From: ds77 <ds77@users.noreply.github.com>
Date: Sun, 12 Feb 2017 09:27:18 +0000 (+0100)
Subject: fix seeking 2GB+ files under Windows
X-Git-Tag: v1.1.4~1^2~70^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=168d9b8006882ed72721272ad6c1c69c1712d87a;p=thirdparty%2Fzstd.git

fix seeking 2GB+ files under Windows

Replace fseek() in FIO_fwriteSparse() and FIO_fwriteSparseEnd() with macro expanding to 64-bit fseek version provided by the platform (includes  fallback workaround using Win32 API).
---

diff --git a/programs/fileio.c b/programs/fileio.c
index 087bf9504..51b1a94ec 100644
--- a/programs/fileio.c
+++ b/programs/fileio.c
@@ -91,6 +91,32 @@ static clock_t g_time = 0;
 
 #define MIN(a,b)    ((a) < (b) ? (a) : (b))
 
+#if defined(_MSC_VER) && _MSC_VER >= 1400
+#   define LONG_SEEK _fseeki64
+#elif defined(__MINGW32__) && !defined(__STRICT_ANSI__) && !defined(__NO_MINGW_LFS) && defined(__MSVCRT__)
+#   define LONG_SEEK fseeko64
+#elif defined(_WIN32) && !defined(__DJGPP__)
+#   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;
+    }
+#else
+#   define LONG_SEEK fseek
+#endif
+
 
 /*-*************************************
 *  Local Parameters - Not thread safe
@@ -598,7 +624,7 @@ static unsigned FIO_fwriteSparse(FILE* file, const void* buffer, size_t bufferSi
 
     /* avoid int overflow */
     if (storedSkips > 1 GB) {
-        int const seekResult = fseek(file, 1 GB, SEEK_CUR);
+        int const seekResult = LONG_SEEK(file, 1 GB, SEEK_CUR);
         if (seekResult != 0) EXM_THROW(71, "1 GB skip error (sparse file support)");
         storedSkips -= 1 GB;
     }
@@ -614,7 +640,7 @@ static unsigned FIO_fwriteSparse(FILE* file, const void* buffer, size_t bufferSi
         storedSkips += (unsigned)(nb0T * sizeof(size_t));
 
         if (nb0T != seg0SizeT) {   /* not all 0s */
-            int const seekResult = fseek(file, storedSkips, SEEK_CUR);
+            int const seekResult = LONG_SEEK(file, storedSkips, SEEK_CUR);
             if (seekResult) EXM_THROW(72, "Sparse skip error ; try --no-sparse");
             storedSkips = 0;
             seg0SizeT -= nb0T;
@@ -634,7 +660,7 @@ static unsigned FIO_fwriteSparse(FILE* file, const void* buffer, size_t bufferSi
             for ( ; (restPtr < restEnd) && (*restPtr == 0); restPtr++) ;
             storedSkips += (unsigned) (restPtr - restStart);
             if (restPtr != restEnd) {
-                int seekResult = fseek(file, storedSkips, SEEK_CUR);
+                int seekResult = LONG_SEEK(file, storedSkips, SEEK_CUR);
                 if (seekResult) EXM_THROW(74, "Sparse skip error ; try --no-sparse");
                 storedSkips = 0;
                 {   size_t const sizeCheck = fwrite(restPtr, 1, restEnd - restPtr, file);
@@ -647,7 +673,7 @@ static unsigned FIO_fwriteSparse(FILE* file, const void* buffer, size_t bufferSi
 static void FIO_fwriteSparseEnd(FILE* file, unsigned storedSkips)
 {
     if (storedSkips-->0) {   /* implies g_sparseFileSupport>0 */
-        int const seekResult = fseek(file, storedSkips, SEEK_CUR);
+        int const seekResult = LONG_SEEK(file, storedSkips, SEEK_CUR);
         if (seekResult != 0) EXM_THROW(69, "Final skip error (sparse file)\n");
         {   const char lastZeroByte[1] = { 0 };
             size_t const sizeCheck = fwrite(lastZeroByte, 1, 1, file);