mydb/internal/sqladapter/exql/template.go

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3.1 KiB
Go
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2023-09-18 15:15:42 +08:00
package exql
import (
"bytes"
"reflect"
"sync"
"text/template"
"git.hexq.cn/tiglog/mydb/internal/adapter"
"git.hexq.cn/tiglog/mydb/internal/cache"
)
// Type is the type of SQL query the statement represents.
type Type uint8
// Values for Type.
const (
NoOp Type = iota
Truncate
DropTable
DropDatabase
Count
Insert
Select
Update
Delete
SQL
)
func (t Type) Hash() uint64 {
return cache.NewHash(FragmentType_StatementType, uint8(t))
}
type (
// Limit represents the SQL limit in a query.
Limit int64
// Offset represents the SQL offset in a query.
Offset int64
)
func (t Limit) Hash() uint64 {
return cache.NewHash(FragmentType_Limit, uint64(t))
}
func (t Offset) Hash() uint64 {
return cache.NewHash(FragmentType_Offset, uint64(t))
}
// Template is an SQL template.
type Template struct {
AndKeyword string
AscKeyword string
AssignmentOperator string
ClauseGroup string
ClauseOperator string
ColumnAliasLayout string
ColumnSeparator string
ColumnValue string
CountLayout string
DeleteLayout string
DescKeyword string
DropDatabaseLayout string
DropTableLayout string
GroupByLayout string
IdentifierQuote string
IdentifierSeparator string
InsertLayout string
JoinLayout string
OnLayout string
OrKeyword string
OrderByLayout string
SelectLayout string
SortByColumnLayout string
TableAliasLayout string
TruncateLayout string
UpdateLayout string
UsingLayout string
ValueQuote string
ValueSeparator string
WhereLayout string
ComparisonOperator map[adapter.ComparisonOperator]string
templateMutex sync.RWMutex
templateMap map[string]*template.Template
*cache.Cache
}
func (layout *Template) MustCompile(templateText string, data interface{}) string {
var b bytes.Buffer
v, ok := layout.getTemplate(templateText)
if !ok {
v = template.
Must(template.New("").
Funcs(map[string]interface{}{
"defined": func(in Fragment) bool {
if in == nil || reflect.ValueOf(in).IsNil() {
return false
}
if check, ok := in.(hasIsEmpty); ok {
if check.IsEmpty() {
return false
}
}
return true
},
"compile": func(in Fragment) (string, error) {
s, err := layout.doCompile(in)
if err != nil {
return "", err
}
return s, nil
},
}).
Parse(templateText))
layout.setTemplate(templateText, v)
}
if err := v.Execute(&b, data); err != nil {
panic("There was an error compiling the following template:\n" + templateText + "\nError was: " + err.Error())
}
return b.String()
}
func (t *Template) getTemplate(k string) (*template.Template, bool) {
t.templateMutex.RLock()
defer t.templateMutex.RUnlock()
if t.templateMap == nil {
t.templateMap = make(map[string]*template.Template)
}
v, ok := t.templateMap[k]
return v, ok
}
func (t *Template) setTemplate(k string, v *template.Template) {
t.templateMutex.Lock()
defer t.templateMutex.Unlock()
t.templateMap[k] = v
}