update LONG_FSEEK/TELL

src/io.c

@@ -2,46 +2,53 @@
 #include "report.h"
 #include <limits.h>
 
-// Avoid fseek()'s 2GiB barrier with MSVC, macOS, *BSD, MinGW
-// Credits to ZSTD library
+/* Avoid fseek()'s 2GiB barrier with MSVC, macOS, *BSD, MinGW */
+/* Credits to ZSTD library */
 #if defined(_MSC_VER) && _MSC_VER >= 1400
 #define LONG_SEEK _fseeki64
 #define LONG_TELL _ftelli64
-typedef __int64 OFF_T;
-#define OFF_T_MAX +9223372036854775807 /* this is a guess */
-#define OFF_T_MIN -9223372036854775807 /* this is a guess */
 #elif !defined(__64BIT__) &&                                                                  \
     (PLATFORM_POSIX_VERSION >= 200112L) /* No point defining Large file for 64 bit */
 #define LONG_SEEK fseeko
 #define LONG_TELL ftello
-typedef off_t OFF_T;
-#define OFF_T_MAX +9223372036854775807 /* this is a guess */
-#define OFF_T_MIN -9223372036854775807 /* this is a guess */
 #elif defined(__MINGW32__) && !defined(__STRICT_ANSI__) && !defined(__NO_MINGW_LFS) &&        \
     defined(__MSVCRT__)
 #define LONG_SEEK fseeko64
 #define LONG_TELL ftello64
-typedef off64_t OFF_T;
-#define OFF_T_MAX +9223372036854775807 /* this is a guess */
-#define OFF_T_MIN -9223372036854775807 /* this is a guess */
 #elif defined(_WIN32) && !defined(__DJGPP__)
-static_assert(0, "Code does not work on the DJGPP compiler.");
+#include <windows.h>
+static int LONG_SEEK(FILE* file, __int64 offset, int origin)
+{
+    LARGE_INTEGER off;
+    DWORD         method;
+    off.QuadPart = offset;
+    if (origin == SEEK_END)
+        method = FILE_END;
+    else if (origin == SEEK_CUR)
+        method = FILE_CURRENT;
+    else
+        method = FILE_BEGIN;
+
+    if (SetFilePointerEx((HANDLE)_get_osfhandle(_fileno(file)), off, NULL, method))
+        return 0;
+    else
+        return -1;
+}
+static __int64 LONG_TELL(FILE* file)
+{
+    LARGE_INTEGER off, newOff;
+    off.QuadPart = 0;
+    newOff.QuadPart = 0;
+    SetFilePointerEx((HANDLE)_get_osfhandle(_fileno(file)), off, &newOff, FILE_CURRENT);
+    return newOff.QuadPart;
+}
 #else
 #define LONG_SEEK fseek
 #define LONG_TELL ftell
-typedef long OFF_T;
-#define OFF_T_MAX LONG_MAX
-#define OFF_T_MIN LONG_MIN
 #endif
 
 int bgen_fseek(FILE* stream, int64_t offset, int origin)
 {
-    if (offset > OFF_T_MAX)
-        bgen_die("fseek overflow");
-
-    if (offset < OFF_T_MIN)
-        bgen_die("fseek underflow");
-
     return LONG_SEEK(stream, offset, origin);
 }