[feat] utilize system's libsqlite3HEADtrunknext

Add support for using the system's libsqlite3 library by adding a driver
using "github.com/mattn/go-sqlite3".

6 files changed, 248 insertions, 2 deletions

diff --git a/go.mod b/go.mod
index 1dff4fe44..29fc2717e 100644
--- a/go.mod
+++ b/go.mod
@@ -44,6 +44,7 @@ require (
 	github.com/gorilla/websocket v1.5.3
 	github.com/jackc/pgx/v5 v5.7.2
 	github.com/k3a/html2text v1.2.1
+	github.com/mattn/go-sqlite3 v1.14.24
 	github.com/microcosm-cc/bluemonday v1.0.27
 	github.com/miekg/dns v1.1.63
 	github.com/minio/minio-go/v7 v7.0.85
diff --git a/go.sum b/go.sum
index d1713cceb..fde798506 100644
--- a/go.sum
+++ b/go.sum
@@ -397,6 +397,8 @@ github.com/mattn/go-colorable v0.1.7/go.mod h1:u6P/XSegPjTcexA+o6vUJrdnUu04hMope
 github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
 github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
 github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
+github.com/mattn/go-sqlite3 v1.14.24 h1:tpSp2G2KyMnnQu99ngJ47EIkWVmliIizyZBfPrBWDRM=
+github.com/mattn/go-sqlite3 v1.14.24/go.mod h1:Uh1q+B4BYcTPb+yiD3kU8Ct7aC0hY9fxUwlHK0RXw+Y=
 github.com/microcosm-cc/bluemonday v1.0.27 h1:MpEUotklkwCSLeH+Qdx1VJgNqLlpY2KXwXFM08ygZfk=
 github.com/microcosm-cc/bluemonday v1.0.27/go.mod h1:jFi9vgW+H7c3V0lb6nR74Ib/DIB5OBs92Dimizgw2cA=
 github.com/miekg/dns v1.1.63 h1:8M5aAw6OMZfFXTT7K5V0Eu5YiiL8l7nUAkyN6C9YwaY=
diff --git a/internal/db/sqlite/driver.go b/internal/db/sqlite/driver.go
index 203edaff3..e659d1ffa 100644
--- a/internal/db/sqlite/driver.go
+++ b/internal/db/sqlite/driver.go
@@ -15,7 +15,7 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-//go:build !moderncsqlite3 && !nowasm
+//go:build !moderncsqlite3 && !nowasm && !libsqlite3
 
