Add Capella & Deneb light client support (#4946)

* rebase and add comment

* conditional test

* test

* optimistic chould be working now

* finality should be working now

* try again

* try again

* clippy fix

* add lc bootstrap beacon api

* add lc optimistic/finality update to events

* fmt

* That error isn't occuring on my computer but I think this should fix it

* Merge branch 'unstable' into light_client_beacon_api_1

# Conflicts:
#	beacon_node/beacon_chain/src/events.rs
#	beacon_node/http_api/src/lib.rs
#	beacon_node/http_api/src/test_utils.rs
#	beacon_node/http_api/tests/main.rs
#	beacon_node/lighthouse_network/src/rpc/codec/ssz_snappy.rs
#	beacon_node/lighthouse_network/src/rpc/methods.rs
#	beacon_node/lighthouse_network/src/service/api_types.rs
#	beacon_node/network/src/beacon_processor/worker/rpc_methods.rs
#	beacon_node/tests/test.rs
#	common/eth2/src/types.rs
#	lighthouse/src/main.rs

* Add missing test file

* Update light client types to comply with Altair light client spec.

* Fix test compilation

* Merge branch 'unstable' into light_client_beacon_api_1

* Support deserializing light client structures for the Bellatrix fork

* Move `get_light_client_bootstrap` logic to `BeaconChain`. `LightClientBootstrap` API to return `ForkVersionedResponse`.

* Misc fixes.
- log cleanup
- move http_api config mutation to `config::get_config` for consistency
- fix light client API responses

* Add light client bootstrap API test and fix existing ones.

* Merge branch 'unstable' into light_client_beacon_api_1

* Fix test for `light-client-server` http api config.

* Appease clippy

* Add Altair light client SSZ tests

* Merge branch 'unstable' of https://github.com/sigp/lighthouse into light_client_beacon_api_1

* updates to light client header

* light client header from signed beacon block

* using options

* implement helper functions

* placeholder conversion from vec hash256 to exec branch

* add deneb

* using fixed vector

* remove unwraps

* by epoch

* compute merkle proof

* merkle proof

* update comments

* resolve merge conflicts

* linting

* Merge branch 'unstable' into light-client-ssz-tests

# Conflicts:
#	beacon_node/beacon_chain/src/beacon_chain.rs
#	consensus/types/src/light_client_bootstrap.rs
#	consensus/types/src/light_client_header.rs

* superstruct attempt

* superstruct changes

* lint

* altair

* update

* update

* changes to light_client_optimistic_ and finality

* merge unstable

* refactor

* resolved merge conflicts

* Merge branch 'unstable' of https://github.com/sigp/lighthouse into capella_deneb_light_client_types

* block_to_light_client_header fork aware

* fmt

* comment fix

* comment fix

* include merge fork, update deserialize_by_fork, refactor

* fmt

* pass by ref to prevent clone

* rename merkle proof fn

* add FIXME

* LightClientHeader TestRandom

* fix comments

* fork version deserialize

* merge unstable

* move fn arguments, fork name calc

* use task executor

* remove unneeded fns

* remove dead code

* add manual ssz decoding/encoding and add ssz_tests_by_fork macro

* merge deneb types with tests

* merge ssz tests, revert code deletion, cleanup

* move chainspec

* update ssz tests

* fmt

* light client ssz tests

* change to superstruct

* changes from feedback

* linting

* Merge branch 'unstable' of https://github.com/sigp/lighthouse into capella_deneb_light_client_types

* test fix

* cleanup

* Remove unused `derive`.

* Merge branch 'unstable' of https://github.com/sigp/lighthouse into capella_deneb_light_client_types

* beta compiler fix

* merge

beacon_node/beacon_chain/src/light_client_server_cache.rs

@@ -8,7 +8,7 @@ use types::light_client_update::{FinalizedRootProofLen, FINALIZED_ROOT_INDEX};
 use types::non_zero_usize::new_non_zero_usize;
 use types::{
     BeaconBlockRef, BeaconState, ChainSpec, EthSpec, ForkName, Hash256, LightClientFinalityUpdate,
-    LightClientHeader, LightClientOptimisticUpdate, Slot, SyncAggregate,
+    LightClientOptimisticUpdate, Slot, SyncAggregate,
 };
 
 /// A prev block cache miss requires to re-generate the state of the post-parent block. Items in the
@@ -71,11 +71,12 @@ impl<T: BeaconChainTypes> LightClientServerCache<T> {
     /// results are cached either on disk or memory to be served via p2p and rest API
     pub fn recompute_and_cache_updates(
         &self,
-        log: &Logger,
         store: BeaconStore<T>,
         block_parent_root: &Hash256,
         block_slot: Slot,
         sync_aggregate: &SyncAggregate<T::EthSpec>,
+        log: &Logger,
+        chain_spec: &ChainSpec,
     ) -> Result<(), BeaconChainError> {
         let _timer =
             metrics::start_timer(&metrics::LIGHT_CLIENT_SERVER_CACHE_RECOMPUTE_UPDATES_TIMES);
@@ -83,12 +84,13 @@ impl<T: BeaconChainTypes> LightClientServerCache<T> {
         let signature_slot = block_slot;
         let attested_block_root = block_parent_root;
 
