PVer4: V4Database: Return stores that have a hash prefix for a given full hash

components/safe_browsing_db/v4_database.cc

Index: components/safe_browsing_db/v4_database.cc
diff --git a/components/safe_browsing_db/v4_database.cc b/components/safe_browsing_db/v4_database.cc
index 3c1cf1c51a64a8a85df58616ccd8e5c6a0e781db..59bea71a173cbbe51756d6d8333a402e2c1ef61e 100644
--- a/components/safe_browsing_db/v4_database.cc
+++ b/components/safe_browsing_db/v4_database.cc
@@ -168,4 +168,19 @@ std::unique_ptr<StoreStateMap> V4Database::GetStoreStateMap() {
   return store_state_map;
 }
 
+void V4Database::GetStoresMatchingFullHash(
+    const FullHash& full_hash,
+    const base::hash_set<UpdateListIdentifier>& stores_to_look,
+    MatchedHashPrefixMap* matched_hash_prefix_map) {
+  for (const UpdateListIdentifier& identifier : stores_to_look) {
+    const auto& store_pair = store_map_->find(identifier);
+    DCHECK(store_pair != store_map_->end());
+    const std::unique_ptr<V4Store>& store = store_pair->second;
+    HashPrefix hash_prefix = store->GetMatchingHashPrefix(full_hash);
+    if (!hash_prefix.empty()) {
+      (*matched_hash_prefix_map)[identifier] = hash_prefix;
+    }
+  }
+}
+
 }  // namespace safe_browsing