delay savefile flush to the end of the frame

src/NDS.cpp

@@ -1000,6 +1000,8 @@ u32 RunFrame()
            GPU3D::Timestamp-SysTimestamp);
 #endif
 
+    NDSCart::FlushSRAMFile();
+
     NumFrames++;
 
     return GPU::TotalScanlines;

src/NDSCart.cpp

@@ -37,6 +37,7 @@ u8* SRAM;
 u32 SRAMLength;
 
 char SRAMPath[1024];
+bool SRAMFileDirty;
 
 void (*WriteFunc)(u8 val, bool islast);
 
@@ -445,14 +446,21 @@ void Write(u8 val, u32 hold)
         break;
     }
 
-    if (islast && (CurCmd == 0x02 || CurCmd == 0x0A) && (SRAMLength > 0))
+    SRAMFileDirty |= islast && (CurCmd == 0x02 || CurCmd == 0x0A) && (SRAMLength > 0);
+}
+
+void FlushSRAMFile()
+{
+    if (!SRAMFileDirty)
+        return;
+
+    SRAMFileDirty = false;
+
+    FILE* f = Platform::OpenFile(SRAMPath, "wb");
+    if (f)
     {
-        FILE* f = Platform::OpenFile(SRAMPath, "wb");
-        if (f)
-        {
-            fwrite(SRAM, SRAMLength, 1, f);
-            fclose(f);
-        }
+        fwrite(SRAM, SRAMLength, 1, f);
+        fclose(f);
     }
 }
 
@@ -1034,6 +1042,11 @@ void RelocateSave(const char* path, bool write)
     NDSCart_SRAM::RelocateSave(path, write);
 }
 
+void FlushSRAMFile()
+{
+    NDSCart_SRAM::FlushSRAMFile();
+}
+
 int ImportSRAM(const u8* data, u32 length)
 {
     memcpy(NDSCart_SRAM::SRAM, data, std::min(length, NDSCart_SRAM::SRAMLength));

src/NDSCart.h

@@ -46,6 +46,9 @@ void DoSavestate(Savestate* file);
 
 void DecryptSecureArea(u8* out);
 bool LoadROM(const char* path, const char* sram, bool direct);
+
+void FlushSRAMFile();
+
 void RelocateSave(const char* path, bool write);
 
 int ImportSRAM(const u8* data, u32 length);