handle "changed" status properly

* original backend implementation uses unionfs-specific "changes only" dir to determine "changed" status. this breaks when it involves deactivated nodes.
* new library design uses explicit per-node "changed" marker. however, since previously "commit" only handles a root "changed" marker, the new library could not implement this scheme and used a workaround instead.
* now add API functions for "commit" to properly clean up "changed" markers.
* modify "commit" to use these API functions and remove the workaround from the new library.

6 files changed, 63 insertions, 0 deletions

diff --git a/src/cstore/cstore-c.cpp b/src/cstore/cstore-c.cpp
index fd818a5..c835efe 100644
--- a/src/cstore/cstore-c.cpp
+++ b/src/cstore/cstore-c.cpp
@@ -143,6 +143,19 @@ cstore_cfg_path_get_effective_value(void *handle, const char *path_comps[],
   return NULL;
 }
 
+int
+cstore_unmark_cfg_path_changed(void *handle, const char *path_comps[],
+                               int num_comps)
+{
+  if (handle) {
+    vector<string> vs;
+    _get_str_vec(vs, path_comps, num_comps);
+    Cstore *cs = (Cstore *) handle;
+    return (cs->unmarkCfgPathChanged(vs) ? 1 : 0);
+  }
+  return 0;
+}
+
 char **
 cstore_path_string_to_path_comps(const char *path_str, int *num_comps)
 {
diff --git a/src/cstore/cstore-c.h b/src/cstore/cstore-c.h
index a2ad844..4f33672 100644
--- a/src/cstore/cstore-c.h
+++ b/src/cstore/cstore-c.h
@@ -38,6 +38,9 @@ char *cstore_cfg_path_get_effective_value(void *handle,
                                           const char *path_comps[],
                                           int num_comps);
 
+int cstore_unmark_cfg_path_changed(void *handle, const char *path_comps[],
+                                   int num_comps);
+
 /* the following are internal APIs for the library. they can only be used
  * during cstore operations since they operate on "current" paths constructed
  * by the operations.
diff --git a/src/cstore/cstore.cpp b/src/cstore/cstore.cpp
index ebf9585..0634988 100644
--- a/src/cstore/cstore.cpp
+++ b/src/cstore/cstore.cpp
@@ -1791,6 +1791,22 @@ Cstore::markCfgPathChanged(const vector<string>& path_comps)
   return true;
 }
 
+/* unmark "changed" status of specified path in working config.
+ * this is used, e.g., at the end of "commit" to reset a subtree.
+ * note: unmarking a node means all of its descendants are also unmarked,
+ *       i.e., they become "unchanged".
+ * return true if successful. otherwise return false.
+ */
+bool
+Cstore::unmarkCfgPathChanged(const vector<string>& path_comps)
+{
+  SAVE_PATHS;
+  append_cfg_path(path_comps);
+  bool ret = unmark_changed_with_descendants();
+  RESTORE_PATHS;
+  return ret;
+}
+
 
 ////// protected functions
 void
diff --git a/src/cstore/cstore.hpp b/src/cstore/cstore.hpp
index 37a3e06..4b07fab 100644
--- a/src/cstore/cstore.hpp
+++ b/src/cstore/cstore.hpp
@@ -144,6 +144,7 @@ public:
   virtual bool inSession() = 0;
   // common
   bool markCfgPathChanged(const vector<string>& path_comps);
+  bool unmarkCfgPathChanged(const vector<string>& path_comps);
   // XXX load
   //bool unmarkCfgPathDeactivatedDescendants(const vector<string>& path_comps);
 
@@ -306,6 +307,7 @@ private:
   virtual bool mark_deactivated() = 0;
   virtual bool unmark_deactivated() = 0;
   virtual bool unmark_deactivated_descendants() = 0;
+  virtual bool unmark_changed_with_descendants() = 0;
   virtual bool mark_changed() = 0;
   virtual bool remove_comment() = 0;
   virtual bool set_comment(const string& comment) = 0;
diff --git a/src/cstore/unionfs/cstore-unionfs.cpp b/src/cstore/unionfs/cstore-unionfs.cpp
index 860d553..7f14483 100644
--- a/src/cstore/unionfs/cstore-unionfs.cpp
+++ b/src/cstore/unionfs/cstore-unionfs.cpp
@@ -749,6 +749,34 @@ UnionfsCstore::unmark_deactivated_descendants()
   return ret;
 }
 
+/* remove all "changed" markers under the current work path. this is used,
+ * e.g., at the end of "commit" to reset a subtree.
+ */
+bool
+UnionfsCstore::unmark_changed_with_descendants()
+{
+  try {
+    vector<b_fs::path> markers;
+    b_fs::recursive_directory_iterator di(get_work_path());
+    for (; di != b_fs::recursive_directory_iterator(); ++di) {
+      if (!b_fs_is_regular(di->path())
+          || di->path().filename() != C_MARKER_CHANGED) {
+        // not marker
+        continue;
+      }
+      markers.push_back(di->path());
+    }
+    for (size_t i = 0; i < markers.size(); i++) {
+      b_fs::remove(markers[i]);
+    }
+  } catch (...) {
+    output_internal("failed to unmark changed with descendants [%s]\n",
+                    get_work_path().file_string().c_str());
+    return false;
+  }
+  return true;
+}
+
 bool
 UnionfsCstore::mark_changed()
 {
diff --git a/src/cstore/unionfs/cstore-unionfs.hpp b/src/cstore/unionfs/cstore-unionfs.hpp
index 9e49064..bff4844 100644
--- a/src/cstore/unionfs/cstore-unionfs.hpp
+++ b/src/cstore/unionfs/cstore-unionfs.hpp
@@ -158,6 +158,7 @@ private:
   bool mark_deactivated();
   bool unmark_deactivated();
   bool unmark_deactivated_descendants();
+  bool unmark_changed_with_descendants();
   bool mark_changed();
   bool remove_comment();
   bool set_comment(const string& comment);