[libvirt] [PATCH] Fix up the python bindings for snapshotting.

[Cole Robinson]

On 05/20/2010 11:14 AM, Chris Lalancette wrote:
> This involved a few fixes.  To start with,
> an virDomainSnapshot object is really tied to a
> domain, not a connection, so we have to generate
> a slightly different object so that we can get
> at self._dom for the object.
> 
> Next, we had to "dummy" up an override piece of
> XML with a bogus argument that the function doesn't
> actually take.  That's so that the generator places
> virDomainRevertToSnapshot underneath the correct
> class (namely, the virDomain class).
> 
> Finally, we had to hand-implement the
> virDomainRevertToSnapshot implementation, ignoring the
> bogus pointer we are being passed.
> 
> With all of this in place, I was able to successfully
> take a snapshot and revert to it using only the
> Python bindings.
> 
> Signed-off-by: Chris Lalancette <clalance at redhat.com>
> ---
>  python/generator.py             |   26 +++++++++++++++++++++++---
>  python/libvirt-override-api.xml |    7 +++++++
>  python/libvirt-override.c       |   23 +++++++++++++++++++++++
>  3 files changed, 53 insertions(+), 3 deletions(-)
> 
> diff --git a/python/generator.py b/python/generator.py
> index a243c82..d876df6 100755
> --- a/python/generator.py
> +++ b/python/generator.py
> @@ -331,7 +331,7 @@ skip_impl = (
>      'virNodeListDevices',
>      'virNodeDeviceListCaps',
>      'virConnectBaselineCPU',
> -    'virDomainSnapshotListNames',
> +    'virDomainRevertToSnapshot',
>  )
>  
>  
> @@ -385,6 +385,10 @@ skip_function = (
>      "virStorageVolGetConnect",
>  )
>  
> +function_skip_index_one = (
> +    "virDomainRevertToSnapshot",
> +)
> +
>  
>  def print_function_wrapper(name, output, export, include):
>      global py_types
> @@ -688,9 +692,13 @@ classes_destructors = {
>  }
>  
>  class_skip_connect_impl = {
> -    "virConnect" : True
> +    "virConnect" : True,
> +    "virDomainSnapshot": True,
>  }
>  
> +class_domain_impl = {
> +    "virDomainSnapshot": True,
> +}
>  
>  functions_noexcept = {
>      'virDomainGetID': True,
> @@ -986,7 +994,7 @@ def buildWrappers():
>  		info = (0, func, name, ret, args, file)
>  		function_classes[classe].append(info)
>  	    elif name[0:3] == "vir" and len(args) >= 2 and args[1][1] == type \
> -	        and file != "python_accessor":
> +	        and file != "python_accessor" and not name in function_skip_index_one:
>  		found = 1
>  		func = nameFixup(name, classe, type, file)
>  		info = (1, func, name, ret, args, file)
> @@ -1128,6 +1136,8 @@ def buildWrappers():
>                                    "virStorageVol", "virNodeDevice", "virSecret","virStream",
>                                    "virNWFilter" ]:
>                      classes.write("    def __init__(self, conn, _obj=None):\n")
> +                elif classname in [ 'virDomainSnapshot' ]:
> +                    classes.write("    def __init__(self, dom, _obj=None):\n")
>                  else:
>                      classes.write("    def __init__(self, _obj=None):\n")
>  		if reference_keepers.has_key(classname):
> @@ -1142,6 +1152,8 @@ def buildWrappers():
>                      classes.write("        self._conn = conn\n" + \
>                                    "        if not isinstance(conn, virConnect):\n" + \
>                                    "            self._conn = conn._conn\n")
> +                elif classname in [ "virDomainSnapshot" ]:
> +                    classes.write("        self._dom = dom\n")
>  		classes.write("        if _obj != None:self._o = _obj;return\n")
>  		classes.write("        self._o = None\n\n");
>  	    destruct=None
> @@ -1158,6 +1170,10 @@ def buildWrappers():
>                  classes.write("    def connect(self):\n")
