[libvirt] [PATCH v5 13/15] util: Introduce virObjectLookupHashPrune

[John Ferlan]

A convenience API that will utilize the virHashForEach API for the
LookupHash in order to remove elements from the hash table(s) that
match some requirement from the callback.

NB: Once elements are removed from objsUUID - if something goes wrong
in objsName, the best that can be done is to issue an error message
and hope for the best.

Signed-off-by: John Ferlan <jferlan at redhat.com>
---
 src/libvirt_private.syms |  1 +
 src/util/virobject.c     | 39 +++++++++++++++++++++++++++++++++++++++
 src/util/virobject.h     |  5 +++++
 3 files changed, 45 insertions(+)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index ecbd84a..e4c465f 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -2337,6 +2337,7 @@ virObjectLookupHashFindLocked;
 virObjectLookupHashForEachName;
 virObjectLookupHashForEachUUID;
 virObjectLookupHashNew;
+virObjectLookupHashPrune;
 virObjectLookupHashRemove;
 virObjectLookupHashSearchName;
 virObjectLookupHashSearchNameLocked;
diff --git a/src/util/virobject.c b/src/util/virobject.c
index 7152b17..c259ccc 100644
--- a/src/util/virobject.c
+++ b/src/util/virobject.c
@@ -1262,3 +1262,42 @@ virObjectLookupHashClone(void *srcAnyobj,
 
     return 0;
 }
+
+
+/**
+ * virObjectLookupHashPrune
+ * @anyobj: LookupHash object
+ * @callback: callback function to handle the object specific checks
+ * @opaque: callback data
+ *
+ * Call the callback function from virHashRemoveSet in order to determine
+ * if the incoming opaque data should be removed from the hash table(s)
+ * for the LookupHash. If a second hash table exists and we fail to remove
+ * the same number of elements, then issue an ERROR message, but continue
+ * on as there's not much we can do now to restore the data other than
+ * attempt to let someone know.
+ */
+void
+virObjectLookupHashPrune(void *anyobj,
+                         virHashSearcher callback,
+                         void *opaque)
+{
+    virObjectLookupHashPtr hashObj = virObjectGetLookupHashObj(anyobj);
+    ssize_t cntUUIDs = 0;
+    ssize_t cntNames = 0;
+
+    if (!hashObj)
+        return;
+
+    virObjectRWLockWrite(hashObj);
+    if (hashObj->objsUUID)
+        cntUUIDs = virHashRemoveSet(hashObj->objsUUID, callback, opaque);
+
+    if (hashObj->objsName)
+        cntNames = virHashRemoveSet(hashObj->objsName, callback, opaque);
+
+    if (hashObj->objsUUID && hashObj->objsName && cntNames != cntUUIDs)
+        VIR_ERROR(_("removed %zd elems from objsUUID and %zd elems "
+                    "from objsName"), cntUUIDs, cntNames);
+    virObjectRWUnlock(hashObj);
+}
diff --git a/src/util/virobject.h b/src/util/virobject.h
index 66b44ca..a6038fc 100644
--- a/src/util/virobject.h
+++ b/src/util/virobject.h
@@ -264,5 +264,10 @@ virObjectLookupHashClone(void *srcAnyobj,
                          virObjectLookupHashCloneCallback cb)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3);
 
+void
+virObjectLookupHashPrune(void *anyobj,
+                         virHashSearcher callback,
+                         void *opaque)
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
 
 #endif /* __VIR_OBJECT_H */
-- 
2.9.5