WIP

FerretDB · AlekSi · May 18, 2023 · May 16, 2023 · May 16, 2023 · May 16, 2023
commit 0c8d1f8d6cc0945efc94f1b1417e9813f1653e4e
@@ -36,7 +36,6 @@ type NewBackendParams struct {
 
 // NewBackend creates a new SQLite backend.
 func NewBackend(params *NewBackendParams) (backends.Backend, error) {
-	// TODO: we should close it when backend is closed.
 	pool := newConnPool()
 
 	storage, err := newMetadataStorage(params.Dir, pool)
@@ -53,14 +52,24 @@ func NewBackend(params *NewBackendParams) (backends.Backend, error) {
 
 // Database implements backends.Backend interface.
 func (b *backend) Database(ctx context.Context, params *backends.DatabaseParams) backends.Database {
-	return newDatabase(b)
+	return newDatabase(params.Name, b)
 }
 
 // ListDatabases implements backends.Backend interface.
 //
 //nolint:lll // for readability
 func (b *backend) ListDatabases(ctx context.Context, params *backends.ListDatabasesParams) (*backends.ListDatabasesResult, error) {
-	panic("not implemented") // TODO: Implement
+	list, err := b.metadataStorage.ListDatabases()
+	if err != nil {
+		return nil, err
+	}
+
+	var result backends.ListDatabasesResult
+	for _, db := range list {
+		result.Databases = append(result.Databases, backends.DatabaseInfo{Name: db})
+	}
+
+	return &result, nil
 }
 
 // DropDatabase implements backends.Backend interface.

@@ -22,13 +22,16 @@ import (
 
 // database implements backends.Database interface.
 type database struct {
+	name string
+
 	b *backend
 }
 
 // newDatabase creates a new Database.
-func newDatabase(b *backend) backends.Database {
+func newDatabase(name string, b *backend) backends.Database {
 	return backends.DatabaseContract(&database{
-		b: b,
+		b:    b,
+		name: name,
 	})
 }
 
@@ -41,7 +44,20 @@ func (db *database) Collection(params *backends.CollectionParams) backends.Colle
 //
 //nolint:lll // for readability
 func (db *database) ListCollections(ctx context.Context, params *backends.ListCollectionsParams) (*backends.ListCollectionsResult, error) {
-	panic("not implemented") // TODO: Implement
+	list, err := db.b.metadataStorage.ListCollections(ctx, db.name)
+	if err != nil {
+		return nil, err
+	}
+
+	var result backends.ListCollectionsResult
+
+	for _, name := range list {
+		result.Collections = append(result.Collections, backends.CollectionInfo{
+			Name: name,
+		})
+	}
+
+	return &result, nil
 }
 
 // CreateCollection implements backends.Database interface.

@@ -223,7 +223,7 @@ func (m *metadataStorage) load(ctx context.Context, dbName string) (*dbInfo, err
 	// TODO: check error
 	defer result.Close()
 
-	var metadata = dbInfo{
+	metadata := dbInfo{
 		collections: map[string]string{},
 	}
 

@@ -18,20 +18,29 @@ import (
 	"database/sql"
 	"errors"
 	"sync"
+
+	"github.com/FerretDB/FerretDB/internal/util/resource"
 )
 
 // newConnPool creates a new connection pool.
 func newConnPool() *connPool {
-	return &connPool{
-		mx:  sync.Mutex{},
-		dbs: map[string]*sql.DB{},
+	pool := &connPool{
+		mx:    sync.Mutex{},
+		dbs:   map[string]*sql.DB{},
+		token: resource.NewToken(),
 	}
+
+	resource.Track(pool, pool.token)
+
+	return pool
 }
 
 // connPool is a pool of database connections.
-type connPool struct {
-	dbs map[string]*sql.DB
+type connPool struct { //nolint:vet // for readability
 	mx  sync.Mutex
+	dbs map[string]*sql.DB
+
+	token *resource.Token
 }
 
 // DB returns a database connection for the given name.
@@ -66,5 +75,7 @@ func (c *connPool) Close() error {
 		}
 	}
 
+	resource.Untrack(c, c.token)
+
 	return errs
 }
diff --git a/internal/handlers/sqlite/cmd_query.go b/internal/handlers/sqlite/cmd_query.go
@@ -16,11 +16,47 @@ package sqlite
 
 import (
 	"context"
+	"fmt"
+	"time"
 
+	"github.com/FerretDB/FerretDB/internal/handlers/common"
+	"github.com/FerretDB/FerretDB/internal/handlers/commonerrors"
+	"github.com/FerretDB/FerretDB/internal/types"
+	"github.com/FerretDB/FerretDB/internal/util/must"
 	"github.com/FerretDB/FerretDB/internal/wire"
 )
 
