gitroast/vendor/github.com/go-xorm/xorm/session_get.go

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// 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 (
"errors"
"reflect"
"strconv"
"github.com/go-xorm/core"
)
// Get retrieve one record from database, bean's non-empty fields
// will be as conditions
func (session *Session) Get(bean interface{}) (bool, error) {
defer session.resetStatement()
if session.IsAutoClose {
defer session.Close()
}
beanValue := reflect.ValueOf(bean)
if beanValue.Kind() != reflect.Ptr {
return false, errors.New("needs a pointer")
}
if beanValue.Elem().Kind() == reflect.Struct {
session.Statement.setRefValue(beanValue.Elem())
}
var sqlStr string
var args []interface{}
if session.Statement.RawSQL == "" {
if len(session.Statement.TableName()) <= 0 {
return false, ErrTableNotFound
}
session.Statement.Limit(1)
sqlStr, args = session.Statement.genGetSQL(bean)
} else {
sqlStr = session.Statement.RawSQL
args = session.Statement.RawParams
}
if session.canCache() && beanValue.Elem().Kind() == reflect.Struct {
if cacher := session.Engine.getCacher2(session.Statement.RefTable); cacher != nil &&
!session.Statement.unscoped {
has, err := session.cacheGet(bean, sqlStr, args...)
if err != ErrCacheFailed {
return has, err
}
}
}
return session.nocacheGet(beanValue.Elem().Kind(), bean, sqlStr, args...)
}
func (session *Session) nocacheGet(beanKind reflect.Kind, bean interface{}, sqlStr string, args ...interface{}) (bool, error) {
session.queryPreprocess(&sqlStr, args...)
var rawRows *core.Rows
var err error
if session.IsAutoCommit {
_, rawRows, err = session.innerQuery(sqlStr, args...)
} else {
rawRows, err = session.Tx.Query(sqlStr, args...)
}
if err != nil {
return false, err
}
defer rawRows.Close()
if rawRows.Next() {
switch beanKind {
case reflect.Struct:
fields, err := rawRows.Columns()
if err != nil {
// WARN: Alougth rawRows return true, but get fields failed
return true, err
}
dataStruct := rValue(bean)
session.Statement.setRefValue(dataStruct)
_, err = session.row2Bean(rawRows, fields, len(fields), bean, &dataStruct, session.Statement.RefTable)
case reflect.Slice:
err = rawRows.ScanSlice(bean)
case reflect.Map:
err = rawRows.ScanMap(bean)
default:
err = rawRows.Scan(bean)
}
return true, err
}
return false, nil
}
func (session *Session) cacheGet(bean interface{}, sqlStr string, args ...interface{}) (has bool, err error) {
// if has no reftable, then don't use cache currently
if !session.canCache() {
return false, ErrCacheFailed
}
for _, filter := range session.Engine.dialect.Filters() {
sqlStr = filter.Do(sqlStr, session.Engine.dialect, session.Statement.RefTable)
}
newsql := session.Statement.convertIDSQL(sqlStr)
if newsql == "" {
return false, ErrCacheFailed
}
cacher := session.Engine.getCacher2(session.Statement.RefTable)
tableName := session.Statement.TableName()
session.Engine.logger.Debug("[cacheGet] find sql:", newsql, args)
ids, err := core.GetCacheSql(cacher, tableName, newsql, args)
table := session.Statement.RefTable
if err != nil {
var res = make([]string, len(table.PrimaryKeys))
rows, err := session.DB().Query(newsql, args...)
if err != nil {
return false, err
}
defer rows.Close()
if rows.Next() {
err = rows.ScanSlice(&res)
if err != nil {
return false, err
}
} else {
return false, ErrCacheFailed
}
var pk core.PK = make([]interface{}, len(table.PrimaryKeys))
for i, col := range table.PKColumns() {
if col.SQLType.IsText() {
pk[i] = res[i]
} else if col.SQLType.IsNumeric() {
n, err := strconv.ParseInt(res[i], 10, 64)
if err != nil {
return false, err
}
pk[i] = n
} else {
return false, errors.New("unsupported")
}
}
ids = []core.PK{pk}
session.Engine.logger.Debug("[cacheGet] cache ids:", newsql, ids)
err = core.PutCacheSql(cacher, ids, tableName, newsql, args)
if err != nil {
return false, err
}
} else {
session.Engine.logger.Debug("[cacheGet] cache hit sql:", newsql)
}
if len(ids) > 0 {
structValue := reflect.Indirect(reflect.ValueOf(bean))
id := ids[0]
session.Engine.logger.Debug("[cacheGet] get bean:", tableName, id)
sid, err := id.ToString()
if err != nil {
return false, err
}
cacheBean := cacher.GetBean(tableName, sid)
if cacheBean == nil {
cacheBean = bean
has, err = session.nocacheGet(reflect.Struct, cacheBean, sqlStr, args...)
if err != nil || !has {
return has, err
}
session.Engine.logger.Debug("[cacheGet] cache bean:", tableName, id, cacheBean)
cacher.PutBean(tableName, sid, cacheBean)
} else {
session.Engine.logger.Debug("[cacheGet] cache hit bean:", tableName, id, cacheBean)
has = true
}
structValue.Set(reflect.Indirect(reflect.ValueOf(cacheBean)))
return has, nil
}
return false, nil
}