db methods

crud.go

@@ -27,7 +27,7 @@ func (e *ErrorWithStack) Stack() string {
 }
 
 // CreateDocument creates a document from specified model
-func CreateDocument(db *Database, m ModelInterface) error {
+func (db *Database) CreateDocument(m ModelInterface) error {
 	m.PrepareInsert()
 
 	c := db.C(GetCollectionName(m))
@@ -37,7 +37,7 @@ func CreateDocument(db *Database, m ModelInterface) error {
 }
 
 // ReadDocument gets one document via its id
-func ReadDocument(db *Database, m ModelInterface, selector bson.M) error {
+func (db *Database) ReadDocument(m ModelInterface, selector bson.M) error {
 	c := db.C(GetCollectionName(m))
 
 	q := c.FindId(m.GetID())
@@ -136,7 +136,7 @@ func idToObjectID(filter interface{}) {
 }
 
 // ReadCollection gets the filtered collection of the model
-func ReadCollection(db *Database, results interface{}, filter bson.M, selector bson.M, offset int, limit int, sort []string, pipelineModifier PipelineModifierFunction) (err error) {
+func (db *Database) ReadCollection(results interface{}, filter bson.M, selector bson.M, offset int, limit int, sort []string, pipelineModifier PipelineModifierFunction) (err error) {
 	defer func() {
 		if r := recover(); r != nil {
 			err = &ErrorWithStack{Message: fmt.Sprintf("%v", r), StackTrace: string(debug.Stack())}
@@ -243,7 +243,7 @@ func ReadCollection(db *Database, results interface{}, filter bson.M, selector b
 }
 
 // ReadCollectionCount gets the count of elements in filtered collection
-func ReadCollectionCount(db *Database, m ModelInterface, filter bson.M) (count int, err error) {
+func (db *Database) ReadCollectionCount(m ModelInterface, filter bson.M) (count int, err error) {
 	defer func() {
 		if r := recover(); r != nil {
 			err = fmt.Errorf("%v", r)
@@ -255,7 +255,7 @@ func ReadCollectionCount(db *Database, m ModelInterface, filter bson.M) (count i
 }
 
 // UpdateDocument updates a document from specified model
-func UpdateDocument(db *Database, m ModelInterface, changes bson.M) error {
+func (db *Database) UpdateDocument(m ModelInterface, changes bson.M) error {
 	m.PrepareUpdate()
 	changes["updateTime"] = time.Now()
 
@@ -266,7 +266,7 @@ func UpdateDocument(db *Database, m ModelInterface, changes bson.M) error {
 }
 
 // UpsertDocument updates a document from specified model or inserts it, of not found
-func UpsertDocument(db *Database, m ModelInterface, changes bson.M) error {
+func (db *Database) UpsertDocument(m ModelInterface, changes bson.M) error {
 	m.PrepareUpdate()
 	changes["updateTime"] = time.Now()
 
@@ -277,7 +277,7 @@ func UpsertDocument(db *Database, m ModelInterface, changes bson.M) error {
 }
 
 // DeleteDocument deletes one document via its id
-func DeleteDocument(db *Database, m ModelInterface) error {
+func (db *Database) DeleteDocument(m ModelInterface) error {
 	c := db.C(GetCollectionName(m))
 
 	err := c.RemoveId(m.GetID())
@@ -286,7 +286,7 @@ func DeleteDocument(db *Database, m ModelInterface) error {
 }
 
 // DeleteDocuments deletes documents found by filter
-func DeleteDocuments(db *Database, m ModelInterface, filter bson.M) (removed int, err error) {
+func (db *Database) DeleteDocuments(m ModelInterface, filter bson.M) (removed int, err error) {
 	c := db.C(GetCollectionName(m))
 
 	info, err := c.RemoveAll(filter)

lookup.go

@@ -8,7 +8,7 @@ import (
 )
 
