changes

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/datastores/sharedmemory/SharedMemory.cpp

@@ -1,6 +1,34 @@
 #include "SharedMemory.h"
 #include "Config.h"
 
+/*
+Function: invalidateMapping
+Description: Releases all mapping resources and resets the mapping to an invalid state.
+Parameters:
+    - mapping: MappingInfo&, mapping information and handles
+Returns:
+    - None
+*/
+static void invalidateMapping(MappingInfo& mapping)
+{
+    if (mapping.mappedView != nullptr)
+    {
+        UnmapViewOfFile(mapping.mappedView);
+        mapping.mappedView = nullptr;
+    }
+    if (mapping.mappingHandle != NULL)
+    {
+        CloseHandle(mapping.mappingHandle);
+        mapping.mappingHandle = NULL;
+    }
+    if (mapping.fileHandle != INVALID_HANDLE_VALUE)
+    {
+        CloseHandle(mapping.fileHandle);
+        mapping.fileHandle = INVALID_HANDLE_VALUE;
+    }
+    mapping.mappedCapacity = 0;
+}
+
 /*
 Function: createOrOpenMapping
 Description: Creates or opens a file mapping and maps it into the process address space.
@@ -31,8 +59,7 @@ bool SharedMemory::createOrOpenMapping(MappingInfo& mapping)
     LARGE_INTEGER fileSize;
     if (!GetFileSizeEx(mapping.fileHandle, &fileSize))
     {
-        CloseHandle(mapping.fileHandle);
+        invalidateMapping(mapping);
-        mapping.fileHandle = INVALID_HANDLE_VALUE;
         return false;
     }
     bool isNewFile = (fileSize.QuadPart == 0);
@@ -43,14 +70,12 @@ bool SharedMemory::createOrOpenMapping(MappingInfo& mapping)
         newSize.QuadPart = sizeof(FileHeader) + initialCapacity * mapping.recordSize;
         if (!SetFilePointerEx(mapping.fileHandle, newSize, NULL, FILE_BEGIN))
         {
-            CloseHandle(mapping.fileHandle);
+            invalidateMapping(mapping);
-            mapping.fileHandle = INVALID_HANDLE_VALUE;
             return false;
         }
         if (!SetEndOfFile(mapping.fileHandle))
         {
-            CloseHandle(mapping.fileHandle);
+            invalidateMapping(mapping);
-            mapping.fileHandle = INVALID_HANDLE_VALUE;
             return false;
         }
     }
@@ -64,8 +89,7 @@ bool SharedMemory::createOrOpenMapping(MappingInfo& mapping)
             NULL);
     if (mapping.mappingHandle == NULL)
     {
-        CloseHandle(mapping.fileHandle);
+        invalidateMapping(mapping);
-        mapping.fileHandle = INVALID_HANDLE_VALUE;
         return false;
     }
     mapping.mappedView =
@@ -77,13 +101,15 @@ bool SharedMemory::createOrOpenMapping(MappingInfo& mapping)
             0);
     if (mapping.mappedView == nullptr)
     {
-        CloseHandle(mapping.mappingHandle);
+        invalidateMapping(mapping);
-        CloseHandle(mapping.fileHandle);
+        return false;
-        mapping.mappingHandle = NULL;
+    }
-        mapping.fileHandle = INVALID_HANDLE_VALUE;
+    FileHeader* header = getHeader(mapping);
+    if (header == nullptr)
+    {
+        invalidateMapping(mapping);
         return false;
     }
-    FileHeader* header = reinterpret_cast<FileHeader*>(mapping.mappedView);
     if (isNewFile)
     {
         header->recordCount = 0;
@@ -103,22 +129,7 @@ Returns:
 */
 void SharedMemory::closeMapping(MappingInfo& mapping)
 {
-    if (mapping.mappedView != nullptr)
+    invalidateMapping(mapping);
-    {
-        UnmapViewOfFile(mapping.mappedView);
-        mapping.mappedView = nullptr;
-    }
-    if (mapping.mappingHandle != NULL)
-    {
-        CloseHandle(mapping.mappingHandle);
-        mapping.mappingHandle = NULL;
-    }
-    if (mapping.fileHandle != INVALID_HANDLE_VALUE)
-    {
-        CloseHandle(mapping.fileHandle);
-        mapping.fileHandle = INVALID_HANDLE_VALUE;
-    }
-    mapping.mappedCapacity = 0;
 }
 
 /*
@@ -135,7 +146,6 @@ FileHeader* SharedMemory::getHeader(MappingInfo& mapping)
     {
         return nullptr;
     }
-
     return reinterpret_cast<FileHeader*>(mapping.mappedView);
 }
 
@@ -229,3 +239,92 @@ size_t SharedMemory::getCapacity(MappingInfo& mapping)
     }
     return header->capacity;
 }
+
+/*
+Function: resizeMapping
+Description: Resizes the file mapping to the specified capacity.
+Parameters:
+    - mapping: MappingInfo&, mapping information and handles
+    - newCapacity: size_t, new mapping capacity
+Returns:
+    - bool: True if the resize succeeded, otherwise false
+*/
+bool SharedMemory::resizeMapping(MappingInfo& mapping, size_t newCapacity)
+{
+    FileHeader* header = getHeader(mapping);
+    if (header == nullptr)
+    {
+        invalidateMapping(mapping);
+        return false;
+    }
+    header->capacity = newCapacity;
+    if (!FlushViewOfFile(mapping.mappedView, sizeof(FileHeader)))
+    {
+        return false;
+    }
+    if (!UnmapViewOfFile(mapping.mappedView))
+    {
+        return false;
+    }
+    mapping.mappedView = nullptr;
+    CloseHandle(mapping.mappingHandle);
+    mapping.mappingHandle = NULL;
+    LARGE_INTEGER newSize;
+    newSize.QuadPart = sizeof(FileHeader) + newCapacity * mapping.recordSize;
+    if (!SetFilePointerEx(mapping.fileHandle, newSize, NULL, FILE_BEGIN))
+    {
+        invalidateMapping(mapping);
+        return false;
+    }
+    if (!SetEndOfFile(mapping.fileHandle))
+    {
+        invalidateMapping(mapping);
+        return false;
+    }
+    mapping.mappingHandle =
+        CreateFileMappingA(
+            mapping.fileHandle,
+            NULL,
+            PAGE_READWRITE,
+            0,
+            0,
+            NULL);
+    if (mapping.mappingHandle == NULL)
+    {
+        invalidateMapping(mapping);
+        return false;
+    }
+    mapping.mappedView =
+        MapViewOfFile(
+            mapping.mappingHandle,
+            FILE_MAP_ALL_ACCESS,
+            0,
+            0,
+            0);
+    if (mapping.mappedView == nullptr)
+    {
+        invalidateMapping(mapping);
+        return false;
+    }
+    mapping.mappedCapacity = newCapacity;
+    return true;
+}
+
+/*
+Function: ensureCapacityForInsert
+Description: Ensures that the mapping has space for at least one additional record, growing it if necessary.
+Parameters:
+    - mapping: MappingInfo&, mapping information and handles
+Returns:
+    - bool: True if capacity is available, otherwise false
+*/
+bool SharedMemory::ensureCapacityForInsert(MappingInfo& mapping)
+{
+    size_t recordCount = getRecordCount(mapping);
+    size_t capacity = getCapacity(mapping);
+    if (recordCount < capacity)
+    {
+        return true;
+    }
+    return resizeMapping(mapping, capacity * 2);
+}