106 lines
2.4 KiB
Go
106 lines
2.4 KiB
Go
// Copyright 2016 The Xorm Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package xorm
|
|
|
|
import (
|
|
"reflect"
|
|
|
|
"xorm.io/xorm/internal/utils"
|
|
)
|
|
|
|
// IterFunc only use by Iterate
|
|
type IterFunc func(idx int, bean interface{}) error
|
|
|
|
// Rows return sql.Rows compatible Rows obj, as a forward Iterator object for iterating record by record, bean's non-empty fields
|
|
// are conditions.
|
|
func (session *Session) Rows(bean interface{}) (*Rows, error) {
|
|
return newRows(session, bean)
|
|
}
|
|
|
|
// Iterate record by record handle records from table, condiBeans's non-empty fields
|
|
// are conditions. beans could be []Struct, []*Struct, map[int64]Struct
|
|
// map[int64]*Struct
|
|
func (session *Session) Iterate(bean interface{}, fun IterFunc) error {
|
|
if session.isAutoClose {
|
|
defer session.Close()
|
|
}
|
|
|
|
if session.statement.LastError != nil {
|
|
return session.statement.LastError
|
|
}
|
|
|
|
if session.statement.BufferSize > 0 {
|
|
return session.bufferIterate(bean, fun)
|
|
}
|
|
|
|
rows, err := session.Rows(bean)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer rows.Close()
|
|
|
|
i := 0
|
|
for rows.Next() {
|
|
b := reflect.New(rows.beanType).Interface()
|
|
err = rows.Scan(b)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
err = fun(i, b)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
i++
|
|
}
|
|
return rows.Err()
|
|
}
|
|
|
|
// BufferSize sets the buffersize for iterate
|
|
func (session *Session) BufferSize(size int) *Session {
|
|
session.statement.BufferSize = size
|
|
return session
|
|
}
|
|
|
|
func (session *Session) bufferIterate(bean interface{}, fun IterFunc) error {
|
|
var bufferSize = session.statement.BufferSize
|
|
var pLimitN = session.statement.LimitN
|
|
if pLimitN != nil && bufferSize > *pLimitN {
|
|
bufferSize = *pLimitN
|
|
}
|
|
var start = session.statement.Start
|
|
v := utils.ReflectValue(bean)
|
|
sliceType := reflect.SliceOf(v.Type())
|
|
var idx = 0
|
|
session.autoResetStatement = false
|
|
defer func() {
|
|
session.autoResetStatement = true
|
|
}()
|
|
|
|
for bufferSize > 0 {
|
|
slice := reflect.New(sliceType)
|
|
if err := session.NoCache().Limit(bufferSize, start).find(slice.Interface(), bean); err != nil {
|
|
return err
|
|
}
|
|
|
|
for i := 0; i < slice.Elem().Len(); i++ {
|
|
if err := fun(idx, slice.Elem().Index(i).Addr().Interface()); err != nil {
|
|
return err
|
|
}
|
|
idx++
|
|
}
|
|
|
|
if bufferSize > slice.Elem().Len() {
|
|
break
|
|
}
|
|
|
|
start += slice.Elem().Len()
|
|
if pLimitN != nil && start+bufferSize > *pLimitN {
|
|
bufferSize = *pLimitN - start
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|