 package sqlite
 
diff --git a/internal/db/sqlite/driver_libsqlite3.go b/internal/db/sqlite/driver_libsqlite3.go
new file mode 100644
index 000000000..fe9df7aac
--- /dev/null
+++ b/internal/db/sqlite/driver_libsqlite3.go
@@ -0,0 +1,183 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+//go:build !moderncsqlite3 && !nowasm && libsqlite3
+
+package sqlite
+
+import (
+	"context"
+	"database/sql/driver"
+
+	sqlite3 "github.com/mattn/go-sqlite3"
+	"github.com/superseriousbusiness/gotosocial/internal/db"
+)
+
+// Driver is our own wrapper around the
+// driver.SQLite{} type in order to wrap
+// further SQL types with our own
+// functionality, e.g. err processing.
+type Driver struct{ sqlite3.SQLiteDriver }
+
+func (d *Driver) Open(name string) (driver.Conn, error) {
+	conn, err := d.SQLiteDriver.Open(name)
+	if err != nil {
+		err = processSQLiteError(err)
+		return nil, err
+	}
+
+	return &sqliteConn{conn.(connIface)}, nil
+}
+
+type sqliteConn struct{ connIface }
+
+func (c *sqliteConn) Begin() (driver.Tx, error) {
+	return c.BeginTx(context.Background(), driver.TxOptions{})
+}
+
+func (c *sqliteConn) BeginTx(ctx context.Context, opts driver.TxOptions) (tx driver.Tx, err error) {
+	tx, err = c.connIface.BeginTx(ctx, opts)
+	err = processSQLiteError(err)
+	if err != nil {
+		return nil, err
+	}
+	return &sqliteTx{tx}, nil
+}
+
+func (c *sqliteConn) Prepare(query string) (driver.Stmt, error) {
+	return c.PrepareContext(context.Background(), query)
+}
+
+func (c *sqliteConn) PrepareContext(ctx context.Context, query string) (stmt driver.Stmt, err error) {
+	stmt, err = c.connIface.PrepareContext(ctx, query)
+	err = processSQLiteError(err)
+	if err != nil {
+		return nil, err
+	}
+
+	return &sqliteStmt{stmtIface: stmt.(stmtIface)}, nil
+}
+
+func (c *sqliteConn) Exec(query string, args []driver.Value) (driver.Result, error) {
+	return c.ExecContext(context.Background(), query, db.ToNamedValues(args))
+}
+
+func (c *sqliteConn) ExecContext(ctx context.Context, query string, args []driver.NamedValue) (res driver.Result, err error) {
+	res, err = c.connIface.ExecContext(ctx, query, args)
+	err = processSQLiteError(err)
+	return
+}
+
+func (c *sqliteConn) Close() (err error) {
+	// see: https://www.sqlite.org/pragma.html#pragma_optimize
+	const onClose = "PRAGMA optimize;"
+	_, _ = c.connIface.ExecContext(context.Background(), onClose, nil)
+
+	// Finally, close the conn.
+	err = c.connIface.Close()
+	return
+}
+
+type sqliteTx struct{ driver.Tx }
+
+func (tx *sqliteTx) Commit() (err error) {
+	err = tx.Tx.Commit()
+	err = processSQLiteError(err)
+	return
+}
+
+func (tx *sqliteTx) Rollback() (err error) {
+	err = tx.Tx.Rollback()
+	err = processSQLiteError(err)
+	return
+}
+
+type sqliteStmt struct{ stmtIface }
+
+func (stmt *sqliteStmt) Exec(args []driver.Value) (driver.Result, error) {
+	return stmt.ExecContext(context.Background(), db.ToNamedValues(args))
+}
+
+func (stmt *sqliteStmt) ExecContext(ctx context.Context, args []driver.NamedValue) (res driver.Result, err error) {
+	res, err = stmt.stmtIface.ExecContext(ctx, args)
+	err = processSQLiteError(err)
+	return
+}
+
+func (stmt *sqliteStmt) Query(args []driver.Value) (driver.Rows, error) {
+	return stmt.QueryContext(context.Background(), db.ToNamedValues(args))
+}
+
+func (stmt *sqliteStmt) QueryContext(ctx context.Context, args []driver.NamedValue) (rows driver.Rows, err error) {
+	rows, err = stmt.stmtIface.QueryContext(ctx, args)
+	err = processSQLiteError(err)
+	if err != nil {
+		return nil, err
+	}
+	return &sqliteRows{rows.(rowsIface)}, nil
+}
+
+func (stmt *sqliteStmt) Close() (err error) {
+	err = stmt.stmtIface.Close()
+	err = processSQLiteError(err)
+	return
+}
+
+type sqliteRows struct{ rowsIface }
+
+func (r *sqliteRows) Next(dest []driver.Value) (err error) {
+	err = r.rowsIface.Next(dest)
+	err = processSQLiteError(err)
+	return
+}
+
+func (r *sqliteRows) Close() (err error) {
+	err = r.rowsIface.Close()
+	err = processSQLiteError(err)
+	return
+}
+
+// connIface is the driver.Conn interface
+// types (and the like) that go-sqlite3/driver.conn
+// conforms to. Useful so you don't need
+// to repeatedly perform checks yourself.
+type connIface interface {
+	driver.Conn
+	driver.ConnBeginTx
+	driver.ConnPrepareContext
+	driver.ExecerContext
+}
+
+// StmtIface is the driver.Stmt interface
+// types (and the like) that go-sqlite3/driver.stmt
+// conforms to. Useful so you don't need
+// to repeatedly perform checks yourself.
+type stmtIface interface {
+	driver.Stmt
+	driver.StmtExecContext
+	driver.StmtQueryContext
+}
+
+// RowsIface is the driver.Rows interface
+// types (and the like) that go-sqlite3/driver.rows
+// conforms to. Useful so you don't need
+// to repeatedly perform checks yourself.
+type rowsIface interface {
+	driver.Rows
+	driver.RowsColumnTypeDatabaseTypeName
+	driver.RowsColumnTypeNullable
+}
diff --git a/internal/db/sqlite/errors.go b/internal/db/sqlite/errors.go
index 9429a1bcd..784f9ef2d 100644
--- a/internal/db/sqlite/errors.go
+++ b/internal/db/sqlite/errors.go
@@ -15,7 +15,7 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-//go:build !moderncsqlite3 && !nowasm
+//go:build !moderncsqlite3 && !nowasm && !libsqlite3
 
 package sqlite
 
diff --git a/internal/db/sqlite/errors_libsqlite3.go b/internal/db/sqlite/errors_libsqlite3.go
new file mode 100644
index 000000000..483d9ed14
--- /dev/null
+++ b/internal/db/sqlite/errors_libsqlite3.go
@@ -0,0 +1,60 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+//go:build !moderncsqlite3 && !nowasm && libsqlite3
+
+package sqlite
+
+import (
+	"database/sql/driver"
+	"fmt"
+
+	sqlite3 "github.com/mattn/go-sqlite3"
+	"github.com/superseriousbusiness/gotosocial/internal/db"
+)
+
+// processSQLiteError processes an sqlite3.Error to
+// handle conversion to any of our common db types.
+func processSQLiteError(err error) error {
+	// Attempt to cast as sqlite error.
+	sqliteErr, ok := err.(sqlite3.Error)
+	if !ok {
+		return err
+	}
+
+	// Handle supplied error code:
+	switch sqliteErr.ExtendedCode {
+	case sqlite3.ErrConstraintUnique,
+		sqlite3.ErrConstraintPrimaryKey:
+		return db.ErrAlreadyExists
+
+	// Busy should be very rare, but on
+	// busy tell the database to close the
+	// connection, re-open and re-attempt
+	// which should give necessary timeout.
+	case sqlite3.ErrBusyRecovery,
+		sqlite3.ErrBusySnapshot:
+		return driver.ErrBadConn
+	}
+
+	// Wrap the returned error with the code and
+	// extended code for easier debugging later.
+	return fmt.Errorf("%w (code=%d extended=%d)", err,
+		sqliteErr.Code,
+		sqliteErr.ExtendedCode,
+	)
+}