existing.orphans_since = existing.orphans_since.saturating_add(1);
+                existing
+            }
+            None => ChainBreaker {
+                block_id: header.map(|h| h.block_id),
+                block_hash: header.map(|h| h.hash),
+                prev_block_hash: header.map(|h| h.prev_block_hash),
+                first_seen: header.map(|h| h.timestamp),
+                l1_slot,
+                error,
+                orphans_since: 0,
+            },
+        };
+        self.set_chain_breaker(&Some(breaker))
+    }
+
+    /// Records a breaker for an inscription that could not even be parsed.
+    pub fn record_deserialize_break(
+        &self,
+        l1_slot: serde_json::Value,
+        error: String,
+    ) -> Result<()> {
+        self.record_break(None, l1_slot, BlockIngestError::Deserialize(error))
+    }
+
+    /// Validates `block` against the tip and, if it chains, applies it atomically
+    /// (scratch clone, commit only on full success) and advances the tip. On any
+    /// failure records the breaker and returns `Parked` without touching state.
+    pub async fn accept_block(
+        &self,
+        block: &Block,
+        l1_slot: serde_json::Value,
+    ) -> Result<AcceptOutcome> {
+        if let Some(err) = self.acceptance_error(block)? {
+            self.record_break(Some(&block.header), l1_slot, err.clone())?;
+            return Ok(AcceptOutcome::Parked(err));
+        }
+
+        // TODO: we use scratch state to be atomic, but need to revisit how expensive a clone is
+        let mut scratch = self.current_state.read().await.clone();
+        if let Err(err) = apply_block_to_scratch(block, &mut scratch) {
+            self.record_break(Some(&block.header), l1_slot, err.clone())?;
+            return Ok(AcceptOutcome::Parked(err));
+        }
+
+        let mut stored = block.clone();
+        stored.bedrock_status = BedrockStatus::Finalized;
+        if let Err(err) = self.dbio.put_block(&stored, [0_u8; 32]) {
+            let ingest_err = BlockIngestError::Storage(err.to_string());
+            self.record_break(Some(&block.header), l1_slot, ingest_err.clone())?;
+            return Ok(AcceptOutcome::Parked(ingest_err));
+        }
+
+        // Commit in-memory state (infallible) only after the DB write succeeded.
+        *self.current_state.write().await = scratch;
+        self.set_chain_breaker(&None)?;
+        Ok(AcceptOutcome::Applied)
+    }
+
     pub async fn put_block(&self, mut block: Block, l1_header: HeaderId) -> Result<()> {
         info!("Applying block {}", block.header.block_id);
         {
@@ -219,6 +356,61 @@ impl IndexerStore {
     }
 }
 
+/// Applies a block's transactions to `state`, mapping every failure to a
+/// [`BlockIngestError`] so the caller can park rather than crash. Operates on a
+/// scratch state; the caller commits only on `Ok`.
+fn apply_block_to_scratch(block: &Block, state: &mut V03State) -> Result<(), BlockIngestError> {
+    let (clock_tx, user_txs) =
+        block.body.transactions.split_last().ok_or_else(|| {
+            BlockIngestError::StateTransition("block has no transactions".to_owned())
+        })?;
+
+    let expected_clock = LeeTransaction::Public(clock_invocation(block.header.timestamp));
+    if *clock_tx != expected_clock {
+        return Err(BlockIngestError::StateTransition(
+            "last transaction must be the clock invocation for the block timestamp".to_owned(),
+        ));
+    }
+
+    let is_genesis = block.header.block_id == GENESIS_BLOCK_ID;
+    for transaction in user_txs {
+        if is_genesis {
+            let LeeTransaction::Public(public_tx) = transaction else {
+                return Err(BlockIngestError::StateTransition(
+                    "genesis block should contain only public transactions".to_owned(),
+                ));
+            };
+            state
+                .transition_from_public_transaction(
+                    public_tx,
+                    block.header.block_id,
+                    block.header.timestamp,
+                )
+                .map_err(|err| BlockIngestError::StateTransition(format!("{err:?}")))?;
+        } else {
+            transaction
+                .clone()
+                .execute_on_state(state, block.header.block_id, block.header.timestamp)
+                .map_err(|err| BlockIngestError::StateTransition(format!("{err:?}")))?;
+        }
+    }
+
+    let LeeTransaction::Public(clock_public_tx) = clock_tx else {
+        return Err(BlockIngestError::StateTransition(
+            "clock invocation must be a public transaction".to_owned(),
+        ));
+    };
+    state
+        .transition_from_public_transaction(
+            clock_public_tx,
+            block.header.block_id,
+            block.header.timestamp,
+        )
+        .map_err(|err| BlockIngestError::StateTransition(format!("{err:?}")))?;
+
+    Ok(())
+}
+
 #[cfg(test)]
 mod chain_breaker_tests {
     use common::HashType;
@@ -402,3 +594,103 @@ mod tests {
         assert_eq!(acc2_at_9.balance, 20090);
     }
 }
+
+#[cfg(test)]
+mod accept_tests {
+    use common::{HashType, block::HashableBlockData};
+
+    use super::*;
+    use crate::ingest_error::BlockIngestError;
+
+    fn signing_key() -> lee::PrivateKey {
+        lee::PrivateKey::try_new([7_u8; 32]).expect("valid key")
+    }
+
+    // A block with a correct hash but empty body — enough to exercise the
+    // acceptance checks (id/link/hash), which run before any state application.
