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https://issues.apache.org/jira/browse/ARROW-15878?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Yibo Cai updated ARROW-15878:
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Description:
Escaping a string with quotes (put an extra quote before a quote) is the
hotspot of csv writer [1]. This can probably be improved, possible approaches:
- Find the next quote with memchr, then memcpy blocks without quotes.
- Check if there are quotes with simd in 8 bytes or 16 bytes, do memcpy if no,
otherwise go slow path.
Should make sure the method doesn't decrease performance too much for strings
with many quotes, or short strings.
[1] https://github.com/apache/arrow/blob/master/cpp/src/arrow/csv/writer.cc#L139
was:
Escaping a string with quotes (put an extra quote before a quote) is the
hotspot of csv writer [1]. This can probably be improved, possible approaches:
- Find the next quote with memchr, then memcpy blocks without quotes.
- Check if there are quotes with simd in 8 bytes or 16 bytes, do memcpy if no,
otherwise go slow path.
Should make sure the method doesn't decrease performance too much for strings
with many quotes, or short strings.
> [C++] Optimize csv writer for string with quotes
> ------------------------------------------------
>
> Key: ARROW-15878
> URL: https://issues.apache.org/jira/browse/ARROW-15878
> Project: Apache Arrow
> Issue Type: Improvement
> Components: C++
> Reporter: Yibo Cai
> Assignee: Yibo Cai
> Priority: Major
>
> Escaping a string with quotes (put an extra quote before a quote) is the
> hotspot of csv writer [1]. This can probably be improved, possible approaches:
> - Find the next quote with memchr, then memcpy blocks without quotes.
> - Check if there are quotes with simd in 8 bytes or 16 bytes, do memcpy if
> no, otherwise go slow path.
> Should make sure the method doesn't decrease performance too much for strings
> with many quotes, or short strings.
> [1]
> https://github.com/apache/arrow/blob/master/cpp/src/arrow/csv/writer.cc#L139
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