 // Lookup extends results with data for inline structs
-func Lookup(db *Database, structField string, results interface{}, selector bson.M) error {
+func (db *Database) Lookup(structField string, results interface{}, selector bson.M) error {
 
 	t := reflect.TypeOf(results)
 	v := reflect.ValueOf(results)
@@ -122,7 +122,7 @@ func Lookup(db *Database, structField string, results interface{}, selector bson
 		return fmt.Errorf("ID type in objects struct %+v is not bson.ObjectId", fieldType)
 	}
 
-	err := ReadCollection(db, objectResults, sQuery, selector, 0, 0, nil, nil)
+	err := db.ReadCollection(objectResults, sQuery, selector, 0, 0, nil, nil)
 	if err != nil {
 		panic(err)
 	}

session.go

@@ -6,6 +6,10 @@ import (
 	mgo "gopkg.in/mgo.v2"
 )
 
+var (
+	ErrNotFound = errors.New("not found")
+)
+
 type Session struct {
 	session *mgo.Session
 }
@@ -14,6 +18,10 @@ func (s *Session) Close() {
 	s.session.Close()
 }
 
+func (s *Session) Copy() *Session {
+	return &Session{session: s.session.Copy()}
+}
+
 func NewSession(dial string) (*Session, error) {
 	session, err := mgo.Dial(dial)
 	if err != nil {
@@ -25,16 +33,21 @@ func NewSession(dial string) (*Session, error) {
 
 type Database struct {
 	database *mgo.Database
+	session  *Session
 }
 
 func (s *Session) DB(name string) *Database {
-	return &Database{database: s.session.DB(name)}
+	return &Database{database: s.session.DB(name), session: s}
 }
 
 type Collection struct {
 	collection *mgo.Collection
 }
 
+func (db *Database) Session() *Session {
+	return db.session
+}
+
 func (db *Database) C(name string) *Collection {
 	return &Collection{collection: db.database.C(name)}
 }
@@ -105,7 +118,11 @@ func (q *Query) Select(selector interface{}) *Query {
 }
 
 func (q *Query) One(result interface{}) error {
-	return q.query.One(result)
+	err := q.query.One(result)
+	if err == mgo.ErrNotFound {
+		err = ErrNotFound
+	}
+	return err
 }
 
 func (q *Query) Sort(fields ...string) *Query {
@@ -124,11 +141,19 @@ func (q *Query) Limit(n int) *Query {
 }
 
 func (q *Query) All(result interface{}) error {
-	return q.query.All(result)
+	err := q.query.All(result)
+	if err == mgo.ErrNotFound {
+		err = ErrNotFound
+	}
+	return err
 }
 
 func (q *Query) Count() (int, error) {
-	return q.query.Count()
+	c, err := q.query.Count()
+	if err == mgo.ErrNotFound {
+		err = ErrNotFound
+	}
+	return c, err
 }
 
 type Index struct {
@@ -151,7 +176,11 @@ type Pipe struct {
 }
 
 func (p *Pipe) All(result interface{}) error {
-	return p.pipe.All(result)
+	err := p.pipe.All(result)
+	if err == mgo.ErrNotFound {
+		err = ErrNotFound
+	}
+	return err
 }
 
 func (c *Collection) Pipe(pipeline interface{}) *Pipe {

setup.go

@@ -9,7 +9,7 @@ import (
 )
 
 // EnsureIndex ensured mongodb index reflecting model struct index tag
-func EnsureIndex(db *Database, m ModelInterface) error {
+func (db *Database) EnsureIndex(m ModelInterface) error {
 	colName := GetCollectionName(m)
 	col := db.C(colName)
 

validator.go

@@ -6,7 +6,7 @@ import (
 )
 
 // ValidateObject validates object via validator tag and custom method
-func ValidateObject(db *Database, m ModelInterface, changes bson.M) error {
+func (db *Database) ValidateObject(m ModelInterface, changes bson.M) error {
 	// first validate via struct tag
 	validator := validator.New(&validator.Config{
 		TagName: "validator",