Fix setting of symlink mtimes on restore. This required switching to using lutimes(2) rather than os.utime. Wrote wrapper for lutimes and rename fadvisemodule.c to _obnammodule.c.

1 files changed, 92 insertions, 0 deletions

diff --git a/_obnammodule.c b/_obnammodule.c
new file mode 100644
index 00000000..0230ac99
--- /dev/null
+++ b/_obnammodule.c
@@ -0,0 +1,92 @@
+/*
+ * _obnammodule.c -- Python extensions for Obna
+ *
+ * Copyright (C) 2008, 2009  Lars Wirzenius <liw@liw.fi>
+ * 
+ * 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 2 of the License, 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+
+/*
+ * This is a Python extension module written for Obnam, the backup
+ * software. 
+ *
+ * This module provides a way to call the posix_fadvise function from
+ * Python. Obnam uses this to use set the POSIX_FADV_SEQUENTIAL and
+ * POSIX_FADV_DONTNEED flags, to make sure the kernel knows that it will
+ * read files sequentially and that the data does not need to be cached.
+ * This makes Obnam not trash the disk buffer cache, which is nice.
+ */
+
+
+#include <Python.h>
+
+
+#define _XOPEN_SOURCE 600
+#include <fcntl.h>
+#include <stdio.h>
+
+
+static PyObject *
+fadvise_dontneed(PyObject *self, PyObject *args)
+{
+    int fd;
+    /* Can't use off_t for offset and len, since PyArg_ParseTuple
+       doesn't know it. */
+    unsigned long long offset;
+    unsigned long long len;
+    int ret;
+
+    if (!PyArg_ParseTuple(args, "iLL", &fd, &offset, &len))
+        return NULL;
+    ret = posix_fadvise(fd, offset, len, POSIX_FADV_DONTNEED);
+    return Py_BuildValue("i", ret);
+}
+
+
+static PyObject *
+lutimes_wrapper(PyObject *self, PyObject *args)
+{
+    int ret;
+    long atime;
+    long mtime;
+    struct timeval tv[2];
+    const char *filename;
+
+    if (!PyArg_ParseTuple(args, "sll", &filename, &atime, &mtime))
+        return NULL;
+    tv[0].tv_sec = atime;
+    tv[0].tv_usec = 0;
+    tv[1].tv_sec = mtime;
+    tv[1].tv_usec = 0;
+    ret = lutimes(filename, tv);
+    return Py_BuildValue("i", ret);
+}
+
+
+static PyMethodDef methods[] = {
+    {"fadvise_dontneed",  fadvise_dontneed, METH_VARARGS, 
+     "Call posix_fadvise(2) with POSIX_FADV_DONTNEED argument."},
+    {"lutimes", lutimes_wrapper, METH_VARARGS,
+     "lutimes(2) wrapper; args are filename, atime, and mtime."},
+    {NULL, NULL, 0, NULL}        /* Sentinel */
+};
+
+
+PyMODINIT_FUNC
+init_obnam(void)
+{
+    (void) Py_InitModule("_obnam", methods);
+}