add stdioext.h

src/util/meson.build

@@ -30,6 +30,7 @@ endif
 subdir('blake3')
 
 files_mesa_util = files(
+  'stdioext.h',
   'anon_file.h',
   'anon_file.c',
   'bigmath.h',

src/util/stdioext.h

@@ -0,0 +1,28 @@
+#ifndef  _STDIOEXT_H
+#define  _STDIOEXT_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdio.h>
+#include <stdint.h>
+
+typedef struct cookie_io_functions_t {
+  ssize_t (*read)(void *cookie, char *buf, size_t n);
+  ssize_t (*write)(void *cookie, const char *buf, size_t n);
+  int (*seek)(void *cookie, off_t *pos, int whence);
+  int (*close)(void *cookie);
+} cookie_io_functions_t;
+
+FILE *fopencookie(void *cookie, const char *mode, cookie_io_functions_t functions);
+
+FILE *fmemopen(void *buf, size_t size, const char *mode);
+
+FILE *open_memstream(char **buf, size_t *size);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif  /* _STDIOEXT_H */