>                  classes.write("        return self._conn\n\n")
>  
> +            if class_domain_impl.has_key(classname):
> +                classes.write("    def domain(self):\n")
> +                classes.write("        return self._dom\n\n")
> +
>  	    flist = function_classes[classname]
>  	    flist.sort(functionCompare)
>  	    oldfile = ""
> @@ -1252,6 +1268,10 @@ def buildWrappers():
>                                  classes.write(
>  		     "        if ret is None:raise libvirtError('%s() failed', vol=self)\n" %
>                                                (name))
> +                            elif classname == "virDomainSnapshot":
> +                                classes.write(
> +                     "        if ret is None:raise libvirtError('%s() failed', dom=self._dom)\n" %
> +                                              (name))
>                              else:
>                                  classes.write(
>  		     "        if ret is None:raise libvirtError('%s() failed')\n" %
> diff --git a/python/libvirt-override-api.xml b/python/libvirt-override-api.xml
> index 9ba8e4e..be28b40 100644
> --- a/python/libvirt-override-api.xml
> +++ b/python/libvirt-override-api.xml
> @@ -277,5 +277,12 @@
>        <arg name='flags' type='unsigned int' info='flags, curently unused'/>
>        <return type='str *' info='the list of Names of None in case of error'/>
>      </function>
> +    <function name='virDomainRevertToSnapshot' file='python'>
> +      <info>revert the domain to the given snapshot</info>
> +      <arg name='dom' type='virDomainPtr' info='dummy domain pointer'/>
> +      <arg name='snap' type='virDomainSnapshotPtr' info='pointer to the snapshot'/>
> +      <arg name='flags' type='unsigned int' info='flags, curently unused'/>
> +      <return type='int' info="0 on success, -1 on error"/>
> +    </function>
>    </symbols>
>  </api>
> diff --git a/python/libvirt-override.c b/python/libvirt-override.c
> index c9721f7..ad55940 100644
> --- a/python/libvirt-override.c
> +++ b/python/libvirt-override.c
> @@ -988,6 +988,28 @@ libvirt_virDomainSnapshotListNames(PyObject *self ATTRIBUTE_UNUSED,
>  }
>  
>  static PyObject *
> +libvirt_virDomainRevertToSnapshot(PyObject *self ATTRIBUTE_UNUSED,
> +                                  PyObject *args) {
> +    int c_retval;
> +    virDomainSnapshotPtr snap;
> +    PyObject *pyobj_snap;
> +    PyObject *pyobj_dom;
> +    int flags;
> +
> +    if (!PyArg_ParseTuple(args, (char *)"OOi:virDomainRevertToSnapshot", &pyobj_dom, &pyobj_snap, &flags))
> +        return(NULL);
> +    snap = (virDomainSnapshotPtr) PyvirDomainSnapshot_Get(pyobj_snap);
> +
> +    LIBVIRT_BEGIN_ALLOW_THREADS;
> +    c_retval = virDomainRevertToSnapshot(snap, flags);
> +    LIBVIRT_END_ALLOW_THREADS;
> +    if (c_retval < 0)
> +        return VIR_PY_INT_FAIL;
> +
> +    return PyInt_FromLong(c_retval);
> +}
> +
> +static PyObject *
>  libvirt_virDomainGetInfo(PyObject *self ATTRIBUTE_UNUSED, PyObject *args) {
>      PyObject *py_retval;
>      int c_retval;
> @@ -3527,6 +3549,7 @@ static PyMethodDef libvirtMethods[] = {
>      {(char *) "virConnectBaselineCPU", libvirt_virConnectBaselineCPU, METH_VARARGS, NULL},
>      {(char *) "virDomainGetJobInfo", libvirt_virDomainGetJobInfo, METH_VARARGS, NULL},
>      {(char *) "virDomainSnapshotListNames", libvirt_virDomainSnapshotListNames, METH_VARARGS, NULL},
> +    {(char *) "virDomainRevertToSnapshot", libvirt_virDomainRevertToSnapshot, METH_VARARGS, NULL},
>      {NULL, NULL, 0, NULL}
>  };
>  

ACK, change looks fine. Might be worth checking the python bindings diff
though, the generator is fragile and changes can sometimes muck up
existing APIs.

- Cole