refactor ContextCache

README.md

@@ -34,7 +34,7 @@ Xorm is a simple and powerful ORM for Go.
 
 * Postgres schema support
 
-* Context Get Cache
+* Context Cache support
 
 ## Drivers Support
 
@@ -360,14 +360,37 @@ if _, err := session.Exec("delete from userinfo where username = ?", user2.Usern
 return session.Commit()
 ```
 
+* Or you can use `Transaction` to replace above codes.
+
+```Go
+res, err := engine.Transaction(func(sess *xorm.Session) (interface{}, error) {
+    user1 := Userinfo{Username: "xiaoxiao", Departname: "dev", Alias: "lunny", Created: time.Now()}
+    if _, err := session.Insert(&user1); err != nil {
+        return nil, err
+    }
+
+    user2 := Userinfo{Username: "yyy"}
+    if _, err := session.Where("id = ?", 2).Update(&user2); err != nil {
+        return nil, err
+    }
+
+    if _, err := session.Exec("delete from userinfo where username = ?", user2.Username); err != nil {
+        return nil, err
+    }
+    return nil, nil
+})
+```
+
 * Context Cache, if enabled, current query result will be cached on session and be used by next same statement on the same session.
 
 ```Go
     sess := engine.NewSession()
 	defer sess.Close()
 
+    var context = xorm.NewContextCache()
+
 	var c2 ContextGetStruct
-	has, err := sess.ID(1).ContextCache().Get(&c2)
+	has, err := sess.ID(1).ContextCache(context).Get(&c2)
 	assert.NoError(t, err)
 	assert.True(t, has)
 	assert.EqualValues(t, 1, c2.Id)
@@ -377,7 +400,7 @@ return session.Commit()
 	assert.True(t, len(args) > 0)
 
 	var c3 ContextGetStruct
-	has, err = sess.ID(1).Get(&c3)
+	has, err = sess.ID(1).ContextCache(context).Get(&c3)
 	assert.NoError(t, err)
 	assert.True(t, has)
 	assert.EqualValues(t, 1, c3.Id)

