1. 实现配置文件解析

2. 实现数据库连接

vendor/gorm.io/gorm/schema/serializer.go

@@ -0,0 +1,170 @@
+package schema
+
+import (
+	"bytes"
+	"context"
+	"database/sql"
+	"database/sql/driver"
+	"encoding/gob"
+	"encoding/json"
+	"fmt"
+	"reflect"
+	"strings"
+	"sync"
+	"time"
+)
+
+var serializerMap = sync.Map{}
+
+// RegisterSerializer register serializer
+func RegisterSerializer(name string, serializer SerializerInterface) {
+	serializerMap.Store(strings.ToLower(name), serializer)
+}
+
+// GetSerializer get serializer
+func GetSerializer(name string) (serializer SerializerInterface, ok bool) {
+	v, ok := serializerMap.Load(strings.ToLower(name))
+	if ok {
+		serializer, ok = v.(SerializerInterface)
+	}
+	return serializer, ok
+}
+
+func init() {
+	RegisterSerializer("json", JSONSerializer{})
+	RegisterSerializer("unixtime", UnixSecondSerializer{})
+	RegisterSerializer("gob", GobSerializer{})
+}
+
+// Serializer field value serializer
+type serializer struct {
+	Field           *Field
+	Serializer      SerializerInterface
+	SerializeValuer SerializerValuerInterface
+	Destination     reflect.Value
+	Context         context.Context
+	value           interface{}
+	fieldValue      interface{}
+}
+
+// Scan implements sql.Scanner interface
+func (s *serializer) Scan(value interface{}) error {
+	s.value = value
+	return nil
+}
+
+// Value implements driver.Valuer interface
+func (s serializer) Value() (driver.Value, error) {
+	return s.SerializeValuer.Value(s.Context, s.Field, s.Destination, s.fieldValue)
+}
+
+// SerializerInterface serializer interface
+type SerializerInterface interface {
+	Scan(ctx context.Context, field *Field, dst reflect.Value, dbValue interface{}) error
+	SerializerValuerInterface
+}
+
+// SerializerValuerInterface serializer valuer interface
+type SerializerValuerInterface interface {
+	Value(ctx context.Context, field *Field, dst reflect.Value, fieldValue interface{}) (interface{}, error)
+}
+
+// JSONSerializer json serializer
+type JSONSerializer struct{}
+
+// Scan implements serializer interface
+func (JSONSerializer) Scan(ctx context.Context, field *Field, dst reflect.Value, dbValue interface{}) (err error) {
+	fieldValue := reflect.New(field.FieldType)
+
+	if dbValue != nil {
+		var bytes []byte
+		switch v := dbValue.(type) {
+		case []byte:
+			bytes = v
+		case string:
+			bytes = []byte(v)
+		default:
+			return fmt.Errorf("failed to unmarshal JSONB value: %#v", dbValue)
+		}
+
+		if len(bytes) > 0 {
+			err = json.Unmarshal(bytes, fieldValue.Interface())
+		}
+	}
+
+	field.ReflectValueOf(ctx, dst).Set(fieldValue.Elem())
+	return
+}
+
+// Value implements serializer interface
+func (JSONSerializer) Value(ctx context.Context, field *Field, dst reflect.Value, fieldValue interface{}) (interface{}, error) {
+	result, err := json.Marshal(fieldValue)
+	if string(result) == "null" {
+		if field.TagSettings["NOT NULL"] != "" {
+			return "", nil
+		}
+		return nil, err
+	}
+	return string(result), err
+}
+
+// UnixSecondSerializer json serializer
+type UnixSecondSerializer struct{}
+
+// Scan implements serializer interface
+func (UnixSecondSerializer) Scan(ctx context.Context, field *Field, dst reflect.Value, dbValue interface{}) (err error) {
+	t := sql.NullTime{}
+	if err = t.Scan(dbValue); err == nil && t.Valid {
+		err = field.Set(ctx, dst, t.Time.Unix())
+	}
+
+	return
+}
+
+// Value implements serializer interface
+func (UnixSecondSerializer) Value(ctx context.Context, field *Field, dst reflect.Value, fieldValue interface{}) (result interface{}, err error) {
+	rv := reflect.ValueOf(fieldValue)
+	switch v := fieldValue.(type) {
+	case int64, int, uint, uint64, int32, uint32, int16, uint16:
+		result = time.Unix(reflect.Indirect(rv).Int(), 0)
+	case *int64, *int, *uint, *uint64, *int32, *uint32, *int16, *uint16:
+		if rv.IsZero() {
+			return nil, nil
+		}
+		result = time.Unix(reflect.Indirect(rv).Int(), 0)
+	default:
+		err = fmt.Errorf("invalid field type %#v for UnixSecondSerializer, only int, uint supported", v)
+	}
+	return
+}
+
+// GobSerializer gob serializer
+type GobSerializer struct{}
+
+// Scan implements serializer interface
+func (GobSerializer) Scan(ctx context.Context, field *Field, dst reflect.Value, dbValue interface{}) (err error) {
+	fieldValue := reflect.New(field.FieldType)
+
+	if dbValue != nil {
+		var bytesValue []byte
+		switch v := dbValue.(type) {
+		case []byte:
+			bytesValue = v
+		default:
+			return fmt.Errorf("failed to unmarshal gob value: %#v", dbValue)
+		}
+		if len(bytesValue) > 0 {
+			decoder := gob.NewDecoder(bytes.NewBuffer(bytesValue))
+			err = decoder.Decode(fieldValue.Interface())
+		}
+	}
+	field.ReflectValueOf(ctx, dst).Set(fieldValue.Elem())
+	return
+}
+
+// Value implements serializer interface
+func (GobSerializer) Value(ctx context.Context, field *Field, dst reflect.Value, fieldValue interface{}) (interface{}, error) {
+	buf := new(bytes.Buffer)
+	err := gob.NewEncoder(buf).Encode(fieldValue)
+	return buf.Bytes(), err
+}