Small improvement in get_real_os_version() function.

diff --git a/.gitignore b/.gitignore
index df3644b..605b4a3 100644 (file)
--- a/.gitignore
+++ b/.gitignore
@@ -11,3 +11,4 @@
 /obj
 /out
 /tmp
+*.db

diff --git a/src/OSSupport_Win32.cpp b/src/OSSupport_Win32.cpp
index 3775155..f4fc18e 100644 (file)
--- a/src/OSSupport_Win32.cpp
+++ b/src/OSSupport_Win32.cpp
@@ -304,33 +304,43 @@ namespace MUtils
                        bool os_version_t::operator<= (const os_version_t &rhs) const { return (type == rhs.type) && ((versionMajor < rhs.versionMajor) || ((versionMajor == rhs.versionMajor) && (versionMinor <= rhs.versionMinor))); }
 
                        //Known Windows NT versions
-                       const os_version_t WINDOWS_WIN2K = { OS_WINDOWS,  5, 0 };       // 2000
-                       const os_version_t WINDOWS_WINXP = { OS_WINDOWS,  5, 1 };       // XP
-                       const os_version_t WINDOWS_XPX64 = { OS_WINDOWS,  5, 2 };       // XP_x64
-                       const os_version_t WINDOWS_VISTA = { OS_WINDOWS,  6, 0 };       // Vista
-                       const os_version_t WINDOWS_WIN70 = { OS_WINDOWS,  6, 1 };       // 7
-                       const os_version_t WINDOWS_WIN80 = { OS_WINDOWS,  6, 2 };       // 8
-                       const os_version_t WINDOWS_WIN81 = { OS_WINDOWS,  6, 3 };       // 8.1
-                       const os_version_t WINDOWS_WN100 = { OS_WINDOWS, 10, 0 };       // 10
+                       const os_version_t WINDOWS_WIN2K = { OS_WINDOWS,  5, 0,  2195 };        // 2000
+                       const os_version_t WINDOWS_WINXP = { OS_WINDOWS,  5, 1,  2600 };        // XP
+                       const os_version_t WINDOWS_XPX64 = { OS_WINDOWS,  5, 2,  3790 };        // XP_x64
+                       const os_version_t WINDOWS_VISTA = { OS_WINDOWS,  6, 0,  6000 };        // Vista
+                       const os_version_t WINDOWS_WIN70 = { OS_WINDOWS,  6, 1,  7600 };        // 7
+                       const os_version_t WINDOWS_WIN80 = { OS_WINDOWS,  6, 2,  9200 };        // 8
+                       const os_version_t WINDOWS_WIN81 = { OS_WINDOWS,  6, 3,  9600 };        // 8.1
+                       const os_version_t WINDOWS_WN100 = { OS_WINDOWS, 10, 0, 10240 };        // 10
 
                        //Unknown OS
-                       const os_version_t UNKNOWN_OPSYS = { OS_UNKNOWN, 0, 0 };        // N/A
+                       const os_version_t UNKNOWN_OPSYS = { OS_UNKNOWN, 0,  0,     0 };        // N/A
                }
        }
 }
 
-static inline DWORD SAFE_ADD(const DWORD &a, const DWORD &b)
+static inline DWORD SAFE_ADD(const DWORD &a, const DWORD &b, const DWORD &limit = MAXDWORD)
 {
-       const DWORD temp = a + b;
-       return ((temp >= a) && (temp >= b)) ? temp : MAXDWORD;
+       return ((a >= limit) || (b >= limit) || ((limit - a) <= b)) ? limit : (a + b);
 }
 
+
 static void initialize_os_version(OSVERSIONINFOEXW *const osInfo)
 {
        memset(osInfo, 0, sizeof(OSVERSIONINFOEXW));
        osInfo->dwOSVersionInfoSize = sizeof(OSVERSIONINFOEXW);
 }
 
+static inline DWORD initialize_step_size(const DWORD &limit)
+{
+       DWORD result = 1;
+       while (result < limit)
+       {
+               result = SAFE_ADD(result, result);
+       }
+       return result;
+}
+
 static bool rtl_get_version(OSVERSIONINFOEXW *const osInfo)
 {
        typedef LONG(__stdcall *RtlGetVersion)(LPOSVERSIONINFOEXW);
@@ -432,6 +442,7 @@ static bool verify_os_build(const DWORD build)
 static bool get_real_os_version(unsigned int *major, unsigned int *minor, unsigned int *build, bool *pbOverride)
 {
        static const DWORD MAX_VERSION = 0xFFFF;
+       static const DWORD MAX_BUILDNO = MAXINT;
 
        *major = *minor = *build = 0;
        *pbOverride = false;
@@ -496,21 +507,24 @@ static bool get_real_os_version(unsigned int *major, unsigned int *minor, unsign
        }
 
        //Build Version
-       DWORD stepSize = 32768;
-       for (DWORD nextBuildNo = SAFE_ADD((*build), stepSize); (*build) < MAXDWORD; nextBuildNo = SAFE_ADD((*build), stepSize))
+       if (verify_os_build(SAFE_ADD((*build), 1, MAX_BUILDNO)))
        {
-               if (verify_os_build(nextBuildNo))
+               DWORD stepSize = initialize_step_size(MAX_BUILDNO);
+               for (DWORD nextBuildNo = SAFE_ADD((*build), stepSize, MAX_BUILDNO); (*build) < MAX_BUILDNO; nextBuildNo = SAFE_ADD((*build), stepSize, MAX_BUILDNO))
                {
-                       *build = nextBuildNo;
-                       *pbOverride = true;
-                       continue;
-               }
-               if (stepSize > 1)
-               {
-                       stepSize = stepSize / 2;
-                       continue;
+                       if (verify_os_build(nextBuildNo))
+                       {
+                               *build = nextBuildNo;
+                               *pbOverride = true;
+                               continue;
+                       }
+                       if (stepSize > 1)
+                       {
+                               stepSize = stepSize / 2;
+                               continue;
+                       }
+                       break;
                }
-               break;
        }
 
        return true;