This is my test implementation of the UUID code for Fl_Preferences.cxx on win32.

Tested on XP and Vista and seems to be OK, but needs to be checked by others for confirmation.
Any issues and we should just back this out, I think, but I trust that all will be well. 
The actual implementation is probably "sub-optimal" however, so if someone would like to make it better...

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@6991 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

1 files changed, 66 insertions, 31 deletions

diff --git a/src/Fl_Preferences.cxx b/src/Fl_Preferences.cxx
index 120bd99de..2a58adf40 100644
--- a/src/Fl_Preferences.cxx
+++ b/src/Fl_Preferences.cxx
@@ -54,6 +54,10 @@
 
 #ifdef WIN32
 #  include <windows.h>
+#  include <rpc.h>
+// function pointer for the UuidCreate Function
+// RPC_STATUS RPC_ENTRY UuidCreate(UUID __RPC_FAR *Uuid);
+typedef RPC_STATUS (WINAPI* uuid_func)(UUID __RPC_FAR *Uuid);
 #else
 #  include <sys/time.h>
 #endif // WIN32
@@ -83,39 +87,70 @@ const char *Fl_Preferences::newUUID()
   CFRelease(theUUID);
 #elif defined (WIN32)
 #if defined (__GNUC__)
-#warning MSWindows implementation missing!
+#  warning MSWindows implementation incomplete!
 #endif // (__GNUC__)
-  // UUID b;
-  // UuidCreate(&b);
-  unsigned char b[16];
-  time_t t = time(0); // first 4 byte
-  b[0] = (unsigned char)t;
-  b[1] = (unsigned char)(t>>8);
-  b[2] = (unsigned char)(t>>16);
-  b[3] = (unsigned char)(t>>24);
-  int r = rand(); // four more bytes
-  b[4] = (unsigned char)r;
-  b[5] = (unsigned char)(r>>8);
-  b[6] = (unsigned char)(r>>16);
-  b[7] = (unsigned char)(r>>24);
-  unsigned int a = (unsigned int)&t; // four more bytes
-  b[8] = (unsigned char)a;
-  b[9] = (unsigned char)(a>>8);
-  b[10] = (unsigned char)(a>>16);
-  b[11] = (unsigned char)(a>>24);
-  char name[80]; // last four bytes
-  // BOOL GetComputerName(LPTSTR  lpBuffer, LPDWORD  nSize);
-#if defined (__GNUC__)
-#warning gethostname needs winsock!
-#endif // (__GNUC__)
-  // gethostname(name, 79);	// A.S. temporarily replaced by:
-  strcpy (name,"localhost");	// A.S. FIXME: gethostname
-  memcpy(b+12, name, 4);
-  sprintf(uuidBuffer, "%02X%02X%02X%02X-%02X%02X-%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X",
-          b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7], 
-          b[8], b[9], b[10], b[11], b[12], b[13], b[14], b[15]);
+  // First try and use the win API function UuidCreate(), but if that is not
+  // available, fall back to making something up from scratch.
+  // We do not want to link against the Rpcrt4.dll, as we will rarely use it,
+  // so we load the DLL dynamically, if it is available, and work from there.
+  static HMODULE hMod = NULL;
+  UUID ud;
+  UUID *pu = &ud;
+  int got_uuid = 0;
+
+  if(!hMod){ // first time in?
+    hMod = LoadLibrary("Rpcrt4.dll");
+  }
+
+  if(hMod){ // do we have a usable handle to Rpcrt4.dll?
+    uuid_func uuid_crt = (uuid_func)GetProcAddress(hMod, "UuidCreate");
+    if(uuid_crt != NULL) {
+      RPC_STATUS rpc_res = uuid_crt(pu);
+      if( // is the return status OK for our needs?
+          (rpc_res == RPC_S_OK) || // all is well
+          (rpc_res == RPC_S_UUID_LOCAL_ONLY) || // only unique to this machine
+          (rpc_res == RPC_S_UUID_NO_ADDRESS) // probably only locally unique
+        ) {
+        got_uuid = -1;
+        sprintf(uuidBuffer, "%08lX-%04X-%04X-%02X%02X-%02X%02X%02X%02X%02X%02X",
+            pu->Data1, pu->Data2, pu->Data3, pu->Data4[0], pu->Data4[1],
+            pu->Data4[2], pu->Data4[3], pu->Data4[4],
+            pu->Data4[5], pu->Data4[6], pu->Data4[7]);
+      }
+    }
+  }
+  if(got_uuid == 0) { // did not make a UUID - use fallback logic
+    unsigned char b[16];
+    time_t t = time(0); // first 4 byte
+    b[0] = (unsigned char)t;
+    b[1] = (unsigned char)(t>>8);
+    b[2] = (unsigned char)(t>>16);
+    b[3] = (unsigned char)(t>>24);
+    int r = rand(); // four more bytes
+    b[4] = (unsigned char)r;
+    b[5] = (unsigned char)(r>>8);
+    b[6] = (unsigned char)(r>>16);
+    b[7] = (unsigned char)(r>>24);
+    unsigned int a = (unsigned int)&t; // four more bytes
+    b[8] = (unsigned char)a;
+    b[9] = (unsigned char)(a>>8);
+    b[10] = (unsigned char)(a>>16);
+    b[11] = (unsigned char)(a>>24);
+    TCHAR name[MAX_COMPUTERNAME_LENGTH + 1]; // only used to make last four bytes
+    DWORD nSize = MAX_COMPUTERNAME_LENGTH + 1;
+    // GetComputerName() does not depend on any extra libs, and returns something
+    // analogous to gethostname()
+    GetComputerName(name, &nSize);
+    //  use the first 4 TCHAR's of the name to create the last 4 bytes of our UUID
+    for(int ii = 0; ii < 4; ii++){
+      b[12 + ii] = (unsigned char)name[ii];
+    }
+    sprintf(uuidBuffer, "%02X%02X%02X%02X-%02X%02X-%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X",
+            b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7],
+            b[8], b[9], b[10], b[11], b[12], b[13], b[14], b[15]);
+  }
 #else
-#warning Unix implementation missing!
+#warning Unix implementation incomplete!
   // #include <uuid/uuid.h>
   // void uuid_generate(uuid_t out);
   unsigned char b[16];