From 354bb40e75d94466e91fe6960523612c9d17ccfb Mon Sep 17 00:00:00 2001
From: Karen Arutyunov <karen@codesynthesis.com>
Date: Thu, 2 Nov 2017 23:11:29 +0300
Subject: Add implementation

---
 mysql/mysys/my_chsize.c | 106 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 106 insertions(+)
 create mode 100644 mysql/mysys/my_chsize.c

(limited to 'mysql/mysys/my_chsize.c')

diff --git a/mysql/mysys/my_chsize.c b/mysql/mysys/my_chsize.c
new file mode 100644
index 0000000..ca388dc
--- /dev/null
+++ b/mysql/mysys/my_chsize.c
@@ -0,0 +1,106 @@
+/* Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
+
+   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; version 2 of the License.
+
+   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, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
+
+#include "mysys_priv.h"
+#include "my_sys.h"
+#include "mysys_err.h"
+#include "m_string.h"
+#include "my_thread_local.h"
+
+/*
+  Change size of file.
+
+  SYNOPSIS
+    my_chsize()
+      fd		File descriptor
+      new_length	New file size
+      filler		If we don't have truncate, fill up all bytes after
+			new_length with this character
+      MyFlags		Flags
+
+  DESCRIPTION
+    my_chsize() truncates file if shorter else fill with the filler character.
+    The function also changes the file pointer. Usually it points to the end
+    of the file after execution.
+
+  RETURN VALUE
+    0	Ok
+    1	Error 
+*/
+int my_chsize(File fd, my_off_t newlength, int filler, myf MyFlags)
+{
+  my_off_t oldsize;
+  uchar buff[IO_SIZE];
+  DBUG_ENTER("my_chsize");
+  DBUG_PRINT("my",("fd: %d  length: %lu  MyFlags: %d",fd,(ulong) newlength,
+		   MyFlags));
+
+  if ((oldsize= my_seek(fd, 0L, MY_SEEK_END, MYF(MY_WME+MY_FAE))) == newlength)
+    DBUG_RETURN(0);
+
+  DBUG_PRINT("info",("old_size: %ld", (ulong) oldsize));
+
+  if (oldsize > newlength)
+  {
+#ifdef _WIN32
+    if (my_win_chsize(fd, newlength))
+    {
+      set_my_errno(errno);
+      goto err;
+    }
+    DBUG_RETURN(0);
+#elif defined(HAVE_FTRUNCATE)
+    if (ftruncate(fd, (off_t) newlength))
+    {
+      set_my_errno(errno);
+      goto err;
+    }
+    DBUG_RETURN(0);
+#else
+    /*
+      Fill space between requested length and true length with 'filler'
+      We should never come here on any modern machine
+    */
+    if (my_seek(fd, newlength, MY_SEEK_SET, MYF(MY_WME+MY_FAE))
+        == MY_FILEPOS_ERROR)
+    {
+      goto err;
+    }
+    swap_variables(my_off_t, newlength, oldsize);
+#endif
+  }
+
+  /* Full file with 'filler' until it's as big as requested */
+  memset(buff, filler, IO_SIZE);
+  while (newlength-oldsize > IO_SIZE)
+  {
+    if (my_write(fd, buff, IO_SIZE, MYF(MY_NABP)))
+      goto err;
+    oldsize+= IO_SIZE;
+  }
+  if (my_write(fd,buff,(size_t) (newlength-oldsize), MYF(MY_NABP)))
+    goto err;
+  DBUG_RETURN(0);
+
+err:
+  DBUG_PRINT("error", ("errno: %d", errno));
+  if (MyFlags & MY_WME)
+  {
+    char  errbuf[MYSYS_STRERROR_SIZE];
+    my_error(EE_CANT_CHSIZE, MYF(0),
+             my_errno(), my_strerror(errbuf, sizeof(errbuf), my_errno()));
+  }
+  DBUG_RETURN(1);
+} /* my_chsize */
-- 
cgit v1.1