 // CmdQuery implements HandlerInterface.
 func (h *Handler) CmdQuery(ctx context.Context, query *wire.OpQuery) (*wire.OpReply, error) {
-	return nil, notImplemented(query.Query.Command())
+	if query.FullCollectionName == "admin.$cmd" {
+		switch cmd := query.Query.Command(); cmd {
+		case "ismaster", "isMaster": // both are valid
+			reply := &wire.OpReply{
+				NumberReturned: 1,
+				Documents: []*types.Document{must.NotFail(types.NewDocument(
+					"ismaster", true, // only lowercase
+					// topologyVersion
+					"maxBsonObjectSize", int32(types.MaxDocumentLen),
+					"maxMessageSizeBytes", int32(wire.MaxMsgLen),
+					"maxWriteBatchSize", int32(100000),
+					"localTime", time.Now(),
+					// logicalSessionTimeoutMinutes
+					"connectionId", int32(42),
+					"minWireVersion", common.MinWireVersion,
+					"maxWireVersion", common.MaxWireVersion,
+					"readOnly", false,
+					"ok", float64(1),
+				))},
+			}
+			return reply, nil
+
+		default:
+			msg := fmt.Sprintf("CmdQuery: unhandled command %q", cmd)
+			return nil, commonerrors.NewCommandErrorMsg(commonerrors.ErrNotImplemented, msg)
+		}
+	}
+
+	msg := fmt.Sprintf("CmdQuery: unhandled collection %q", query.FullCollectionName)
+
+	return nil, commonerrors.NewCommandErrorMsg(commonerrors.ErrNotImplemented, msg)
 }
diff --git a/internal/handlers/sqlite/msg_ismaster.go b/internal/handlers/sqlite/msg_ismaster.go
@@ -16,12 +16,33 @@ package sqlite
 
 import (
 	"context"
+	"time"
 
+	"github.com/FerretDB/FerretDB/internal/handlers/common"
+	"github.com/FerretDB/FerretDB/internal/types"
 	"github.com/FerretDB/FerretDB/internal/util/must"
 	"github.com/FerretDB/FerretDB/internal/wire"
 )
 
 // MsgIsMaster implements HandlerInterface.
 func (h *Handler) MsgIsMaster(ctx context.Context, msg *wire.OpMsg) (*wire.OpMsg, error) {
-	return nil, notImplemented(must.NotFail(msg.Document()).Command())
+	var reply wire.OpMsg
+	must.NoError(reply.SetSections(wire.OpMsgSection{
+		Documents: []*types.Document{must.NotFail(types.NewDocument(
+			"ismaster", true, // only lowercase
+			// topologyVersion
+			"maxBsonObjectSize", int32(types.MaxDocumentLen),
+			"maxMessageSizeBytes", int32(wire.MaxMsgLen),
+			"maxWriteBatchSize", int32(100000),
+			"localTime", time.Now(),
+			// logicalSessionTimeoutMinutes
+			// connectionId
+			"minWireVersion", common.MinWireVersion,
+			"maxWireVersion", common.MaxWireVersion,
+			"readOnly", false,
+			"ok", float64(1),
+		))},
+	}))
+
+	return &reply, nil
 }
diff --git a/internal/handlers/sqlite/msg_listcollections.go b/internal/handlers/sqlite/msg_listcollections.go
@@ -17,11 +17,50 @@ package sqlite
 import (
 	"context"
 
+	"github.com/FerretDB/FerretDB/internal/backends"
+	"github.com/FerretDB/FerretDB/internal/handlers/common"
+	"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/wire"
 )
 
 // MsgListCollections implements HandlerInterface.
 func (h *Handler) MsgListCollections(ctx context.Context, msg *wire.OpMsg) (*wire.OpMsg, error) {
-	return nil, notImplemented(must.NotFail(msg.Document()).Command())
+	document, err := msg.Document()
+	if err != nil {
+		return nil, lazyerrors.Error(err)
+	}
+
+	db, err := common.GetRequiredParam[string](document, "$db")
+	if err != nil {
+		return nil, err
+	}
+
+	result, err := h.b.Database(ctx, &backends.DatabaseParams{Name: db}).ListCollections(ctx, nil)
+
+	collections := types.MakeArray(len(result.Collections))
+	for _, col := range result.Collections {
+		d := must.NotFail(types.NewDocument(
+			"name", col.Name,
+			"type", "collection",
+		))
+
+		collections.Append(d)
+	}
+
+	var reply wire.OpMsg
+
+	must.NoError(reply.SetSections(wire.OpMsgSection{
+		Documents: []*types.Document{must.NotFail(types.NewDocument(
+			"cursor", must.NotFail(types.NewDocument(
+				"id", int64(0),
+				"ns", db+".$cmd.listCollections",
+				"firstBatch", collections,
+			)),
+			"ok", float64(1),
+		))},
+	}))
+
+	return &reply, nil
 }
@@ -17,11 +17,40 @@ package sqlite
 import (
 	"context"
 
+	"github.com/FerretDB/FerretDB/internal/backends"
+	"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/wire"
 )
 
 // MsgListDatabases implements HandlerInterface.
 func (h *Handler) MsgListDatabases(ctx context.Context, msg *wire.OpMsg) (*wire.OpMsg, error) {
-	return nil, notImplemented(must.NotFail(msg.Document()).Command())
+	response, err := h.b.ListDatabases(ctx, &backends.ListDatabasesParams{})
+	if err != nil {
+		return nil, lazyerrors.Error(err)
+	}
+
+	databases := types.MakeArray(len(response.Databases))
+
+	for _, db := range response.Databases {
+		databases.Append(types.NewDocument(
+			"name", db.Name,
+			"sizeOnDisk", int64(0),
+			"empty", false,
+		))
+	}
+
+	var reply wire.OpMsg
+
+	must.NoError(reply.SetSections(wire.OpMsgSection{
+		Documents: []*types.Document{must.NotFail(types.NewDocument(
+			"databases", databases,
+			"totalSize", int64(0),
+			"totalSizeMb", int64(0),
+			"ok", float64(1),
+		))},
+	}))
+
+	return &reply, nil
 }