libobs: Add os_generate_uuid() to platform utils

docs/sphinx/reference-libobs-util-platform.rst

@@ -496,3 +496,10 @@ Other Functions
    being translated by Rosetta and running on Apple Silicon Macs. On Windows, it 
    returns true when an x64 binary is being emulated on Windows ARM64 PCs. On all other 
    platforms, it will always returns false.
+
+----------------------
+
+.. function:: char *os_generate_uuid(void)
+
+   Creates a version 4 UUID and returns a NULL-terminated 36-character string.
+   Must be freed with :c:func:`bfree()`.

libobs/CMakeLists.txt

@@ -307,7 +307,7 @@ if(OS_WINDOWS)
     libobs PRIVATE UNICODE _UNICODE _CRT_SECURE_NO_WARNINGS
                    _CRT_NONSTDC_NO_WARNINGS)
 
-  target_link_libraries(libobs PRIVATE dxgi Avrt Dwmapi winmm)
+  target_link_libraries(libobs PRIVATE dxgi Avrt Dwmapi winmm Rpcrt4)
 
   if(MSVC)
     target_link_libraries(libobs PUBLIC OBS::w32-pthreads)
@@ -374,6 +374,7 @@ elseif(OS_POSIX)
     target_compile_definitions(libobs PRIVATE ENABLE_DARRAY_TYPE_TEST)
   endif()
 
+  find_package(LibUUID REQUIRED)
   find_package(X11 REQUIRED)
   find_package(
     XCB
@@ -393,7 +394,7 @@ elseif(OS_POSIX)
             util/pipe-posix.c
             util/platform-nix.c)
 
-  target_link_libraries(libobs PRIVATE X11::X11_xcb XCB::XCB)
+  target_link_libraries(libobs PRIVATE X11::X11_xcb XCB::XCB LibUUID::LibUUID)
 
   if(USE_XDG)
     target_compile_definitions(libobs PRIVATE USE_XDG)

libobs/util/platform-nix.c

@@ -35,6 +35,7 @@
 #include <glob.h>
 #include <time.h>
 #include <signal.h>
+#include <uuid/uuid.h>
 
 #if !defined(__APPLE__)
 #include <sys/times.h>
@@ -1137,3 +1138,13 @@ uint64_t os_get_free_disk_space(const char *dir)
 
 	return (uint64_t)info.f_frsize * (uint64_t)info.f_bavail;
 }
+
+char *os_generate_uuid(void)
+{
+	uuid_t uuid;
+	// 36 char UUID + NULL
+	char *out = bmalloc(37);
+	uuid_generate(uuid);
+	uuid_unparse_lower(uuid, out);
+	return out;
+}

libobs/util/platform-windows.c

@@ -21,6 +21,7 @@
 #include <intrin.h>
 #include <psapi.h>
 #include <math.h>
+#include <rpc.h>
 
 #include "base.h"
 #include "platform.h"
@@ -1479,3 +1480,21 @@ uint64_t os_get_free_disk_space(const char *dir)
 
 	return success ? free.QuadPart : 0;
 }
+
+char *os_generate_uuid(void)
+{
+	UUID uuid;
+
+	RPC_STATUS res = UuidCreate(&uuid);
+	if (res != RPC_S_OK && res != RPC_S_UUID_LOCAL_ONLY)
+		bcrash("Failed to get UUID, RPC_STATUS: %l", res);
+
+	struct dstr uuid_str = {0};
+	dstr_printf(&uuid_str,
+		    "%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x",
+		    uuid.Data1, uuid.Data2, uuid.Data3, uuid.Data4[0],
+		    uuid.Data4[1], uuid.Data4[2], uuid.Data4[3], uuid.Data4[4],
+		    uuid.Data4[5], uuid.Data4[6], uuid.Data4[7]);
+
+	return uuid_str.array;
+}

libobs/util/platform.h

@@ -201,6 +201,10 @@ EXPORT bool os_get_proc_memory_usage(os_proc_memory_usage_t *usage);
 EXPORT uint64_t os_get_proc_resident_size(void);
 EXPORT uint64_t os_get_proc_virtual_size(void);
 
+#define UUID_STR_LENGTH 36
+
+EXPORT char *os_generate_uuid(void);
+
 /* clang-format off */
 #ifdef __APPLE__
 # define ARCH_BITS 64