Optimizations, disable val client sync check & additional lcli tools (#834)

* Start adding interop genesis state to lcli

* Use more efficient method to generate genesis state

* Remove duplicate int_to_bytes32

* Add lcli command to change state genesis time

* Add option to allow VC to start with unsynced BN

* Set VC to do parallel key loading

* Don't default to dummy eth1 backend

* Add endpoint to dump operation pool

* Add metrics for op pool

* Remove state clone for slot notifier

* Add mem size approximation for tree hash cache

* Avoid cloning tree hash when getting head

* Fix failing API tests

* Address Michael's comments

* Add HashMap::from_par_iter

eth2/operation_pool/src/attestation_id.rs

@@ -1,10 +1,13 @@
 use int_to_bytes::int_to_bytes8;
+use serde_derive::{Deserialize, Serialize};
 use ssz::ssz_encode;
 use ssz_derive::{Decode, Encode};
 use types::{AttestationData, BeaconState, ChainSpec, Domain, Epoch, EthSpec};
 
 /// Serialized `AttestationData` augmented with a domain to encode the fork info.
-#[derive(PartialEq, Eq, Clone, Hash, Debug, PartialOrd, Ord, Encode, Decode)]
+#[derive(
+    PartialEq, Eq, Clone, Hash, Debug, PartialOrd, Ord, Encode, Decode, Serialize, Deserialize,
+)]
 pub struct AttestationId {
     v: Vec<u8>,
 }

eth2/operation_pool/src/lib.rs

@@ -284,6 +284,16 @@ impl<T: EthSpec> OperationPool<T> {
         });
     }
 
+    /// Total number of attester slashings in the pool.
+    pub fn num_attester_slashings(&self) -> usize {
+        self.attester_slashings.read().len()
+    }
+
+    /// Total number of proposer slashings in the pool.
+    pub fn num_proposer_slashings(&self) -> usize {
+        self.proposer_slashings.read().len()
+    }
+
     /// Insert a voluntary exit, validating it almost-entirely (future exits are permitted).
     pub fn insert_voluntary_exit(
         &self,
@@ -327,6 +337,11 @@ impl<T: EthSpec> OperationPool<T> {
         self.prune_attester_slashings(finalized_state, spec);
         self.prune_voluntary_exits(finalized_state);
     }
+
+    /// Total number of voluntary exits in the pool.
+    pub fn num_voluntary_exits(&self) -> usize {
+        self.voluntary_exits.read().len()
+    }
 }
 
 /// Filter up to a maximum number of operations out of an iterator.

eth2/operation_pool/src/persistence.rs

@@ -1,6 +1,7 @@
 use crate::attestation_id::AttestationId;
 use crate::OperationPool;
 use parking_lot::RwLock;
+use serde_derive::{Deserialize, Serialize};
 use ssz_derive::{Decode, Encode};
 use types::*;
 
@@ -8,7 +9,8 @@ use types::*;
 ///
 /// Operations are stored in arbitrary order, so it's not a good idea to compare instances
 /// of this type (or its encoded form) for equality. Convert back to an `OperationPool` first.
-#[derive(Clone, Encode, Decode)]
+#[derive(Clone, PartialEq, Debug, Encode, Decode, Serialize, Deserialize)]
+#[serde(bound = "T: EthSpec")]
 pub struct PersistedOperationPool<T: EthSpec> {
     /// Mapping from attestation ID to attestation mappings.
     // We could save space by not storing the attestation ID, but it might