Add new pg backend stub

FerretDB · AlekSi · Aug 25, 2023 · Aug 25, 2023 · Aug 25, 2023 · Aug 25, 2023
commit 29347d781b9133a2f982d89786b8ca7cd3f68d51
diff --git a/internal/backends/pg/backend.go b/internal/backends/pg/backend.go
@@ -0,0 +1,70 @@
+// Copyright 2021 FerretDB Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pg
+
+import (
+	"context"
+
+	"github.com/prometheus/client_golang/prometheus"
+
+	"github.com/FerretDB/FerretDB/internal/backends"
+)
+
+// backend implements backends.Backend interface.
+type backend struct{}
+
+// NewBackendParams represents the parameters of NewBackend function.
+type NewBackendParams struct{}
+
+// NewBackend creates a new backend for PostgreSQL-compatible database.
+func NewBackend(params *NewBackendParams) (backends.Backend, error) {
+	return backends.BackendContract(&backend{}), nil
+}
+
+// Close implements backends.Backend interface.
+func (b *backend) Close() {
+}
+
+// Database implements backends.Backend interface.
+func (b *backend) Database(name string) (backends.Database, error) {
+	return newDatabase(name), nil
+}
+
+// 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")
+}
+
+// DropDatabase implements backends.Backend interface.
+func (b *backend) DropDatabase(ctx context.Context, params *backends.DropDatabaseParams) error {
+	panic("not implemented")
+}
+
+// Describe implements prometheus.Collector.
+func (b *backend) Describe(ch chan<- *prometheus.Desc) {
+	panic("not implemented")
+}
+
+// Collect implements prometheus.Collector.
+func (b *backend) Collect(ch chan<- prometheus.Metric) {
+	panic("not implemented")
+}
+
+// check interfaces
+var (
+	_ backends.Backend = (*backend)(nil)
+)
diff --git a/internal/backends/pg/collection.go b/internal/backends/pg/collection.go
@@ -0,0 +1,65 @@
+// Copyright 2021 FerretDB Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pg
+
+import (
+	"context"
+
+	"github.com/FerretDB/FerretDB/internal/backends"
+)
+
+// collection implements backends.Collection interface.
+type collection struct {
+	dbName string
+	name   string
+}
+
+// newCollection creates a new Collection.
+func newCollection(dbName, name string) backends.Collection {
+	return backends.CollectionContract(&collection{
+		dbName: dbName,
+		name:   name,
+	})
+}
+
+// Query implements backends.Collection interface.
+func (c *collection) Query(ctx context.Context, params *backends.QueryParams) (*backends.QueryResult, error) {
+	panic("not implemented")
+}
+
+// Insert implements backends.Collection interface.
+func (c *collection) Insert(ctx context.Context, params *backends.InsertParams) (*backends.InsertResult, error) {
+	panic("not implemented")
+}
+
+// Update implements backends.Collection interface.
+func (c *collection) Update(ctx context.Context, params *backends.UpdateParams) (*backends.UpdateResult, error) {
+	panic("not implemented")
+}
+
+// Delete implements backends.Collection interface.
+func (c *collection) Delete(ctx context.Context, params *backends.DeleteParams) (*backends.DeleteResult, error) {
+	panic("not implemented")
+}
+
+// Explain implements backends.Collection interface.
+func (c *collection) Explain(ctx context.Context, params *backends.ExplainParams) (*backends.ExplainResult, error) {
+	panic("not implemented")
+}
+
+// check interfaces
+var (
+	_ backends.Collection = (*collection)(nil)
+)
diff --git a/internal/backends/pg/database.go b/internal/backends/pg/database.go
@@ -0,0 +1,70 @@
+// Copyright 2021 FerretDB Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pg
+
+import (
+	"context"
+
+	"github.com/FerretDB/FerretDB/internal/backends"
+)
+
+// database implements backends.Database interface.
+type database struct {
+	name string
+}
+
+// newDatabase creates a new Database.
+func newDatabase(name string) backends.Database {
+	return backends.DatabaseContract(&database{
+		name: name,
+	})
+}
+
+// Close implements backends.Database interface.
+func (db *database) Close() {
+	// nothing
+}
+
+// Collection implements backends.Database interface.
+func (db *database) Collection(name string) (backends.Collection, error) {
+	return newCollection(db.name, name), nil
+}
+
+// ListCollections implements backends.Database interface.
+//
+//nolint:lll // for readability
+func (db *database) ListCollections(ctx context.Context, params *backends.ListCollectionsParams) (*backends.ListCollectionsResult, error) {
+	panic("not implemented")
+}
+
+// CreateCollection implements backends.Database interface.
+func (db *database) CreateCollection(ctx context.Context, params *backends.CreateCollectionParams) error {
+	panic("not implemented")
+}
+
+// DropCollection implements backends.Database interface.
+func (db *database) DropCollection(ctx context.Context, params *backends.DropCollectionParams) error {
+	panic("not implemented")
+}
+
+// RenameCollection implements backends.Database interface.
+func (db *database) RenameCollection(ctx context.Context, params *backends.RenameCollectionParams) error {
+	panic("not implemented")
+}
+
+// check interfaces
+var (
+	_ backends.Database = (*database)(nil)
+)
diff --git a/internal/backends/pg/doc.go b/internal/backends/pg/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2021 FerretDB Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package pg provides backend for PostgreSQL and compatible databases.
+package pg