README_CN.md

@@ -32,6 +32,8 @@ xorm是一个简单而强大的Go语言ORM库. 通过它可以使数据库操作
 
 * 内置SQL Builder支持
 
+* 上下文缓存支持
+
 ## 驱动支持
 
 目前支持的Go数据库驱动和对应的数据库如下：
@@ -360,6 +362,54 @@ if _, err := session.Exec("delete from userinfo where username = ?", user2.Usern
 return session.Commit()
 ```
 
+* 事物的简写方法
+
+```Go
+res, err := engine.Transaction(func(sess *xorm.Session) (interface{}, error) {
+    user1 := Userinfo{Username: "xiaoxiao", Departname: "dev", Alias: "lunny", Created: time.Now()}
+    if _, err := session.Insert(&user1); err != nil {
+        return nil, err
+    }
+
+    user2 := Userinfo{Username: "yyy"}
+    if _, err := session.Where("id = ?", 2).Update(&user2); err != nil {
+        return nil, err
+    }
+
+    if _, err := session.Exec("delete from userinfo where username = ?", user2.Username); err != nil {
+        return nil, err
+    }
+    return nil, nil
+})
+```
+
+* Context Cache, if enabled, current query result will be cached on session and be used by next same statement on the same session.
+
+```Go
+    sess := engine.NewSession()
+	defer sess.Close()
+
+	var c2 ContextGetStruct
+	has, err := sess.ID(1).ContextCache().Get(&c2)
+	assert.NoError(t, err)
+	assert.True(t, has)
+	assert.EqualValues(t, 1, c2.Id)
+	assert.EqualValues(t, "1", c2.Name)
+	sql, args := sess.LastSQL()
+	assert.True(t, len(sql) > 0)
+	assert.True(t, len(args) > 0)
+
+	var c3 ContextGetStruct
+	has, err = sess.ID(1).Get(&c3)
+	assert.NoError(t, err)
+	assert.True(t, has)
+	assert.EqualValues(t, 1, c3.Id)
+	assert.EqualValues(t, "1", c3.Name)
+	sql, args = sess.LastSQL()
+	assert.True(t, len(sql) == 0)
+	assert.True(t, len(args) == 0)
+```
+
 ## 贡献
 
 如果您也想为Xorm贡献您的力量，请查看 [CONTRIBUTING](https://github.com/go-xorm/xorm/blob/master/CONTRIBUTING.md)。您也可以加入QQ群  技术帮助和讨论。

context_cache.go

@@ -0,0 +1,27 @@
+// Copyright 2018 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
+
+// ContextCache is the interface that operates the cache data.
+type ContextCache interface {
+	// Put puts value into cache with key and expire time.
+	Put(key string, val interface{})
+	// Get gets cached value by given key.
+	Get(key string) interface{}
+}
+
+type memoryContextCache map[string]interface{}
+
+func NewMemoryContextCache() memoryContextCache {
+	return make(map[string]interface{})
+}
+
+func (m memoryContextCache) Put(key string, val interface{}) {
+	m[key] = val
+}
+
+func (m memoryContextCache) Get(key string) interface{} {
+	return m[key]
+}

session.go

@@ -5,7 +5,6 @@
 package xorm
 
 import (
-	"context"
 	"database/sql"
 	"encoding/json"
 	"errors"
@@ -52,8 +51,7 @@ type Session struct {
 	lastSQL     string
 	lastSQLArgs []interface{}
 
-	err     error
-	context context.Context
+	err error
 }
 
 // Clone copy all the session's content and return a new session
@@ -84,7 +82,6 @@ func (session *Session) Init() {
 
 	session.lastSQL = ""
 	session.lastSQLArgs = []interface{}{}
-	session.context = nil
 }
 
 // Close release the connection from pool
@@ -106,8 +103,8 @@ func (session *Session) Close() {
 }
 
 // ContextCache enable context cache or not
-func (session *Session) ContextCache() *Session {
-	session.statement.enableContextCache = true
+func (session *Session) ContextCache(context ContextCache) *Session {
+	session.statement.context = context
 	return session
 }
 

session_get.go

@@ -5,7 +5,6 @@
 package xorm
 
 import (
-	"context"
 	"database/sql"
 	"errors"
 	"fmt"
@@ -68,9 +67,9 @@ func (session *Session) get(bean interface{}) (bool, error) {
 		}
 	}
 
-	var enableContextCache = session.statement.enableContextCache
-	if session.context != nil {
-		res := session.context.Value(fmt.Sprintf("%v-%v", sqlStr, args))
+	context := session.statement.context
+	if context != nil {
+		res := context.Get(fmt.Sprintf("%v-%v", sqlStr, args))
 		if res != nil {
 			structValue := reflect.Indirect(reflect.ValueOf(bean))
 			structValue.Set(reflect.Indirect(reflect.ValueOf(res)))
@@ -85,11 +84,8 @@ func (session *Session) get(bean interface{}) (bool, error) {
 		return has, err
 	}
 
-	if enableContextCache {
-		if session.context == nil {
-			session.context = context.Background()
-		}
-		session.context = context.WithValue(session.context, fmt.Sprintf("%v-%v", sqlStr, args), bean)
+	if context != nil {
+		context.Put(fmt.Sprintf("%v-%v", sqlStr, args), bean)
 	}
 
 	return true, nil

