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https://issues.apache.org/jira/browse/HDFS-8058?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14482423#comment-14482423
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Yi Liu commented on HDFS-8058:
------------------------------
Zhe, Jing, thanks for your comments!
{quote}
The only concern I can think of is type safety: on the surface, a generic
BlockInfo[] could contain mixed types.. We need some extra logic to prevent a
striped block to be added to a non-striped file, and vice versa.
{quote}
In my thought, this would never happen, although the type is {{BlockInfo[]}},
the actual instance type is {{BlockInfoContiguous[]}} or
{{BlockInfoStriped[]}}, and we also do {{assertBlock}} check before
{{setBlock}}, {{addBlock}}, etc. So I think it can never contain mixed types,
since you can't add {{BlockInfoContiguous}} instance to a
{{BlockInfoStriped[]}}, and vice versa. Do I miss anything?
{code}
private void assertBlock(BlockInfo blk) {
if (isStriped()) {
assert blk.isStriped();
} else {
assert !blk.isStriped();
}
}
{code}
> Erasure coding: use BlockInfo[] for both striped and contiguous blocks in
> INodeFile
> -----------------------------------------------------------------------------------
>
> Key: HDFS-8058
> URL: https://issues.apache.org/jira/browse/HDFS-8058
> Project: Hadoop HDFS
> Issue Type: Sub-task
> Affects Versions: HDFS-7285
> Reporter: Yi Liu
> Assignee: Yi Liu
> Attachments: HDFS-8058.001.patch, HDFS-8058.002.patch
>
>
> This JIRA is to use {{BlockInfo[] blocks}} for both striped and contiguous
> blocks in INodeFile.
> Currently {{FileWithStripedBlocksFeature}} keeps separate list for striped
> blocks, and the methods there duplicate with those in INodeFile, and current
> code need to judge {{isStriped}} then do different things. Also if file is
> striped, the {{blocks}} in INodeFile occupy a reference memory space.
> These are not necessary, and we can use the same {{blocks}} to make code more
> clear.
> I keep {{FileWithStripedBlocksFeature}} as empty for follow use: I will file
> a new JIRA to move {{dataBlockNum}} and {{parityBlockNum}} from
> *BlockInfoStriped* to INodeFile, since ideally they are the same for all
> striped blocks in a file, and store them in block will waste NN memory.
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