Fix cache refresh handling for unsaved records

- Preserve NEW_RECORD entries during cache refresh - Prevent accidental deletion of pending datastore changes - Clean up only stale persisted records
Clean up legacy code
2026-06-15 15:16:56 +05:30 · 2026-06-15 15:16:55 +05:30 · 2026-06-15 15:16:55 +05:30 · 2026-06-15 15:16:55 +05:30 · 2026-06-15 15:16:15 +05:30 · 2026-06-15 14:46:37 +05:30
31 changed files with 635 additions and 1277 deletions
@@ -427,5 +427,5 @@ FodyWeavers.xsd
 *.msm
 *.msp

-# CSV Files
-*.csv
+# DAT Files
+*.dat
@@ -140,7 +140,6 @@
    <ClCompile Include="models\User.cpp" />
    <ClCompile Include="services\AuthenticationManagementService.cpp" />
    <ClCompile Include="services\InventoryManagementService.cpp" />
-    <ClCompile Include="services\NotificationManagementService.cpp" />
    <ClCompile Include="services\PaymentManagementService.cpp" />
    <ClCompile Include="services\ServiceManagementService.cpp" />
    <ClCompile Include="services\UserManagementService.cpp" />
@@ -157,6 +156,7 @@
    <ClInclude Include="core\patterns\Observer.h" />
    <ClInclude Include="core\patterns\Subject.h" />
    <ClInclude Include="datastores\DataStore.h" />
+    <ClInclude Include="datastores\DataStoreLockGuard.h" />
    <ClInclude Include="datastores\sharedmemory\FileHeader.h" />
    <ClInclude Include="datastores\sharedmemory\MappingInfo.h" />
    <ClInclude Include="datastores\sharedmemory\RecordState.h" />
@@ -181,7 +181,6 @@
    <ClInclude Include="utilities\Config.h" />
    <ClInclude Include="utilities\Enums.h" />
    <ClInclude Include="utilities\FileHelper.h" />
-    <ClInclude Include="utilities\FileManager.h" />
    <ClInclude Include="utilities\InputHelper.h" />
    <ClInclude Include="utilities\Map.h" />
    <ClInclude Include="utilities\OutputHelper.h" />
@@ -114,9 +114,6 @@
    <ClCompile Include="datastores\DataStore.cpp">
      <Filter>Source Files\DataStores</Filter>
    </ClCompile>
-    <ClCompile Include="services\NotificationManagementService.cpp">
-      <Filter>Source Files\Services</Filter>
-    </ClCompile>
    <ClCompile Include="core\patterns\Observer.cpp">
      <Filter>Source Files\Core\Patterns</Filter>
    </ClCompile>
@@ -245,9 +242,6 @@
    <ClInclude Include="utilities\Config.h">
      <Filter>Header Files\Utilities</Filter>
    </ClInclude>
-    <ClInclude Include="utilities\FileManager.h">
-      <Filter>Header Files\Utilities</Filter>
-    </ClInclude>
    <ClInclude Include="utilities\StringHelper.h">
      <Filter>Header Files\Utilities</Filter>
    </ClInclude>
@@ -278,5 +272,8 @@
    <ClInclude Include="datastores\sharedmemory\SharedMemory.h">
      <Filter>Header Files\DataStores\SharedMemory</Filter>
    </ClInclude>
+    <ClInclude Include="datastores\DataStoreLockGuard.h">
+      <Filter>Header Files\DataStores</Filter>
+    </ClInclude>
  </ItemGroup>
 </Project>
@@ -588,63 +588,37 @@ void Controller::configureNotifications(bool paymentNotifications, bool serviceN
 }

 /*
-Function: loadSystemData
-Description: Loads all system data from persistent storage into memory.
-             Invokes the respective management services to load users, inventory items, services,
-             combo packages, service bookings, job cards, invoices, and observers.
+Function: initialize
+Description: Initializes the system and run system checks to ensure critical configurations, such as verifying admin existence.
 Parameters:
    - None
 Returns:
-    - void
+    - bool
 */
-void Controller::loadSystemData()
+bool Controller::initialize()
 {
-    m_userManagementService.loadUsers();
-    m_inventoryManagementService.loadInventoryItems();
-    m_serviceManagementService.loadServices();
-    m_serviceManagementService.loadComboPackages();
-    m_serviceManagementService.loadServiceBookings();
-    m_serviceManagementService.loadJobCards();
-    m_paymentManagementService.loadInvoices();
-    m_serviceManagementService.loadObservers();
-    m_paymentManagementService.loadObservers();
-    m_inventoryManagementService.loadObservers();
-}
+    auto& dataStore = DataStore::getInstance();

-/*
-Function: saveSystemData
-Description: Saves all system data from memory back to persistent storage.
-             Invokes the respective management services to save users, inventory items, services,
-             combo packages, service bookings, job cards, invoices, and observers.
-Parameters:
-    - None
-Returns:
-    - void
-*/
-void Controller::saveSystemData()
-{
-    m_userManagementService.saveUsers();
-    m_inventoryManagementService.saveInventoryItems();
-    m_serviceManagementService.saveServices();
-    m_serviceManagementService.saveComboPackages();
-    m_serviceManagementService.saveServiceBookings();
-    m_serviceManagementService.saveJobCards();
-    m_paymentManagementService.saveInvoices();
-    m_serviceManagementService.saveObservers();
-    m_paymentManagementService.saveObservers();
-    m_inventoryManagementService.saveObservers();
-}
-
-/*
-Function: runSystemChecks
-Description: Runs system checks to ensure critical configurations, such as verifying admin existence.
-Parameter: None
-Return type: void
-*/
-void Controller::runSystemChecks()
-{
+    if (!dataStore.initialize())
+    {
+        return false;
+    }
    m_userManagementService.ensureAdminExists();
    m_inventoryManagementService.sendLowStockAlerts();
    m_paymentManagementService.sendPaymentReminders();
+    return true;
 }

+/*
+Function: shutdown
+Description: Shutdown the system, and do necessary cleanups
+Parameters:
+    - None
+Returns:
+    - void
+*/
+void Controller::shutdown()
+{
+    auto& dataStore = DataStore::getInstance();
+    dataStore.shutdown();
+}
@@ -70,7 +70,6 @@ public:
    util::Vector<const Notification*> getNotifications();
    void deleteNotification(const std::string& notificationID);
    void configureNotifications(bool paymentNotifications, bool serviceNotifications);
-    void loadSystemData();
-    void saveSystemData();
-    void runSystemChecks();
+    bool initialize();
+    void shutdown();
 };
@@ -7,11 +7,8 @@ Date: 19-May-2026

 #pragma once

-class Notification;
-
 class Observer
 {
 public:
    virtual ~Observer() = default;
-    virtual void addNotification(Notification* notification) = 0;
 };
@@ -13,9 +13,42 @@ Date: 19-May-2026
 #include "SerializedRecords.h"
 #include "FileHelper.h"

+/*
+Function: DataStore
+Description: Constructs the DataStore singleton and initializes
+             internal handles to their default values.
+Parameters:
+    - None
+Returns:
+    - None
+*/
 DataStore::DataStore() :
    m_globalMutex(NULL) {}

+/*
+Function: ~DataStore
+Description: Destroys the DataStore singleton and releases all
+             cached application objects owned by the datastore.
+             This includes users, notifications, services,
+             combo packages, inventory items, service bookings,
+             job cards, and invoices.
+Parameters:
+    - None
+Returns:
+    - None
+*/
+DataStore::~DataStore()
+{
+    clearCache(m_userCache);
+    clearCache(m_notificationCache);
+    clearCache(m_serviceCache);
+    clearCache(m_comboPackageCache);
+    clearCache(m_inventoryItemCache);
+    clearCache(m_serviceBookingCache);
+    clearCache(m_jobCardCache);
+    clearCache(m_invoiceCache);
+}
+
 /*
 Function: initialize
 Description: Initializes the shared-memory datastore.
@@ -111,11 +144,6 @@ bool DataStore::initialize()
            success = false;
            break;
        }
-        if (!SharedMemory::createOrOpenMapping(m_payments))
-        {
-            success = false;
-            break;
-        }
        if (!SharedMemory::createOrOpenMapping(m_serviceManagementObservers))
        {
            success = false;
@@ -160,7 +188,6 @@ void DataStore::shutdown()
    SharedMemory::closeMapping(m_serviceBookings);
    SharedMemory::closeMapping(m_jobCards);
    SharedMemory::closeMapping(m_invoices);
-    SharedMemory::closeMapping(m_payments);
    SharedMemory::closeMapping(m_serviceManagementObservers);
    SharedMemory::closeMapping(m_paymentManagementObservers);
    SharedMemory::closeMapping(m_inventoryManagementObservers);
@@ -193,9 +220,11 @@ Parameters:
 Returns:
    - util::Map<std::string, TrackedRecord<User>>: Collection of user records
 */
-util::Map<std::string, TrackedRecord<User>> DataStore::getUsers()
+util::Map<std::string, TrackedRecord<User>>& DataStore::getUsers()
 {
-    return util::Map<std::string, TrackedRecord<User>>();
+    auto users = loadRecords<User, SerializedUser>(m_users);
+    refreshCache(m_userCache, users);
+    return m_userCache;
 }

 /*
@@ -206,9 +235,11 @@ Parameters:
 Returns:
    - util::Map<std::string, TrackedRecord<Notification>>: Collection of notification records
 */
-util::Map<std::string, TrackedRecord<Notification>> DataStore::getNotifications()
+util::Map<std::string, TrackedRecord<Notification>>& DataStore::getNotifications()
 {
-    return util::Map<std::string, TrackedRecord<Notification>>();
+    auto notifications = loadRecords<Notification, SerializedNotification>(m_notifications);
+    refreshCache(m_notificationCache, notifications);
+    return m_notificationCache;
 }

 /*
@@ -219,9 +250,9 @@ Parameters:
 Returns:
    - util::Map<std::string, TrackedRecord<Service>>: Collection of service records
 */
-util::Map<std::string, TrackedRecord<Service>> DataStore::getServices()
+util::Map<std::string, TrackedRecord<Service>>& DataStore::getServices()
 {
-    return util::Map<std::string, TrackedRecord<Service>>();
+    return m_serviceCache;
 }

 /*
@@ -232,9 +263,9 @@ Parameters:
 Returns:
    - util::Map<std::string, TrackedRecord<ComboPackage>>: Collection of combo package records
 */
-util::Map<std::string, TrackedRecord<ComboPackage>> DataStore::getComboPackages()
+util::Map<std::string, TrackedRecord<ComboPackage>>& DataStore::getComboPackages()
 {
-    return util::Map<std::string, TrackedRecord<ComboPackage>>();
+    return m_comboPackageCache;
 }

 /*
@@ -245,9 +276,9 @@ Parameters:
 Returns:
    - util::Map<std::string, TrackedRecord<InventoryItem>>: Collection of inventory item records
 */
-util::Map<std::string, TrackedRecord<InventoryItem>> DataStore::getInventoryItems()
+util::Map<std::string, TrackedRecord<InventoryItem>>& DataStore::getInventoryItems()
 {
-    return util::Map<std::string, TrackedRecord<InventoryItem>>();
+    return m_inventoryItemCache;
 }

 /*
@@ -258,9 +289,9 @@ Parameters:
 Returns:
    - util::Map<std::string, TrackedRecord<ServiceBooking>>: Collection of service booking records
 */
-util::Map<std::string, TrackedRecord<ServiceBooking>> DataStore::getServiceBookings()
+util::Map<std::string, TrackedRecord<ServiceBooking>>& DataStore::getServiceBookings()
 {
-    return util::Map<std::string, TrackedRecord<ServiceBooking>>();
+    return m_serviceBookingCache;
 }

 /*
@@ -271,9 +302,9 @@ Parameters:
 Returns:
    - util::Map<std::string, TrackedRecord<JobCard>>: Collection of job card records
 */
-util::Map<std::string, TrackedRecord<JobCard>> DataStore::getJobCards()
+util::Map<std::string, TrackedRecord<JobCard>>& DataStore::getJobCards()
 {
-    return util::Map<std::string, TrackedRecord<JobCard>>();
+    return m_jobCardCache;
 }

 /*
@@ -284,22 +315,40 @@ Parameters:
 Returns:
    - util::Map<std::string, TrackedRecord<Invoice>>: Collection of invoice records
 */
-util::Map<std::string, TrackedRecord<Invoice>> DataStore::getInvoices()
+util::Map<std::string, TrackedRecord<Invoice>>& DataStore::getInvoices()
 {
-    return util::Map<std::string, TrackedRecord<Invoice>>();
+    return m_invoiceCache;
 }

 /*
-Function: getPayments
-Description: Retrieves all payment records from the datastore.
+Function: getObservers
+Description: Retrieves observer records from the specified observer mapping
+             and resolves them to User objects.
 Parameters:
-    - None
+    - mapping: Observer mapping to read from
 Returns:
-    - util::Map<std::string, TrackedRecord<Payment>>: Collection of payment records
+    - util::Map<std::string, User*>: Collection of observer records
+Throws:
+    - std::runtime_error if an observer references an invalid user ID
 */
-util::Map<std::string, TrackedRecord<Payment>> DataStore::getPayments()
+util::Map<std::string, User*> DataStore::getObservers(MappingInfo& mapping)
 {
-    return util::Map<std::string, TrackedRecord<Payment>>();
+    auto& users = getUsers();
+    util::Map<std::string, User*> observers;
+    SharedMemory::ensureLatestMapping(mapping);
+    size_t recordCount = SharedMemory::getRecordCount(mapping);
+    for (size_t index = 0; index < recordCount; index++)
+    {
+        const SerializedObserver* observer = static_cast<SerializedObserver*>(SharedMemory::getRecordAddress(mapping, index));
+        int userIndex = users.find(observer->id);
+        if (userIndex == -1)
+        {
+            throw std::runtime_error("Invalid observer user ID");
+        }
+        User* user = users.getValueAt(userIndex).data;
+        observers.insert(user->getId(), user);
+    }
+    return observers;
 }