session_get_test.go

@@ -335,8 +335,10 @@ func TestContextGet(t *testing.T) {
 	sess := testEngine.NewSession()
 	defer sess.Close()
 
+	context := NewMemoryContextCache()
+
 	var c2 ContextGetStruct
-	has, err := sess.ID(1).ContextCache().Get(&c2)
+	has, err := sess.ID(1).ContextCache(context).Get(&c2)
 	assert.NoError(t, err)
 	assert.True(t, has)
 	assert.EqualValues(t, 1, c2.Id)
@@ -346,7 +348,7 @@ func TestContextGet(t *testing.T) {
 	assert.True(t, len(args) > 0)
 
 	var c3 ContextGetStruct
-	has, err = sess.ID(1).Get(&c3)
+	has, err = sess.ID(1).ContextCache(context).Get(&c3)
 	assert.NoError(t, err)
 	assert.True(t, has)
 	assert.EqualValues(t, 1, c3.Id)
@@ -355,3 +357,32 @@ func TestContextGet(t *testing.T) {
 	assert.True(t, len(sql) == 0)
 	assert.True(t, len(args) == 0)
 }
+
+func TestContextGet2(t *testing.T) {
+	type ContextGetStruct2 struct {
+		Id   int64
+		Name string
+	}
+
+	assert.NoError(t, prepareEngine())
+	assertSync(t, new(ContextGetStruct2))
+
+	_, err := testEngine.Insert(&ContextGetStruct2{Name: "1"})
+	assert.NoError(t, err)
+
+	context := NewMemoryContextCache()
+
+	var c2 ContextGetStruct2
+	has, err := testEngine.ID(1).ContextCache(context).Get(&c2)
+	assert.NoError(t, err)
+	assert.True(t, has)
+	assert.EqualValues(t, 1, c2.Id)
+	assert.EqualValues(t, "1", c2.Name)
+
+	var c3 ContextGetStruct2
+	has, err = testEngine.ID(1).ContextCache(context).Get(&c3)
+	assert.NoError(t, err)
+	assert.True(t, has)
+	assert.EqualValues(t, 1, c3.Id)
+	assert.EqualValues(t, "1", c3.Name)
+}

statement.go

@@ -19,47 +19,47 @@ import (
 
 // Statement save all the sql info for executing SQL
 type Statement struct {
-	RefTable           *core.Table
-	Engine             *Engine
-	Start              int
-	LimitN             int
-	idParam            *core.PK
-	OrderStr           string
-	JoinStr            string
-	joinArgs           []interface{}
-	GroupByStr         string
-	HavingStr          string
-	ColumnStr          string
-	selectStr          string
-	useAllCols         bool
-	OmitStr            string
-	AltTableName       string
-	tableName          string
-	RawSQL             string
-	RawParams          []interface{}
-	UseCascade         bool
-	UseAutoJoin        bool
-	StoreEngine        string
-	Charset            string
-	UseCache           bool
-	UseAutoTime        bool
-	noAutoCondition    bool
-	IsDistinct         bool
-	IsForUpdate        bool
-	TableAlias         string
-	allUseBool         bool
-	checkVersion       bool
-	unscoped           bool
-	columnMap          columnMap
-	omitColumnMap      columnMap
-	mustColumnMap      map[string]bool
-	nullableMap        map[string]bool
-	incrColumns        map[string]incrParam
-	decrColumns        map[string]decrParam
-	exprColumns        map[string]exprParam
-	cond               builder.Cond
-	bufferSize         int
-	enableContextCache bool
+	RefTable        *core.Table
+	Engine          *Engine
+	Start           int
+	LimitN          int
+	idParam         *core.PK
+	OrderStr        string
+	JoinStr         string
+	joinArgs        []interface{}
+	GroupByStr      string
+	HavingStr       string
+	ColumnStr       string
+	selectStr       string
+	useAllCols      bool
+	OmitStr         string
+	AltTableName    string
+	tableName       string
+	RawSQL          string
+	RawParams       []interface{}
+	UseCascade      bool
+	UseAutoJoin     bool
+	StoreEngine     string
+	Charset         string
+	UseCache        bool
+	UseAutoTime     bool
+	noAutoCondition bool
+	IsDistinct      bool
+	IsForUpdate     bool
+	TableAlias      string
+	allUseBool      bool
+	checkVersion    bool
+	unscoped        bool
+	columnMap       columnMap
+	omitColumnMap   columnMap
+	mustColumnMap   map[string]bool
+	nullableMap     map[string]bool
+	incrColumns     map[string]incrParam
+	decrColumns     map[string]decrParam
+	exprColumns     map[string]exprParam
+	cond            builder.Cond
+	bufferSize      int
+	context         ContextCache
 }
 
 // Init reset all the statement's fields
@@ -100,7 +100,7 @@ func (statement *Statement) Init() {
 	statement.exprColumns = make(map[string]exprParam)
 	statement.cond = builder.NewCond()
 	statement.bufferSize = 0
-	statement.enableContextCache = false
+	statement.context = nil
 }
 
 // NoAutoCondition if you do not want convert bean's field as query condition, then use this function