+    fn valid_hash_block(block_id: u64, prev: HashType) -> common::block::Block {
+        HashableBlockData {
+            block_id,
+            prev_block_hash: prev,
+            timestamp: 0,
+            transactions: vec![],
+        }
+        .into_pending_block(&signing_key())
+    }
+
+    #[tokio::test]
+    async fn non_genesis_first_block_parks_with_unexpected_id() {
+        let dir = tempfile::tempdir().expect("tempdir");
+        let store = IndexerStore::open_db(dir.path()).expect("open store");
+
+        let block = valid_hash_block(2, HashType([0_u8; 32]));
+        let outcome = store
+            .accept_block(&block, serde_json::Value::Null)
+            .await
+            .expect("accept");
+
+        assert!(matches!(
+            outcome,
+            AcceptOutcome::Parked(BlockIngestError::UnexpectedBlockId {
+                expected: 1,
+                got: 2
+            })
+        ));
+        let breaker = store.get_chain_breaker().expect("get").expect("present");
+        assert_eq!(breaker.block_id, Some(2));
+        assert_eq!(breaker.orphans_since, 0);
+    }
+
+    #[tokio::test]
+    async fn hash_mismatch_parks() {
+        let dir = tempfile::tempdir().expect("tempdir");
+        let store = IndexerStore::open_db(dir.path()).expect("open store");
+
+        let mut block = valid_hash_block(1, HashType([0_u8; 32]));
+        block.header.timestamp = 999; // invalidates the stored hash
+
+        let outcome = store
+            .accept_block(&block, serde_json::Value::Null)
+            .await
+            .expect("accept");
+        assert!(matches!(
+            outcome,
+            AcceptOutcome::Parked(BlockIngestError::HashMismatch { .. })
+        ));
+    }
+
+    #[tokio::test]
+    async fn second_break_bumps_orphan_count_and_keeps_first() {
+        let dir = tempfile::tempdir().expect("tempdir");
+        let store = IndexerStore::open_db(dir.path()).expect("open store");
+
+        let first = valid_hash_block(2, HashType([0_u8; 32]));
+        store
+            .accept_block(&first, serde_json::Value::Null)
+            .await
+            .expect("accept");
+        let second = valid_hash_block(3, HashType([0_u8; 32]));
+        store
+            .accept_block(&second, serde_json::Value::Null)
+            .await
+            .expect("accept");
+
+        let breaker = store.get_chain_breaker().expect("get").expect("present");
+        assert_eq!(breaker.block_id, Some(2), "first breaker preserved");
+        assert_eq!(breaker.orphans_since, 1, "second break counted as orphan");
+    }
+
+    #[tokio::test]
+    async fn deserialize_break_records_breaker_without_header() {
+        let dir = tempfile::tempdir().expect("tempdir");
+        let store = IndexerStore::open_db(dir.path()).expect("open store");
+
+        store
+            .record_deserialize_break(serde_json::Value::Null, "bad bytes".to_owned())
+            .expect("record");
+
+        let breaker = store.get_chain_breaker().expect("get").expect("present");
+        assert_eq!(breaker.block_id, None);
+        assert!(matches!(breaker.error, BlockIngestError::Deserialize(_)));
+    }
+}