 /*
@@ -308,11 +357,11 @@ Description: Retrieves all service management observer records from the datastor
 Parameters:
    - None
 Returns:
-    - util::Map<std::string, TrackedRecord<std::string>>: Collection of observer records
+    - util::Map<std::string, User*>: Collection of observer records
 */
-util::Map<std::string, TrackedRecord<std::string>> DataStore::getServiceManagementObservers()
+util::Map<std::string, User*> DataStore::getServiceManagementObservers()
 {
-    return util::Map<std::string, TrackedRecord<std::string>>();
+    return getObservers(m_serviceManagementObservers);
 }

 /*
@@ -321,11 +370,11 @@ Description: Retrieves all payment management observer records from the datastor
 Parameters:
    - None
 Returns:
-    - util::Map<std::string, TrackedRecord<std::string>>: Collection of observer records
+    - util::Map<std::string, User*>: Collection of observer records
 */
-util::Map<std::string, TrackedRecord<std::string>> DataStore::getPaymentManagementObservers()
+util::Map<std::string, User*> DataStore::getPaymentManagementObservers()
 {
-    return util::Map<std::string, TrackedRecord<std::string>>();
+    return getObservers(m_paymentManagementObservers);
 }

 /*
@@ -334,46 +383,48 @@ Description: Retrieves all inventory management observer records from the datast
 Parameters:
    - None
 Returns:
-    - util::Map<std::string, TrackedRecord<std::string>>: Collection of observer records
+    - util::Map<std::string, User*>: Collection of observer records
 */
-util::Map<std::string, TrackedRecord<std::string>> DataStore::getInventoryManagementObservers()
+util::Map<std::string, User*> DataStore::getInventoryManagementObservers()
 {
-    return util::Map<std::string, TrackedRecord<std::string>>();
+    return getObservers(m_inventoryManagementObservers);
 }

 /*
 Function: saveUsers
 Description: Persists all user records to the datastore.
 Parameters:
-    - users: util::Map<std::string, TrackedRecord<User>>&, collection of user records
+    - None
 Returns:
    - None
 */
-void DataStore::saveUsers(util::Map<std::string, TrackedRecord<User>>& users)
+void DataStore::saveUsers()
 {
+    saveRecords<User, SerializedUser>(m_users, m_userCache);
 }

 /*
 Function: saveNotifications
 Description: Persists all notification records to the datastore.
 Parameters:
-    - notifications: util::Map<std::string, TrackedRecord<Notification>>&, collection of notification records
+    - None
 Returns:
    - None
 */
-void DataStore::saveNotifications(util::Map<std::string, TrackedRecord<Notification>>& notifications)
+void DataStore::saveNotifications()
 {
+    saveRecords<Notification, SerializedNotification>(m_notifications, m_notificationCache);
 }

 /*
 Function: saveServices
 Description: Persists all service records to the datastore.
 Parameters:
-    - services: util::Map<std::string, TrackedRecord<Service>>&, collection of service records
+    - None
 Returns:
    - None
 */
-void DataStore::saveServices(util::Map<std::string, TrackedRecord<Service>>& services)
+void DataStore::saveServices()
 {
 }

@@ -381,11 +432,11 @@ void DataStore::saveServices(util::Map<std::string, TrackedRecord<Service>>& ser
 Function: saveComboPackages
 Description: Persists all combo package records to the datastore.
 Parameters:
-    - comboPackages: util::Map<std::string, TrackedRecord<ComboPackage>>&, collection of combo package records
+    - None
 Returns:
    - None
 */
-void DataStore::saveComboPackages(util::Map<std::string, TrackedRecord<ComboPackage>>& comboPackages)
+void DataStore::saveComboPackages()
 {
 }

@@ -393,11 +444,11 @@ void DataStore::saveComboPackages(util::Map<std::string, TrackedRecord<ComboPack
 Function: saveInventoryItems
 Description: Persists all inventory item records to the datastore.
 Parameters:
-    - inventoryItems: util::Map<std::string, TrackedRecord<InventoryItem>>&, collection of inventory item records
+    - None
 Returns:
    - None
 */
-void DataStore::saveInventoryItems(util::Map<std::string, TrackedRecord<InventoryItem>>& inventoryItems)
+void DataStore::saveInventoryItems()
 {
 }

@@ -405,11 +456,11 @@ void DataStore::saveInventoryItems(util::Map<std::string, TrackedRecord<Inventor
 Function: saveServiceBookings
 Description: Persists all service booking records to the datastore.
 Parameters:
-    - bookings: util::Map<std::string, TrackedRecord<ServiceBooking>>&, collection of service booking records
+    - None
 Returns:
    - None
 */
-void DataStore::saveServiceBookings(util::Map<std::string, TrackedRecord<ServiceBooking>>& bookings)
+void DataStore::saveServiceBookings()
 {
 }

@@ -417,11 +468,11 @@ void DataStore::saveServiceBookings(util::Map<std::string, TrackedRecord<Service
 Function: saveJobCards
 Description: Persists all job card records to the datastore.
 Parameters:
-    - jobCards: util::Map<std::string, TrackedRecord<JobCard>>&, collection of job card records
+    - None
 Returns:
    - None
 */
-void DataStore::saveJobCards(util::Map<std::string, TrackedRecord<JobCard>>& jobCards)
+void DataStore::saveJobCards()
 {
 }

@@ -429,86 +480,83 @@ void DataStore::saveJobCards(util::Map<std::string, TrackedRecord<JobCard>>& job
 Function: saveInvoices
 Description: Persists all invoice records to the datastore.
 Parameters:
-    - invoices: util::Map<std::string, TrackedRecord<Invoice>>&, collection of invoice records
+    - None
 Returns:
    - None
 */
-void DataStore::saveInvoices(util::Map<std::string, TrackedRecord<Invoice>>& invoices)
+void DataStore::saveInvoices()
 {
 }

 /*
-Function: savePayments
-Description: Persists all payment records to the datastore.
+Function: saveObservers
+Description: Persists observer records to the specified observer mapping.
 Parameters:
-    - payments: util::Map<std::string, TrackedRecord<Payment>>&, collection of payment records
+    - mapping: MappingInfo&, observer mapping to save to
+    - observers: util::Map<std::string, User*>&, collection of observer records
 Returns:
    - None
 */
-void DataStore::savePayments(util::Map<std::string, TrackedRecord<Payment>>& payments)
+void DataStore::saveObservers(MappingInfo& mapping, util::Map<std::string, User*>& observers)
 {
+    size_t observerCount = static_cast<size_t>(observers.getSize());
+    size_t capacity = config::file::INITIAL_CAPACITY;
+    while (capacity < observerCount)
+    {
+        capacity *= config::file::GROWTH_FACTOR;
+    }
+    if (!SharedMemory::resizeMapping(mapping, capacity))
+    {
+        throw std::runtime_error("Failed to resize observer mapping");
+    }
+    SharedMemory::setRecordCount(mapping, observerCount);
+    for (size_t index = 0; index < observerCount; index++)
+    {
+        SerializedObserver serializedObserver;
+        User* user = observers.getValueAt(static_cast<int>(index));
+        strcpy_s(serializedObserver.id, sizeof(serializedObserver.id), user->getId().c_str());
+        SerializedObserver* destination = static_cast<SerializedObserver*>(SharedMemory::getRecordAddress(mapping, index));
+        *destination = serializedObserver;
+    }
 }

 /*
 Function: saveServiceManagementObservers
 Description: Persists all service management observer records to the datastore.
 Parameters:
-    - observers: util::Map<std::string, TrackedRecord<std::string>>&, collection of observer records
+    - observers: util::Map<std::string, User*>&, collection of observer records
 Returns:
    - None
 */
-void DataStore::saveServiceManagementObservers(util::Map<std::string, TrackedRecord<std::string>>& observers)
+void DataStore::saveServiceManagementObservers(util::Map<std::string, User*>& observers)
 {
+    saveObservers(m_serviceManagementObservers, observers);
 }

 /*
 Function: savePaymentManagementObservers
 Description: Persists all payment management observer records to the datastore.
 Parameters:
-    - observers: util::Map<std::string, TrackedRecord<std::string>>&, collection of observer records
+    - observers: util::Map<std::string, User*>&, collection of observer records
 Returns:
    - None
 */
-void DataStore::savePaymentManagementObservers(util::Map<std::string, TrackedRecord<std::string>>& observers)
+void DataStore::savePaymentManagementObservers(util::Map<std::string, User*>& observers)
 {
+    saveObservers(m_paymentManagementObservers, observers);
 }

 /*
 Function: saveInventoryManagementObservers
 Description: Persists all inventory management observer records to the datastore.
 Parameters:
-    - observers: util::Map<std::string, TrackedRecord<std::string>>&, collection of observer records
+    - observers: util::Map<std::string, User*>&, collection of observer records
 Returns:
    - None
 */
-void DataStore::saveInventoryManagementObservers(util::Map<std::string, TrackedRecord<std::string>>& observers)
+void DataStore::saveInventoryManagementObservers(util::Map<std::string, User*>& observers)
 {
-}
-
-/*
-Function: lockDataStore
-Description: Acquires exclusive access to the datastore.
-Parameters:
-    - None
-Returns:
-    - bool: True if the datastore was successfully locked, otherwise false
-*/
-bool DataStore::lockDataStore()
-{
-    return false;
-}
-
-/*
-Function: unlockDataStore
-Description: Releases exclusive access to the datastore.
-Parameters:
-    - None
-Returns:
-    - bool: True if the datastore was successfully unlocked, otherwise false
-*/
-bool DataStore::unlockDataStore()
-{
-    return false;
+    saveObservers(m_inventoryManagementObservers, observers);
 }

 /*
@@ -553,4 +601,5 @@ bool DataStore::unlockDataStore()
        return false;
    }
    return ReleaseMutex(m_globalMutex) != 0;
-}
+}
+
@@ -12,20 +12,20 @@ Date: 19-May-2026
 #include "MappingInfo.h"
 #include "TrackedRecord.h"
 #include "SharedMemory.h"
-class User;
-class Notification;
-class Service;
-class ComboPackage;
-class InventoryItem;
-class ServiceBooking;
-class JobCard;
-class Invoice;
-class Payment;
+#include "User.h"
+#include "Notification.h"
+#include "Service.h"
+#include "ComboPackage.h"
+#include "InventoryItem.h"
+#include "ServiceBooking.h"
+#include "JobCard.h"
+#include "Invoice.h"

