Deserialize snapshots (#5417)

* Deserialize snapshots

core/src/validator.rs

@@ -16,6 +16,7 @@ use crate::rpc_pubsub_service::PubSubService;
 use crate::rpc_service::JsonRpcService;
 use crate::rpc_subscriptions::RpcSubscriptions;
 use crate::service::Service;
+use crate::snapshot_utils;
 use crate::storage_stage::StorageState;
 use crate::tpu::Tpu;
 use crate::tvu::{Sockets, Tvu};
@@ -314,21 +315,36 @@ fn get_bank_forks(
     let (mut bank_forks, bank_forks_info, leader_schedule_cache) = {
         let mut result = None;
         if snapshot_config.is_some() {
-            let bank_forks = BankForks::load_from_snapshot(
-                &genesis_block,
-                account_paths.clone(),
-                snapshot_config.as_ref().unwrap(),
+            let snapshot_config = snapshot_config.as_ref().unwrap();
+
+            // Get the path to the tar
+            let tar = snapshot_utils::get_snapshot_tar_path(
+                &snapshot_config.snapshot_package_output_path(),
             );
-            match bank_forks {
-                Ok(v) => {
-                    let bank = &v.working_bank();
-                    let fork_info = BankForksInfo {
-                        bank_slot: bank.slot(),
-                        entry_height: bank.tick_height(),
-                    };
-                    result = Some((v, vec![fork_info], LeaderScheduleCache::new_from_bank(bank)));
-                }
-                Err(_) => warn!("Failed to load from snapshot, fallback to load from ledger"),
+
+            // Check that the snapshot tar exists, try to load the snapshot if it does
+            if tar.exists() {
+                // Fail hard here if snapshot fails to load, don't silently continue
+                let bank_forks = BankForks::load_from_snapshot(
+                    //&genesis_block,
+                    account_paths
+                        .clone()
+                        .expect("Account paths not present when booting from snapshot"),
+                    snapshot_config,
+                    tar,
+                )
+                .expect("Load from snapshot failed");
+
+                let bank = &bank_forks.working_bank();
+                let fork_info = BankForksInfo {
+                    bank_slot: bank.slot(),
+                    entry_height: bank.tick_height(),
+                };
+                result = Some((
+                    bank_forks,
+                    vec![fork_info],
+                    LeaderScheduleCache::new_from_bank(bank),
+                ));
             }
         }