ActionGroups can be used as a context manager for the 'with' statement.

2 files changed, 28 insertions, 5 deletions

diff --git a/debian/changelog b/debian/changelog
index e8e14306..30d54a29 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -2,6 +2,7 @@ python-apt (0.7.91) UNRELEASED; urgency=low
 
   * Rename all methods,functions,attributes to conform to PEP 8 (Closes: #481061)
   * Where possible, derive apt.package.Record from collections.Mapping.
+  * ActionGroups can be used as a context manager for the 'with' statement.
 
  -- Julian Andres Klode <jak@debian.org>  Fri, 17 Apr 2009 17:48:27 +0200
 
diff --git a/python/depcache.cc b/python/depcache.cc
index 0cadee64..70d5af4e 100644
--- a/python/depcache.cc
+++ b/python/depcache.cc
@@ -852,9 +852,24 @@ static PyObject *PkgActionGroupRelease(PyObject *Self,PyObject *Args)
    return HandleErrors(Py_None);
 }
 
+static PyObject *PkgActionGroupEnter(PyObject *Self,PyObject *Args) {
+   if (PyArg_ParseTuple(Args,"") == 0)
+      return 0;
+    return Self;
+}
+static PyObject *PkgActionGroupExit(PyObject *Self,PyObject *Args) {
+   pkgDepCache::ActionGroup *ag = GetCpp<pkgDepCache::ActionGroup*>(Self);
+   ag->release();
+   Py_RETURN_FALSE;
+}
+
 static PyMethodDef PkgActionGroupMethods[] =
 {
    {"release", PkgActionGroupRelease, METH_VARARGS, "release()"},
+   {"__exit__", PkgActionGroupExit, METH_VARARGS, "__exit__(...) -> "
+               "Release the action group, for 'with' statement."},
+   {"__enter__", PkgActionGroupEnter, METH_VARARGS, "__enter__() -> "
+               "Enter, for the 'with' statement. Does nothing."},
    {}
 };
 
@@ -879,11 +894,18 @@ static PyObject *PkgActionGroupNew(PyTypeObject *type,PyObject *Args,PyObject *k
 }
 
 static const char *doc_PkgActionGroup = "ActionGroup(depcache)\n\n"
-    "Create a new ActionGroup() object. ActionGroups disable certain cleanup\n"
-    "actions, so modifying many packages is much faster.\n\n"
-    "Creating an ActionGroup() makes it active, use release() to disable it\n"
-    "again.\n\n"
-    "The parameter *depcache* refers to an apt_pkg.DepCache() object.";
+    "Create a new ActionGroup() object. The parameter *depcache* refers to an\n"
+    "apt_pkg.DepCache() object.\n\n"
+    "ActionGroups disable certain cleanup actions, so modifying many packages\n"
+    "is much faster.\n\n"
+    "ActionGroup() can also be used with the 'with' statement, but be aware\n"
+    "that the ActionGroup() is active as soon as it is created, and not just\n"
+    "when entering the context. This means you can write::\n\n"
+    "    with apt_pkg.ActionGroup(depcache):\n"
+    "        depcache.markInstall(pkg)\n\n"
+    "Once the block of the with statement is left, the action group is \n"
+    "automatically released from the cache.";
+
 
 PyTypeObject PkgActionGroupType =
 {