From 1269e348fb0f0a1955c6194f0c089b565a16f7a6 Mon Sep 17 00:00:00 2001
From: sakridge <sakridge@gmail.com>
Date: Mon, 6 Jul 2020 12:42:41 -0700
Subject: [PATCH] Add a way to re-hash the bank (#10765)

---
 ledger-tool/src/main.rs | 12 +++++++++++-
 runtime/src/bank.rs     |  9 +++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/ledger-tool/src/main.rs b/ledger-tool/src/main.rs
index 18d1c13f2e..0749ca4102 100644
--- a/ledger-tool/src/main.rs
+++ b/ledger-tool/src/main.rs
@@ -949,7 +949,13 @@ fn main() {
                     .help("After loading the snapshot slot warp the ledger to WARP_SLOT, \
                            which could be a slot in a galaxy far far away"),
             )
-
+            .arg(
+                Arg::with_name("rehash")
+                    .required(false)
+                    .long("rehash")
+                    .takes_value(false)
+                    .help("Re-calculate the bank hash and overwrite the original bank hash."),
+            )
         ).subcommand(
             SubCommand::with_name("accounts")
             .about("Print account contents after processing in the ledger")
@@ -1289,6 +1295,7 @@ fn main() {
             let snapshot_slot = value_t_or_exit!(arg_matches, "snapshot_slot", Slot);
             let output_directory = value_t_or_exit!(arg_matches, "output_directory", String);
             let warp_slot = value_t!(arg_matches, "warp_slot", Slot).ok();
+            let rehash = arg_matches.is_present("rehash");
             let snapshot_version =
                 arg_matches
                     .value_of("snapshot_version")
@@ -1340,6 +1347,9 @@ fn main() {
                     bank.squash();
                     bank.clean_accounts();
                     bank.update_accounts_hash();
+                    if rehash {
+                        bank.rehash();
+                    }
 
                     let temp_dir = tempfile::tempdir_in(ledger_path).unwrap_or_else(|err| {
                         eprintln!("Unable to create temporary directory: {}", err);
diff --git a/runtime/src/bank.rs b/runtime/src/bank.rs
index d426ecdf0d..cdc33c1b5c 100644
--- a/runtime/src/bank.rs
+++ b/runtime/src/bank.rs
@@ -817,6 +817,15 @@ impl Bank {
         }
     }
 
+    pub fn rehash(&self) {
+        let mut hash = self.hash.write().unwrap();
+        let new = self.hash_internal_state();
+        if new != *hash {
+            warn!("Updating bank hash to {}", new);
+            *hash = new;
+        }
+    }
+
     pub fn freeze(&self) {
         let mut hash = self.hash.write().unwrap();