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https://issues.apache.org/jira/browse/HADOOP-10389?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14032698#comment-14032698
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Haohui Mai edited comment on HADOOP-10389 at 6/16/14 6:47 PM:
--------------------------------------------------------------
bq. If the code is so impenetrable that review is truly impossible, please
consider demonstrating the virtues of C++11 in a competing branch.
As a weekend project, I've uploaded a proof-of-concept patch in C++ for this
jira. It implements a synchronous RPC engine and the {{exists()}} call for
libhdfs.
The main point is not (and never intends to be) to demonstrate c++ is superior
to c, but to show that it is practical to using current technology to improve
code quality and to cut down the maintenance cost down the road. In my personal
opinion it is important to ensure that the code can be easily maintained by the
community. The patch demonstrates a viable way to approach this goal.
Just a couple points to highlight:
# Simpler implementation. Thanks to the standard libraries, there is no need to
put things like RB trees, hash tables, linked lists into the patch and to ask
for reviews. Though not fully equivalent, the patch is an order of magnitude
smaller in terms of size.
# Automatic resource management. Explicit resource management, (e.g.,
{{malloc()}} / {{free()}}, and closing sockets) are no longer required. The
life time of resource matches the scope of the code. It is a systematic way to
avoid resource leaks.
# Stronger claims from the type systems. Modern language allows the code to be
written in a mostly type-safe way, where the type system is able to show that
the majority of the code is safe. There is only one cast required in the code
compared to many (each in the linked list) in the old implementation. New
constructs like {{std::array}} also allow integrate bounds check in the code to
help prevent buffer overflows.
Just to reiterate, by no means I'm trying to claim that the current patch is
perfect and free of bugs. People myself included make mistakes all the time. A
modern tool, however, can help people to catch the mistakes at the beginning of
the development cycle and to avoid them. Thoughts?
was (Author: wheat9):
bq. If the code is so impenetrable that review is truly impossible, please
consider demonstrating the virtues of C++11 in a competing branch.
As a weekend project, I've uploaded a proof-of-concept patch in C++ for this
jira. It implements a synchronous RPC engine and the {{exists()}} call for
libhdfs.
The main point is not (and never intends to be) to demonstrate c++ is superior
to c, but to show that it is practical to using current technology to improve
code quality and to cut down the maintenance cost down the road. In my personal
opinion it is important to ensure that the code can be easily maintained by the
community. The patch demonstrates a viable way to approach this goal.
Just a couple points to highlight:
# Simpler implementation. Thanks to the standard libraries, there is no need to
put things like RB trees, hash tables, linked lists into the patch and to ask
for reviews. Though not fully equivalent, the patch is an order of magnitude
smaller in terms of size.
# Automatic resource management. Explicit resource management, (e.g.,
{{malloc()}} / {{free()}}, and closing sockets) are no longer required. The
life time of resource matches the scope of the code. It is a systematic way to
avoid resource leaks.
# Stronger claims from the type systems. Modern language allows the code to be
written in a mostly type-safe way, where the type system is able to show that
the majority of the code is safe. There is only one cast required in the code
compared to many (each in the linked list) in the old implementation. New
constructs like {{std::array}} also allow integrate bounds check in the code to
help prevent buffer overflows.
Just to reiterate, by no means I'm trying to claim that the current patch is
perfect and free of bugs. People myself included make mistakes all the time. A
modern tool, however, can help people to catch the mistakes at the beginning of
the development cycle and to avoid them. I believe that this is what good
software engineering practice should do. I don't see why this is a
philosophical debate on which language is better (though I can be happily
convinced in either way), and why writing safer, and easier to approach
correctness can be out-of-the-scope during development.
> Native RPCv9 client
> -------------------
>
> Key: HADOOP-10389
> URL: https://issues.apache.org/jira/browse/HADOOP-10389
> Project: Hadoop Common
> Issue Type: Sub-task
> Affects Versions: HADOOP-10388
> Reporter: Binglin Chang
> Assignee: Colin Patrick McCabe
> Attachments: HADOOP-10388.001.patch,
> HADOOP-10389-alternative.000.patch, HADOOP-10389.002.patch,
> HADOOP-10389.004.patch, HADOOP-10389.005.patch
>
>
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