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https://issues.apache.org/jira/browse/HDFS-16463?focusedWorklogId=778690&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-778690
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ASF GitHub Bot logged work on HDFS-16463:
-----------------------------------------

                Author: ASF GitHub Bot
            Created on: 06/Jun/22 16:44
            Start Date: 06/Jun/22 16:44
    Worklog Time Spent: 10m 
      Work Description: GauthamBanasandra commented on code in PR #4370:
URL: https://github.com/apache/hadoop/pull/4370#discussion_r890332363


##########
hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/x-platform/c-api/dirent.cc:
##########
@@ -0,0 +1,100 @@
+/**
+ * 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.
+ */
+
+#include <algorithm>
+#include <cerrno>
+#include <iostream>
+#include <iterator>
+#include <system_error>
+#include <variant>
+
+#include "x-platform/c-api/dirent.h"
+#include "x-platform/dirent.h"
+
+#if defined(WIN32) && defined(__cplusplus)

Review Comment:
   The C++ compiler will mangle the method signature. Since these APIs are 
invoked in 
[jni_helper.c](https://github.com/apache/hadoop/blob/a234d00c1ce57427202d4c9587f891ec0164d10c/hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfs/jni_helper.c)
 (which is compiled by C compiler), the C linker won't be able to find the 
mangled version of these methods. Thus, we need to wrap the implementation with 
an `extern "C"` block to prevent the C++ compiler from mangling these APIs. It 
results in an `Undefined reference error` otherwise.
   
   This is the standard approach whenever C code tries to invoke C++ code.





Issue Time Tracking
-------------------

    Worklog Id:     (was: 778690)
    Time Spent: 3.5h  (was: 3h 20m)

> Make dirent cross platform compatible
> -------------------------------------
>
>                 Key: HDFS-16463
>                 URL: https://issues.apache.org/jira/browse/HDFS-16463
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>          Components: libhdfs++
>    Affects Versions: 3.4.0
>         Environment: Windows 10
>            Reporter: Gautham Banasandra
>            Assignee: Gautham Banasandra
>            Priority: Major
>              Labels: libhdfscpp, pull-request-available
>          Time Spent: 3.5h
>  Remaining Estimate: 0h
>
> [jnihelper.c|https://github.com/apache/hadoop/blob/1fed18bb2d8ac3dbaecc3feddded30bed918d556/hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfs/jni_helper.c#L28]
>  in HDFS native client uses *dirent.h*. This header file isn't available on 
> Windows. Thus, we need to replace this with a cross platform compatible 
> implementation for dirent.



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