From 4830673b523fe35af4ad86f4ebe2dcb3408a20ae Mon Sep 17 00:00:00 2001
From: Ryan Izard <rizard@g.clemson.edu>
Date: Fri, 20 Feb 2015 12:46:58 -0500
Subject: [PATCH] Account for cases where we might try to remove a CounterNode
from an empty hierarchy.
---
.../debugcounter/CounterNode.java | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/src/main/java/net/floodlightcontroller/debugcounter/CounterNode.java b/src/main/java/net/floodlightcontroller/debugcounter/CounterNode.java
index 1f3c87aae..99f32f371 100644
--- a/src/main/java/net/floodlightcontroller/debugcounter/CounterNode.java
+++ b/src/main/java/net/floodlightcontroller/debugcounter/CounterNode.java
@@ -11,6 +11,9 @@ import java.util.regex.Pattern;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
import com.google.common.base.Joiner;
import com.google.common.collect.ImmutableList;
@@ -27,6 +30,7 @@ import com.google.common.collect.ImmutableList;
*/
class CounterNode implements Iterable<DebugCounterImpl> {
private static final String QUOTED_SEP = Pattern.quote("/");
+ private static final Logger log = LoggerFactory.getLogger(CounterNode.class);
/** path/hierarchy of this counter without leading /. An empty string
* represents the root. A string without a / is a module name
@@ -168,6 +172,14 @@ class CounterNode implements Iterable<DebugCounterImpl> {
* We're directly reusing the shrunken hierarchyElements List and
* keyToRemove String, which IMHO is pretty cool how it works out.
*/
+
+ /*
+ * Make sure it's possible to remove something.
+ */
+ if (hierarchyElements.isEmpty()) {
+ log.error("Cannot remove a CounterNode from an empty list of hierarchy elements. Returning null.");
+ return null;
+ }
String keyToRemove = hierarchyElements.remove(hierarchyElements.size() - 1);
for (String element: hierarchyElements) {
cur = cur.children.get(element);
--
GitLab