Extract settings

FerretDB · rumyantseva · Oct 5, 2023 · Sep 26, 2023 · Sep 26, 2023 · Sep 26, 2023
commit f26890179dafabff3ecf393d64853ee79254b2e8
@@ -16,12 +16,11 @@
 package metadata
 
 import (
-	"errors"
-
-	"golang.org/x/exp/slices"
+	"database/sql"
+	"database/sql/driver"
 
+	"github.com/FerretDB/FerretDB/internal/handlers/sjson"
 	"github.com/FerretDB/FerretDB/internal/types"
-	"github.com/FerretDB/FerretDB/internal/util/iterator"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
 	"github.com/FerretDB/FerretDB/internal/util/must"
 )
@@ -57,151 +56,83 @@ func (c *Collection) deepCopy() *Collection {
 	}
 }
 
-// Marshal returns [*types.Document] for that collection.
-func (c *Collection) Marshal() *types.Document {
-	return must.NotFail(types.NewDocument(
-		"_id", c.Name,
-		"table", c.TableName,
-		"settings", c.Settings.Marshal(),
-	))
-}
-
-// Unmarshal sets collection metadata from [*types.Document].
-func (c *Collection) Unmarshal(doc *types.Document) error {
-	c.Name = must.NotFail(doc.Get("_id")).(string)
-	c.TableName = must.NotFail(doc.Get("table")).(string)
-
-	var settings Settings
-	must.NoError(settings.Unmarshal(must.NotFail(doc.Get("settings")).(*types.Document)))
-	c.Settings = settings
-
-	return nil
-}
+// Value implements driver.Valuer interface.
+func (c Collection) Value() (driver.Value, error) {
+	b, err := sjson.Marshal(c.marshal())
+	if err != nil {
+		return nil, lazyerrors.Error(err)
+	}
 
-// Settings represents collection settings.
-type Settings struct {
-	Indexes []IndexInfo `json:"indexes"`
+	return b, nil
 }
 
-// deepCopy returns a deep copy.
-func (s Settings) deepCopy() Settings {
-	indexes := make([]IndexInfo, len(s.Indexes))
-
-	for i, index := range s.Indexes {
-		indexes[i] = IndexInfo{
-			Name:           index.Name,
-			TableIndexName: index.TableIndexName,
-			Key:            slices.Clone(index.Key),
-			Unique:         index.Unique,
-		}
+// Scan implements sql.Scanner interface.
+func (c *Collection) Scan(src any) error {
+	var doc *types.Document
+	var err error
+	switch src := src.(type) {
+	case nil:
+		*c = Collection{}
+		return nil
+	case []byte:
+		doc, err = sjson.Unmarshal(src)
+	case string:
+		doc, err = sjson.Unmarshal([]byte(src))
+	default:
+		panic("can't scan collection")
 	}
 
-	return Settings{
-		Indexes: indexes,
+	if err != nil {
+		return lazyerrors.Error(err)
 	}
-}
-
-// Marshal returns [*types.Document] for settings.
-func (s Settings) Marshal() *types.Document {
-	indexes := types.MakeArray(len(s.Indexes))
 
-	for _, index := range s.Indexes {
-		key := types.MakeDocument(len(index.Key))
-
-		// The format of the index key storing was defined in the early versions of FerretDB,
-		// it's kept for backward compatibility.
-		for _, pair := range index.Key {
-			order := int32(1) // order is set as int32 to be sjson-marshaled correctly
-
-			if pair.Descending {
-				order = -1
-			}
-
-			key.Set(pair.Field, order)
-		}
-
-		indexes.Append(must.NotFail(types.NewDocument(
-			"pgindex", index.TableIndexName,
-			"name", index.Name,
-			"key", key,
-			"unique", index.Unique,
-		)))
+	if err = c.unmarshal(doc); err != nil {
+		return lazyerrors.Error(err)
 	}
 
+	return nil
+}
+
+// marshal returns [*types.Document] for that collection.
+func (c *Collection) marshal() *types.Document {
 	return must.NotFail(types.NewDocument(
-		"indexes", indexes,
+		"_id", c.Name,
+		"table", c.TableName,
+		"settings", c.Settings.marshal(),
 	))
 }
 
-// Unmarshal sets settings from [*types.Document].
-func (s *Settings) Unmarshal(doc *types.Document) error {
-	indexes := must.NotFail(doc.Get("indexes")).(*types.Array)
-
-	s.Indexes = make([]IndexInfo, indexes.Len())
-
-	iter := indexes.Iterator()
-	defer iter.Close()
-
-	for {
-		i, v, err := iter.Next()
-		if errors.Is(err, iterator.ErrIteratorDone) {
-			break
-		}
-
-		if err != nil {
-			return lazyerrors.Error(err)
-		}
-
-		doc := v.(*types.Document)
-
-		keyDoc := must.NotFail(doc.Get("key")).(*types.Document)
-		keyIter := keyDoc.Iterator()
-		key := make([]IndexKeyPair, keyDoc.Len())
-
-		defer keyIter.Close()
-
-		for j := 0; ; j++ {
-			field, order, err := keyIter.Next()
-			if errors.Is(err, iterator.ErrIteratorDone) {
-				break
-			}
+// unmarshal sets collection metadata from [*types.Document].
+func (c *Collection) unmarshal(doc *types.Document) error {
+	v, _ := doc.Get("_id")
+	c.Name, _ = v.(string)
+	if c.Name == "" {
+		return lazyerrors.New("collection name is empty")
+	}
 
