tables: fix prefix index, when the charset is utf8, truncate it from runes #7109
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winkyao
added
type/bugfix
|
/run-all-tests |
crazycs520
added
status/LGT2
coocood
reviewed
Jul 19, 2018
table/tables/index.go
Outdated
| rs := bytes.Runes(val) | ||
| truncateStr := string(rs[:ic.Length]) | ||
| // truncate value and limit its length | ||
| v.SetBytes([]byte(truncateStr)) |
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SetString can save a memory allocation.
birdstorm
reviewed
Jul 19, 2018
| ic := c.idxInfo.Columns[i] | ||
| if ic.Tp.Charset == charset.CharsetUTF8 || ic.Tp.Charset == charset.CharsetUTF8MB4 { | ||
| val := v.GetBytes() | ||
| if ic.Length != types.UnspecifiedLength && utf8.RuneCount(val) > ic.Length { |
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I think we can use utf8.RuneCountInString() instead, and thus eliminate the usage of val.
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But RuneCountInString needs to convert bytes to string first, it's unworthy.
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@coocood @birdstorm PTAL |
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LGTM |
coocood
approved these changes
Jul 19, 2018
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What have you changed? (mandatory)
fix #7104 , before this PR, the index length is counted by its bytes. when the charset is utf8 or utf8mb4, the length should be counted by its runes. This PR fixes this.
What is the type of the changes? (mandatory)
How has this PR been tested? (mandatory)
UT
Does this PR affect documentation (docs/docs-cn) update? (mandatory)
NO
Does this PR affect tidb-ansible update? (mandatory)
NO
Does this PR need to be added to the release notes? (mandatory)
release note:
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