-        let attested_block = store.get_blinded_block(attested_block_root)?.ok_or(
-            BeaconChainError::DBInconsistent(format!(
-                "Block not available {:?}",
-                attested_block_root
-            )),
-        )?;
+        let attested_block =
+            store
+                .get_full_block(attested_block_root)?
+                .ok_or(BeaconChainError::DBInconsistent(format!(
+                    "Block not available {:?}",
+                    attested_block_root
+                )))?;
 
         let cached_parts = self.get_or_compute_prev_block_cache(
             store.clone(),
@@ -109,11 +111,12 @@ impl<T: BeaconChainTypes> LightClientServerCache<T> {
         };
         if is_latest_optimistic {
             // can create an optimistic update, that is more recent
-            *self.latest_optimistic_update.write() = Some(LightClientOptimisticUpdate {
-                attested_header: block_to_light_client_header(attested_block.message()),
-                sync_aggregate: sync_aggregate.clone(),
+            *self.latest_optimistic_update.write() = Some(LightClientOptimisticUpdate::new(
+                &attested_block,
+                sync_aggregate.clone(),
                 signature_slot,
-            });
+                chain_spec,
+            )?);
         };
 
         // Spec: Full nodes SHOULD provide the LightClientFinalityUpdate with the highest
@@ -127,17 +130,16 @@ impl<T: BeaconChainTypes> LightClientServerCache<T> {
         if is_latest_finality & !cached_parts.finalized_block_root.is_zero() {
             // Immediately after checkpoint sync the finalized block may not be available yet.
             if let Some(finalized_block) =
-                store.get_blinded_block(&cached_parts.finalized_block_root)?
+                store.get_full_block(&cached_parts.finalized_block_root)?
             {
-                *self.latest_finality_update.write() = Some(LightClientFinalityUpdate {
-                    // TODO: may want to cache this result from latest_optimistic_update if producing a
-                    // light_client header becomes expensive
-                    attested_header: block_to_light_client_header(attested_block.message()),
-                    finalized_header: block_to_light_client_header(finalized_block.message()),
-                    finality_branch: cached_parts.finality_branch.clone(),
-                    sync_aggregate: sync_aggregate.clone(),
+                *self.latest_finality_update.write() = Some(LightClientFinalityUpdate::new(
+                    &attested_block,
+                    &finalized_block,
+                    cached_parts.finality_branch.clone(),
+                    sync_aggregate.clone(),
                     signature_slot,
-                });
+                    chain_spec,
+                )?);
             } else {
                 debug!(
                     log,
@@ -214,7 +216,7 @@ impl LightClientCachedData {
     }
 }
 
-// Implements spec priorization rules:
+// Implements spec prioritization rules:
 // > Full nodes SHOULD provide the LightClientFinalityUpdate with the highest attested_header.beacon.slot (if multiple, highest signature_slot)
 //
 // ref: https://github.com/ethereum/consensus-specs/blob/113c58f9bf9c08867f6f5f633c4d98e0364d612a/specs/altair/light-client/full-node.md#create_light_client_finality_update
@@ -223,14 +225,15 @@ fn is_latest_finality_update<T: EthSpec>(
     attested_slot: Slot,
     signature_slot: Slot,
 ) -> bool {
-    if attested_slot > prev.attested_header.beacon.slot {
+    let prev_slot = prev.get_attested_header_slot();
+    if attested_slot > prev_slot {
         true
     } else {
-        attested_slot == prev.attested_header.beacon.slot && signature_slot > prev.signature_slot
+        attested_slot == prev_slot && signature_slot > *prev.signature_slot()
     }
 }
 
-// Implements spec priorization rules:
+// Implements spec prioritization rules:
 // > Full nodes SHOULD provide the LightClientOptimisticUpdate with the highest attested_header.beacon.slot (if multiple, highest signature_slot)
 //
 // ref: https://github.com/ethereum/consensus-specs/blob/113c58f9bf9c08867f6f5f633c4d98e0364d612a/specs/altair/light-client/full-node.md#create_light_client_optimistic_update
@@ -239,18 +242,10 @@ fn is_latest_optimistic_update<T: EthSpec>(
     attested_slot: Slot,
     signature_slot: Slot,
 ) -> bool {
-    if attested_slot > prev.attested_header.beacon.slot {
+    let prev_slot = prev.get_slot();
+    if attested_slot > prev_slot {
         true
     } else {
-        attested_slot == prev.attested_header.beacon.slot && signature_slot > prev.signature_slot
-    }
-}
-
-fn block_to_light_client_header<T: EthSpec>(
-    block: BeaconBlockRef<T, types::BlindedPayload<T>>,
-) -> LightClientHeader {
-    // TODO: make fork aware
-    LightClientHeader {
-        beacon: block.block_header(),
+        attested_slot == prev_slot && signature_slot > *prev.signature_slot()
     }
 }