-			if err != nil {
-				return lazyerrors.Error(err)
-			}
+	v, _ = doc.Get("table")
+	c.TableName, _ = v.(string)
+	if c.TableName == "" {
+		return lazyerrors.New("table name is empty")
+	}
 
-			descending := false
-			if order.(int32) == -1 {
-				descending = true
-			}
+	v, _ = doc.Get("settings")
+	s, _ := v.(*types.Document)
+	if s == nil {
+		return lazyerrors.New("settings are empty")
+	}
 
-			key[j] = IndexKeyPair{
-				Field:      field,
-				Descending: descending,
-			}
-		}
+	c.Settings.unmarshal(doc)
 
-		s.Indexes[i] = IndexInfo{
-			Name:           must.NotFail(doc.Get("name")).(string),
-			TableIndexName: must.NotFail(doc.Get("pgindex")).(string),
-			Key:            key,
-			Unique:         must.NotFail(doc.Get("unique")).(bool),
-		}
-	}
+	var settings Settings
+	must.NoError(settings.unmarshal(must.NotFail(doc.Get("settings")).(*types.Document)))
+	c.Settings = settings
 
 	return nil
 }
 
-// IndexInfo represents information about a single index.
-type IndexInfo struct {
-	Name           string
-	TableIndexName string // how the index is created in the DB, like TableName for Collection
-	Key            []IndexKeyPair
-	Unique         bool
-}
-
-// IndexKeyPair consists of a field name and a sort order that are part of the index.
-type IndexKeyPair struct {
-	Field      string
-	Descending bool
-}
+// check interfaces
+var (
+	_ driver.Valuer = Collection{}
+	_ sql.Scanner   = (*Collection)(nil)
+)
@@ -34,7 +34,6 @@ import (
 	"github.com/FerretDB/FerretDB/internal/backends/postgresql/metadata/pool"
 	"github.com/FerretDB/FerretDB/internal/clientconn/conninfo"
 	"github.com/FerretDB/FerretDB/internal/handlers/sjson"
-	"github.com/FerretDB/FerretDB/internal/types"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
 	"github.com/FerretDB/FerretDB/internal/util/must"
 	"github.com/FerretDB/FerretDB/internal/util/observability"
@@ -221,19 +220,8 @@ func (r *Registry) initCollections(ctx context.Context, dbName string, p *pgxpoo
 	colls := map[string]*Collection{}
 
 	for rows.Next() {
-		var b []byte
-		if err = rows.Scan(&b); err != nil {
-			return lazyerrors.Error(err)
-		}
-
-		var doc *types.Document
-
-		if doc, err = sjson.Unmarshal(b); err != nil {
-			return lazyerrors.Error(err)
-		}
-
 		var c Collection
-		if err = c.Unmarshal(doc); err != nil {
+		if err = rows.Scan(&c); err != nil {
 			return lazyerrors.Error(err)
 		}
 
@@ -525,17 +513,11 @@ func (r *Registry) collectionCreate(ctx context.Context, p *pgxpool.Pool, dbName
 		TableName: tableName,
 	}
 
-	b, err := sjson.Marshal(c.Marshal())
-	if err != nil {
-		return false, lazyerrors.Error(err)
-	}
-
 	q := fmt.Sprintf(
 		`CREATE TABLE %s (%s jsonb)`,
 		pgx.Identifier{dbName, tableName}.Sanitize(),
 		DefaultColumn,
 	)
-
 	if _, err = p.Exec(ctx, q); err != nil {
 		return false, lazyerrors.Error(err)
 	}
@@ -545,8 +527,7 @@ func (r *Registry) collectionCreate(ctx context.Context, p *pgxpool.Pool, dbName
 		pgx.Identifier{dbName, metadataTableName}.Sanitize(),
 		DefaultColumn,
 	)
-
-	if _, err = p.Exec(ctx, q, string(b)); err != nil {
+	if _, err = p.Exec(ctx, q, c); err != nil {
 		q = fmt.Sprintf(`DROP TABLE %s`, pgx.Identifier{dbName, tableName}.Sanitize())
 		_, _ = p.Exec(ctx, q)
 
@@ -558,15 +539,11 @@ func (r *Registry) collectionCreate(ctx context.Context, p *pgxpool.Pool, dbName
 	}
 	r.colls[dbName][collectionName] = c
 
