Refactor for performance

callbacks/create.go

@@ -192,19 +192,22 @@ func ConvertToCreateValues(stmt *gorm.Statement) clause.Values {
 		return ConvertSliceOfMapToValuesForCreate(stmt, value)
 	default:
 		var (
-			values                    = clause.Values{}
+			values                    = clause.Values{Columns: make([]clause.Column, len(stmt.Schema.DBNames))}
 			selectColumns, restricted = SelectAndOmitColumns(stmt, true, false)
 			curTime                   = stmt.DB.NowFunc()
 			isZero                    = false
 		)
 
+		var columns int
 		for _, db := range stmt.Schema.DBNames {
 			if field := stmt.Schema.FieldsByDBName[db]; !field.HasDefaultValue || field.DefaultValueInterface != nil {
 				if v, ok := selectColumns[db]; (ok && v) || (!ok && !restricted) {
-					values.Columns = append(values.Columns, clause.Column{Name: db})
+					values.Columns[columns] = clause.Column{Name: db}
+					columns++
 				}
 			}
 		}
+		values.Columns = values.Columns[:columns]
 
 		switch stmt.ReflectValue.Kind() {
 		case reflect.Slice, reflect.Array:

callbacks/query.go

@@ -53,38 +53,28 @@ func BuildQuerySQL(db *gorm.DB) {
 	}
 
 	if len(db.Statement.Selects) > 0 {
-		for _, name := range db.Statement.Selects {
+		clauseSelect.Columns = make([]clause.Column, len(db.Statement.Selects))
+		for idx, name := range db.Statement.Selects {
 			if db.Statement.Schema == nil {
-				clauseSelect.Columns = append(clauseSelect.Columns, clause.Column{
-					Name: name,
-					Raw:  true,
-				})
+				clauseSelect.Columns[idx] = clause.Column{Name: name, Raw: true}
 			} else if f := db.Statement.Schema.LookUpField(name); f != nil {
-				clauseSelect.Columns = append(clauseSelect.Columns, clause.Column{
-					Name: f.DBName,
-				})
+				clauseSelect.Columns[idx] = clause.Column{Name: f.DBName}
 			} else {
-				clauseSelect.Columns = append(clauseSelect.Columns, clause.Column{
-					Name: name,
-					Raw:  true,
-				})
+				clauseSelect.Columns[idx] = clause.Column{Name: name, Raw: true}
 			}
 		}
 	}
 
 	// inline joins
 	if len(db.Statement.Joins) != 0 {
-		joins := []clause.Join{}
-
 		if len(db.Statement.Selects) == 0 {
-			for _, dbName := range db.Statement.Schema.DBNames {
-				clauseSelect.Columns = append(clauseSelect.Columns, clause.Column{
-					Table: db.Statement.Table,
-					Name:  dbName,
-				})
+			clauseSelect.Columns = make([]clause.Column, len(db.Statement.Schema.DBNames))
+			for idx, dbName := range db.Statement.Schema.DBNames {
+				clauseSelect.Columns[idx] = clause.Column{Table: db.Statement.Table, Name: dbName}
 			}
 		}
 
+		joins := []clause.Join{}
 		for name, conds := range db.Statement.Joins {
 			if db.Statement.Schema == nil {
 				joins = append(joins, clause.Join{
@@ -101,24 +91,24 @@ func BuildQuerySQL(db *gorm.DB) {
 					})
 				}
 
-				var exprs []clause.Expression
-				for _, ref := range relation.References {
+				exprs := make([]clause.Expression, len(relation.References))
+				for idx, ref := range relation.References {
 					if ref.OwnPrimaryKey {
-						exprs = append(exprs, clause.Eq{
+						exprs[idx] = clause.Eq{
 							Column: clause.Column{Table: db.Statement.Schema.Table, Name: ref.PrimaryKey.DBName},
 							Value:  clause.Column{Table: tableAliasName, Name: ref.ForeignKey.DBName},
-						})
+						}
 					} else {
 						if ref.PrimaryValue == "" {
-							exprs = append(exprs, clause.Eq{
+							exprs[idx] = clause.Eq{
 								Column: clause.Column{Table: db.Statement.Schema.Table, Name: ref.ForeignKey.DBName},
 								Value:  clause.Column{Table: tableAliasName, Name: ref.PrimaryKey.DBName},
-							})
+							}
 						} else {
-							exprs = append(exprs, clause.Eq{
+							exprs[idx] = clause.Eq{
 								Column: clause.Column{Table: tableAliasName, Name: ref.ForeignKey.DBName},
 								Value:  ref.PrimaryValue,
-							})
+							}
 						}
 					}
 				}
@@ -146,42 +136,40 @@ func BuildQuerySQL(db *gorm.DB) {
 }
 