 class DataStore
 {
 private:
    DataStore();
+    ~DataStore();
    DataStore(const DataStore&) = delete;
    DataStore& operator=(const DataStore&) = delete;
    DataStore(DataStore&&) = delete;
@@ -39,38 +39,43 @@ private:
    MappingInfo m_serviceBookings;
    MappingInfo m_jobCards;
    MappingInfo m_invoices;
-    MappingInfo m_payments;
    MappingInfo m_serviceManagementObservers;
    MappingInfo m_paymentManagementObservers;
    MappingInfo m_inventoryManagementObservers;
+    util::Map<std::string, TrackedRecord<User>> m_userCache;
+    util::Map<std::string, TrackedRecord<Notification>> m_notificationCache;
+    util::Map<std::string, TrackedRecord<Service>> m_serviceCache;
+    util::Map<std::string, TrackedRecord<ComboPackage>> m_comboPackageCache;
+    util::Map<std::string, TrackedRecord<InventoryItem>> m_inventoryItemCache;
+    util::Map<std::string, TrackedRecord<ServiceBooking>> m_serviceBookingCache;
+    util::Map<std::string, TrackedRecord<JobCard>> m_jobCardCache;
+    util::Map<std::string, TrackedRecord<Invoice>> m_invoiceCache;
 public:
    static DataStore& getInstance();
    bool initialize();
    void shutdown();
-    util::Map<std::string, TrackedRecord<User>> getUsers();
-    util::Map<std::string, TrackedRecord<Notification>> getNotifications();
-    util::Map<std::string, TrackedRecord<Service>> getServices();
-    util::Map<std::string, TrackedRecord<ComboPackage>> getComboPackages();
-    util::Map<std::string, TrackedRecord<InventoryItem>> getInventoryItems();
-    util::Map<std::string, TrackedRecord<ServiceBooking>> getServiceBookings();
-    util::Map<std::string, TrackedRecord<JobCard>> getJobCards();
-    util::Map<std::string, TrackedRecord<Invoice>> getInvoices();
-    util::Map<std::string, TrackedRecord<Payment>> getPayments();
-    util::Map<std::string, TrackedRecord<std::string>> getServiceManagementObservers();
-    util::Map<std::string, TrackedRecord<std::string>> getPaymentManagementObservers();
-    util::Map<std::string, TrackedRecord<std::string>> getInventoryManagementObservers();
-    void saveUsers(util::Map<std::string, TrackedRecord<User>>& users);
-    void saveNotifications(util::Map<std::string, TrackedRecord<Notification>>& notifications);
-    void saveServices(util::Map<std::string, TrackedRecord<Service>>& services);
-    void saveComboPackages(util::Map<std::string, TrackedRecord<ComboPackage>>& comboPackages);
-    void saveInventoryItems(util::Map<std::string, TrackedRecord<InventoryItem>>& inventoryItems);
-    void saveServiceBookings(util::Map<std::string, TrackedRecord<ServiceBooking>>& bookings);
-    void saveJobCards(util::Map<std::string, TrackedRecord<JobCard>>& jobCards);
-    void saveInvoices(util::Map<std::string, TrackedRecord<Invoice>>& invoices);
-    void savePayments(util::Map<std::string, TrackedRecord<Payment>>& payments);
-    void saveServiceManagementObservers(util::Map<std::string, TrackedRecord<std::string>>& observers);
-    void savePaymentManagementObservers(util::Map<std::string, TrackedRecord<std::string>>& observers);
-    void saveInventoryManagementObservers(util::Map<std::string, TrackedRecord<std::string>>& observers);
+    util::Map<std::string, TrackedRecord<User>>& getUsers();
+    util::Map<std::string, TrackedRecord<Notification>>& getNotifications();
+    util::Map<std::string, TrackedRecord<Service>>& getServices();
+    util::Map<std::string, TrackedRecord<ComboPackage>>& getComboPackages();
+    util::Map<std::string, TrackedRecord<InventoryItem>>& getInventoryItems();
+    util::Map<std::string, TrackedRecord<ServiceBooking>>& getServiceBookings();
+    util::Map<std::string, TrackedRecord<JobCard>>& getJobCards();
+    util::Map<std::string, TrackedRecord<Invoice>>& getInvoices();
+    util::Map<std::string, User*> getServiceManagementObservers();
+    util::Map<std::string, User*> getPaymentManagementObservers();
+    util::Map<std::string, User*> getInventoryManagementObservers();
+    void saveUsers();
+    void saveNotifications();
+    void saveServices();
+    void saveComboPackages();
+    void saveInventoryItems();
+    void saveServiceBookings();
+    void saveJobCards();
+    void saveInvoices();
+    void saveServiceManagementObservers(util::Map<std::string, User*>& observers);
+    void savePaymentManagementObservers(util::Map<std::string, User*>& observers);
+    void saveInventoryManagementObservers(util::Map<std::string, User*>& observers);
    bool lockDataStore();
    bool unlockDataStore();
 private:
@@ -78,6 +83,10 @@ private:
    util::Map<std::string, TrackedRecord<TObject>> loadRecords(MappingInfo& mapping);
    template<typename TObject, typename TSerialized>
    void saveRecords(MappingInfo& mapping, util::Map<std::string, TrackedRecord<TObject>>& records);
+    template<typename TObject> void clearCache(util::Map<std::string, TrackedRecord<TObject>>&cache);
+    template<typename TObject> void refreshCache(util::Map<std::string, TrackedRecord<TObject>>&cache, util::Map<std::string, TrackedRecord<TObject>>&refreshedCache);
+    util::Map<std::string, User*> getObservers(MappingInfo& mapping);
+    void saveObservers(MappingInfo& mapping, util::Map<std::string, User*>& observers);
 };

 /*
@@ -123,9 +132,7 @@ Description: Persists all modified and newly added records
             shared-memory mapping. Modified records overwrite
             their existing slots, while new records are
             appended to the end of the mapping. Records marked
-             as CLEAN are ignored. After persistence, all
-             temporary objects owned by the tracked records are
-             destroyed to release memory.
+             as CLEAN are ignored.
 Parameter:
    - mapping: Reference to the mapping where records are
               stored.
@@ -158,14 +165,82 @@ template<typename TObject, typename TSerialized> void DataStore::saveRecords(Map
                continue;
            }
            size_t recordCount = SharedMemory::getRecordCount(mapping);
-            TSerialized* destination = static_cast<TSerialized*>(SharedMemory::getRecordAddress(mapping, recordCount));
+            TSerialized* destination = static_cast<TSerialized*>(SharedMemory::getRecordAddress(mapping,recordCount));
            *destination = serialized;
            SharedMemory::setRecordCount(mapping, recordCount + 1);
+            record.slotIndex = recordCount;
+        }
+        record.state = RecordState::CLEAN;
+    }
+}
+
+/*
+Function: clearCache
+Description: Releases all objects owned by the cache and
+             clears the cache contents.
+Parameters:
+    - cache: Cache to be cleared.
+Returns:
+    - None
+*/
+template<typename TObject>
+void DataStore::clearCache(util::Map<std::string, TrackedRecord<TObject>>&cache)
+{
+    for (int index = 0; index < cache.getSize(); ++index)
+    {
+        delete cache.getValueAt(index).data;
+        cache.getValueAt(index).data = nullptr;
+    }
+    cache.clear();
+}
+
+/*
+Function: refreshCache
+Description: Refreshes the cache while preserving object addresses
+             for records that already exist. Existing objects are
+             updated in-place so that pointers held elsewhere remain
+             valid after the refresh.
+Parameters:
+    - cache: Existing cache to refresh.
+    - refreshedCache: Newly loaded cache contents.
+Returns:
+    - None
+*/
+template<typename TObject>
+void DataStore::refreshCache(util::Map<std::string, TrackedRecord<TObject>>& cache, util::Map<std::string, TrackedRecord<TObject>>& refreshedCache)
+{
+    util::Map<std::string, TrackedRecord<TObject>> oldCache = cache;
+    cache.clear();
+    for (int index = 0; index < refreshedCache.getSize(); ++index)
+    {
+        const std::string& id = refreshedCache.getKeyAt(index);
+        TrackedRecord<TObject>& refreshedRecord = refreshedCache.getValueAt(index);
+        int oldIndex = oldCache.find(id);
+        if (oldIndex != -1)
+        {
+            TrackedRecord<TObject>& oldRecord = oldCache.getValueAt(oldIndex);
+            *oldRecord.data = *refreshedRecord.data;
+            oldRecord.slotIndex = refreshedRecord.slotIndex;
+            oldRecord.state = refreshedRecord.state;
+            delete refreshedRecord.data;
+            refreshedRecord.data = oldRecord.data;
+        }
+        cache.insert(id, refreshedRecord);
+    }
+    for (int index = 0; index < oldCache.getSize(); ++index)
+    {
+        const std::string& id = oldCache.getKeyAt(index);
+        const TrackedRecord<TObject>& localTrackedRecord = oldCache.getValueAt(index);
+        if (cache.find(id) == -1)
+        {
+            if (localTrackedRecord.state == RecordState::NEW_RECORD)
+            {
+                cache.insert(id, localTrackedRecord);
+            }
+            else
+            {
+                delete localTrackedRecord.data;
+            }
        }
    }
-    for (int index = 0; index < records.getSize(); ++index)
-    {
-        delete records.getValueAt(index).data;
-        records.getValueAt(index).data = nullptr;
-    }
 }
@@ -0,0 +1,28 @@
+/*
+File: DataStoreLockGuard.h
+Description: Defines the DataStoreLockGuard class used to manage DataStore
+             locking and unlocking automatically within a scope.
+Author: Trenser
+Date: 12-June-2026
+*/
+
+#pragma once
+#include "DataStore.h"
+
+class DataStoreLockGuard
+{
+public:
+    explicit DataStoreLockGuard(DataStore& dataStore)
+        : m_dataStore(dataStore)
+    {
+        m_dataStore.lockDataStore();
+    }
+    ~DataStoreLockGuard()
+    {
+        m_dataStore.unlockDataStore();
+    }
+    DataStoreLockGuard(const DataStoreLockGuard&) = delete;
+    DataStoreLockGuard& operator=(const DataStoreLockGuard&) = delete;
+private:
+    DataStore& m_dataStore;
+};
@@ -10,6 +10,7 @@ Created: 11-June-2026
 */

 #include "SharedMemory.h"
+#include "Windows.h"
 #include "Config.h"

 /*
@@ -319,7 +320,7 @@ bool SharedMemory::ensureCapacityForInsert(MappingInfo& mapping)
    {
        return true;
    }
-    return resizeMapping(mapping, capacity * 2);
+    return resizeMapping(mapping, capacity * config::file::GROWTH_FACTOR);
 }

 /*
@@ -12,6 +12,7 @@ Date: 19-May-2026
 #include "Enums.h"

 class Service;
+struct SerializedComboPackage;

 class ComboPackage
 {
@@ -1,12 +1,13 @@
 /*
 File: Notification.cpp
 Description: Implements the Notification class which represents system notifications in the Vehicle Service Management System.
-             Provides constructors, accessors, and mutators for notification details such as ID, recipient, title, message, and timestamp.
+             Provides constructors, accessors, and mutators for notification details such as ID, recipientID, title, message, and timestamp.
 Author: Trenser
 Date: 19-May-2026
 */

 #include <sstream>
+#include "SerializedRecords.h"
 #include "Notification.h"
 #include "StringHelper.h"
 #include "Factory.h"
@@ -22,8 +23,8 @@ Returns:
    - A new Notification object.
 */
 Notification::Notification()
-    : m_id("NOT" + std::to_string(++m_uid)),
-    m_recipient(nullptr) {}
+    : m_id("NOT" + std::to_string(++m_uid)), 
+    m_state(util::State::ACTIVE) {}

 /*
 Function: Notification
@@ -37,13 +38,14 @@ Parameters:
 Returns:
    - A new Notification object.
 */
-Notification::Notification(const std::string& recipientUserId, User* recipient, const std::string& title, const std::string& message, const util::Timestamp& createdAt)
+Notification::Notification(const std::string& recipientUserId, const std::string& title, const std::string& message, const util::Timestamp& createdAt)
    : m_id("NOT" + std::to_string(++m_uid)),
    m_recipientUserId(recipientUserId),
-    m_recipient(recipient),
    m_title(title),
    m_message(message),
-    m_createdAt(createdAt) {}
+    m_state(util::State::ACTIVE),
+    m_createdAt(createdAt) {
+}

 /*
 Function: Notification (parameterized constructor with ID)
@@ -58,13 +60,13 @@ Parameters:
 Returns:
    - A new Notification object
 */
-Notification::Notification(const std::string& id, const std::string& recipientUserId, const std::string& title, const std::string& message, const util::Timestamp& createdAt)
+Notification::Notification(const std::string& id, const std::string& recipientUserId, const std::string& title, const std::string& message, const util::Timestamp& createdAt, const util::State& state)
    : m_id(id),
    m_recipientUserId(recipientUserId),
-    m_recipient(nullptr),
    m_title(title),
    m_message(message),
-    m_createdAt(createdAt) 
+    m_createdAt(createdAt),
+    m_state(state)
 {
    int idNumber = util::extractNumber(m_id);
    if (idNumber > m_uid)
@@ -79,7 +81,7 @@ Description: Retrieves the unique ID of the notification.
 Returns:
    - const std::string& representing the notification ID.
 */
-const std::string& Notification::getId() const 
+const std::string& Notification::getId() const
 {
    return m_id;
 }
@@ -95,17 +97,6 @@ const std::string& Notification::getRecipientUserId() const
    return m_recipientUserId;
 }

-/*
-Function: getRecipient
-Description: Retrieves the pointer to the recipient user.
-Returns:
-    - User* representing the recipient.
-*/
-User* Notification::getRecipient() const
-{
-    return m_recipient;
-}
-
 /*
 Function: getTitle
 Description: Retrieves the title of the notification.
@@ -139,6 +130,17 @@ const util::Timestamp& Notification::getCreatedAt() const
    return m_createdAt;
 }

+/*
+Function: getState
+Description: Retrieves the Notification state
+Returns:
+    - const util::Timestamp& representing the creation timestamp.
+*/
+util::State Notification::getState() const
+{
+    return m_state;
+}
+
 /*
 Function: setId
 Description: Sets the unique ID of the notification.
@@ -165,19 +167,6 @@ void Notification::setRecipientUserId(const std::string& recipientUserId)
    m_recipientUserId = recipientUserId;
 }

-/*
-Function: setRecipient
-Description: Sets the recipient user pointer for the notification.
-Parameters:
-    - recipient: Pointer to the User object.
-Returns:
-    - void
-*/
-void Notification::setRecipient(User* recipient)
-{
-    m_recipient = recipient;
-}
-
 /*
 Function: setTitle
 Description: Sets the title of the notification.
@@ -217,71 +206,54 @@ void Notification::setCreatedAt(const util::Timestamp& createdAt)
    m_createdAt = createdAt;
 }

+/*
+Function: setState
+Description: Sets the Notification state.
+Parameters:
+    - state: Notification state value.
+Returns:
+    - void
+*/
+void Notification::setState(util::State state)
+{
+    m_state = state;
+}
+
 /*
 Function: serialize
-Description: Serializes the notification into a CSV-formatted string.
+Description: Serializes the Notification object into a SerializedNotification record.
 Parameters:
    - None
 Returns:
-    - std::string: Serialized notification record
+    - SerializedNotification: Serialized representation of the notification
 */
-std::string Notification::serialize() const
+SerializedNotification Notification::serialize() const
 {
-    std::ostringstream serializedNotification;
-    serializedNotification << m_id << ','
-        << m_recipientUserId << ','
-        << m_title << ','
-        << m_message << ','
-        << m_createdAt.toString();
-    return serializedNotification.str();
+    SerializedNotification serialized = {};
+    strcpy_s(serialized.id, sizeof(serialized.id), m_id.c_str());
+    strcpy_s(serialized.recipientUserId, sizeof(serialized.recipientUserId), m_recipientUserId.c_str());
+    strcpy_s(serialized.title, sizeof(serialized.title), m_title.c_str());
+    strcpy_s(serialized.message, sizeof(serialized.message), m_message.c_str());
+    serialized.createdAt = m_createdAt;
+    serialized.state = m_state;
+    return serialized;
 }

