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Posted to issues@orc.apache.org by "Fang Zheng (JIRA)" <ji...@apache.org> on 2019/01/05 03:15:00 UTC
[jira] [Updated] (ORC-456) [C++] Simplify code logic in
RleEncoderV2
[ https://issues.apache.org/jira/browse/ORC-456?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Fang Zheng updated ORC-456:
---------------------------
Description:
There is suboptimal code in RleEncoderV2::write() function (between lines 132-146).
When a tailing min repeat run (i.e., 3 identical values) is detected and there is an ongoing variable run, the code copies the three tailing identical values to a buffer named "tailVals", writes values before these values in literals buffer out, and then copies the 3 values back to the beginning of literals buffer.
Given that the last 3 values are known to be equal to the current value passed in write() function, we do not need to copy those values back and forth through the tailVals buffer.
was:
There is suboptimal code in RleEncoderV2::write() function (between lines 132-146).
When a tailing min repeat run (i.e., 3 identical values) is detected and there is an ongoing variable run, the code copies the tailing identical values to a buffer named "tailVals", writes values before these values in literals buffer out, and then copies the 3 values back to the beginning of literals buffer.
Given that the last 3 values are known to be equal to the current value passed in write() function, we do not need to copy those values back and forth through the tailVals buffer.
> [C++] Simplify code logic in RleEncoderV2
> -----------------------------------------
>
> Key: ORC-456
> URL: https://issues.apache.org/jira/browse/ORC-456
> Project: ORC
> Issue Type: Improvement
> Components: C++
> Reporter: Fang Zheng
> Priority: Minor
>
> There is suboptimal code in RleEncoderV2::write() function (between lines 132-146).
> When a tailing min repeat run (i.e., 3 identical values) is detected and there is an ongoing variable run, the code copies the three tailing identical values to a buffer named "tailVals", writes values before these values in literals buffer out, and then copies the 3 values back to the beginning of literals buffer.
> Given that the last 3 values are known to be equal to the current value passed in write() function, we do not need to copy those values back and forth through the tailVals buffer.
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