gorm/schema/index.go
2021-06-14 11:23:25 +08:00

138 lines
3.0 KiB
Go

package schema
import (
"sort"
"strconv"
"strings"
)
type Index struct {
Name string
Class string // UNIQUE | FULLTEXT | SPATIAL
Type string // btree, hash, gist, spgist, gin, and brin
Where string
Comment string
Option string // WITH PARSER parser_name
Fields []IndexOption
}
type IndexOption struct {
*Field
Expression string
Sort string // DESC, ASC
Collate string
Length int
priority int
}
// ParseIndexes parse schema indexes
func (schema *Schema) ParseIndexes() map[string]Index {
indexes := make(map[string]Index, len(schema.Fields)+1)
for _, field := range schema.Fields {
if field.TagSettings["INDEX"] != "" || field.TagSettings["UNIQUEINDEX"] != "" {
for _, index := range parseFieldIndexes(field) {
idx, ok := indexes[index.Name]
if !ok {
indexes[index.Name] = Index{
Name: index.Name,
Class: index.Class,
Type: index.Type,
Where: index.Where,
Comment: index.Comment,
Option: index.Option,
Fields: make([]IndexOption, 0, 10), // Fields cap default is 10
}
}
idx.Fields = append(idx.Fields, index.Fields...)
if len(idx.Fields) >= 2 {
sort.Slice(idx.Fields, func(i, j int) bool {
return idx.Fields[i].priority < idx.Fields[j].priority
})
}
indexes[index.Name] = idx
}
}
}
return indexes
}
func (schema *Schema) LookIndex(name string) *Index {
if schema != nil {
indexes := schema.ParseIndexes()
for _, index := range indexes {
if index.Name == name {
return &index
}
for _, field := range index.Fields {
if field.Name == name {
return &index
}
}
}
}
return nil
}
func parseFieldIndexes(field *Field) (indexes []Index) {
for _, value := range strings.Split(field.Tag.Get("gorm"), ";") {
if value != "" {
v := strings.Split(value, ":")
k := strings.TrimSpace(strings.ToUpper(v[0]))
if k == "INDEX" || k == "UNIQUEINDEX" {
var (
name string
tag = strings.Join(v[1:], ":")
idx = strings.Index(tag, ",")
settings = ParseTagSetting(tag, ",")
length, _ = strconv.Atoi(settings["LENGTH"])
)
if idx == -1 {
idx = len(tag)
}
if idx != -1 {
name = tag[0:idx]
}
if name == "" {
name = field.Schema.namer.IndexName(field.Schema.Table, field.Name)
}
if (k == "UNIQUEINDEX") || settings["UNIQUE"] != "" {
settings["CLASS"] = "UNIQUE"
}
priority, err := strconv.Atoi(settings["PRIORITY"])
if err != nil {
priority = 10
}
indexes = append(indexes, Index{
Name: name,
Class: settings["CLASS"],
Type: settings["TYPE"],
Where: settings["WHERE"],
Comment: settings["COMMENT"],
Option: settings["OPTION"],
Fields: []IndexOption{{
Field: field,
Expression: settings["EXPRESSION"],
Sort: settings["SORT"],
Collate: settings["COLLATE"],
Length: length,
priority: priority,
}},
})
}
}
}
return
}