 func Preload(db *gorm.DB) {
-	if db.Error == nil {
-		if len(db.Statement.Preloads) > 0 {
-			preloadMap := map[string][]string{}
-			for name := range db.Statement.Preloads {
-				preloadFields := strings.Split(name, ".")
-				for idx := range preloadFields {
-					preloadMap[strings.Join(preloadFields[:idx+1], ".")] = preloadFields[:idx+1]
+	if db.Error == nil && len(db.Statement.Preloads) > 0 {
+		preloadMap := map[string][]string{}
+		for name := range db.Statement.Preloads {
+			preloadFields := strings.Split(name, ".")
+			for idx := range preloadFields {
+				preloadMap[strings.Join(preloadFields[:idx+1], ".")] = preloadFields[:idx+1]
+			}
+		}
+
+		preloadNames := make([]string, len(preloadMap))
+		idx := 0
+		for key := range preloadMap {
+			preloadNames[idx] = key
+			idx++
+		}
+		sort.Strings(preloadNames)
+
+		for _, name := range preloadNames {
+			var (
+				curSchema     = db.Statement.Schema
+				preloadFields = preloadMap[name]
+				rels          = make([]*schema.Relationship, len(preloadFields))
+			)
+
+			for idx, preloadField := range preloadFields {
+				if rel := curSchema.Relationships.Relations[preloadField]; rel != nil {
+					rels[idx] = rel
+					curSchema = rel.FieldSchema
+				} else {
+					db.AddError(fmt.Errorf("%v: %w", name, gorm.ErrUnsupportedRelation))
 				}
 			}
 
-			preloadNames := make([]string, len(preloadMap))
-			idx := 0
-			for key := range preloadMap {
-				preloadNames[idx] = key
-				idx++
-			}
-			sort.Strings(preloadNames)
-
-			for _, name := range preloadNames {
-				var (
-					curSchema     = db.Statement.Schema
-					preloadFields = preloadMap[name]
-					rels          = make([]*schema.Relationship, len(preloadFields))
-				)
-
-				for idx, preloadField := range preloadFields {
-					if rel := curSchema.Relationships.Relations[preloadField]; rel != nil {
-						rels[idx] = rel
-						curSchema = rel.FieldSchema
-					} else {
-						db.AddError(fmt.Errorf("%v: %w", name, gorm.ErrUnsupportedRelation))
-					}
-				}
-
-				preload(db, rels, db.Statement.Preloads[name])
-			}
+			preload(db, rels, db.Statement.Preloads[name])
 		}
 	}
 }

callbacks/update.go

@@ -140,7 +140,7 @@ func ConvertToAssignments(stmt *gorm.Statement) (set clause.Set) {
 	case map[string]interface{}:
 		set = make([]clause.Assignment, 0, len(value))
 
-		var keys []string
+		keys := make([]string, 0, len(value))
 		for k := range value {
 			keys = append(keys, k)
 		}

clause/set.go

@@ -38,20 +38,15 @@ func (set Set) MergeClause(clause *Clause) {
 }
 
 func Assignments(values map[string]interface{}) Set {
-	var keys []string
-	var assignments []Assignment
-
+	keys := make([]string, 0, len(values))
 	for key := range values {
 		keys = append(keys, key)
 	}
-
 	sort.Strings(keys)
 
-	for _, key := range keys {
-		assignments = append(assignments, Assignment{
-			Column: Column{Name: key},
-			Value:  values[key],
-		})
+	assignments := make([]Assignment, len(keys))
+	for idx, key := range keys {
+		assignments[idx] = Assignment{Column: Column{Name: key}, Value: values[key]}
 	}
 	return assignments
 }

gorm.go

@@ -205,53 +205,11 @@ func (db *DB) InstanceGet(key string) (interface{}, bool) {
 	return db.Statement.Settings.Load(fmt.Sprintf("%p", db.Statement) + key)
 }
 