 /*
 Function: deserialize
-Description: Deserializes a CSV-formatted string into a Notification object.
+Description: Deserializes a SerializedNotification record into a Notification object.
 Parameters:
-    - record: const std::string&, serialized notification record
+    - serializedNotification: const SerializedNotification&, serialized notification record
 Returns:
    - Notification*: Pointer to the deserialized Notification object
-Throws:
-    - std::runtime_error if timestamp parsing fails
 */
-Notification* Notification::deserialize(const std::string& record)
+Notification* Notification::deserialize(const SerializedNotification& serializedNotification)
 {
-    std::string id, recipientUserId, title, message, createdAtTimestampString;
-    std::istringstream serializedNotification(record);
-    getline(serializedNotification, id, ',');
-    getline(serializedNotification, recipientUserId, ',');
-    getline(serializedNotification, title, ',');
-    getline(serializedNotification, message, ',');
-    getline(serializedNotification, createdAtTimestampString, ',');
-    util::Timestamp createdAtTimestamp;
-    try
-    {
-        createdAtTimestamp = util::Timestamp::fromString(createdAtTimestampString);
-    }
-    catch (...)
-    {
-        throw std::runtime_error("Invalid createdAt timestamp");
-    }
    return Factory::getObject<Notification>(
-        id,
-        recipientUserId,
-        title,
-        message,
-        createdAtTimestamp
-    );
-}
-
-/*
-Function: getHeaders
-Description: Retrieves the CSV headers for notification serialization.
-Parameters:
-    - None
-Returns:
-    - std::string: Header string ("ID,RecipientID,Title,Message,Timestamp")
-*/
-std::string Notification::getHeaders()
-{
-    return "ID,RecipientID,Title,Message,Timestamp";
+        serializedNotification.id,
+        serializedNotification.recipientUserId,
+        serializedNotification.title,
+        serializedNotification.message,
+        serializedNotification.createdAt,
+        serializedNotification.state);
 }
@@ -9,8 +9,10 @@ Date: 19-May-2026
 #pragma once
 #include <string>
 #include "Timestamp.h"
+#include "Enums.h"

 class User;
+struct SerializedNotification;

 class Notification
 {
@@ -18,27 +20,26 @@ private:
    static int m_uid;
    std::string m_id;
    std::string m_recipientUserId;
-    User* m_recipient;
    std::string m_title;
    std::string m_message;
    util::Timestamp m_createdAt;
+    util::State m_state;
 public:
    Notification();
-    Notification(const std::string& recipientUserId, User* recipient, const std::string& title, const std::string& message, const util::Timestamp& createdAt);
-    Notification(const std::string& id, const std::string& recipientUserId, const std::string& title, const std::string& message, const util::Timestamp& createdAt);
+    Notification(const std::string& recipientUserId, const std::string& title, const std::string& message, const util::Timestamp& createdAt);
+    Notification(const std::string& id, const std::string& recipientUserId, const std::string& title, const std::string& message, const util::Timestamp& createdAt, const util::State& state);
    const std::string& getId() const;
    const std::string& getRecipientUserId() const;
-    User* getRecipient() const;
    const std::string& getTitle() const;
    const std::string& getMessage() const;
    const util::Timestamp& getCreatedAt() const;
    void setId(const std::string& id);
    void setRecipientUserId(const std::string& recipientUserId);
-    void setRecipient(User* recipient);
    void setTitle(const std::string& title);
    void setMessage(const std::string& message);
    void setCreatedAt(const util::Timestamp& createdAt);
-    std::string serialize() const;
-    static Notification* deserialize(const std::string&);
-    static std::string getHeaders();
+    util::State getState() const;
+    void setState(util::State state);
+    SerializedNotification serialize() const;
+    static Notification* deserialize(const SerializedNotification&);
 };
@@ -89,23 +89,6 @@ User::User(const std::string& userId, const std::string& userName, const std::st
    }
 }

-/*
-Function: ~User
-Description: Destructor that cleans up dynamically allocated notifications associated with the user.
-Parameters:
-    - None
-Returns:
-    - void
-*/
-User::~User()
-{
-    auto values = m_notifications.getValues();
-    for (int index = 0; index < values.getSize(); index++)
-    {
-        delete values[index];
-    }
-}
-
 /*
 Function: getId
 Description: Retrieves the unique ID of the user.
@@ -172,17 +155,6 @@ const std::string& User::getEmail() const
    return m_email;
 }

-/*
-Function: getNotifications
-Description: Retrieves the map of notifications associated with the user.
-Returns:
-    - util::Map<std::string, Notification*>& representing the notifications.
-*/
-util::Map<std::string, Notification*>& User::getNotifications()
-{
-    return m_notifications;
-}
-
 /*
 Function: getUserType
 Description: Retrieves the role of the user.
@@ -283,22 +255,6 @@ void User::setEmail(const std::string& email)
    m_email = email;
 }

-/*
-Function: addNotification
-Description: Adds a new notification to the user’s notification map.
-Parameters:
-    - notification: Pointer to the Notification object.
-Returns:
-    - void
-*/
-void User::addNotification(Notification* notification)
-{
-    if (notification)
-    {
-        m_notifications.insert(notification->getId(), notification);
-    }
-}
-
 /*
 Function: setRole
 Description: Sets the role of the user.
@@ -26,21 +26,19 @@ private:
    std::string m_name;
    std::string m_phone;
    std::string m_email;
-    util::Map<std::string, Notification*> m_notifications;
    util::UserType m_type;
    util::State m_status;
 public:
    User();
    User(const std::string& userName, const std::string& password, const std::string& name, const std::string& phone, const std::string& email, util::UserType role);
    User(const std::string& userId, const std::string& userName, const std::string& password, const std::string& name, const std::string& phone, const std::string& email, util::UserType role, util::State status);
-    ~User();
+    ~User() = default;
    const std::string& getId() const;
    const std::string& getUserName() const;
    const std::string& getPassword() const;
    const std::string& getName() const;
    const std::string& getPhone() const;
    const std::string& getEmail() const;
-    util::Map<std::string, Notification*>& getNotifications();
    util::UserType getUserType() const;
    util::State getState() const;
    void setId(const std::string& id);
@@ -49,7 +47,6 @@ public:
    void setName(const std::string& name);
    void setPhone(const std::string& phone);
    void setEmail(const std::string& email);
-    void addNotification(Notification* notification) override;
    void setRole(util::UserType role);
    void setState(util::State status);
    SerializedUser serialize() const;
@@ -12,14 +12,13 @@ Date: 22-May-2026
 #include "Config.h"
 #include "Enums.h"
 #include "Factory.h"
-#include "FileManager.h"
 #include "InventoryItem.h"
 #include "InventoryManagementService.h"
 #include "Timestamp.h"
 #include "User.h"
 #include "Utility.h"
 #include "Vector.h"
-
+#include "DataStoreLockGuard.h"

 util::Map<std::string, User*> InventoryManagementService::m_observers{};

@@ -90,95 +89,6 @@ void InventoryManagementService::sendLowStockAlerts()
 	}
 }

-/*
-Function: getObserverIDs
-Description: Retrieves the IDs of all observers currently attached to the
-			 InventoryManagementService.
-Parameters:
-	- None
-Returns:
-	- util::Vector<std::string>: Vector of observer user IDs
-*/
-util::Vector<std::string> InventoryManagementService::getObserverIDs()
-{
-	util::Vector<std::string> observerIDs;
-	int numberOfObservers = m_observers.getSize();
-	for (int index = 0; index < numberOfObservers; index++)
-	{
-		User* observer = m_observers.getValueAt(index);
-		if (observer)
-		{
-			observerIDs.push_back(observer->getId());
-		}
-	}
-	return observerIDs;
-}
-
-/*
-Function: loadInventoryItems
-Description: Loads inventory items from persistent storage into the datastore.
-			 Uses FileManager to deserialize inventory items from the configured file.
-Parameters:
-	- None
-Returns:
-	- void
-*/
-void InventoryManagementService::loadInventoryItems()
-{
-	util::FileManager<InventoryItem> inventoryItemFileManager(config::file::INVENTORYITEM_FILE);
-	auto& inventoryItems = m_dataStore.getInventoryItems();
-	auto inventoryItemsMap = inventoryItemFileManager.load();
-	int numberOfInventoryItems = inventoryItemsMap.getSize();
-	for (int index = 0; index < numberOfInventoryItems; index++)
-	{
-		inventoryItems[inventoryItemsMap.getKeyAt(index)] = inventoryItemsMap.getValueAt(index);
-	}
-}
-
-/*
-Function: saveInventoryItems
-Description: Saves inventory items from the datastore to persistent storage.
-			 Uses FileManager to serialize inventory items into the configured file.
-Parameters:
-	- None
-Returns:
-	- void
-*/
-void InventoryManagementService::saveInventoryItems()
-{
-	util::FileManager<InventoryItem> inventoryItemFileManager(config::file::INVENTORYITEM_FILE);
-	auto& inventoryItems = m_dataStore.getInventoryItems();
-	inventoryItemFileManager.save(inventoryItems);
-}
-
-/*
-Function: loadObservers
-Description: Loads observer IDs from persistent storage and attaches corresponding
-			 users as observers to the InventoryManagementService.
-Parameters:
-	- None
-Returns:
-	- void
-*/
-void InventoryManagementService::loadObservers()
-{
-	util::loadObservers(config::file::INVENTORYMANAGEMENTOBSERVERS, this, m_dataStore);
-}
-
-/*
-Function: saveObservers
-Description: Saves the current observer IDs of the InventoryManagementService
-			 to persistent storage for future retrieval.
-Parameters:
-	- None
-Returns:
-	- void
-*/
-void InventoryManagementService::saveObservers()
-{
-	util::saveObservers(config::file::INVENTORYMANAGEMENTOBSERVERS, this);
-}
-
 /*
 Function: addInventoryItem
 Description: Creates a new inventory item using the Factory and inserts it
@@ -271,6 +181,9 @@ Returns:
 */
 void InventoryManagementService::attach(User* user)
 {
+	DataStoreLockGuard lock(m_dataStore);
+	m_observers.clear();
+	m_observers = m_dataStore.getInventoryManagementObservers();
 	if (user)
 	{
 		const std::string& userID = user->getId();
@@ -279,6 +192,7 @@ void InventoryManagementService::attach(User* user)
 			m_observers[userID] = user;
 		}
 	}
+	m_dataStore.saveInventoryManagementObservers(m_observers);
 }

 /*
@@ -291,6 +205,9 @@ Returns:
 */
 void InventoryManagementService::detach(User* user)
 {
+	DataStoreLockGuard lock(m_dataStore);
+	m_observers.clear();
+	m_observers = m_dataStore.getInventoryManagementObservers();
 	if (user)
 	{
 		const std::string& userID = user->getId();
@@ -299,6 +216,7 @@ void InventoryManagementService::detach(User* user)
 			m_observers.remove(userID);
 		}
 	}
+	m_dataStore.saveInventoryManagementObservers(m_observers);
 }

 /*
@@ -315,27 +233,27 @@ Throws:
 */
 void InventoryManagementService::sendNotification(User* user, const std::string& title, const std::string& message)
 {
-	if (user)
+	if (!user)
 	{
-		if (m_observers.find(user->getId()) != -1)
-		{
-			Notification* notification =
-				Factory::getObject<Notification>(
-					user->getId(),
-					user,
-					title,
-					message,
-					util::Timestamp()
-				);
-			if (notification)
-			{
-				user->addNotification(notification);
-			}
-			else
-			{
-				throw std::runtime_error("Failed to create notification");
-			}
-		}
+		return;
 	}
+	DataStoreLockGuard lock(m_dataStore);
+	m_observers = m_dataStore.getInventoryManagementObservers();
+	if (m_observers.find(user->getId()) == -1)
+	{
+		return;
+	}
+	Notification* notification = Factory::getObject<Notification>(
+		user->getId(),
+		title,
+		message,
+		util::Timestamp());
+	if (!notification)
+	{
+		throw std::runtime_error("Failed to create notification");
+	}
+	auto& trackedNotificationsMap = m_dataStore.getNotifications();
+	trackedNotificationsMap.insert(notification->getId(), util::createNewRecord(notification));
+	m_dataStore.saveNotifications();
 }

@@ -21,7 +21,6 @@ class InventoryManagementService : public NotificationManagementService
 private:
    DataStore& m_dataStore;
    static util::Map<std::string, User*> m_observers;
-    util::Vector<std::string> getObserverIDs() override;
 public:
    InventoryManagementService() : m_dataStore(DataStore::getInstance()) {}
    util::Map<std::string, InventoryItem*> getInventoryItems();
@@ -33,8 +32,4 @@ public:
    void sendNotification(User* user, const std::string& title, const std::string& message) override;
    void attach(User* user) override;
    void detach(User* user) override;
-    void loadInventoryItems();
-    void saveInventoryItems();
-    void loadObservers();
-    void saveObservers();
 };
@@ -1 +0,0 @@
-#include "NotificationManagementService.h"
@@ -19,5 +19,4 @@ public:
 	virtual void sendNotification(User* recipient, const std::string& title, const std::string& message) = 0;
 	virtual void attach(User* user) = 0;
 	virtual void detach(User* user) = 0;
-	virtual util::Vector<std::string> getObserverIDs() = 0;
 };
@@ -11,7 +11,6 @@ Date: 20-May-2026
 #include "Config.h"
 #include "Enums.h"
 #include "Factory.h"
-#include "FileManager.h"
 #include "InventoryItem.h"
 #include "Invoice.h"
 #include "JobCard.h"
@@ -21,6 +20,7 @@ Date: 20-May-2026
 #include "Timestamp.h"
 #include "User.h"
 #include "Utility.h"
+#include "DataStoreLockGuard.h"

 util::Map<std::string, User*> PaymentManagementService::m_observers{};

