optimize MigrateColumn method for regexp (#4188)

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heige 2021-03-17 11:32:17 +08:00 committed by GitHub
parent 2055e29eb8
commit 07f3795f93
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1 changed files with 9 additions and 2 deletions

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@ -12,6 +12,11 @@ import (
"gorm.io/gorm/schema"
)
var (
regRealDataType = regexp.MustCompile(`[^\d](\d+)[^\d]?`)
regFullDataType = regexp.MustCompile(`[^\d]*(\d+)[^\d]?`)
)
// Migrator m struct
type Migrator struct {
Config
@ -373,8 +378,10 @@ func (m Migrator) MigrateColumn(value interface{}, field *schema.Field, columnTy
alterColumn = true
} else {
// has size in data type and not equal
matches := regexp.MustCompile(`[^\d](\d+)[^\d]?`).FindAllStringSubmatch(realDataType, -1)
matches2 := regexp.MustCompile(`[^\d]*(\d+)[^\d]?`).FindAllStringSubmatch(fullDataType, -1)
// Since the following code is frequently called in the for loop, reg optimization is needed here
matches := regRealDataType.FindAllStringSubmatch(realDataType, -1)
matches2 := regFullDataType.FindAllStringSubmatch(fullDataType, -1)
if (len(matches) == 1 && matches[0][1] != fmt.Sprint(field.Size) || !field.PrimaryKey) && (len(matches2) == 1 && matches2[0][1] != fmt.Sprint(length)) {
alterColumn = true
}