Refactor block val. into "BlockValidationContext"

lighthouse/state/block/validation/benches.rs

@@ -5,7 +5,7 @@ use self::test::Bencher;
 use std::sync::Arc;
 
 use super::{
-    validate_ssz_block,
+    BlockValidationContext,
     AttesterMap,
     ProposerMap,
 };
@@ -50,17 +50,18 @@ fn bench_block_validation_scenario<F>(
     let proposer_map = Arc::new(proposer_map);
     let attester_map = Arc::new(attester_map);
     b.iter(|| {
-        validate_ssz_block(
+        let context = BlockValidationContext {
-            &ssz_block,
+            present_slot: validation_slot,
-            validation_slot,
+            cycle_length: params.cycle_length,
-            params.cycle_length,
+            last_justified_slot: validation_last_justified_slot,
-            validation_last_justified_slot,
+            parent_hashes: parent_hashes.clone(),
-            &parent_hashes.clone(),
+            proposer_map: proposer_map.clone(),
-            &proposer_map.clone(),
+            attester_map: attester_map.clone(),
-            &attester_map.clone(),
+            block_store: stores.block.clone(),
-            &stores.block.clone(),
+            validator_store: stores.validator.clone(),
-            &stores.validator.clone(),
+            pow_store: stores.pow_chain.clone()
-            &stores.pow_chain.clone())
+        };
+        context.validate_ssz_block(&ssz_block)
     });
 }
 

lighthouse/state/block/validation/mod.rs

@@ -18,7 +18,7 @@ use super::common::maps::{
     ProposerMap,
 };
 pub use self::validate_ssz_block::{
-    validate_ssz_block,
+    BlockValidationContext,
     SszBlockValidationError,
     BlockStatus,
 };

lighthouse/state/block/validation/tests.rs

@@ -5,7 +5,7 @@ use self::ssz::{
 };
 use std::sync::Arc;
 use super::{
-    validate_ssz_block,
+    BlockValidationContext,
     SszBlockValidationError,
     BlockStatus,
     AttesterMap,
@@ -101,21 +101,7 @@ pub fn setup_block_validation_scenario(params: &TestParams)
         proposer_map.insert(block_slot, validator_index);
         proposer_map
     };
-    /*
+
-    let attestation_slot = block_slot - 1;
-    let (attester_map, attestations, _keypairs) =
-        generate_attestations_for_slot(
-            attestation_slot,
-            block_slot,
-            shards_per_slot,
-            validators_per_shard,
-            cycle_length,
-            &parent_hashes,
-            &Hash256::from("shard_hash".as_bytes()),
-            &justified_block_hash,
-            attestations_justified_slot,
-            &stores);
-    */
     let (attester_map, attestations, _keypairs) = {
         let mut i = 0;
         let attestation_slot = block_slot - 1;
@@ -244,17 +230,18 @@ pub fn run_block_validation_scenario<F>(
     let ssz_block = SszBlock::from_slice(&ssz_bytes[..])
         .unwrap();
 
-    validate_ssz_block(
+    let context = BlockValidationContext {
-        &ssz_block,
+        present_slot: validation_slot,
-        validation_slot,
+        cycle_length: params.cycle_length,
-        params.cycle_length,
+        last_justified_slot: validation_last_justified_slot,
-        validation_last_justified_slot,
+        parent_hashes: Arc::new(parent_hashes),
-        &Arc::new(parent_hashes),
+        proposer_map: Arc::new(proposer_map),
-        &Arc::new(proposer_map),
+        attester_map: Arc::new(attester_map),
-        &Arc::new(attester_map),
+        block_store: stores.block.clone(),
-        &stores.block.clone(),
+        validator_store: stores.validator.clone(),
-        &stores.validator.clone(),
+        pow_store: stores.pow_chain.clone()
-        &stores.pow_chain.clone())
+    };
+    context.validate_ssz_block(&ssz_block)
 }
 
 fn get_simple_params() -> TestParams {

lighthouse/state/block/validation/validate_ssz_block.rs

@@ -60,8 +60,35 @@ pub enum SszBlockValidationError {
     DatabaseError(String),
 }
 
