Add migrate

common/migrate/source/raw.go

@@ -0,0 +1,98 @@
+package source
+
+import (
+	"io"
+	"io/fs"
+	"io/ioutil"
+	"strconv"
+	"strings"
+
+	"github.com/golang-migrate/migrate/v4/source"
+	E "github.com/sagernet/sing/common/exceptions"
+)
+
+type RawDriver struct {
+	migrations    *source.Migrations
+	rawMigrations map[string]string
+}
+
+func NewRawDriver(rawMigrations map[string]string) *RawDriver {
+	return &RawDriver{rawMigrations: rawMigrations}
+}
+
+func (d *RawDriver) Init() error {
+	ms := source.NewMigrations()
+	for key := range d.rawMigrations {
+		m, err := source.DefaultParse(key)
+		if err != nil {
+			continue
+		}
+		if !ms.Append(m) {
+			return source.ErrDuplicateMigration{
+				Migration: *m,
+			}
+		}
+	}
+	d.migrations = ms
+	return nil
+}
+
+func (d *RawDriver) Open(url string) (source.Driver, error) {
+	return nil, E.New("open() cannot be called")
+}
+
+func (d *RawDriver) Close() error {
+	return nil
+}
+
+func (d *RawDriver) First() (version uint, err error) {
+	if version, ok := d.migrations.First(); ok {
+		return version, nil
+	}
+	return 0, &fs.PathError{
+		Op:  "first",
+		Err: fs.ErrNotExist,
+	}
+}
+
+func (d *RawDriver) Prev(version uint) (prevVersion uint, err error) {
+	if version, ok := d.migrations.Prev(version); ok {
+		return version, nil
+	}
+	return 0, &fs.PathError{
+		Op:  "prev for version " + strconv.FormatUint(uint64(version), 10),
+		Err: fs.ErrNotExist,
+	}
+}
+
+func (d *RawDriver) Next(version uint) (nextVersion uint, err error) {
+	if version, ok := d.migrations.Next(version); ok {
+		return version, nil
+	}
+	return 0, &fs.PathError{
+		Op:  "next for version " + strconv.FormatUint(uint64(version), 10),
+		Err: fs.ErrNotExist,
+	}
+}
+
+func (d *RawDriver) ReadUp(version uint) (r io.ReadCloser, identifier string, err error) {
+	if m, ok := d.migrations.Up(version); ok {
+		body := ioutil.NopCloser(strings.NewReader(d.rawMigrations[m.Raw]))
+		return body, m.Identifier, nil
+	}
+	return nil, "", &fs.PathError{
+		Op:  "read up for version " + strconv.FormatUint(uint64(version), 10),
+		Err: fs.ErrNotExist,
+	}
+}
+
+func (d *RawDriver) ReadDown(version uint) (r io.ReadCloser, identifier string, err error) {
+	if m, ok := d.migrations.Down(version); ok {
+		body := ioutil.NopCloser(strings.NewReader(d.rawMigrations[m.Raw]))
+		return body, m.Identifier, nil
+	}
+	return nil, "", &fs.PathError{
+		Op:  "read down for version " + strconv.FormatUint(uint64(version), 10),
+		Err: fs.ErrNotExist,
+	}
+}