@@ -34,6 +34,9 @@ Returns:
 */
 void PaymentManagementService::attach(User* user)
 {
+	DataStoreLockGuard lock(m_dataStore);
+	m_observers.clear();
+	m_observers = m_dataStore.getPaymentManagementObservers();
 	if (user)
 	{
 		const std::string& userID = user->getId();
@@ -42,6 +45,7 @@ void PaymentManagementService::attach(User* user)
 			m_observers[userID] = user;
 		}
 	}
+	m_dataStore.savePaymentManagementObservers(m_observers);
 }

 /*
@@ -54,6 +58,9 @@ Returns:
 */
 void PaymentManagementService::detach(User* user)
 {
+	DataStoreLockGuard lock(m_dataStore);
+	m_observers.clear();
+	m_observers = m_dataStore.getPaymentManagementObservers();
 	if (user)
 	{
 		const std::string& userID = user->getId();
@@ -62,6 +69,7 @@ void PaymentManagementService::detach(User* user)
 			m_observers.remove(userID);
 		}
 	}
+	m_dataStore.savePaymentManagementObservers(m_observers);
 }

 /*
@@ -78,28 +86,28 @@ Throws:
 */
 void PaymentManagementService::sendNotification(User* user, const std::string& title, const std::string& message)
 {
-	if (user)
+	if (!user)
 	{
-		if (m_observers.find(user->getId()) != -1)
-		{
-			Notification* notification =
-				Factory::getObject<Notification>(
-					user->getId(),
-					user,
-					title,
-					message,
-					util::Timestamp()
-				);
-			if (notification)
-			{
-				user->addNotification(notification);
-			}
-			else
-			{
-				throw std::runtime_error("Failed to create notification");
-			}
-		}
+		return;
 	}
+	DataStoreLockGuard lock(m_dataStore);
+	m_observers = m_dataStore.getPaymentManagementObservers();
+	if (m_observers.find(user->getId()) == -1)
+	{
+		return;
+	}
+	Notification* notification = Factory::getObject<Notification>(
+		user->getId(),
+		title,
+		message,
+		util::Timestamp());
+	if (!notification)
+	{
+		throw std::runtime_error("Failed to create notification");
+	}
+	auto& trackedNotificationsMap = m_dataStore.getNotifications();
+	trackedNotificationsMap.insert(notification->getId(), util::createNewRecord(notification));
+	m_dataStore.saveNotifications();
 }

 /*
@@ -140,123 +148,6 @@ void PaymentManagementService::sendPaymentReminders()
 	}
 }

-/*
-Function: getObserverIDs
-Description: Retrieves the IDs of all observers currently attached to the
-             PaymentManagementService.
-Parameters:
-    - None
-Returns:
-    - util::Vector<std::string>: Vector of observer user IDs
-*/
-util::Vector<std::string> PaymentManagementService::getObserverIDs()
-{
-	util::Vector<std::string> observerIDs;
-	int numberOfObservers = m_observers.getSize();
-	for (int index = 0; index < numberOfObservers; index++)
-	{
-		User* observer = m_observers.getValueAt(index);
-		if (observer)
-		{
-			observerIDs.push_back(observer->getId());
-		}
-	}
-	return observerIDs;
-}
-
-/*
-Function: loadInvoices
-Description: Loads invoices from persistent storage into the datastore.
-             Validates associated service bookings and inventory parts before
-             attaching them to each invoice. Throws exceptions if invalid IDs
-             are encountered.
-Parameters:
-    - None
-Returns:
-    - void
-Throws:
-    - std::runtime_error if a booking ID or part ID is invalid
-*/
-void PaymentManagementService::loadInvoices()
-{
-    util::FileManager<Invoice> invoiceFileManager(config::file::INVOICE_FILE);
-    auto& invoices = m_dataStore.getInvoices();
-    auto& serviceBookings = m_dataStore.getServiceBookings();
-    auto& inventoryItems = m_dataStore.getInventoryItems();
-    auto invoicesMap = invoiceFileManager.load();
-    for (int invoiceIndex = 0; invoiceIndex < invoicesMap.getSize(); invoiceIndex++)
-    {
-        Invoice* invoice = invoicesMap.getValueAt(invoiceIndex);
-        int bookingIndex = serviceBookings.find(invoice->getBookingId());
-        if (bookingIndex == -1)
-        {
-            throw std::runtime_error("Invalid Booking ID");
-        }
-        ServiceBooking* booking = serviceBookings.getValueAt(bookingIndex);
-        invoice->setBooking(booking);
-        util::Map<std::string, InventoryItem*> invoiceParts;
-        auto& partIDs = invoice->getPartIDs();
-        for (int partIndex = 0; partIndex < partIDs.getSize(); partIndex++)
-        {
-            const std::string& partID = partIDs[partIndex];
-            int inventoryIndex = inventoryItems.find(partID);
-            if (inventoryIndex == -1)
-            {
-                throw std::runtime_error("Invalid Part ID");
-            }
-            invoiceParts[partID] = inventoryItems.getValueAt(inventoryIndex);
-        }
-        invoice->setParts(invoiceParts);
-        invoices[invoice->getId()] = invoice;
-    }
-}
-
-/*
-Function: saveInvoices
-Description: Saves invoices from the datastore to persistent storage.
-             Uses FileManager to serialize invoices into the configured file.
-Parameters:
-    - None
-Returns:
-    - void
-*/
-void PaymentManagementService::saveInvoices()
-{
-    util::FileManager<Invoice> invoiceFileManager(config::file::INVOICE_FILE);
-    auto& invoices = m_dataStore.getInvoices();
-    invoiceFileManager.save(invoices);
-}
-
-/*
-Function: loadObservers
-Description: Loads observer IDs from persistent storage and attaches corresponding
-             users as observers to the PaymentManagementService.
-Parameters:
-    - None
-Returns:
-    - void
-Throws:
-    - std::runtime_error if an observer ID is invalid (not found in datastore)
-*/
-void PaymentManagementService::loadObservers()
-{
-    util::loadObservers(config::file::PAYMENTMANAGEMENTOBSERVERS, this, m_dataStore);
-}
-
-/*
-Function: saveObservers
-Description: Saves the current observer IDs of the PaymentManagementService
-             to persistent storage for future retrieval.
-Parameters:
-    - None
-Returns:
-    - void
-*/
-void PaymentManagementService::saveObservers()
-{
-    util::saveObservers(config::file::PAYMENTMANAGEMENTOBSERVERS, this);
-}
-
 /*
 Function: createInventoryItemsMap (static helper)
 Description: Builds a map of inventory items required for a given service and adds them to the booking’s inventory map.
@@ -22,7 +22,6 @@ class PaymentManagementService : public NotificationManagementService
 private:
    DataStore& m_dataStore;
    static util::Map<std::string, User*> m_observers;
-    util::Vector<std::string> getObserverIDs() override;
 public:
    PaymentManagementService() : m_dataStore(DataStore::getInstance()) {}
    void generateInvoice(ServiceBooking* booking);
@@ -34,8 +33,4 @@ public:
    void sendNotification(User* user, const std::string& title, const std::string& message) override;
    void attach(User* user) override;
    void detach(User* user) override;
-    void loadInvoices();
-    void saveInvoices();
-    void loadObservers();
-    void saveObservers();
 };
@@ -14,7 +14,6 @@ Date:19-May-2026
 #include "DataStore.h"
 #include "Enums.h"
 #include "Factory.h"
-#include "FileManager.h"
 #include "InventoryItem.h"
 #include "JobCard.h"
 #include "NotificationManagementService.h"
@@ -26,6 +25,7 @@ Date:19-May-2026
 #include "User.h"
 #include "UserManagementService.h"
 #include "Utility.h"
+#include "DataStoreLockGuard.h"

 /*
 Function: purchaseService
@@ -122,6 +122,9 @@ Returns:
 */
 void ServiceManagementService::attach(User* user)
 {
+    DataStoreLockGuard lock(m_dataStore);
+    m_observers.clear();
+    m_observers = m_dataStore.getServiceManagementObservers();
 	if (user)
 	{
 		const std::string& userID = user->getId();
@@ -130,6 +133,7 @@ void ServiceManagementService::attach(User* user)
 			m_observers[userID] = user;
 		}
 	}
+    m_dataStore.saveServiceManagementObservers(m_observers);
 }

 /*
@@ -142,6 +146,9 @@ Returns:
 */
 void ServiceManagementService::detach(User* user)
 {
+    DataStoreLockGuard lock(m_dataStore);
+    m_observers.clear();
+    m_observers = m_dataStore.getServiceManagementObservers();
 	if (user)
 	{
 		const std::string& userID = user->getId();
@@ -150,6 +157,7 @@ void ServiceManagementService::detach(User* user)
 			m_observers.remove(userID);
 		}
 	}
+    m_dataStore.saveServiceManagementObservers(m_observers);
 }

