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https://issues.apache.org/jira/browse/KNOX-3035?focusedWorklogId=988317&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-988317
]
ASF GitHub Bot logged work on KNOX-3035:
----------------------------------------
Author: ASF GitHub Bot
Created on: 22/Oct/25 08:14
Start Date: 22/Oct/25 08:14
Worklog Time Spent: 10m
Work Description: smolnar82 commented on code in PR #1101:
URL: https://github.com/apache/knox/pull/1101#discussion_r2450849116
##########
gateway-spi/src/main/java/org/apache/knox/gateway/util/GroupUtils.java:
##########
@@ -0,0 +1,97 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.knox.gateway.util;
+
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+
+public class GroupUtils {
+
+ public static List<String> getGroupStrings(Collection<String> groupNames,
final int lengthLimit, final int sizeLimitBytes) {
+ if (groupNames.isEmpty()) {
+ return Collections.emptyList();
+ }
+
+ if (sizeLimitBytes > 0) {
+ return getGroupStringsBySize(groupNames, sizeLimitBytes);
+ } else {
+ return getGroupStringsByLength(groupNames, lengthLimit);
+ }
+ }
+
+ private static List<String> getGroupStringsBySize(Collection<String>
groupNames, int sizeLimitBytes) {
+ final List<String> groupStrings = new ArrayList<>();
+ StringBuilder sb = new StringBuilder();
Review Comment:
The good news: this method is thread-safe as written. Here’s why:
- It creates only local variables (`groupStrings`, StringBuilder `sb`, etc.)
inside the method or its private helpers.
- It doesn’t modify shared mutable state (no static fields, caches, or
mutable class members).
- All the objects it operates on (Collection<String> groupNames, lists,
builders) are created fresh per call.
- It doesn’t store anything globally, nor depend on any external resource
that could be concurrently modified.
So, even though multiple threads will execute it simultaneously, each will
have its own independent stack and its own local `groupStrings` and `sb` — no
interference.
The only caveat: the input collection. If `groupNames` is not thread-safe
and can be modified concurrently by other threads while this method is reading
it, then that _could_ cause a problem. I'll fix this issue soon and ensure
safety even if the caller passes in a shared mutable collection (which is not
the cast, tbh).
Wrt. to the `StringBuilder` concern, it’s not a problem because each call to
`getGroupStrings(...)` creates and uses its own `StringBuilder` instance
**locally inside the method**. There’s no shared mutable state between threads.
Issue Time Tracking
-------------------
Worklog Id: (was: 988317)
Time Spent: 1.5h (was: 1h 20m)
> Group header value should be based on data size and not number
> --------------------------------------------------------------
>
> Key: KNOX-3035
> URL: https://issues.apache.org/jira/browse/KNOX-3035
> Project: Apache Knox
> Issue Type: Bug
> Components: Server
> Reporter: Sandeep More
> Assignee: Sandor Molnar
> Priority: Major
> Fix For: 3.0.0
>
> Time Spent: 1.5h
> Remaining Estimate: 0h
>
> KNOX-2974 and KNOX-3023 support adding group headers to requests flowing to
> downstream endpoints. Currently the groups headers is based on number of
> groups (1000 default). A lot of webservers and loadbalancers support header
> sizes between 4KB - 8KB which be an issue when header sizes are large.
> This JIRA is to update this logic to limit groups in one header to configured
> size in KBs.
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