-func (db *DB) SetupJoinTable(model interface{}, field string, joinTable interface{}) error {
-	var (
-		tx                      = db.getInstance()
-		stmt                    = tx.Statement
-		modelSchema, joinSchema *schema.Schema
-	)
-
-	if err := stmt.Parse(model); err == nil {
-		modelSchema = stmt.Schema
-	} else {
-		return err
-	}
-
-	if err := stmt.Parse(joinTable); err == nil {
-		joinSchema = stmt.Schema
-	} else {
-		return err
-	}
-
-	if relation, ok := modelSchema.Relationships.Relations[field]; ok && relation.JoinTable != nil {
-		for _, ref := range relation.References {
-			if f := joinSchema.LookUpField(ref.ForeignKey.DBName); f != nil {
-				f.DataType = ref.ForeignKey.DataType
-				ref.ForeignKey = f
-			} else {
-				return fmt.Errorf("missing field %v for join table", ref.ForeignKey.DBName)
-			}
-		}
-
-		relation.JoinTable = joinSchema
-	} else {
-		return fmt.Errorf("failed to found relation: %v", field)
-	}
-
-	return nil
-}
-
 // Callback returns callback manager
 func (db *DB) Callback() *callbacks {
 	return db.callbacks
 }
 
-// AutoMigrate run auto migration for given models
-func (db *DB) AutoMigrate(dst ...interface{}) error {
-	return db.Migrator().AutoMigrate(dst...)
-}
-
 // AddError add error to db
 func (db *DB) AddError(err error) error {
 	if db.Error == nil {
@@ -289,3 +247,40 @@ func (db *DB) getInstance() *DB {
 func Expr(expr string, args ...interface{}) clause.Expr {
 	return clause.Expr{SQL: expr, Vars: args}
 }
+
+func (db *DB) SetupJoinTable(model interface{}, field string, joinTable interface{}) error {
+	var (
+		tx                      = db.getInstance()
+		stmt                    = tx.Statement
+		modelSchema, joinSchema *schema.Schema
+	)
+
+	if err := stmt.Parse(model); err == nil {
+		modelSchema = stmt.Schema
+	} else {
+		return err
+	}
+
+	if err := stmt.Parse(joinTable); err == nil {
+		joinSchema = stmt.Schema
+	} else {
+		return err
+	}
+
+	if relation, ok := modelSchema.Relationships.Relations[field]; ok && relation.JoinTable != nil {
+		for _, ref := range relation.References {
+			if f := joinSchema.LookUpField(ref.ForeignKey.DBName); f != nil {
+				f.DataType = ref.ForeignKey.DataType
+				ref.ForeignKey = f
+			} else {
+				return fmt.Errorf("missing field %v for join table", ref.ForeignKey.DBName)
+			}
+		}
+
+		relation.JoinTable = joinSchema
+	} else {
+		return fmt.Errorf("failed to found relation: %v", field)
+	}
+
+	return nil
+}

migrator.go

@@ -9,6 +9,11 @@ func (db *DB) Migrator() Migrator {
 	return db.Dialector.Migrator(db)
 }
 
+// AutoMigrate run auto migration for given models
+func (db *DB) AutoMigrate(dst ...interface{}) error {
+	return db.Migrator().AutoMigrate(dst...)
+}
+
 // ViewOption view option
 type ViewOption struct {
 	Replace     bool

scan.go

@@ -71,20 +71,27 @@ func Scan(rows *sql.Rows, db *DB, initialized bool) {
 	default:
 		switch db.Statement.ReflectValue.Kind() {
 		case reflect.Slice, reflect.Array:
-			reflectValueType := db.Statement.ReflectValue.Type().Elem()
-			isPtr := reflectValueType.Kind() == reflect.Ptr
+			var (
+				reflectValueType = db.Statement.ReflectValue.Type().Elem()
+				isPtr            = reflectValueType.Kind() == reflect.Ptr
+				fields           = make([]*schema.Field, len(columns))
+				joinFields       [][2]*schema.Field
+			)
+
 			if isPtr {
 				reflectValueType = reflectValueType.Elem()
 			}
 
 			db.Statement.ReflectValue.Set(reflect.MakeSlice(db.Statement.ReflectValue.Type(), 0, 0))
-			fields := make([]*schema.Field, len(columns))
-			joinFields := make([][2]*schema.Field, len(columns))
 
 			for idx, column := range columns {
 				if field := db.Statement.Schema.LookUpField(column); field != nil && field.Readable {
 					fields[idx] = field
 				} else if names := strings.Split(column, "__"); len(names) > 1 {
+					if len(joinFields) == 0 {
+						joinFields = make([][2]*schema.Field, len(columns))
+					}
+
 					if rel, ok := db.Statement.Schema.Relationships.Relations[names[0]]; ok {
 						if field := rel.FieldSchema.LookUpField(strings.Join(names[1:], "__")); field != nil && field.Readable {
 							fields[idx] = field
@@ -98,26 +105,26 @@ func Scan(rows *sql.Rows, db *DB, initialized bool) {
 				}
 			}
 