 /*
@@ -166,345 +174,28 @@ Throws:
 */
 void ServiceManagementService::sendNotification(User* user, const std::string& title, const std::string& message)
 {
-	if (user)
-	{
-		if (m_observers.find(user->getId()) != -1)
-		{
-			Notification* notification =
-				Factory::getObject<Notification>(
-					user->getId(),
-					user,
-					title,
-					message,
-					util::Timestamp()
-				);
-			if (notification)
-			{
-				user->addNotification(notification);
-			}
-			else
-			{
-				throw std::runtime_error("Failed to create notification");
-			}
-		}
-	}
-}
-
-/*
-Function: getObserverIDs
-Description: Retrieves the IDs of all observers currently attached to the
-             ServiceManagementService.
-Parameters:
-    - None
-Returns:
-    - util::Vector<std::string>: Vector of observer user IDs
-*/
-util::Vector<std::string> ServiceManagementService::getObserverIDs()
-{
-	util::Vector<std::string> observerIDs;
-	int numberOfObservers = m_observers.getSize();
-	for (int index = 0; index < numberOfObservers; index++)
-	{
-		User* observer = m_observers.getValueAt(index);
-		if (observer)
-		{
-			observerIDs.push_back(observer->getId());
-		}
-	}
-	return observerIDs;
-}
-
-/*
-Function: loadServices
-Description: Loads services from persistent storage into the datastore.
-             Validates required inventory items and attaches them to each service.
-Parameters:
-    - None
-Returns:
-    - void
-Throws:
-    - std::runtime_error if an inventory item ID is invalid
-*/
-void ServiceManagementService::loadServices()
-{
-    util::FileManager<Service> serviceFileManager(config::file::SERVICE_FILE);
-    auto& services = m_dataStore.getServices();
-    auto& inventoryItems = m_dataStore.getInventoryItems();
-    auto servicesMap = serviceFileManager.load();
-    for (int serviceIndex = 0; serviceIndex < servicesMap.getSize(); serviceIndex++)
+    if (!user)
    {
-        Service* service = servicesMap.getValueAt(serviceIndex);
-        services[service->getId()] = service;
-        util::Map<std::string, InventoryItem*> inventoryItemsMap;
-        auto& inventoryItemIDs = service->getRequiredInventoryItemIDs();
-        for (int inventoryItemIndex = 0; inventoryItemIndex < inventoryItemIDs.getSize(); inventoryItemIndex++)
-        {
-            const std::string& inventoryItemID = inventoryItemIDs[inventoryItemIndex];
-            int index = inventoryItems.find(inventoryItemID);
-            if (index == -1)
-            {
-                throw std::runtime_error("Invalid Inventory Item ID");
-            }
-            inventoryItemsMap[inventoryItemID] = inventoryItems.getValueAt(index);
-        }
-        service->setRequiredInventoryItems(inventoryItemsMap);
+        return;
    }
-}
-
-/*
-Function: saveServices
-Description: Saves services from the datastore to persistent storage.
-             Uses FileManager to serialize services into the configured file.
-Parameters:
-    - None
-Returns:
-    - void
-*/
-void ServiceManagementService::saveServices()
-{
-	util::FileManager<Service> serviceFileManager(config::file::SERVICE_FILE);
-	auto& services = m_dataStore.getServices();
-	serviceFileManager.save(services);
-}
-
-/*
-Function: loadComboPackages
-Description: Loads combo packages from persistent storage into the datastore.
-             Validates associated services and attaches them to each package.
-Parameters:
-    - None
-Returns:
-    - void
-Throws:
-    - std::runtime_error if a service ID is invalid
-*/
-void ServiceManagementService::loadComboPackages()
-{
-    util::FileManager<ComboPackage> comboPackageFileManager(config::file::COMBOPACKAGE_FILE);
-    auto& comboPackages = m_dataStore.getComboPackages();
-    auto& services = m_dataStore.getServices();
-    auto comboPackagesMap = comboPackageFileManager.load();
-    for (int packageIndex = 0; packageIndex < comboPackagesMap.getSize(); packageIndex++)
+    DataStoreLockGuard lock(m_dataStore);
+    m_observers = m_dataStore.getServiceManagementObservers();
+    if (m_observers.find(user->getId()) == -1)
    {
-        ComboPackage* comboPackage = comboPackagesMap.getValueAt(packageIndex);
-        util::Map<std::string, Service*> packageServices;
-        auto& serviceIDs = comboPackage->getServiceIDs();
-        for (int serviceIndex = 0; serviceIndex < serviceIDs.getSize(); serviceIndex++)
-        {
-            const std::string& serviceID = serviceIDs[serviceIndex];
-            int serviceMapIndex = services.find(serviceID);
-            if (serviceMapIndex == -1)
-            {
-                throw std::runtime_error("Invalid Service ID");
-            }
-            packageServices[serviceID] = services.getValueAt(serviceMapIndex);
-        }
-        comboPackage->setServices(packageServices);
-        comboPackages[comboPackage->getId()] = comboPackage;
+        return;
    }
-}
-
-/*
-Function: saveComboPackages
-Description: Saves combo packages from the datastore to persistent storage.
-             Uses FileManager to serialize combo packages into the configured file.
-Parameters:
-    - None
-Returns:
-    - void
-*/
-void ServiceManagementService::saveComboPackages()
-{
-    util::FileManager<ComboPackage> comboPackageFileManager(config::file::COMBOPACKAGE_FILE);
-    auto& comboPackages = m_dataStore.getComboPackages();
-    comboPackageFileManager.save(comboPackages);
-}
-
-/*
-Function: loadServiceBookings
-Description: Loads service bookings from persistent storage into the datastore.
-             Validates associated services, customers, and technicians before
-             attaching them to each booking.
-Parameters:
-    - None
-Returns:
-    - void
-Throws:
-    - std::runtime_error if a service ID, customer ID, or technician ID is invalid
-    - std::runtime_error if a user is not of the expected type (customer/technician)
-*/
-void ServiceManagementService::loadServiceBookings()
-{
-    util::FileManager<ServiceBooking> bookingFileManager(config::file::SERVICEBOOKING_FILE);
-    auto& serviceBookings = m_dataStore.getServiceBookings();
-    auto& services = m_dataStore.getServices();
-    auto& users = m_dataStore.getUsers();
-    auto bookingsMap = bookingFileManager.load();
-    for (int bookingIndex = 0; bookingIndex < bookingsMap.getSize(); bookingIndex++)
+    Notification* notification = Factory::getObject<Notification>(
+        user->getId(),
+        title,
+        message,
+        util::Timestamp());
+    if (!notification)
    {
-        ServiceBooking* booking = bookingsMap.getValueAt(bookingIndex);
-        util::Map<std::string, Service*> bookingServices;
-        auto& serviceIDs = booking->getServiceIDs();
-        for (int serviceIndex = 0; serviceIndex < serviceIDs.getSize(); serviceIndex++)
-        {
-            const std::string& serviceID = serviceIDs[serviceIndex];
-            int serviceMapIndex = services.find(serviceID);
-            if (serviceMapIndex == -1)
-            {
-                throw std::runtime_error("Invalid Service ID");
-            }
-
-            bookingServices[serviceID] = services.getValueAt(serviceMapIndex);
-        }
-        booking->setServices(bookingServices);
-        int customerIndex = users.find(booking->getCustomerId());
-        if (customerIndex == -1)
-        {
-            throw std::runtime_error("Invalid Customer ID");
-        }
-        User* customer = users.getValueAt(customerIndex);
-        if (customer->getUserType() != util::UserType::CUSTOMER)
-        {
-            throw std::runtime_error("User is not a customer");
-        }
-        booking->setCustomer(customer);
-        const std::string& technicianId = booking->getAssignedTechnicianId();
-        if (!technicianId.empty())
-        {
-            int technicianIndex = users.find(technicianId);
-            if (technicianIndex == -1)
-            {
-                throw std::runtime_error("Invalid Technician ID");
-            }
-            User* technician = users.getValueAt(technicianIndex);
-            if (technician->getUserType() != util::UserType::TECHNICIAN)
-            {
-                throw std::runtime_error("User is not a technician");
-            }
-            booking->setAssignedTechnician(technician);
-        }
-        serviceBookings[booking->getId()] = booking;
+        throw std::runtime_error("Failed to create notification");
    }
-}
-
-/*
-Function: saveServiceBookings
-Description: Saves service bookings from the datastore to persistent storage.
-             Uses FileManager to serialize bookings into the configured file.
-Parameters:
-    - None
-Returns:
-    - void
-*/
-void ServiceManagementService::saveServiceBookings()
-{
-    util::FileManager<ServiceBooking> bookingFileManager(config::file::SERVICEBOOKING_FILE);
-    auto& serviceBookings = m_dataStore.getServiceBookings();
-    bookingFileManager.save(serviceBookings);
-}
-
-/*
-Function: loadJobCards
-Description: Loads job cards from persistent storage into the datastore.
-             Validates associated bookings, services, and technicians before
-             attaching them to each job card.
-Parameters:
-    - None
-Returns:
-    - void
-Throws:
-    - std::runtime_error if a booking ID, service ID, or technician ID is invalid
-    - std::runtime_error if a service does not belong to the booking
-    - std::runtime_error if a user is not a technician
-*/
-void ServiceManagementService::loadJobCards()
-{
-    util::FileManager<JobCard> jobCardFileManager(config::file::JOBCARD_FILE);
-    auto& jobCards = m_dataStore.getJobCards();
-    auto& serviceBookings = m_dataStore.getServiceBookings();
-    auto& services = m_dataStore.getServices();
-    auto& users = m_dataStore.getUsers();
-    auto jobCardsMap = jobCardFileManager.load();
-    for (int jobCardIndex = 0; jobCardIndex < jobCardsMap.getSize(); jobCardIndex++)
-    {
-        JobCard* jobCard = jobCardsMap.getValueAt(jobCardIndex);
-        int bookingIndex = serviceBookings.find(jobCard->getBookingId());
-        if (bookingIndex == -1)
-        {
-            throw std::runtime_error("Invalid Booking ID");
-        }
-        ServiceBooking* booking = serviceBookings.getValueAt(bookingIndex);
-        jobCard->setBooking(booking);
-        int serviceIndex = services.find(jobCard->getServiceId());
-        if (serviceIndex == -1)
-        {
-            throw std::runtime_error("Invalid Service ID");
-        }
-        Service* service = services.getValueAt(serviceIndex);
-        if (booking->getServices().find(jobCard->getServiceId()) == -1)
-        {
-            throw std::runtime_error("Service does not belong to booking");
-        }
-        jobCard->setService(service);
-        int technicianIndex = users.find(jobCard->getTechnicianId());
-        if (technicianIndex == -1)
-        {
-            throw std::runtime_error("Invalid Technician ID");
-        }
-        User* technician = users.getValueAt(technicianIndex);
-        if (technician->getUserType() != util::UserType::TECHNICIAN)
-        {
-            throw std::runtime_error("User is not a technician");
-        }
-        jobCard->setTechnician(technician);
-        jobCards[jobCard->getId()] = jobCard;
-    }
-}
-
-/*
-Function: saveJobCards
-Description: Saves job cards from the datastore to persistent storage.
-             Uses FileManager to serialize job cards into the configured file.
-Parameters:
-    - None
-Returns:
-    - void
-*/
-void ServiceManagementService::saveJobCards()
-{
-    util::FileManager<JobCard> jobCardFileManager(config::file::JOBCARD_FILE);
-    auto& jobCards = m_dataStore.getJobCards();
-    jobCardFileManager.save(jobCards);
-}
-
-/*
-Function: loadObservers
-Description: Loads observer IDs from persistent storage and attaches corresponding
-             users as observers to the ServiceManagementService.
-Parameters:
-    - None
-Returns:
-    - void
-Throws:
-    - std::runtime_error if an observer ID is invalid (not found in datastore)
-*/
-void ServiceManagementService::loadObservers()
-{
-    util::loadObservers(config::file::SERVICEMANAGEMENTOBSERVERS, this, m_dataStore);
-}
-
-/*
-Function: saveObservers
-Description: Saves the current observer IDs of the ServiceManagementService
-             to persistent storage for future retrieval.
-Parameters:
-    - None
-Returns:
-    - void
-*/
-void ServiceManagementService::saveObservers()
-{
-    util::saveObservers(config::file::SERVICEMANAGEMENTOBSERVERS, this);
+    auto& trackedNotificationsMap = m_dataStore.getNotifications();
+    trackedNotificationsMap.insert(notification->getId(), util::createNewRecord(notification));
+    m_dataStore.saveNotifications();
 }

 /*
@@ -23,7 +23,6 @@ class ServiceManagementService : public NotificationManagementService
 private:
    DataStore& m_dataStore;
    static util::Map<std::string, User*> m_observers;
-    util::Vector<std::string> getObserverIDs() override;
 public:
    ServiceManagementService() : m_dataStore(DataStore::getInstance()) {}
    util::Map<std::string, Service*> getServices();
@@ -45,14 +44,4 @@ public:
    void sendNotification(User* user, const std::string& title, const std::string& message) override;
    void attach(User* user) override;
    void detach(User* user) override;
-    void loadServices();
-    void saveServices();
-    void loadComboPackages();
-    void saveComboPackages();
-    void loadServiceBookings();
-    void saveServiceBookings();
-    void loadJobCards();
-    void saveJobCards();
-    void loadObservers();
-    void saveObservers();
 };
@@ -11,7 +11,6 @@ Date:19-May-2026
 #include "Config.h"
 #include "Enums.h"
 #include "Factory.h"
-#include "FileManager.h"
 #include "InventoryManagementService.h"
 #include "Notification.h"
 #include "PaymentManagementService.h"
@@ -20,6 +19,9 @@ Date:19-May-2026
 #include "UserManagementService.h"
 #include "Vector.h"
 #include "Validator.h"
+#include "Utility.h"
+#include "TrackedRecord.h"
+#include "DataStoreLockGuard.h"

 /*
 Function: ensureAdminExists
@@ -31,12 +33,13 @@ Return type: void
 */
 void UserManagementService::ensureAdminExists()
 {
+	DataStoreLockGuard lock(m_dataStore);
 	auto& usersMap = m_dataStore.getUsers();
 	int usersMapSize = usersMap.getSize();
 	bool isAdminFound = false;
 	for (int index = 0; index < usersMapSize; index++)
 	{
-		User* user = usersMap.getValueAt(index);
+		User* user = usersMap.getValueAt(index).data;
 		if (user && user->getUserType() == util::UserType::ADMIN)
 		{
 			isAdminFound = true;
@@ -73,7 +76,9 @@ void UserManagementService::createUser(const std::string& username, const std::s
 	InventoryManagementService inventoryManagementService;
 	PaymentManagementService paymentManagementService;
 	ServiceManagementService serviceManagementService;
-	auto& usersMap = m_dataStore.getUsers();
+	DataStoreLockGuard lock(m_dataStore);
+	auto& trackedUsersMap = m_dataStore.getUsers();
+	auto usersMap = util::getObjects(trackedUsersMap);
 	if (util::isUsernameDuplicate(username, usersMap))
 	{
 		throw std::runtime_error("Username already exists");
@@ -87,13 +92,14 @@ void UserManagementService::createUser(const std::string& username, const std::s
 		throw std::runtime_error("Phone already exists");
 	}
 	User* newUser = Factory::getObject<User>(username, password, name, phone, email, type);
-	usersMap.insert(newUser->getId(), newUser);
+	trackedUsersMap.insert(newUser->getId(), util::createNewRecord(newUser));
 	paymentManagementService.attach(newUser);
 	serviceManagementService.attach(newUser);
 	if (newUser->getUserType() == util::UserType::ADMIN)
 	{
 		inventoryManagementService.attach(newUser);
 	}
+	m_dataStore.saveUsers();
 }

 /*
@@ -107,19 +113,24 @@ Return type: void
 */
 void UserManagementService::updateUserDetails(const std::string& userID, const std::string& email, const std::string& phone)
 {
-	auto& usersMap = m_dataStore.getUsers();
-	int index = usersMap.find(userID);
+	DataStoreLockGuard lock(m_dataStore);
+	auto& trackedUsersMap = m_dataStore.getUsers();
+	auto usersMap = util::getObjects(trackedUsersMap);
+	int index = trackedUsersMap.find(userID);
 	if (index == -1)
 	{
 		throw std::runtime_error("User does not exist!\n");
 	}
-	User* user = usersMap.getValueAt(index);
+	User* user = trackedUsersMap.getValueAt(index).data;
+	bool isModified = false;
 	if (email != user->getEmail())
 	{
 		if (util::isEmailDuplicate(email, usersMap))
 		{
 			throw std::runtime_error("Email already exists!\n");
 		}
+		user->setEmail(email);
+		isModified = true;
 	}
 	if (phone != user->getPhone())
 	{
@@ -127,9 +138,14 @@ void UserManagementService::updateUserDetails(const std::string& userID, const s
 		{
 			throw std::runtime_error("Phone number already exists!\n");
 		}
+		user->setPhone(phone);
+		isModified = true;
+	}
+	if (isModified)
+	{
+		trackedUsersMap.getValueAt(index).state = RecordState::MODIFIED;
+		m_dataStore.saveUsers();
 	}
-	user->setEmail(email);
-	user->setPhone(phone);
 }

