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>

syncapi/storage/sqlite3/stream_id_table.go

@@ -0,0 +1,58 @@
+package sqlite3
+
+import (
+	"context"
+	"database/sql"
+
+	"github.com/matrix-org/dendrite/common"
+	"github.com/matrix-org/dendrite/syncapi/types"
+)
+
+const streamIDTableSchema = `
+-- Global stream ID counter, used by other tables.
+CREATE TABLE IF NOT EXISTS syncapi_stream_id (
+  stream_name TEXT NOT NULL PRIMARY KEY,
+  stream_id INT DEFAULT 0,
+
+  UNIQUE(stream_name)
+);
+INSERT INTO syncapi_stream_id (stream_name, stream_id) VALUES ("global", 0)
+  ON CONFLICT DO NOTHING;
+`
+
+const increaseStreamIDStmt = "" +
+	"UPDATE syncapi_stream_id SET stream_id = stream_id + 1 WHERE stream_name = $1"
+
+const selectStreamIDStmt = "" +
+	"SELECT stream_id FROM syncapi_stream_id WHERE stream_name = $1"
+
+type streamIDStatements struct {
+	increaseStreamIDStmt *sql.Stmt
+	selectStreamIDStmt   *sql.Stmt
+}
+
+func (s *streamIDStatements) prepare(db *sql.DB) (err error) {
+	_, err = db.Exec(streamIDTableSchema)
+	if err != nil {
+		return
+	}
+	if s.increaseStreamIDStmt, err = db.Prepare(increaseStreamIDStmt); err != nil {
+		return
+	}
+	if s.selectStreamIDStmt, err = db.Prepare(selectStreamIDStmt); err != nil {
+		return
+	}
+	return
+}
+
+func (s *streamIDStatements) nextStreamID(ctx context.Context, txn *sql.Tx) (pos types.StreamPosition, err error) {
+	increaseStmt := common.TxStmt(txn, s.increaseStreamIDStmt)
+	selectStmt := common.TxStmt(txn, s.selectStreamIDStmt)
+	if _, err = increaseStmt.ExecContext(ctx, "global"); err != nil {
+		return
+	}
+	if err = selectStmt.QueryRowContext(ctx, "global").Scan(&pos); err != nil {
+		return
+	}
+	return
+}