-/// Validate some SszBlock. An SszBlock varies from a Block in that is a read-only structure
+/// The context against which a block should be validated.
-/// that reads directly from encoded SSZ.
+pub struct BlockValidationContext<T>
+    where T: ClientDB + Sized
+{
+    /// The slot as determined by the system time.
+    pub present_slot: u64,
+    /// The cycle_length as determined by the chain configuration.
+    pub cycle_length: u8,
+    /// The last justified slot as per the client's view of the canonical chain.
+    pub last_justified_slot: u64,
+    /// A vec of the hashes of the blocks preceeding the present slot.
+    pub parent_hashes: Arc<Vec<Hash256>>,
+    /// A map of slots to a block proposer validation index.
+    pub proposer_map: Arc<ProposerMap>,
+    /// A map of (slot, shard_id) to the attestation set of validation indices.
+    pub attester_map: Arc<AttesterMap>,
+    /// The store containing block information.
+    pub block_store: Arc<BlockStore<T>>,
+    /// The store containing validator information.
+    pub validator_store: Arc<ValidatorStore<T>>,
+    /// The store containing information about the proof-of-work chain.
+    pub pow_store: Arc<PoWChainStore<T>>,
+}
+
+impl<T> BlockValidationContext<T>
+    where T: ClientDB
+{
+    /// Validate some SszBlock against a block validation context. An SszBlock varies from a Block in
+    /// that is a read-only structure that reads directly from encoded SSZ.
     ///
     /// The reason to validate an SzzBlock is to avoid decoding it in its entirety if there is
     /// a suspicion that the block might be invalid. Such a suspicion should be applied to
@@ -77,16 +104,7 @@ pub enum SszBlockValidationError {
     /// Note: this function does not implement randao_reveal checking as it is not in the
     /// specification.
     #[allow(dead_code)]
-pub fn validate_ssz_block<T>(b: &SszBlock,
+    pub fn validate_ssz_block(&self, b: &SszBlock)
-                             expected_slot: u64,
-                             cycle_length: u8,
-                             last_justified_slot: u64,
-                             parent_hashes: &Arc<Vec<Hash256>>,
-                             proposer_map: &Arc<ProposerMap>,
-                             attester_map: &Arc<AttesterMap>,
-                             block_store: &Arc<BlockStore<T>>,
-                             validator_store: &Arc<ValidatorStore<T>>,
-                             pow_store: &Arc<PoWChainStore<T>>)
         -> Result<(BlockStatus, Option<Block>), SszBlockValidationError>
         where T: ClientDB + Sized
     {
@@ -96,7 +114,7 @@ pub fn validate_ssz_block<T>(b: &SszBlock,
          * drop it.
          */
         let block_slot = b.slot_number();
-    if block_slot > expected_slot {
+        if block_slot > self.present_slot {
             return Err(SszBlockValidationError::FutureSlot);
         }
 
@@ -104,7 +122,7 @@ pub fn validate_ssz_block<T>(b: &SszBlock,
          * If this block is already known, return immediately.
          */
         let block_hash = &b.block_hash();
-    if block_store.block_exists(&block_hash)? {
+        if self.block_store.block_exists(&block_hash)? {
             return Ok((BlockStatus::KnownBlock, None));
         }
 
@@ -118,7 +136,7 @@ pub fn validate_ssz_block<T>(b: &SszBlock,
          * it means "sufficienty deep in the canonical PoW chain".
          */
         let pow_chain_ref = b.pow_chain_ref();
-    if !pow_store.block_hash_exists(b.pow_chain_ref())? {
+        if !self.pow_store.block_hash_exists(b.pow_chain_ref())? {
             return Err(SszBlockValidationError::UnknownPoWChainRef);
         }
 
@@ -146,12 +164,12 @@ pub fn validate_ssz_block<T>(b: &SszBlock,
         let attestation_voters = validate_attestation(
             &first_attestation,
             block_slot,
-        cycle_length,
+            self.cycle_length,
-        last_justified_slot,
+            self.last_justified_slot,
-        &parent_hashes,
+            &self.parent_hashes,
-        &block_store,
+            &self.block_store,
-        &validator_store,
+            &self.validator_store,
-        &attester_map)?;
+            &self.attester_map)?;
 
         /*
          * If the set of voters is None, the attestation was invalid.
@@ -163,7 +181,7 @@ pub fn validate_ssz_block<T>(b: &SszBlock,
         /*
          * Read the proposer from the map of slot -> validator index.
          */
-    let proposer = proposer_map.get(&block_slot)
+        let proposer = self.proposer_map.get(&block_slot)
             .ok_or(SszBlockValidationError::BadProposerMap)?;
 
         /*
@@ -222,12 +240,12 @@ pub fn validate_ssz_block<T>(b: &SszBlock,
                         let result = validate_attestation(
                             &attestation,
                             block_slot,
-                        cycle_length,
+                            self.cycle_length,
-                        last_justified_slot,
+                            self.last_justified_slot,
-                        &parent_hashes,
+                            &self.parent_hashes,
-                        &block_store,
+                            &self.block_store,
-                        &validator_store,
+                            &self.validator_store,
-                        &attester_map);
+                            &self.attester_map);
                         match result {
                             /*
                              * Attestation validation failed with some error.
@@ -276,7 +294,7 @@ pub fn validate_ssz_block<T>(b: &SszBlock,
          * new block in the canonical chain. Otherwise, it's a new block in a fork chain.
          */
         let parent_hash = b.parent_hash();
-    let status = if block_store.block_exists_in_canonical_chain(&parent_hash)? {
+        let status = if self.block_store.block_exists_in_canonical_chain(&parent_hash)? {
             BlockStatus::NewBlockInCanonicalChain
         } else {
             BlockStatus::NewBlockInForkChain
@@ -292,6 +310,7 @@ pub fn validate_ssz_block<T>(b: &SszBlock,
         };
         Ok((status, Some(block)))
     }
+}
 
 impl From<DBError> for SszBlockValidationError {
     fn from(e: DBError) -> Self {