 /*
@@ -144,20 +160,25 @@ Throws:
 */
 util::Vector<Notification*> UserManagementService::getUserNotifications(const std::string& userID)
 {
-	auto& usersMap = m_dataStore.getUsers();
-	if (usersMap.find(userID) == -1)
+	DataStoreLockGuard lock(m_dataStore);
+	auto& trackedUsersMap = m_dataStore.getUsers(); 
+	if (trackedUsersMap.find(userID) == -1)
 	{
 		throw std::runtime_error("No user found with given UserID");
 	}
-	User* user = usersMap[userID];
+	User* user = trackedUsersMap[userID].data;
 	if (user)
 	{
-		auto& notifications = user->getNotifications();
-		int numberOfNotifications = notifications.getSize();
+		auto& trackedNotificationMap = m_dataStore.getNotifications();
+		int numberOfNotifications = trackedNotificationMap.getSize();
 		util::Vector<Notification*> notificationsVector;
 		for (int index = 0; index < numberOfNotifications; index++)
 		{
-		    notificationsVector.push_back(notifications.getValueAt(index));
+			Notification* notification = trackedNotificationMap.getValueAt(index).data;
+			if (notification->getRecipientUserId() == userID && notification->getState() == util::State::ACTIVE)
+			{
+				notificationsVector.push_back(notification);
+			}
 		}
 		return notificationsVector;
 	}
@@ -169,97 +190,39 @@ util::Vector<Notification*> UserManagementService::getUserNotifications(const st

 /*
 Function: deleteNotification
-Description: Deletes a specific notification associated with a given user ID.
+Description: Marks a specific notification associated with a given user
+			 as inactive.
 Parameters:
 	- notificationID: The unique ID of the notification to be deleted.
 	- userID: The unique ID of the user whose notification is to be deleted.
 Returns:
 	- void
 Throws:
-	- std::runtime_error if no user is found with the given UserID or if no notification is found with the given NotificationID.
+	- std::runtime_error if no user is found with the given UserID or
+	  if no notification is found with the given NotificationID.
 */
 void UserManagementService::deleteNotification(const std::string& notificationID, const std::string& userID)
 {
-	auto& usersMap = m_dataStore.getUsers();
-	if (usersMap.find(userID) == -1)
+	DataStoreLockGuard lock(m_dataStore);
+	auto& trackedUsersMap = m_dataStore.getUsers();
+	auto& trackedNotificationsMap = m_dataStore.getNotifications();
+	int userIndex = trackedUsersMap.find(userID);
+	if (userIndex == -1)
 	{
 		throw std::runtime_error("No user found with given UserID");
 	}
-	User* user = usersMap[userID];
-	auto& notifications = user->getNotifications();
-	if (notifications.find(notificationID) == -1)
+	int notificationIndex = trackedNotificationsMap.find(notificationID);
+	if (notificationIndex == -1)
 	{
 		throw std::runtime_error("No notification found with given NotificationID");
 	}
-	notifications.remove(notificationID);
-}
-
-/*
-Function: loadUsers
-Description: Loads users and notifications from persistent storage into the datastore.
-             Validates that each notification’s recipient exists and attaches the
-             notification to the corresponding user.
-Parameters:
-    - None
-Returns:
-    - void
-Throws:
-    - std::runtime_error if a notification recipient user ID is invalid
-*/
-void UserManagementService::loadUsers()
-{
-    util::FileManager<User> userFileManager(config::file::USER_FILE);
-    util::FileManager<Notification> notificationFileManager(config::file::NOTIFICATION_FILE);
-    auto& users = m_dataStore.getUsers();
-    auto usersMap = userFileManager.load();
-    auto notificationsMap = notificationFileManager.load();
-    int numberOfUsers = usersMap.getSize();
-    int numberOfNotifications = notificationsMap.getSize();
-    for (int index = 0; index < numberOfUsers; index++)
-    {
-        users[usersMap.getKeyAt(index)] = usersMap.getValueAt(index);
-    }
-    for (int index = 0; index < numberOfNotifications; index++)
-    {
-        Notification* notification = notificationsMap.getValueAt(index);
-        const std::string& recipientUserId = notification->getRecipientUserId();
-        int userIndex = users.find(recipientUserId);
-        if (userIndex == -1)
-        {
-            throw std::runtime_error("Invalid recipient user ID");
-        }
-        User* user = users.getValueAt(userIndex);
-        user->addNotification(notification);
-    }
-}
-
-/*
-Function: saveUsers
-Description: Saves users and their notifications from the datastore to persistent storage.
-             Collects notifications from all users into a single map before saving.
-Parameters:
-    - None
-Returns:
-    - void
-*/
-void UserManagementService::saveUsers()
-{
-    util::FileManager<User> userFileManager(config::file::USER_FILE);
-    util::FileManager<Notification> notificationFileManager(config::file::NOTIFICATION_FILE);
-    auto& users = m_dataStore.getUsers();
-    util::Map<std::string, Notification*> notifications;
-    for (int userIndex = 0; userIndex < users.getSize(); userIndex++)
-    {
-        User* user = users.getValueAt(userIndex);
-        auto& userNotifications = user->getNotifications();
-        for (int notificationIndex = 0; notificationIndex < userNotifications.getSize(); notificationIndex++)
-        {
-            notifications[userNotifications.getKeyAt(notificationIndex)] =
-                userNotifications.getValueAt(notificationIndex);
-        }
-    }
-    userFileManager.save(users);
-    notificationFileManager.save(notifications);
+	Notification* notification = trackedNotificationsMap.getValueAt(notificationIndex).data;
+	if (notification->getRecipientUserId() == userID)
+	{
+		notification->setState(util::State::INACTIVE);
+		trackedNotificationsMap.getValueAt(notificationIndex).state = RecordState::MODIFIED;
+		m_dataStore.saveNotifications();
+	}
 }

 /*
@@ -270,7 +233,9 @@ Return type: util::Map<std::string, User*>
 */
 util::Map<std::string, User*> UserManagementService::getUsers()
 {
-	return m_dataStore.getUsers();
+	DataStoreLockGuard lock(m_dataStore);
+	auto users = util::getObjects(m_dataStore.getUsers());
+	return users;
 }

 /*
@@ -281,10 +246,12 @@ Return type: User*
 */
 User* UserManagementService::getUser(const std::string& userID)
 {
-	int index = m_dataStore.getUsers().find(userID);
+	DataStoreLockGuard lock(m_dataStore);
+	auto& trackedUsersMap = m_dataStore.getUsers();
+	int index = trackedUsersMap.find(userID);
 	if (index != -1)
 	{
-		return m_dataStore.getUsers().getValueAt(index);
+		return trackedUsersMap.getValueAt(index).data;
 	}
 	return nullptr;
 }
@@ -300,35 +267,53 @@ void UserManagementService::removeUser(const std::string& userID)
 	InventoryManagementService inventoryManagementService;
 	PaymentManagementService paymentManagementService;
 	ServiceManagementService serviceManagementService;
-	int index = m_dataStore.getUsers().find(userID);
+	DataStoreLockGuard lock(m_dataStore);
+	auto& trackedUsersMap = m_dataStore.getUsers();
+	int index = trackedUsersMap.find(userID);
 	if (index != -1)
 	{
-		User* user = m_dataStore.getUsers().getValueAt(index);
+		User* user = trackedUsersMap.getValueAt(index).data;
 		if (user != nullptr)
 		{
 			if (user->getUserType() == util::UserType::CUSTOMER)
 			{
-				serviceManagementService.cancelCustomerServiceBookings(userID);	
+				serviceManagementService.cancelCustomerServiceBookings(userID);
 			}
 			if (user->getUserType() == util::UserType::TECHNICIAN)
 			{
 				serviceManagementService.cancelTechnicianJobs(userID);
 			}
-			user->setState(util::State::INACTIVE);
 			inventoryManagementService.detach(user);
 			paymentManagementService.detach(user);
 			serviceManagementService.detach(user);
+			user->setState(util::State::INACTIVE);
+			trackedUsersMap.getValueAt(index).state = RecordState::MODIFIED;
+			m_dataStore.saveUsers();
 		}
 	}
 }

-util::Map<std::string, User*> UserManagementService::getUsers(util::UserType type)
+/*
+Function: getUsers
+Description: Retrieves all active users of the specified type from
+			 the DataStore.
+Parameters:
+	- type: The user type to filter by
+			(ADMIN, CUSTOMER, or TECHNICIAN).
+Returns:
+	- util::Map<std::string, User*>:
+	  Collection of active users matching the specified type,
+	  keyed by user ID.
+*/
+util::Map<std::string, User*> UserManagementService::getUsers(util::UserType type) 
 {
-	util::Map<std::string, User*>& currentUsers = m_dataStore.getUsers();
+	DataStoreLockGuard lock(m_dataStore);
+	auto& trackedUsersMap = m_dataStore.getUsers();
+	util::Map<std::string, User*> currentUsers = util::getObjects(trackedUsersMap);
 	util::Map<std::string, User*> filteredUsersMap;
-	for (int iterator = 0; iterator < currentUsers.getSize(); iterator++)
+	for (int index = 0; index < currentUsers.getSize(); index++)
 	{
-		User* currentUser = currentUsers.getValueAt(iterator);
+		User* currentUser = currentUsers.getValueAt(index);
 		if (currentUser && currentUser->getState() == util::State::ACTIVE && currentUser->getUserType() == type)
 		{
 			filteredUsersMap.insert(currentUser->getId(), currentUser);
@@ -31,6 +31,4 @@ public:
    util::Vector<Notification*> getUserNotifications(const std::string& userID);
    void deleteNotification(const std::string& notificationID, const std::string& userID);
    void ensureAdminExists();
-    void loadUsers();
-    void saveUsers();
 };
@@ -29,6 +29,7 @@ namespace config
 	namespace file
 	{
 		const size_t INITIAL_CAPACITY = 100;
+		const size_t GROWTH_FACTOR = 2;
 		constexpr const char* DIRECTORY = "files/";
 		constexpr const char* INVENTORYITEM_FILE = "files/InventoryItem.dat";
 		constexpr const char* USER_FILE = "files/User.dat";
@@ -43,67 +43,4 @@ namespace util
            position++;
        }
    }
-
-    /*
-    Function: loadRecords
-    Description: Loads records from a given file path into a vector of strings.
-                 Skips the header line if present. Creates the file if it does not exist.
-    Parameters:
-        - filePath: const std::string&, path to the file
-    Returns:
-        - util::Vector<std::string>: Vector containing all records (excluding header)
-    Throws:
-        - None (creates file if missing)
-    */
-    inline util::Vector<std::string> loadRecords(const std::string& filePath)
-    {
-        util::Vector<std::string> records;
-        std::ifstream file(filePath);
-        if (!file.is_open())
-        {
-            ensureDirectoryExists(filePath);
-            std::ofstream newFile(filePath);
-            newFile.close();
-            file.open(filePath);
-        }
-        std::string line;
-        bool isHeader = true;
-        while (std::getline(file, line))
-        {
-            if (isHeader)
-            {
-                isHeader = false;
-                continue;
-            }
-            records.push_back(line);
-        }
-        return records;
-    }
-
-    /*
-    Function: saveRecords
-    Description: Saves records to a given file path. Overwrites existing content
-                 and writes a header line followed by all records.
-    Parameters:
-        - filePath: const std::string&, path to the file
-        - records: const util::Vector<std::string>&, vector of records to save
-    Returns:
-        - void
-    Throws:
-        - std::runtime_error if the file cannot be opened for writing
-    */
-    inline void saveRecords(const std::string& filePath, const util::Vector<std::string>& records)
-    {
-        std::ofstream file(filePath, std::ios::trunc);
-        if (!file.is_open())
-        {
-            throw std::runtime_error("Failed to open file " + filePath);
-        }
-        file << "Values" << '\n';
-        int numberOfRecords = records.getSize();
-        for (int index = 0; index < numberOfRecords; index++)
-        {
-            file << records[index] << '\n';
-        }
-    }
 }
@@ -1,119 +0,0 @@
-/*
-File: FileManager.h
-Description: Declares and implements a generic FileManager template class for
-			 loading and saving objects to and from files. Uses serialization
-			 and deserialization methods defined in the object type T.
-			 Provides persistence support for system entities such as Users,
-			 Services, InventoryItems, etc.
-Author: Trenser
-Date: 22-May-2026
-*/
-
-#pragma once
-#include <stdexcept>
-#include <string>
-#include <fstream>
-#include "Vector.h"
-#include "Map.h"
-#include "FileHelper.h"
-
-namespace util
-{
-	template <typename T> using objects = util::Map<std::string, T*>;
-
-	template <typename T>
-	class FileManager
-	{
-	private:
-		std::string m_filePath;
-	public:
-		FileManager() : m_filePath("") {}
-		FileManager(const std::string& filePath) : m_filePath(filePath) {}
-		objects<T> load();
-		void save(const objects<T>&);
-	};
-
-	/*
-	Function: load
-	Description: Loads records from the file into a map of objects.
-				 Skips the header line, deserializes each record into an object of type T,
-				 and stores them in a map keyed by object ID.
-	Parameters:
-		- None
-	Returns:
-		- util::Map<std::string, T*> containing deserialized objects
-	Throws:
-		- std::runtime_error if deserialization fails for any record
-	*/
-	template <typename T>
-	objects<T> FileManager<T>::load()
-	{
-		objects<T> records;
-		std::ifstream file(m_filePath);
-		if (!file.is_open())
-		{
-			ensureDirectoryExists(m_filePath);
-			std::ofstream newFile(m_filePath);
-			newFile.close();
-			file.open(m_filePath);
-		}
-		util::Vector<std::string> lines;
-		std::string line;
-		while (std::getline(file, line))
-		{
-			lines.push_back(line);
-		}
-		int numberOfLines = lines.getSize();
-		bool isHeader = true;
-		for (int lineIndex = 0; lineIndex < numberOfLines; lineIndex++)
-		{
-			const auto& record = lines[lineIndex];
-			if (isHeader)
-			{
-				isHeader = false;
-				continue;
-			}
-			auto object = T::deserialize(record);
-			if (!object)
-			{
-				throw std::runtime_error("Failed to deserialize record");
-			}
-			records[object->getId()] = object;
-		}
-		return records;
-	}
-
-	/*
-	Function: save
-	Description: Saves records to the file. Serializes each object of type T into a string,
-				 writes a header line, and then writes all serialized records to the file.
-	Parameters:
-		- records: const util::Map<std::string, T*>&, map of objects to save
-	Returns:
-		- void
-	Throws:
-		- std::runtime_error if the file cannot be opened for writing
-	*/
-	template <typename T>
-	void FileManager<T>::save(const objects<T>& records)
-	{
-		util::Vector<std::string> lines;
-		lines.push_back(T::getHeaders());
-		int numberOfRecords = records.getSize();
-		for (int recordIndex = 0; recordIndex < numberOfRecords; recordIndex++)
-		{
-			const auto& record = records.getValueAt(recordIndex);
-			lines.push_back(record->serialize());
-		}
-		std::ofstream file(m_filePath, std::ios::trunc);
-		if (!file.is_open())
-		{
-			throw std::runtime_error("Failed to open file " + m_filePath);
-		}
-		int numberOfLines = lines.getSize();
-		for (int lineIndex = 0; lineIndex < numberOfLines; lineIndex++)
-		{
-			file << lines[lineIndex] << '\n';
-		}
-	}
-}
@@ -28,7 +28,7 @@ namespace util
        if (!(std::cin >> value))
        {
            std::cin.clear();
-            std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
+            std::cin.ignore((std::numeric_limits<std::streamsize>::max)(), '\n');
            throw std::runtime_error("Invalid console input");
        }
    }
@@ -54,49 +54,79 @@ namespace util
        return cost;
    }

