2 files changed, 37 insertions, 0 deletions
diff --git a/osdep/io.c b/osdep/io.c
index e0caa56f79..819cdcbf69 100644
--- a/osdep/io.c
+++ b/osdep/io.c
@@ -310,6 +310,41 @@ int mp_mkdir(const char *path, int mode)
     return res;
 }
 
+FILE *mp_tmpfile(void)
+{
+    // Reserve a file name in the format %TMP%\mpvXXXX.TMP
+    wchar_t tmp_path[MAX_PATH + 1];
+    if (!GetTempPathW(MAX_PATH + 1, tmp_path))
+        return NULL;
+    wchar_t tmp_name[MAX_PATH + 1];
+    if (!GetTempFileNameW(tmp_path, L"mpv", 0, tmp_name))
+        return NULL;
+
+    // Create the file. FILE_ATTRIBUTE_TEMPORARY indicates the file will be
+    // short-lived. Windows should avoid flushing it to disk while there is
+    // sufficient cache.
+    HANDLE file = CreateFileW(tmp_name, GENERIC_READ | GENERIC_WRITE | DELETE,
+        FILE_SHARE_READ | FILE_SHARE_DELETE, NULL, CREATE_ALWAYS,
+        FILE_ATTRIBUTE_TEMPORARY | FILE_FLAG_DELETE_ON_CLOSE, NULL);
+    if (file == INVALID_HANDLE_VALUE) {
+        DeleteFileW(tmp_name);
+        return NULL;
+    }
+
+    int fd = _open_osfhandle((intptr_t)file, 0);
+    if (fd < 0) {
+        CloseHandle(file);
+        return NULL;
+    }
+    FILE *fp = fdopen(fd, "w+b");
+    if (!fp) {
+        close(fd);
+        return NULL;
+    }
+
+    return fp;
+}
+
 static char **utf8_environ;
 static void *utf8_environ_ctx;
 
diff --git a/osdep/io.h b/osdep/io.h
index 306e2ac6ec..ae3cdc1802 100644
--- a/osdep/io.h
+++ b/osdep/io.h
@@ -75,6 +75,7 @@ DIR *mp_opendir(const char *path);
 struct dirent *mp_readdir(DIR *dir);
 int mp_closedir(DIR *dir);
 int mp_mkdir(const char *path, int mode);
+FILE *mp_tmpfile(void);
 char *mp_getenv(const char *name);
 
 typedef struct {
@@ -101,6 +102,7 @@ void mp_globfree(mp_glob_t *pglob);
 #define readdir(...) mp_readdir(__VA_ARGS__)
 #define closedir(...) mp_closedir(__VA_ARGS__)
 #define mkdir(...) mp_mkdir(__VA_ARGS__)
+#define tmpfile(...) mp_tmpfile(__VA_ARGS__)
 #define getenv(...) mp_getenv(__VA_ARGS__)
 
 #ifndef GLOB_NOMATCH