X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fftruncate.c;h=db7f7ddf40cf176db29d987db8689b5df09664ef;hb=6fea8a94379432b41d19aa2e9701de0af4db244d;hp=d5a3be144c6393e5c250f48b1a2ed89f78bf15eb;hpb=d8710037842f70e32a5b56c685437b51165d2f5b;p=gnulib.git

diff --git a/lib/ftruncate.c b/lib/ftruncate.c
index d5a3be144..db7f7ddf4 100644
--- a/lib/ftruncate.c
+++ b/lib/ftruncate.c
@@ -1,5 +1,18 @@
 /* ftruncate emulations for native Windows.
-   This file is in the public domain.  */
+   Copyright (C) 1992-2013 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, see <http://www.gnu.org/licenses/>.  */
 
 #include <config.h>
 
@@ -7,8 +20,163 @@
 #include <unistd.h>
 
 #if HAVE_CHSIZE
+/* A native Windows platform.  */
+
+# include <errno.h>
+
+# if _GL_WINDOWS_64_BIT_OFF_T
+
+/* Large File Support: off_t is 64-bit, but chsize() takes only a 32-bit
+   argument.  So, define a 64-bit safe SetFileSize function ourselves.  */
+
+/* Ensure that <windows.h> declares GetFileSizeEx.  */
+#  undef _WIN32_WINNT
+#  define _WIN32_WINNT 0x500
+
+/* Get declarations of the native Windows API functions.  */
+#  define WIN32_LEAN_AND_MEAN
+#  include <windows.h>
+
+/* Get _get_osfhandle.  */
+#  include "msvc-nothrow.h"
+
+static BOOL
+SetFileSize (HANDLE h, LONGLONG size)
+{
+  LARGE_INTEGER old_size;
+
+  if (!GetFileSizeEx (h, &old_size))
+    return FALSE;
+
+  if (size != old_size.QuadPart)
+    {
+      /* Duplicate the handle, so we are free to modify its file position.  */
+      HANDLE curr_process = GetCurrentProcess ();
+      HANDLE tmph;
+
+      if (!DuplicateHandle (curr_process,           /* SourceProcessHandle */
+                            h,                      /* SourceHandle */
+                            curr_process,           /* TargetProcessHandle */
+                            (PHANDLE) &tmph,        /* TargetHandle */
+                            (DWORD) 0,              /* DesiredAccess */
+                            FALSE,                  /* InheritHandle */
+                            DUPLICATE_SAME_ACCESS)) /* Options */
+        return FALSE;
 
-# include <io.h>
+      if (size < old_size.QuadPart)
+        {
+          /* Reduce the size.  */
+          LONG size_hi = (LONG) (size >> 32);
+          if (SetFilePointer (tmph, (LONG) size, &size_hi, FILE_BEGIN)
+              == INVALID_SET_FILE_POINTER
+              && GetLastError() != NO_ERROR)
+            {
+              CloseHandle (tmph);
+              return FALSE;
+            }
+          if (!SetEndOfFile (tmph))
+            {
+              CloseHandle (tmph);
+              return FALSE;
+            }
+        }
+      else
+        {
+          /* Increase the size by adding zero bytes at the end.  */
+          static char zero_bytes[1024];
+          LONG pos_hi = 0;
+          LONG pos_lo = SetFilePointer (tmph, (LONG) 0, &pos_hi, FILE_END);
+          LONGLONG pos;
+          if (pos_lo == INVALID_SET_FILE_POINTER
+              && GetLastError() != NO_ERROR)
+            {
+              CloseHandle (tmph);
+              return FALSE;
+            }
+          pos = ((LONGLONG) pos_hi << 32) | (ULONGLONG) (ULONG) pos_lo;
+          while (pos < size)
+            {
+              DWORD written;
+              LONGLONG count = size - pos;
+              if (count > sizeof (zero_bytes))
+                count = sizeof (zero_bytes);
+              if (!WriteFile (tmph, zero_bytes, (DWORD) count, &written, NULL)
+                  || written == 0)
+                {
+                  CloseHandle (tmph);
+                  return FALSE;
+                }
+              pos += (ULONGLONG) (ULONG) written;
+            }
+        }
+      /* Close the handle.  */
+      CloseHandle (tmph);
+    }
+  return TRUE;
+}
+
+int
+ftruncate (int fd, off_t length)
+{
+  HANDLE handle = (HANDLE) _get_osfhandle (fd);
+
+  if (handle == INVALID_HANDLE_VALUE)
+    {
+      errno = EBADF;
+      return -1;
+    }
+  if (length < 0)
+    {
+      errno = EINVAL;
+      return -1;
+    }
+  if (!SetFileSize (handle, length))
+    {
+      switch (GetLastError ())
+        {
+        case ERROR_ACCESS_DENIED:
+          errno = EACCES;
+          break;
+        case ERROR_HANDLE_DISK_FULL:
+        case ERROR_DISK_FULL:
+        case ERROR_DISK_TOO_FRAGMENTED:
+          errno = ENOSPC;
+          break;
+        default:
+          errno = EIO;
+          break;
+        }
+      return -1;
+    }
+  return 0;
+}
+
+# else
+
+#  include <io.h>
+
+#  if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+#   include "msvc-inval.h"
+static int
+chsize_nothrow (int fd, long length)
+{
+  int result;
+
+  TRY_MSVC_INVAL
+    {
+      result = chsize (fd, length);
+    }
+  CATCH_MSVC_INVAL
+    {
+      result = -1;
+      errno = EBADF;
+    }
+  DONE_MSVC_INVAL;
+
+  return result;
+}
+#   define chsize chsize_nothrow
+#  endif
 
 int
 ftruncate (int fd, off_t length)
@@ -16,4 +184,5 @@ ftruncate (int fd, off_t length)
   return chsize (fd, length);
 }
 
+# endif
 #endif