-    /*
-    Function: loadObservers
-    Description: Loads observer IDs from a file and attaches the corresponding users
-                 to the notification management service. Validates that each observer ID
-                 exists in the datastore before attaching.
-    Parameters:
-        - filePath: const std::string&, path to the file containing observer IDs
-        - service: NotificationManagementService*, pointer to the notification service
-        - dataStore: DataStore&, reference to the datastore containing users
-    Returns:
-        - void
-    Throws:
-        - std::runtime_error if an observer ID is invalid (not found in datastore)
-    */
-    inline void loadObservers(const std::string& filePath, NotificationManagementService* service, DataStore& dataStore)
-    {
-        auto observerIDs = util::loadRecords(filePath);
-        auto& users = dataStore.getUsers();
-        for (int index = 0; index < observerIDs.getSize(); index++)
-        {
-            const std::string& observerID = observerIDs[index];
-            int userIndex = users.find(observerID);
-            if (userIndex == -1)
-            {
-                throw std::runtime_error("Invalid Observer ID");
-            }
-            service->attach(users.getValueAt(userIndex));
-        }
-    }
+    template<typename TObject>
+    Map<std::string, TObject*> getObjects(const Map<std::string, TrackedRecord<TObject>>& trackedRecords);

-    /*
-    Function: saveObservers
-    Description: Saves the current observer IDs from the notification management service
-                 to a file for persistence.
-    Parameters:
-        - filePath: const std::string&, path to the file where observer IDs will be saved
-        - service: NotificationManagementService*, pointer to the notification service
-    Returns:
-        - void
-    */
-    inline void saveObservers(const std::string& filePath, NotificationManagementService* service)
+    template<typename TObject>
+    Map<std::string, const TObject*> getConstObjects(const Map<std::string, TrackedRecord<TObject>>& trackedRecords);
+
+    template<typename TObject>
+    TrackedRecord<TObject> createNewRecord(TObject* object);
+}
+
+/*
+Function: getObjects
+Description: Extracts the object pointers from a tracked-record
+             collection and returns them as a map keyed by the
+             same identifiers.
+Parameters:
+    - trackedRecords: Collection of tracked records.
+Returns:
+    - Map<std::string, TObject*>: Collection of object pointers.
+*/
+template<typename TObject>
+util::Map<std::string, TObject*> util::getObjects(const util::Map<std::string, TrackedRecord<TObject>>& trackedRecords)
+{
+    util::Map<std::string, TObject*> objects;
+    for (int index = 0; index < trackedRecords.getSize(); ++index)
    {
-        auto observerIDs = service->getObserverIDs();
-        util::saveRecords(filePath, observerIDs);
+        const std::string& key = trackedRecords.getKeyAt(index);
+        TObject* object = trackedRecords.getValueAt(index).data;
+        objects.insert(key, object);
    }
+    return objects;
+}
+
+/*
+Function: getConstObjects
+Description: Extracts the object pointers from a tracked-record
+             collection and returns them as a read-only map
+             keyed by the same identifiers.
+Parameters:
+    - trackedRecords: Collection of tracked records.
+Returns:
+    - Map<std::string, const TObject*>:
+      Collection of read-only object pointers.
+*/
+template<typename TObject>
+util::Map<std::string, const TObject*> util::getConstObjects(
+    const util::Map<std::string, TrackedRecord<TObject>>& trackedRecords)
+{
+    util::Map<std::string, const TObject*> objects;
+    for (int index = 0; index < trackedRecords.getSize(); ++index)
+    {
+        const std::string& key = trackedRecords.getKeyAt(index);
+        const TObject* object = trackedRecords.getValueAt(index).data;
+        objects.insert(key, object);
+    }
+    return objects;
+}
+
+/*
+Function: createNewRecord
+Description: Creates a tracked record for a newly created
+             object. The record is initialized with
+             NEW_RECORD state.
+Parameters:
+    - object: Pointer to the newly created object.
+Returns:
+    - TrackedRecord<TObject>: Initialized tracked record.
+*/
+template<typename TObject>
+TrackedRecord<TObject> util::createNewRecord(TObject* object)
+{
+    TrackedRecord<TObject> record;
+    record.data = object;
+    record.state = RecordState::NEW_RECORD;
+    return record;
 }
@@ -27,8 +27,11 @@ void UserInterface::run()
 {
 	try
 	{
-		m_controller.loadSystemData();
-		m_controller.runSystemChecks();
+		if (!m_controller.initialize())
+		{
+			std::cout << "Error: Failed to initialize the system!";
+			return;
+		}
 		bool isMenuActive = true;
 		while (isMenuActive)
 		{
@@ -49,7 +52,7 @@ void UserInterface::run()
 				util::pressEnter();
 			}
 		}
-		m_controller.saveSystemData();
+		m_controller.shutdown();
 	}
 	catch (const std::invalid_argument& exception)
 	{
Author	SHA1	Message	Date
joelthomastrenser	f484c62a1e	Fix cache refresh handling for unsaved records - Preserve NEW_RECORD entries during cache refresh - Prevent accidental deletion of pending datastore changes - Clean up only stale persisted records	2026-06-15 15:16:56 +05:30
joelthomastrenser	404d217504	Clean up legacy code - Remove FileManager and related file-based persistence logic - Remove obsolete observer persistence utilities - Remove unused service APIs and includes - Delete duplicate DataStore mutex stubs - Perform general dead-code cleanup	2026-06-15 15:16:55 +05:30
joelthomastrenser	67ac7f6625	Implement Service Refactoring <UserStory> 1954: Implement Service Refactoring </UserStory> UserStory #1954 <Changes> 1. Refactored notification handling to persist notifications directly in the datastore instead of maintaining notification collections within User objects. 2. Removed recipient User pointer dependencies from Notification and retained recipient user identification through recipientUserId. 3. Implemented generic observer persistence support in DataStore with shared helper methods for loading and saving observer subscriptions. 4. Added datastore-backed observer management for ServiceManagementService, PaymentManagementService, and InventoryManagementService. 5. Updated attach() and detach() operations to load, modify, and persist observer subscriptions using shared memory mappings. 6. Refactored sendNotification() implementations to create and persist Notification records directly to the datastore for subscribed observers. 7. Updated UserManagementService notification retrieval and deletion logic to operate on datastore notification records filtered by recipient user ID. 8. Removed notification ownership and observer-specific notification APIs from User and Observer classes. 9. Added configurable shared memory growth factor support and updated mapping expansion logic to use centralized configuration values. 10. Removed obsolete NotificationManagementService implementation and updated project configuration references. 11. Added DataStoreLockGuard integration for observer and notification persistence operations to ensure synchronized datastore access. </Changes> <Test> N/A </Test> <Review> Sreeja Reghukumar, please review </Review>	2026-06-15 15:16:55 +05:30
joelthomastrenser	5f4ee72ffe	Implement Notification Model Refactoring <UserStory> 1953: Model Refactoring </UserStory> UserStory #1953 <Changes> 1. Replaced CSV-based Notification serialization and deserialization with SerializedNotification record-based serialization for shared memory storage. 2. Implemented Notification::serialize() to convert Notification objects into fixed-size SerializedNotification structures. 3. Implemented Notification::deserialize() to reconstruct Notification objects directly from SerializedNotification records. 4. Added Notification state persistence by introducing util::State support in constructors, serialization, and deserialization flows. 5. Updated Notification class interfaces to use SerializedNotification types instead of std::string serialization APIs. 6. Removed legacy CSV serialization support, including CSV parsing logic and header generation functionality. 7. Added SerializedNotification dependencies through SerializedRecords.h inclusion and forward declaration support. 8. Initialized Notification objects with ACTIVE state by default and added state getter/setter APIs. </Changes> <Test> N/A </Test> <Review> Sreeja Reghukumar, please review </Review>	2026-06-15 15:16:55 +05:30
joelthomastrenser	1a4821ea8a	Merged PR 1166: User Management Refactoring - 1925 User Story #1959 User Story #1960 Changes - Refactored User serialization/deserialization to use SerializedUser. - Removed user loading and saving responsibilities from UserManagementService. - Added DataStoreLockGuard for automatic datastore locking/unlocking. - Updated user operations to work with tracked records. - Added persistence support for user creation, updates, notification changes, and user removal. - Refactored notification handling to use datastore-managed notifications. - Updated DataStore to load and save users and notifications using shared memory records. - Reworked application startup and shutdown flow using Controller::initialize() and Controller::shutdown(). - Updated UI flow to use the new initialization and shutdown methods. - Added required project and shared memory updates to support the refactoring. Related work items: #1925, #1959, #1960	2026-06-15 15:16:15 +05:30
joelthomastrenser	b5c8b1ee9b	Implement review fixes	2026-06-15 14:46:37 +05:30
joelthomastrenser	89fc662181	Implement Service Refactoring <UserStory> 1960: Service Refactoring </UserStory> UserStory #1960 <Changes> 1. Replaced the Controller load/save workflow with initialize() and shutdown() methods. 2. Moved startup checks such as admin verification, low stock alerts, and payment reminders into Controller::initialize(). 3. Updated UserInterface to use the new Controller initialization and shutdown flow. 4. Updated DataStore::getUsers() and DataStore::getNotifications() to load data directly from shared memory. 5. Added logic to rebuild user notification mappings when user data is loaded from shared memory. 6. Implemented user and notification persistence through DataStore::saveUsers() and DataStore::saveNotifications(). 7. Updated UserManagementService to use TrackedRecord-based shared memory records. 8. Added DataStore locking and unlocking to user management operations for synchronization. 9. Updated createUser(), updateUserDetails(), removeUser(), and deleteNotification() to persist changes through shared memory. 10. Removed legacy loadUsers() and saveUsers() implementations from UserManagementService. 11. Added required header dependencies for shared memory support. </Changes> <Test> N/A </Test> <Review> Sreeja Reghukumar, please review </Review>	2026-06-12 13:04:23 +05:30
joelthomastrenser	929f609f24	Implement Model Refactoring <UserStory> 1959: Model Refactoring </UserStory> UserStory #1959 <Changes> 1. Replaced CSV-based User serialization and deserialization with SerializedUser record-based serialization for shared memory storage. 2. Implemented User::serialize() to convert User objects into fixed-size SerializedUser structures containing user details and enum values. 3. Implemented User::deserialize() to reconstruct User objects directly from SerializedUser records. 4. Updated User class interfaces to use SerializedUser types instead of std::string serialization APIs. 5. Removed legacy CSV serialization support, including CSV parsing logic and header generation functionality. 6. Added SerializedUser dependencies through SerializedRecords.h inclusion and forward declaration support. </Changes> <Test> N/A </Test> <Review> Sreeja Reghukumar, please review </Review>	2026-06-12 03:19:43 +05:30
joelthomastrenser	3b1f3301d6	Implemented datastore shared memory codebase Changes: - Added SharedMemory module for file-backed memory-mapped storage - Added MappingInfo, FileHeader, RecordState and TrackedRecord infrastructure - Replaced CSV-based serialization with binary struct serialization - Added DataStore initialization and shutdown lifecycle management - Added datastore mutex synchronization for multi-process access - Added shared-memory mapping configuration for all datastore entities - Added generic loadRecords and saveRecords template infrastructure - Added automatic datastore directory creation and .dat file storage - Updated configuration to use binary datastore files and initial capacities - Added enum underlying types for serialization compatibility - Added password masking support for login, registration and password change flows - Added Visual Studio project configuration for shared-memory components - Added datastore-owned record caches for runtime object management - Updated datastore APIs to return cached tracked-record collections by reference - Added generic cache refresh and cleanup infrastructure - Updated save operations to persist datastore caches directly - Added automatic cache cleanup during datastore destruction - Prepared datastore for multi-process shared-memory persistence	2026-06-12 03:18:15 +05:30