Support sqlite in addition to postgres (#869)

* Move current work into single branch

* Initial massaging of clientapi etc (not working yet)

* Interfaces for accounts/devices databases

* Duplicate postgres package for sqlite3 (no changes made to it yet)

* Some keydb, accountdb, devicedb, common partition fixes, some more syncapi tweaking

* Fix accounts DB, device DB

* Update naffka dependency for SQLite

* Naffka SQLite

* Update naffka to latest master

* SQLite support for federationsender

* Mostly not-bad support for SQLite in syncapi (although there are problems where lots of events get classed incorrectly as backward extremities, probably because of IN/ANY clauses that are badly supported)

* Update Dockerfile -> Go 1.13.7, add build-base (as gcc and friends are needed for SQLite)

* Implement GET endpoints for account_data in clientapi

* Nuke filtering for now...

* Revert "Implement GET endpoints for account_data in clientapi"

This reverts commit 4d80dff4583d278620d9b3ed437e9fcd8d4674ee.

* Implement GET endpoints for account_data in clientapi (#861)

* Implement GET endpoints for account_data in clientapi

* Fix accountDB parameter

* Remove fmt.Println

* Fix insertAccountData SQLite query

* Fix accountDB storage interfaces

* Add empty push rules into account data on account creation (#862)

* Put SaveAccountData into the right function this time

* Not sure if roomserver is better or worse now

* sqlite work

* Allow empty last sent ID for the first event

* sqlite: room creation works

* Support sending messages

* Nuke fmt.println

* Move QueryVariadic etc into common, other device fixes

* Fix some linter issues

* Fix bugs

* Fix some linting errors

* Fix errcheck lint errors

* Make naffka use postgres as fallback, fix couple of compile errors

* What on earth happened to the /rooms/{roomID}/send/{eventType} routing

Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>

roomserver/storage/sqlite3/event_json_table.go

@@ -0,0 +1,108 @@
+// Copyright 2017-2018 New Vector Ltd
+// Copyright 2019-2020 The Matrix.org Foundation C.I.C.
+//
+// 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 sqlite3
+
+import (
+	"context"
+	"database/sql"
+	"strings"
+
+	"github.com/matrix-org/dendrite/common"
+	"github.com/matrix-org/dendrite/roomserver/types"
+)
+
+const eventJSONSchema = `
+  CREATE TABLE IF NOT EXISTS roomserver_event_json (
+    event_nid INTEGER NOT NULL PRIMARY KEY,
+    event_json TEXT NOT NULL
+  );
+`
+
+const insertEventJSONSQL = `
+	INSERT INTO roomserver_event_json (event_nid, event_json) VALUES ($1, $2)
+	  ON CONFLICT DO NOTHING
+`
+
+// Bulk event JSON lookup by numeric event ID.
+// Sort by the numeric event ID.
+// This means that we can use binary search to lookup by numeric event ID.
+const bulkSelectEventJSONSQL = `
+	SELECT event_nid, event_json FROM roomserver_event_json
+	  WHERE event_nid IN ($1)
+	  ORDER BY event_nid ASC
+`
+
+type eventJSONStatements struct {
+	db                      *sql.DB
+	insertEventJSONStmt     *sql.Stmt
+	bulkSelectEventJSONStmt *sql.Stmt
+}
+
+func (s *eventJSONStatements) prepare(db *sql.DB) (err error) {
+	s.db = db
+	_, err = db.Exec(eventJSONSchema)
+	if err != nil {
+		return
+	}
+	return statementList{
+		{&s.insertEventJSONStmt, insertEventJSONSQL},
+		{&s.bulkSelectEventJSONStmt, bulkSelectEventJSONSQL},
+	}.prepare(db)
+}
+
+func (s *eventJSONStatements) insertEventJSON(
+	ctx context.Context, txn *sql.Tx, eventNID types.EventNID, eventJSON []byte,
+) error {
+	_, err := common.TxStmt(txn, s.insertEventJSONStmt).ExecContext(ctx, int64(eventNID), eventJSON)
+	return err
+}
+
+type eventJSONPair struct {
+	EventNID  types.EventNID
+	EventJSON []byte
+}
+
+func (s *eventJSONStatements) bulkSelectEventJSON(
+	ctx context.Context, txn *sql.Tx, eventNIDs []types.EventNID,
+) ([]eventJSONPair, error) {
+	iEventNIDs := make([]interface{}, len(eventNIDs))
+	for k, v := range eventNIDs {
+		iEventNIDs[k] = v
+	}
+	selectOrig := strings.Replace(bulkSelectEventJSONSQL, "($1)", common.QueryVariadic(len(iEventNIDs)), 1)
+
+	rows, err := txn.QueryContext(ctx, selectOrig, iEventNIDs...)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close() // nolint: errcheck
+
+	// We know that we will only get as many results as event NIDs
+	// because of the unique constraint on event NIDs.
+	// So we can allocate an array of the correct size now.
+	// We might get fewer results than NIDs so we adjust the length of the slice before returning it.
+	results := make([]eventJSONPair, len(eventNIDs))
+	i := 0
+	for ; rows.Next(); i++ {
+		result := &results[i]
+		var eventNID int64
+		if err := rows.Scan(&eventNID, &result.EventJSON); err != nil {
+			return nil, err
+		}
+		result.EventNID = types.EventNID(eventNID)
+	}
+	return results[:i], nil
+}