improve ini performance

cnc-ddraw.vcxproj

@@ -49,6 +49,7 @@
     <ClCompile Include="src\IDirect3D\IDirect3D7.c" />
     <ClCompile Include="src\IAMMediaStream\IAMMediaStream.c" />
     <ClCompile Include="src\IDirectDraw\IDirectDrawGammaControl.c" />
+    <ClCompile Include="src\ini.c" />
     <ClCompile Include="src\utils.c" />
     <ClCompile Include="src\hook.c" />
     <ClCompile Include="src\IDirectDraw\IDirectDraw.c" />
@@ -82,6 +83,7 @@
     <ClInclude Include="inc\IDirect3D.h" />
     <ClInclude Include="inc\IAMMediaStream.h" />
     <ClInclude Include="inc\IDirectDrawGammaControl.h" />
+    <ClInclude Include="inc\ini.h" />
     <ClInclude Include="inc\patch.h" />
     <ClInclude Include="inc\utils.h" />
     <ClInclude Include="inc\hook.h" />

cnc-ddraw.vcxproj.filters

@@ -156,6 +156,9 @@
     <ClCompile Include="src\blt.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="src\ini.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="inc\debug.h">
@@ -269,6 +272,9 @@
     <ClInclude Include="inc\version.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="inc\ini.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ResourceCompile Include="ddraw.rc">

inc/ini.h

@@ -0,0 +1,6 @@
+#ifndef INI_H
+#define INI_H
+
+BOOL ini_section_exists(char* section);
+
+#endif

src/config.c

@@ -10,6 +10,7 @@
 #include "hook.h"
 #include "debug.h"
 #include "dllmain.h"
+#include "ini.h"
 
 static void cfg_init();
 static void cfg_create_ini();
@@ -1098,37 +1099,42 @@ static DWORD cfg_get_string(LPCSTR key, LPCSTR default_value, LPSTR out_string,
     if (!g_config.ini_path[0])
         cfg_init();
 
-    DWORD s = GetPrivateProfileStringA(
-        g_config.process_file_name, key, "", out_string, out_size, g_config.ini_path);
-
     char buf[MAX_PATH] = { 0 };
 
-    if (s > 0)
+    if (ini_section_exists(g_config.process_file_name))
     {
-        if (GetPrivateProfileStringA(
-            g_config.process_file_name, "checkfile", "", buf, sizeof(buf), g_config.ini_path) > 0)
+        DWORD s = GetPrivateProfileStringA(
+            g_config.process_file_name, key, "", out_string, out_size, g_config.ini_path);   
+
+        if (s > 0)
         {
-            if (FILE_EXISTS(buf))
+            if (GetPrivateProfileStringA(
+                g_config.process_file_name, "checkfile", "", buf, sizeof(buf), g_config.ini_path) > 0)
+            {
+                if (FILE_EXISTS(buf))
+                    return s;
+            }
+            else
                 return s;
         }
-        else
-            return s;
     }
 
-    /* Only checking 1 additional section for now (it may be too slow otherwise) */
-    for (int i = 2; i < 3; i++)
+    for (int i = 2; i < 10; i++)
     {
         char section[MAX_PATH] = { 0 };
         _snprintf(section, sizeof(section) - 1, "%s/%d", g_config.process_file_name, i);
 
-        s = GetPrivateProfileStringA(section, key, "", out_string, out_size, g_config.ini_path);
-
-        if (s > 0)
+        if (ini_section_exists(section))
         {
-            if (GetPrivateProfileStringA(section, "checkfile", "", buf, sizeof(buf), g_config.ini_path) > 0)
+            DWORD s = GetPrivateProfileStringA(section, key, "", out_string, out_size, g_config.ini_path);
+
+            if (s > 0)
             {
-                if (FILE_EXISTS(buf))
-                    return s;
+                if (GetPrivateProfileStringA(section, "checkfile", "", buf, sizeof(buf), g_config.ini_path) > 0)
+                {
+                    if (FILE_EXISTS(buf))
+                        return s;
+                }
             }
         }
     }

src/ini.c

@@ -0,0 +1,49 @@
+#include <windows.h>
+#include "debug.h"
+#include "config.h"
+#include "crc32.h"
+
+static unsigned long g_ini_section_hashes[1024];
+
+BOOL ini_section_exists(char* section)
+{
+    if (!g_ini_section_hashes[0])
+    {
+        char* buf = calloc(8192, 1);
+        if (buf)
+        {
+            if (GetPrivateProfileSectionNamesA(buf, 8192, g_config.ini_path) > 0)
+            {
+                for (int i = 0; *buf && i < sizeof(g_ini_section_hashes) / sizeof(g_ini_section_hashes[0]); i++)
+                {
+                    size_t len = strlen(buf);
+
+                    for (char* p = buf; *p; ++p) 
+                        *p = tolower(*p);
+
+                    g_ini_section_hashes[i] = Crc32_ComputeBuf(0, buf, len);
+
+                    buf += len + 1;
+                }
+            }
+            
+            free(buf);
+        }
+    }
+
+    char s[MAX_PATH];
+    strncpy(s, section, sizeof(s) - 1);
+
+    for (char* p = s; *p; ++p)
+        *p = tolower(*p);
+
+    unsigned long hash = Crc32_ComputeBuf(0, s, strlen(s));
+
+    for (int i = 0; i < sizeof(g_ini_section_hashes) / sizeof(g_ini_section_hashes[0]) && g_ini_section_hashes[i]; i++)
+    {
+        if (g_ini_section_hashes[i] == hash)
+            return TRUE;
+    }
+
+    return FALSE;
+}