-	err = r.indexesCreate(ctx, p, dbName, collectionName,
-		[]IndexInfo{
-			{
-				Name:   "_id_",
-				Key:    []IndexKeyPair{{Field: "_id"}},
-				Unique: true,
-			},
-		},
-	)
+	err = r.indexesCreate(ctx, p, dbName, collectionName, []IndexInfo{{
+		Name:   "_id_",
+		Key:    []IndexKeyPair{{Field: "_id"}},
+		Unique: true,
+	}})
 	if err != nil {
 		_, _ = r.collectionDrop(ctx, p, dbName, collectionName)
 		return false, lazyerrors.Error(err)
@@ -710,7 +687,7 @@ func (r *Registry) CollectionRename(ctx context.Context, dbName, oldCollectionNa
 
 	c.Name = newCollectionName
 
-	b, err := sjson.Marshal(c.Marshal())
+	b, err := sjson.Marshal(c.marshal())
 	if err != nil {
 		return false, lazyerrors.Error(err)
 	}
@@ -795,7 +772,7 @@ func (r *Registry) indexesCreate(ctx context.Context, p *pgxpool.Pool, dbName, c
 			tableNamePart = tableNamePart[:tableNamePartMax]
 		}
 
-		index.TableIndexName = fmt.Sprintf("%s_%s_idx", tableNamePart, uuidPart)
+		index.PgName = fmt.Sprintf("%s_%s_idx", tableNamePart, uuidPart)
 
 		q := "CREATE "
 
@@ -825,7 +802,7 @@ func (r *Registry) indexesCreate(ctx context.Context, p *pgxpool.Pool, dbName, c
 
 		q = fmt.Sprintf(
 			q,
-			pgx.Identifier{index.TableIndexName}.Sanitize(),
+			pgx.Identifier{index.PgName}.Sanitize(),
 			pgx.Identifier{dbName, c.TableName}.Sanitize(),
 			strings.Join(columns, ", "),
 		)
@@ -839,7 +816,7 @@ func (r *Registry) indexesCreate(ctx context.Context, p *pgxpool.Pool, dbName, c
 		c.Settings.Indexes = append(c.Settings.Indexes, index)
 	}
 
-	b, err := sjson.Marshal(c.Marshal())
+	b, err := sjson.Marshal(c.marshal())
 	if err != nil {
 		return lazyerrors.Error(err)
 	}
@@ -907,15 +884,15 @@ func (r *Registry) indexesDrop(ctx context.Context, p *pgxpool.Pool, dbName, col
 			continue
 		}
 
-		q := fmt.Sprintf("DROP INDEX %s", pgx.Identifier{dbName, c.Settings.Indexes[i].TableIndexName}.Sanitize())
+		q := fmt.Sprintf("DROP INDEX %s", pgx.Identifier{dbName, c.Settings.Indexes[i].PgName}.Sanitize())
 		if _, err := p.Exec(ctx, q); err != nil {
 			return lazyerrors.Error(err)
 		}
 
 		c.Settings.Indexes = slices.Delete(c.Settings.Indexes, i, i+1)
 	}
 
-	b, err := sjson.Marshal(c.Marshal())
+	b, err := sjson.Marshal(c.marshal())
 	if err != nil {
 		return lazyerrors.Error(err)
 	}

@@ -512,7 +512,7 @@ func TestIndexesCreateDrop(t *testing.T) {
 			return ii.Name == "index_non_unique"
 		})
 		require.GreaterOrEqual(t, i, 0)
-		tableIndexName := collection.Settings.Indexes[i].TableIndexName
+		tableIndexName := collection.Settings.Indexes[i].PgName
 
 		var sql string
 		err = db.QueryRow(
@@ -534,7 +534,7 @@ func TestIndexesCreateDrop(t *testing.T) {
 			return ii.Name == "index_unique"
 		})
 		require.GreaterOrEqual(t, i, 0)
-		tableIndexName := collection.Settings.Indexes[i].TableIndexName
+		tableIndexName := collection.Settings.Indexes[i].PgName
 
 		var sql string
 		err = db.QueryRow(
@@ -556,7 +556,7 @@ func TestIndexesCreateDrop(t *testing.T) {
 			return ii.Name == "nested_fields"
 		})
 		require.GreaterOrEqual(t, i, 0)
-		tableIndexName := collection.Settings.Indexes[i].TableIndexName
+		tableIndexName := collection.Settings.Indexes[i].PgName
 
 		var sql string
 		err = db.QueryRow(
@@ -579,7 +579,7 @@ func TestIndexesCreateDrop(t *testing.T) {
 			return ii.Name == "_id_"
 		})
 		require.GreaterOrEqual(t, i, 0)
-		tableIndexName := collection.Settings.Indexes[i].TableIndexName
+		tableIndexName := collection.Settings.Indexes[i].PgName
 
 		var sql string
 		err = db.QueryRow(