use RAII way to update allocated_file_size

Author: yejj710

mooncake-store/include/replica.h

@@ -11,6 +11,8 @@
 
 #include "types.h"
 #include "allocator.h"
+#include "master_metric_manager.h"
+
 
 namespace mooncake {
 
@@ -92,6 +94,15 @@ struct MemoryReplicaData {
 struct DiskReplicaData {
     std::string file_path;
     uint64_t object_size = 0;
+    // Automatic update allocated_file_size via RAII
+    DiskReplicaData(std::string file_path, uint64_t object_size)
+        : file_path(std::move(file_path)), object_size(object_size) {
+      MasterMetricManager::instance().inc_allocated_file_size(object_size);
+    }
+
+    ~DiskReplicaData() {
+      MasterMetricManager::instance().dec_allocated_file_size(object_size);
+    }
 };
 
 struct MemoryDescriptor {

mooncake-store/src/master_service.cpp

@@ -410,7 +410,6 @@ auto MasterService::PutStart(const std::string& key,
         std::string file_path = ResolvePath(key);
         replicas.emplace_back(file_path, total_length,
                               ReplicaStatus::PROCESSING);
-        MasterMetricManager::instance().inc_allocated_file_size(total_length);
     }
 
     std::vector<Replica::Descriptor> replica_list;
@@ -464,18 +463,7 @@ auto MasterService::PutRevoke(const std::string& key, ReplicaType replica_type)
                    << ", error=invalid_replica_status";
         return tl::make_unexpected(ErrorCode::INVALID_WRITE);
     }
-    // When disk replica is enabled, update allocated_file_size
-    if (use_disk_replica_ && replica_type == ReplicaType::DISK) {
-        for (const auto& replica : metadata.replicas) {
-            if (replica.is_memory_replica()) {
-                continue;
-            }
-            auto disk_descriptor =
-                replica.get_descriptor().get_disk_descriptor();
-            MasterMetricManager::instance().dec_allocated_file_size(
-                disk_descriptor.object_size);
-        }
-    }
+
     metadata.EraseReplica(replica_type);
     if (metadata.IsValid() == false) {
         accessor.Erase();