+			// pluck values into slice of data
+			isPluck := len(fields) == 1 && reflectValueType.Kind() != reflect.Struct
 			for initialized || rows.Next() {
 				initialized = false
 				db.RowsAffected++
 
 				elem := reflect.New(reflectValueType).Elem()
-				if reflectValueType.Kind() != reflect.Struct && len(fields) == 1 {
-					// pluck
-					values[0] = elem.Addr().Interface()
-					db.AddError(rows.Scan(values...))
+				if isPluck {
+					db.AddError(rows.Scan(elem.Addr().Interface()))
 				} else {
 					for idx, field := range fields {
 						if field != nil {
-							values[idx] = reflect.New(reflect.PtrTo(field.FieldType)).Interface()
+							values[idx] = reflect.New(reflect.PtrTo(field.IndirectFieldType)).Interface()
 						}
 					}
 
 					db.AddError(rows.Scan(values...))
 
 					for idx, field := range fields {
-						if joinFields[idx][0] != nil {
+						if len(joinFields) != 0 && joinFields[idx][0] != nil {
 							value := reflect.ValueOf(values[idx]).Elem()
 							relValue := joinFields[idx][0].ReflectValueOf(elem)
 
@@ -145,11 +152,11 @@ func Scan(rows *sql.Rows, db *DB, initialized bool) {
 			if initialized || rows.Next() {
 				for idx, column := range columns {
 					if field := db.Statement.Schema.LookUpField(column); field != nil && field.Readable {
-						values[idx] = reflect.New(reflect.PtrTo(field.FieldType)).Interface()
+						values[idx] = reflect.New(reflect.PtrTo(field.IndirectFieldType)).Interface()
 					} else if names := strings.Split(column, "__"); len(names) > 1 {
 						if rel, ok := db.Statement.Schema.Relationships.Relations[names[0]]; ok {
 							if field := rel.FieldSchema.LookUpField(strings.Join(names[1:], "__")); field != nil && field.Readable {
-								values[idx] = reflect.New(reflect.PtrTo(field.FieldType)).Interface()
+								values[idx] = reflect.New(reflect.PtrTo(field.IndirectFieldType)).Interface()
 								continue
 							}
 						}

statement.go

@@ -63,7 +63,7 @@ func (stmt *Statement) WriteQuoted(value interface{}) error {
 }
 
 // QuoteTo write quoted value to writer
-func (stmt Statement) QuoteTo(writer clause.Writer, field interface{}) {
+func (stmt *Statement) QuoteTo(writer clause.Writer, field interface{}) {
 	switch v := field.(type) {
 	case clause.Table:
 		if v.Name == clause.CurrentTable {
@@ -109,7 +109,7 @@ func (stmt Statement) QuoteTo(writer clause.Writer, field interface{}) {
 	case []string:
 		writer.WriteByte('(')
 		for idx, d := range v {
-			if idx != 0 {
+			if idx > 0 {
 				writer.WriteString(",")
 			}
 			stmt.DB.Dialector.QuoteTo(writer, d)
@@ -121,7 +121,7 @@ func (stmt Statement) QuoteTo(writer clause.Writer, field interface{}) {
 }
 
 // Quote returns quoted value
-func (stmt Statement) Quote(field interface{}) string {
+func (stmt *Statement) Quote(field interface{}) string {
 	var builder strings.Builder
 	stmt.QuoteTo(&builder, field)
 	return builder.String()
@@ -219,7 +219,7 @@ func (stmt *Statement) AddClauseIfNotExists(v clause.Interface) {
 }
 
 // BuildCondition build condition
-func (stmt Statement) BuildCondition(query interface{}, args ...interface{}) (conds []clause.Expression) {
+func (stmt *Statement) BuildCondition(query interface{}, args ...interface{}) (conds []clause.Expression) {
 	if sql, ok := query.(string); ok {
 		// if it is a number, then treats it as primary key
 		if _, err := strconv.Atoi(sql); err != nil {